Radiology Inservice Exam Question Bank

A: Incorrect. Inferior wall ischemia characteristically produces a perfusion defect in this region on stress myocardial perfusion images. In the case of reversible ischemia the defect would be expected to resolve on a resting study.
B: Incorrect. An area of prior myocardial infarction typically produces a “fixed” perfusion defect which would be visible both on stress and resting images. Thus from evaluation of stress images alone it cannot be differentiated from a defect due to exercise-induced ischemia as in item A .
C: Correct. Left bundle branch block may be the result of myocardial ischemia or infarction or may be an incidental finding. It may produce perfusion abnormalities on myocardial perfusion scintigraphy in the absence of coronary artery disease. When it produces abnormalities the most common finding is a reversible perfusion defect in the interventricular septum not in the inferior wall. In patients with known left bundle branch block it is preferable to perform a pharmacologic stress test using dipyridamole or adenosine rather than treadmill exercise in conjunction with the imaging since this artifact is more commonly associated with the latter procedure.
D: Incorrect. Diaphragmatic attenuation artifact commonly produces apparent defects in the inferior wall. These defects may or may not be present both on stress and resting images and may be suspected by inspection of planar rotating images from the raw data set. This artifact most often occurs in male patients and is more common in obese patients as well.

A: Incorrect. FDG PET imaging is not an appropriate or approved study for breast cancer screening. Screening is best done by self-examination and periodic mammography which are more sensitive and cost-effective approaches to breast cancer screening.
B: Incorrect. FDG PET imaging is less sensitive for the initial staging of breast cancer than lymphoscintigraphy with sentinel lymph node biopsy. Very high sensitivity is provided by the latter approach particularly when immunohistochemistry techniques are utilized. This approach to staging is rapidly becoming the standard of care for these patients.
C: Incorrect. FDG PET imaging is not capable of differentiating between a solitary pulmonary metastasis and a primary lung tumor. In most cases both lesions are associated with increased glucose metabolism and thus increased FDG uptake.
D: Correct. As is true for a number of neoplasms FDG PET imaging is very sensitive and specific for assessing the response to therapy in breast carcinoma whether performed after the completion of therapy (re-staging) or during the course of therapy (treatment monitoring).

A: Incorrect. While it is true that it is preferable to scan the non-dominant forearm or hip in DEXA scanning and scanning the dominant side could produce a higher bone density value the differ-ences between the dominant and non-dominant sides are often minimal and this is therefore not the best explanation for the findings.
B: Correct. The bones of the extremities such as the radius and ulna are composed primarily of corti-cal bone and contain relatively less trabecular bone than either the spine or hip. Quantitatively the extremities account for the majority of the whole body bone mineral content. Thus bone density measurements of the forearm are most valuable in patients with metabolic bone disease or other conditions associated with decreases in total skeletal calcium content. Post-menapausal osteoporosis preferentially involves the trabecular bone initially which is present in higher percentages in the vertebral bodies and femoral neck regions. Therefore forearm measurements tend to be relatively insensitive for the early detection of post-menopausal osteoporosis.
C: Incorrect. In fact the opposite is true. The presence of arthritic changes is most often associated with falsely elevated bone density measurements especially in the spine secondary to increased bone density at sites of spurring or sclerosis associated with arthritic involvement.
D: Incorrect. Again the opposite is true. Moving from proximal to distal in the forearm there is a pro-gressive increase in the relative trabecular bone content. Typically bone density measurements of the forearm are performed in the distal third of the radius and ulna in order to maximize the contri-bution of trabecular bone in the measurement. Scanning more distally may also be performed to further increase the percentage of trabecular bone being evaluated. Thus scanning more distally would tend to decrease the measured bone mineral density of the forearm.

A: Incorrect. The correct value is 2.5.
B: Incorrect. The correct value is 2.5.
C: Correct. Many malignant lesions will greatly exceed this value and some lesions with SUV values D: Incorrect. The correct value is 2.5.

A: Correct. While not the sole determinant of uptake the uptake of In-111 labeled leukocytes is dependent upon regional blood flow. For example a walled-off abscess without a direct blood sup-ply will not accumulate In-111 labeled leukocytes and may appear as a photopenic defect.
B: Incorrect. In-111 WBC imaging is very sensitive for active inflammatory bowel disease. It has advantages over Ga-67 citrate imaging in this clinical setting as a result of the absence of normal bowel uptake of the tracer.
C: Incorrect. Transient lung uptake can be seen 4 hours after injection or even longer sometimes mak-ing the diagnosis of pulmonary infection difficult.
D: Incorrect. In-111 WBC’s are less sensitive than Ga-67 citrate for detecting chest infections such as PCP. As a result Ga-67 citrate imaging is preferred in the clinical settings of suspected chest infec-tion or in immunocompromised patients presenting with fever of unknown origin.

A: Incorrect. Assessment of the effects of geometry is required at time of initial setup or after alter-ation/repair of well calibrator only. This insures that variations in radioactive dose volume or posi-tion in counting chamber will not produce aberrant dose determination.
B: Correct. This daily mandated test measures instrument precision and is designed to show repro-ducible readings day after day on all clinical energy settings. This is essentially a mini-accuracy test that does not account for half-life of long-lived low medium and high energy sealed standards. More or less rigor is applied depending on whether a single 137Cs source is counted in all standard energy settings (Tc99m 201TI 123I 131I etc.) and the same reading is compared day to day or a more elaborate daily count of multiple sealed sources (57Co 133Ba 137Cs) is obtained. No more than a 5% daily count rate variation is allowable.
C: Incorrect. Sequential assay of count rates of the same radioisotope from low to high activity usually by counting an initially high activity Tc-99m source as it decays over 48 hours. This multi-day study can’t be performed daily and is usually performed at installation quarterly thereafter and whenever the device undergoes repair.
D: Incorrect. Designed to insure correct readings throughout the entire energy spectrum clinically encountered this rigorous test requires reproduction of count rates with low medium and high energy sealed standard sources 57Ba 137Cs. This elaborate test is performed at installation of the device annually thereafter and whenever the device undergoes repair.

A: Correct. Medical x-rays are the most significant source of man-made radiation sources. They con-tribute an annual effective dose of 0.39 mSv or 39 mrem to the U.S. population.
B: Incorrect. Radon is a naturally occurring source of radiation.
C: Incorrect. High-altitude air travel adds to an individual’s cosmic ray exposure and is of very small quantity.
D: Incorrect. Nuclear does not contribute as much as medical x-rays as a source of exposure to the U.S. population. They contribute an annual effective dose of 0.14 mSv or 14 mrem to the U.S. population.

A: Incorrect. This combination of scan findings and history is associated with the highest relative like-lihood of malignancy of all those listed in the range of 40%.
B: Correct. The finding of multiple cold nodules without prior radiation exposure is consistent with a non-specific multinodular goiter and carries a risk of underlying malignancy of only ~ 5%.
C: Incorrect. While the absence of prior head and neck irradiation reduces the likelihood of malignan-cy the prevalence of malignancy in patients presenting with solitary cold thyroid nodules is still in the range of about 15-20% overall.
D: Incorrect. The history of prior head and neck irradiation significantly increases the likelihood of malignancy in a patient with a solitary cold nodule with the likelihood being somewhere in the range of 30-40% slightly lower than for option A .

A: Incorrect. Symmetrical salivary gland uptake is a normal finding on FDG PET imaging.
B: Correct. The gallbladder is not a normal site of FDG localization. Increased uptake in the gallbladder suggests the presence of cholecystitis or a neoplastic process within the gallbladder.
C: Incorrect. While variable in intensity and extent colonic uptake of FDG is normal.
D: Incorrect. Renal uptake is almost always visualized on FDG PET studies. Renal excretion into the collecting systems and bladder is also seen in the majority of cases.

A: Correct. The situation described is one where the test yields a false-negative result in a patient with pernicious anemia (as indicated in the history). Measurement of the excreted Cobalt-57 labeled vita-min B-12 is performed by counting the urine. Typical window settings used for counting are 50-200 keV for the 122 and 136-keV photons of Cobalt-57. The presence of other radioactive material in the urine that emits photons within the acceptance window will increase the measured counts and can result in an inaccurate determination of the excretion of the radiolabeled vitamin B-12.
B: Incorrect. The situation described is one where the test result is a false-negative. Incomplete urine collection could result in a low measured excretion and a false positive (not a false negative) result
C: Incorrect. The situation described is one where the test result is a false-negative. Prior resection of terminal ileum could result in a reduced absorption of the orally administered vitamin B-12 and thereby a low excretion
D: Incorrect. The situation described is one where the test result is a false-negative. Prior vitamin B-12 therapy may result in a low measured excretion and a false positive study. The patient should not receive parental vitamin B-12 for at least 3 days prior to the study. Biliary excretion of the previous-ly administered vitamin B-12 may decrease the fractional absorption of the test dose. If it does not get absorbed it cannot get excreted into the urine so measured excretion will be low.

A: Correct. The intrinsic uniformity or flood test is performed without the collimator and is an indica-tion of the uniformity of the camera itself. The extrinsic test is performed with the collimator on using a large flood source.
B: Incorrect. Either source material may be used. Typically a syringe of Tc-99m at a distance several time larger than the camera crystal is used for the intrinsic test and the extrinsic test is performed with a large water and Tc-99m filled flood source or a solid Co-57 flood source.
C: Incorrect. Internal electronic checks are different from the measured uniformity tests.
D: Incorrect. There are no internal radiation sources to a gamma camera used for uniformity testing.

A: Incorrect. Hydrolyzed reduced technetium-99m is a colloidal impurity that results in hepatic and reticuloendothelial visualization not thyroid visualization which is typical of the presence of free pertechnetate as an impurity.
B: Incorrect. Only chromatography pre-imaging will detect this radiopharmaceutical impurity.
C: Incorrect. On the contrary Sn(II)ion is a reducing agent protecting MDP from hydrolysis.
D: Correct. The introduction of air into a multidose MDP vial is the most frequent cause of this hydrolyzed technetium-99m contaminant. The more violations of the vial the more likely air will be introduced.

A: Incorrect. Metastron is a pure beta emitter. The absence of an imagable gamma photon precludes verification of bone lesion uptake. By contrast Sm-153 has an imagable gamma photon energy of 103 keV permitting bone scintigraphy to be performed in conjunction with the therapeutic proce-dure.
B: Incorrect. While it is true that the half-life of Metastron is significantly longer resulting in more prolonged lesion irradiation the clinical efficacy of both treatments are quite similar.
C: Incorrect. Due to bremsstrahlung production of high energy photons when high atomic number material (eg. lead) is used for shielding acrylics are the preferred material for handling of these materials. Materials with lower atomic numbers such as plastic or acrylics make ideal shields. In addition bremsstrahlung production is proportional to the atomic number which is lower for these materials.
D: Correct. The major limitation of both therapies is myelosuppression. Metastron causes 15-30% drops in the platelet and WBC counts from pre-injection values and Quadramet 40-50%. However 8-12 weeks are required for full bone marrow recovery from Metastron versus only 6-8 weeks for Quadramet.

A: Incorrect. Alzheimer’s dementia at the earliest stages is associated with temporoparietal and later frontal lobe FDG hypometabolism with typical sparing of sensorimotor and visual cortex (occipital lobe).
B: Incorrect. Pick’s disease is a degenerative dementia predominately involving frontal and temporal lobes. Frontal hypometabolism precedes development of temporal hypometabolism. The visual cor-tex is generally uninvolved.
C: Incorrect. Parkinson’s dementia is a late manifestation of a neurodegenerative disease primarily affecting the basal ganglia. There is occasional involvement of the occipital cortex although tem-poroparietal hypometabolism pattern similar to that of Alzheimer’s but with additional striatal hypometabolism is a more common FDG pattern.
D: Correct. Decreasing cognitive function accompanied by visual disturbance including hallucinations is common presentation in diffuse Lewy body disease (DLBD) which is becoming more widely recognized and accounts for up to 20% of all autopsy confirmed dementias. Medical and lateral occipital lobe FDG metabolism is more severely reduced in DLBD than other dementias. When identified on FDG PET images cholinergic therapy has been useful in controlling the disease.

A: Incorrect. The cardiac blood pool activity gradually decreases with time as Zevalin is distributed to the other organs and a small component is excreted. Persistent but decreased blood pool activity is normal at 48 hours. The development of a HAMA response occurs in B: Incorrect. The Zevalin therapeutic regime should not be given to patient’s with greater than or equal to 25% lymphoma marrow involvement. Altered biodistribution is suggested with rapid blood pool clearance and increased marrow uptake.
C: Incorrect. Normal renal activity with Indium-111 Zevalin is generally manifested as faint activity (moderately low to very low activity) which is much less intense than hepatic uptake. Altered renal biodistribution is present if renal activity greater than liver is demonstrated on the posterior images.
D: Correct. Bowel activity is common and normal. However normal gastrointestinal biodistribution is activity that is less intense than liver and decreases over time (moderately low to very low intensi-ty). Bowel activity more intense than hepatic uptake is indicative of altered biodistribution.

A: Incorrect. While the patient’s symptoms and laboratory findings are consistent with hyperthyroidism the markedly reduced I-123 thyroid uptake and near non-visualization of the thyroid on I-123 imaging are not consistent with Graves’ disease in which an elevated uptake and an enlarged thyroid with diffusely increased uptake on thyroid imaging would be expected.
B: Incorrect. Acute bacterial thyroiditis presents with fever elevated white blood cell count and focal tenderness over a portion of the gland. The thyroid uptake is variable and thyroid imaging would most likely demonstrate a focal hypofunctioning (“cold”) nodule with normal visualization of the remainder of the gland.
C: Incorrect. Plummer’s disease is toxic nodular goiter. The thyroid uptake may be normal or mildly increased in this disorder but would not be decreased. I-123 thyroid imaging in Plummer’s disease demonstrates one or more focal areas of increased tracer uptake with associated areas of suppression of uptake in other parts of the gland findings which are not present in this case.
D: Correct. Subacute or painless thyroiditis is the most likely etiology for these findings. In this viral disorder there is diffuse or focal inflammation of the gland with release of pre-formed thyroid hormone into the circulation during the acute phase resulting in signs and symptoms of hyperthyroidism and elevated thyroid function tests as in this case. There is markedly reduced synthesis of new thyroid hormone by the gland with associated decreased thyroid uptake and poor visualization of the thyroid on I-123 or Tc-99m pertechnetate thyroid imaging. These findings may also be seen in thyrotoxicosis factitia (intake of exogenous thyroid hormone) or in patients with ectopic thyroid hormone production (eg. struma ovarii) but these conditions were not listed as possible answers.
E: Incorrect. Recent iodinated contrast administration may result in a falsely low I-123 thyroid uptake measurement secondary to flooding of the extracellular iodine pool with non-radioactive iodine. In turn poor visualization or non-visualization of the thyroid on thyroid scintigraphy may result. However in most cases these findings would not be associated with clinical evidence of hyperthyroidism as is present in this case.

Findings: There is near-complete non -visualization of the thyroid on I-123 imaging (Figures 1A & 1B) with only faint visualization of the gland which appears grossly normal in size. Thyroid morphology cannot accurately be assessed.

A: Incorrect. The right upper lobe lesion is highly suspicious for bronchogenic carcinoma especially in light of the SUV value of 7.2. However in the absence of mediastinal or hilar adenopathy this lesion is not consistent with Stage IIIA disease which includes patients with primary lesions of any size but only those with ipsilateral mediastinal or hilar adenopathy.
B: Correct. On the basis of this PET scan this patient has a T2 N0 M0 lesion which is consistent with Stage 1B involvement. Despite its 4 cm size only a primary lesion with evidence of invasion of the mediastinum heart great vessels trachea esophagus vertebral body carina or lesions associated with additional tumor nodules or malignant pleural effusions can be placed into the category of Stage III disease without evidence of adenopathy.
C: Incorrect. Lymphomas are in general very FDG-avid. However the MALT type lesion has been shown to be much less FDG-avid than other cell types and FDG PET imaging is not recommended for patients with this disorder. Furthermore a large focal lung nodule would represent an unusual manifestation of lymphoma in any case even for FDG-avid cell types.
D: Incorrect. Mildly increased FDG uptake may occur in infectious and granulomatous processes including histoplasmosis tuberculosis and others. Such occurrences may result in false positive PET scans for bronchogenic carcinoma. However FDG uptake in such lesions is usually mild typically with SUV values E: Incorrect. Bronchoalveolar carcinoma demonstrates variable FDG uptake and has been reported to be a common cause of a false negative FDG PET scan in bronchogenic carcinoma. The presentation of a solitary large focal pulmonary nodule is not the most common appearance for bronchoalveolar carcinoma. Furthermore it is less common than other cell types of bronchogenic carcinoma and this diagnosis would therefore be less likely than other cells types of non-small cell or small cell carcinoma.

Findings: There is a large focal area of markedly increased FDG uptake in the right upper lobe corresponding to the site of the patient’s known pulmonary nodule on prior imaging studies. There is no evidence of mediastinal or hilar lymphadenopathy. No additional pulmonary nodules are identified. The remaining areas of FDG uptake (eg. liver heart bowel kidneys bone marrow) represent normal sites of uptake.

A: Incorrect. The V/Q scan findings of a single moderate ventilation-perfusion mismatch are not consistent with a high probability for pulmonary embolism using any of the commonly employed criteria for interpretation of these studies. Both the modified PIOPED criteria and modified Biello criteria categorize such cases as intermediate probability for pulmonary embolism.
B: Correct. As discussed in item A above a single moderate V/Q mismatch is consistent with an intermediate probability for pulmonary embolism using the two most prevalent sets of diagnostic criteria currently in use. In published retrospective and prospective studies approximately one-third of such cases have been associated with pulmonary embolism on pulmonary angiography.
C: Incorrect. Again a single moderate subsegmental V/Q matching defect is consistent with an intermediate probability for pulmonary embolism both in the modified PIOPED and modified Biello diagnostic criteria. The original PIOPED study incorrectly classified these cases as low probability an error which was corrected when the criteria were subsequently modified following the study.
D: Incorrect. This ventilation-perfusion lung scan demonstrates abnormalities on both the ventilation and perfusion portions of the exam. It is not a normal study.
E: Incorrect. The pattern of perfusion abnormality in this case is not suggestive of lymphangitic carcinomatosis. In that entity the perfusion images typically produce a diffuse pattern of irregularity with numerous small subsegmental perfusion defects corresponding to the interlobular septae. This pattern of abnormality has been termed “contour mapping”. It is not present in this case nor is there an interstitial pattern of pulmonary parenchymal abnormality on the chest radiography to suggest this entity.

Findings: The Xe-133 ventilation study (Figure 3A) demonstrates only mild xenon retention bilaterally most striking at the lung bases. The Tc-99m MAA perfusion images (Figure 3B) demonstrate a single moderate subsegmental perfusion defect in the lateral basal segment of the left lower lobe which does not correspond to a focal ventilatory defect on the ventilation study. The chest radiograph demonstrates no focal infiltrates or pleural effusions.

A: Correct. The findings described above are typical for a stress fracture of the left pars interarticularis of L5 a common injury occurring in children involved in athletic activities such as gymnastics volleyball etc. Radiographs may or may not demonstrate a pars defect and in the case of bilateral pars defects spondylolysis may also be present. SPECT imaging is useful in detecting subtle lesions not evident on planar views as well as localizing the lesion to the region of the pars. Increased bone turnover in the site of the lesion suggests that it is the etiology for the patient’s symptoms of localized back pain.
B: Incorrect. Osteoid osteoma can occur in the spine and may be associated with focal areas of increased uptake on bone scintigraphy. However it is less likely to be associated with normal radiographs usually presenting with a focal area of sclerosis sometimes with a visible central radiolucent nidus. It commonly presents with rigid painful scoliosis and may have the classic presentation of pain worse at night and relieved by aspirin. It is less common than a stress fracture of the pars especially in the present clinical setting.
C: Incorrect. Ewing’s sarcoma is uncommon relative to stress fractures and the vertebral column is an uncommon site of involvement. When arising in the vertebral column the sacrum is the most common site. It is often associated with a long history of pain a soft tissue mass and in many cases associated systemic symptoms. Vertebral involvement most often involves the vertebral bodies primarily may be associated with vertebral collapse and is not usually associated with normal radiographic findings. Ewing’s sarcoma is associated with markedly increased uptake of Tc-99m MDP although usually the lesion is much larger at presentation.
D: Incorrect. Vertebral osteomyelitis is usually located in the vertebral bodies and may also spread to the intervertebral disc spaces. Radiographic findings include areas of bone destruction and/or sclerosis similar to the findings of osteomyelitis in other regions of the skeleton. Fever leukocytosis and systemic symptoms are often present. Vertebral osteomyelitis is less common than stress fractures and does not fit the present clinical setting well. Again normal radiographic findings would not be expected with vertebral osteomyelitis.
E: Incorrect. Findings that may be seen in ankylosing spondylitis include increased uptake in the sacro-iliac joints focal areas of increased uptake in the apophyseal joints increased uptake in the intervertebral disc spaces and other sites of arthritic involvement in the peripheral joints and costovertebral and sternoclavicular joints. These findings are not present in this case. While this patient is at the lower end of the typical age range for this disorder ankylosing spondylitis is more common in males and is far less common than post-traumatic injuries.

Findings: The AP and lateral radiographs of the lumbar spine (Figures 4A and 4B) demonstrate very mild scoliosis of the lower lumbar spine possibly positional. Anterior and posterior planar Tc-99m MDP bone images (Figure 4C) demonstrate a focal area of increased tracer uptake at L5 on the left best seen on the posterior image. The coronal transaxial and sagittal SPECT images (Figures 4D-4F) localize this finding to the region of the lamina in the expected location of the pars interarticularis.

A: The sagittal and coronal ultrasound of the uterus shows a small fluid collection surrounded by an echogenic ring. This echogenic ring confirms that we are dealing with a small gestational sac. This gestational sac is seen separate from the endometrial cavity represented by the echogenic line. The gestational sac is in a subendometrial location within the prominent decidua. This is the earliest manifestation of an intrauterine pregnancy that can be seen on transvaginal ultrasound at 3.5 to 4 weeks menstrual age.
B: Endometriotic cysts also known as endometriomas or chocolate cysts form as a result of endometriosis and typically develop on the surface of the ovaries.
C: The pseudogestational sac sign refers to a fluid collection within the endometrial collection. There is fluid sometimes complex fluid within the endometrial complex surrounded by a single echogenic ring and the endometrial stripe is not seen separately because the fluid is actually within the endometrial cavity.
D: This is not fluid in the endometrium as was discussed above. There is no reason to suspect cervical stenosis in this young woman.

A: Although classically all triple matched findings (ie. corresponding ventilation perfusion and radiographic abnormalities) are consistent with an intermediate probability for pulmonary embolism according to the revised PIOPED criteria a triple match in the upper lobes is much less likely to be due to pulmonary embolism than a lower lobe triple match. This finding is consistent with the fact that pulmonary emboli occur much more commonly in the lower lobes than the upper lobes most likely as a result of the relatively greater blood flow to those areas.
B: A lower lobe triple match is more likely to be associated with pulmonary embolism than an upper lobe match and according to the modified PIOPED criteria is more worrisome than the finding of a triple match overall which is generally considered to be consistent with an intermediate probability for pulmonary embolism.
C: A whole-lung V/Q match is most often associated with primary ventilatory disorders associated with secondary reflex vasoconstriction such as airway obstruction due to central foreign bodies mucus plugging endobronchial masses or other unilateral primary ventilatory disorders such as Swyer-James Syndrome. This finding is consistent with a low probability for acute pulmonary embolism.
D: While classically this finding is consistent with an intermediate probability for pulmonary embolism in general the larger the corresponding pleural effusion the less likely it is due to pulmonary embolism.

A: This is correct as the ultrasound demonstrates a normal lymph node.

A: Incorrect. In prospective ECG gating (also known as ECG triggering) data acquisition is triggered to the R wave of the ECG so data is acquired at a pre specified time. The multi detector CT can be set up to record data at a certain time after the last R wave or before the next R wave of the ECG. Alternatively data can be acquired at a certain percentage of the time between two successive R waves.
B: Correct. Data is ideally only acquired when the heart is relatively motionless as in diastole. So there are parts of the ECG cycle in which data is not being acquired namely during systole (when the heart moves more).
C: Incorrect. Because there is 'missing' data one cannot do a volumetric assessment of the left ventricular cavity. In order to calculate ejection fraction one needs data from both diastole and systole so retrospective ECG gating is needed.
D: Incorrect. Retrospective ECG gating involves more radiation because data is acquired throughout the cardiac cycle. The patient is receiving ionizing radiation throughout the cardiac cycle. The person interpreting the study selects data from selected portions of the cardiac cycle (such as in diastole when the heart is relatively motionless).
References: (1) Wintersperger BJ Nikolaou K. Basics of Cardiac MDCT: techniques and contrast application. European Radiology 2005 15(2):B2-B9

A: Correct. The mass is nearly completely fat density when compared to subcutaneous fat.
B: Incorrect. Although renal cell carcinoma more commonly extends into the IVC and can contain a small amount of fat this mass has no significant soft tissue component.
C: Incorrect. Oncocytomas are not predominantly fat density and can have a central scar.
D: Incorrect. These masses are cystic and commonly extend into the renal pelvis and not the IVC.

Pneumatoceles.
A: Correct. Cystic adenomatoid malformation is a mass of disorganized pulmonary tissue that has a normal communication with the bronchial tree and normal vascular supply and drainage. Three types of cystic adenomatoid malformation are recognized. Type I contains at least one dominant large cyst greater than 2 cm in diameter. Type II is comprised of many small cysts measuring 1 to 10 mm in diameter. Type III appears solid on visual inspection although microscopically there are multiple tiny cysts less than 2 mm in diameter. Most affected patients present in the neonatal period with respiratory distress. Later in life patients present with symptoms related to infection of the lesion as in the test patient. The classic CT appearance of cystic adenomatoid malformation in the neonate is a multilocular mass containing air-filled cysts surrounded by thin walls. Large lesions cause the mediastinum to shift to the opposite hemithorax. In the presence of infection the cysts have thick walls and are surrounded by soft tissue. The most likely diagnosis for the thick-walled multilocular mass in the test patient is an infected cystic adenomatoid malformation.
B: Incorrect. Pulmonary infarction is a rare disease in the pediatric population. Causes of infarction include the pulmonary vasculitides septic emboli and drug abuse. CT findings are a pleural-based wedge-shaped area of parenchymal consolidation with convex bulging borders. The apex of the opacity points toward the hilum. The CT findings in the test patient are not typical for infarction which makes this an unlikely diagnosis. The age of the patient and the absence of any predisposing causes also makes the diagnosis unlikely.
C: Incorrect. Lung abscess is a rare complication of bacterial pneumonitis. CT features include a low attenuation mass with a spherical shape an acute angle with the chest wall thick irregular walls and a poorly defined external surface. Pneumonic infiltrates adjacent to the abscess or elsewhere in the lung and pleural effusion are other common findings. A multilocular mass with otherwise normal lung parenchyma and pleura make abscess an unlikely diagnosis.
D: Incorrect. Necrotizing pneumonitis or cavitary pneumonia refers to an area of non-enhancing low-attenuation parenchyma with a variable number of thin-walled cavities. The decreased parenchymal enhancement after administration of intravenous contrast medium is most likely related to ischemia. With the exception of the multilocular mass the lung in the test patient is normal. There is no evidence of pneumonia. Therefore necrotizing pneumonia is not a good option.
E: Incorrect. Pneumatoceles result when there is obstruction of the smaller airways with destruction of the walls of the subtended alveoli and concomitant overinflation of alveolar spaces. Inflammatory pneumatoceles usually are the result of staphylococcal pneumonitis but they may be associated with other organisms such as Streptococcus pneumoniae Hemophilus influenzae and pneumocystis. In patients with staphylococcal pneumonitis pneumatoceles appear late in the first week of the illness and disappear within 6 weeks. CT findings are a uni- or multilocular cavitary mass with thin walls. Pneumonic infiltrates and pleural disease are also very common. The thick-walled lesion in the test patient and the absence of other pleuroparenchymal disease helps to exclude this diagnosis.

Findings: CT scans demonstrate multiple air-filled cysts with a surrounding rind of soft tissue in the left lower lobe.

A: Incorrect. The findings are not consistent with acute cholecystitis. There is prompt visualization of the gallbladder as early as 5-10 minute post-injection which essentially excludes acute cholecysti-tis. Furthermore acute cholecystitis does not explain the presence of biliary leakage present in this case. Perforation of the gallbladder may occur in gangrenous cholecystitis but that entity is virtual-ly always associated with cystic duct obstruction which would result in non-visualization of the gallbladder as well.
B: Correct. The findings in this case described above are consistent with a relatively large bile leak most likely arising in the region of the gallbladder fossa. In this case the findings may be secondary to trauma from paracentesis.
C: Incorrect. There is prolonged hepatic clearance and non-visualization of the small bowel both find-ings that occur in the presence of common bile duct obstruction. However in common duct obstruc-tion there is often complete non-visualization of the biliary tree including the gallbladder even in the absence of cholecystitis. In addition common duct obstruction is not usually associated with bil-iary leakage which is present in this case.
D: Incorrect. This study is not normal. A significant degree of biliary leakage is demonstrated as described above. Furthermore the images also demonstrate prolonged hepatic clearance and non-visualization of the small bowel both of which are also abnormal findings.

Findings: There is prompt hepatic uptake with early visualization of activity in the region of the gall-bladder fossa. Faint amorphous activity is noted inferior to the liver on the right beginning at 10 min-utes and better seen thereafter. In addition there is accumulation of activity throughout the peritoneal cavity beginning at 15 minutes post-injection and progressively increasing throughout the study. There is also the appearance of abnormal linear activity along the inferior margin of the left lobe of the liver beginning at 25-30 minutes into the study and progressively increasing in intensity. The right lateral image demonstrates activity spreading anterior to the liver also consistent with intraperitoneal biliary leakage. Hepatic clearance is also moderately prolonged.

A: Incorrect. Although initial (left) study appears symmetrically normal there is clearly a bilateral delay in cortical clearance and excretion on the post-captopril study.
B: Incorrect. In unilateral right renal artery stenosis ACE-inhibitor should create an asymmetric delay in right renal washout not the bilaterally delayed washout present in this case.
C: Incorrect. In unilateral left renal artery stenosis ACE-inhibitor should create an asymmetric delay in left renal washout not the bilaterally delayed washout present in this case.
D: Correct. The post-captopril study fails to demonstrate sequential right and left renal pelvis and bladder activity seen at midpoint of the baseline pre-captopril study. Administration of the ACE inhibitor has produced a symmetric delay in renal cortical clearance manifested by marked bilateral cortical retention and non-visualization of the renal pelves and bladder. These findings are typical for bilateral ACE-inhibition of compensatory post-glomerular vascular constriction with resultant delay in transcortical clearance in this child with bilateral congenital renal artery stenosis.

Findings: The baseline pre-captopril study demonstrates mildly decreased tracer uptake bilaterally with normal excretion. The post-captopril images demonstrate significant bilateral deterioration in excretion with marked cortical retention noted bilaterally.

A: Incorrect. The abnormal uptake in this case is located in the posterior mediastinum where adenopa-thy due to lymphoma may occur. However the linear configuration of the activity is characteristic of esophageal activity rather than the typical focal rounded appearance of adenopathy. Furthermore no other sites of adenopathy are present. The findings are characteristic of an esophageal neoplasm making squamous cell carcinoma or adenocarcinoma far more likely than lymphoma.
B: Incorrect. As discussed above the linear uptake located in the posterior mediastinum is characteris-tic in appearance for an esophageal neoplasm. There are no focal pulmonary nodules or foci of mediastinal or hilar adenopathy as would be anticipated in the presence of bronchogenic carcinoma.
C: Correct. The linear pattern of increased FDG uptake in the posterior mediastinum in the expected location of the esophagus is characteristic in appearance for an esophageal neoplasm most likely representing squamous cell carcinoma of the esophagus.
D: Incorrect. Mildly increased uptake near the gastroesophageal junction may be seen as a normal vari-ant or in patients with gastroesophageal reflux. Mild diffuse esophageal uptake may also occur in esophagitis. The uptake in this case is far more intense than would be anticipated as a normal vari-ant and the location of the activity remote from the gastroesophageal junction is not consistent with a normal variant.

A: Correct. CNS lymphoma may produce a ring-enhancing lesion on CT and is thallium-avid. These findings are most consistent with CNS lymphoma arising in an immunocompromised host.
B: Incorrect. CMV is not thallium-avid as is the lesion in this case.
C: Incorrect. Toxoplasmosis can produce cerebral ring-enhancing CT lesion but it is not thallium-avid as is the lesion in this case.
D: Incorrect. The focal area of increased tracer uptake in the midline basal ganglia region represents a striking abnormality which is not attributable to any normal finding. This is not a normal study.

Findings: Transaxial Tl-201 chloride SPECT images of the brain demonstrate a focal area of increased tracer uptake near the midline in the region of the CT lesion in the basal ganglia.

A: Incorrect. The normal biodistribution of Tc-99m methylene diphosphonate (MDP) includes the axial and appendicular skeleton kidneys and bladder. The liver spleen mediastinum and brain which are visualized in this case are not seen on a normal bone scintigram.
B: Incorrect. The normal biodistribution of Tc-99m sulfur colloid includes intense liver and spleen activity. Less intense activity is identified in the central bone marrow (skull ribs sternum vertebral bodies pelvis proximal humeri and femora). The most intense activity in this study is osseous. Moderate activity is seen within the spleen and low level activity in the liver mediastinum and brain. This biodistribution is not typical for sulfur colloid.
C: Correct. The normal biodistribution of F-18 fluorodeoxyglucose (FDG) is accumulation in the brain myocardium blood vessels pharynx liver spleen bone marrow kidneys ureters urinary bladder and GI tract. Intense marrow uptake is seen in this patient with lymphoma after administra-tion of granulocyte colony stimulating factor (G-CSF) which is given to support bone marrow func-tion following therapy. Normal marrow uptake is usually less intense than hepatic uptake. While this distribution is not normal it is more characteristic of FDG than any of the other tracers listed.
D: Incorrect. The normal biodistribution of F-18 sodium fluoride is osseous with uptake dependent on regional blood flow and osteoblastic activity by chemisorption. Hydroxyl groups are exchanged to form fluoroapatite in the hydroxyapatite crystals. Because of the superior spatial resolution and three-dimensional localization afforded by PET imaging there is a high sensitivity for the detection of metabolically active skeletal lesions using F-18 sodium fluoride.

A: Incorrect. Thyroid hormone production is reduced in subacute thyroiditis. The elevated thyroid function tests and signs and symptoms of hyperthyroidism that occur early in the disorder are relat-ed to release of pre-formed thyroid hormone into the circulation from the inflamed thyroid gland.
B: Incorrect. The increased thyroid hormone levels produced by the release of pre-formed hormone into the circulation results in a feedback inhibition of TSH secretion by the pituitary resulting in decreased serum TSH levels.
C: Correct. Subacute thyroiditis is a viral disorder often following a recent upper respiratory infec-tion. The inflammatory response in the gland results in increased permeability and increased release of pre-formed thyroid hormone into the circulation from the colloid. The increased serum thyroid hormone levels in turn result in clinical evidence of hyperthyroidism despite a low thyroid uptake.
D: Incorrect. The pathophysiology of subacute thyroiditis does not involve abnormalties in iodine metabolism per se. The acute inflammatory response in this disorder is associated with decreased iodide uptake and organification during the early stage of the disease.

A: Incorrect. While both radiopharmaceuticals are efficacious for the detection of abdominal abscesses Indium-111 leukocyte imaging is often preferred as the result of the absence of potentially confus-ing normal bowel activity as occurs in Gallium-67 scintigraphy. This normal bowel uptake may lead to false positive gallium studies.
B: Incorrect. Indium-111 leukocyte imaging is superior to gallium-67 scintigraphy in the evaluation of suspected infected joint prostheses in part related to the bone seeking properties of gallium leading to potential false positive gallium studies due to increased tracer localization secondary to increased bone turnover in the absence of infection.
C: Correct. While sensitive for osteomyelitis Indium-111 leukocyte scintigraphy has been found to be less sensitive than gallium-67 scintigraphy for the detection of disc space infection.
D: Incorrect. Again the absence of normal bowel localization makes In-111 leukocyte scintigraphy better suited to the assessment of active inflammatory bowel disease. In gallium-67 scintigraphy normal bowel uptake especially in the colon can be incorrectly attributed to inflammatory bowel disease.

A: Correct. The finding of focal “hot spots” on a Tc-99m MAA scan indicates the aggregation of the radiopharmaceutical into larger particles which lodge in the pulmonary vascular bed. This artifact may be produced by drawing blood back into the syringe during injection or by failing to resuspend the particles prior to injection in the event the dose is left sitting for a prolonged time after being drawn up. While it is not associated with any adverse effects in the patient these foci of increased activity may obscure portions of the underlying lungs resulting in the need to repeat the study after significant radioactive decay has occurred.
B: Incorrect. While technically these foci do represent small iatrogenic pulmonary emboli they are virtually never associated with any clinically demonstrable adverse effects. In general pulmonary perfusion imaging with Tc-99m MAA is associated with transient occlusion of less the 0.1% of the pulmonary capillary bed. Thus this occurrence is unlikely to produce acute hypoxemia.
C: Incorrect. While these “hot spots” may obscure underlying detail in evaluating pulmonary perfu-sion they are not associated with artifactual perfusion defects that would produce a false positive study.
D: Incorrect. Pulmonary AVMs are associated with right to left shunting permitting Tc-99m MAA par-ticles to bypass the pulmonary capillary bed. Thus AVMs would tend to produce focal perfusion defects rather than focal areas of increased tracer localization.

A: Placement of the background ROI over the spleen will result in excessive background subtraction. The relative effect of the extra background subtraction will be greater on the systolic ROI which has fewer counts and therefore will not “cancel out”. Thus the denominator of the ejection fraction equation will be relatively reduced resulting in an artifactually elevated rather than reduced.
B: Too small of a systolic region will result in exclusion of value counts from the systolic region mak-ing the percentage change between systolic and diastolic counts appear to be larger than it actually is. Again this error would result in an artifactually elevated calculated ejection fraction.
C: This technique was initially used when the procedure was originally introduced. However by using the same region for both measurements the systolic region extends beyond the actual margins of the ventricle in end-systole thus including background counts from adjacent structures making the apparent ejection fraction artifactually too low. For this reason the standard method of analysis at present requires assignment of separate diastolic and systolic regions of interest in order to improve the accuracy of the measurement.
D: Inclusion of a portion of the left atrium in the diastolic region of interest will have the effect of introducing additional counts into the region that are not valid ventricular counts. Thus the apparent total end-diastolic counts will be inappropriately high resulting in an apparent higher percentage of ventricular emptying and a falsely elevated ejection fraction calculation. Distractors: SCORE ALL CHOICES AS CORRECT

A: Incorrect. Post-operative ATN is present immediately after transplantation and a 5 day delay before the onset of symptoms would not be expected. In addition ATN is usually associated with disproportionate impairment of renal tubular function with relatively preserved perfusion which is not present in this case. It is also usually less striking in the case of living-related donor transplantation in which cases the ischemic time of the donor kidney is minimized.
B: Incorrect. Renal artery stenosis is a later complication of transplantation and would not be expected within the first post-operative week. The high-grade degree of impaired perfusion in this case is also not typical for renal artery stenosis.
C: Incorrect. Immunosuppressive drug toxicity similar to ATN is most often associated with a disproportionate impairment of renal tubular function relative to perfusion which is not the case in this instance. Complete lack of perfusion to the renal transplant is not an expected finding with drug toxicity.
D: Incorrect. Complete obstruction of the transplanted kidney could conceivably produce these findings. However it would be unusual to see complete non-perfusion and non-function of the transplant as is present in this case. Acute rejection is a more likely etiology for these findings.
E: Correct. Severe acute or accelerated rejection is the most likely explanation for these findings. Rejection is typically associated with impairment both of perfusion and tubular function of the transplanted kidney and is consistent with the time course in this case. While much less common in living-related donor transplants it can occur even in this setting. The most likely differential diagnostic possibility would be acute occlusion or disruption of the renal vessels which is not one of the options listed.

Findings: The flow study (Figure 5A) demonstrates no evidence of perfusion to the transplanted kidney in the left iliac fossa. The delayed static images (Figure 5B) demonstrate increased background activity and photopenic areas in the configuration of bowel loops without visualization of the renal transplant.

A: Incorrect. This limit is for any one month during pregnancy
B: Correct. The nuclear regulatory commission (NRC) limits the dose to an embryo/fetus to be not more than 5 mSv or 500 mrem for entire 9 months.
C: Incorrect. The limit of 50 mSv applies to occupational exposures and not to fetus exposure.
D: Incorrect. See rationale in B .

A: With polycystic ovary disease the ovaries are more modestly increased in size with multiple small peripheral cysts and increased central stroma. These images demonstrate multiple larger diffuse ovarian cysts with associated free fluid which is more typical for theca-lutein cysts associated with ovarian hyperstimulation syndrome.
B: Although serous cystadenomas can be associated with ascites and can rarely be bilateral they are typically a unilocular or multilocular cyst arising from the ovary. These images demonstrate multiple diffuse unilocular ovarian cysts which are more typical for theca-lutein cysts associated with ovarian hyperstimulation syndrome.
C: Although endometriosis can result in multiple pelvic cysts (endometriomas) some of which may arise on surface of ovaries those cysts are typically complex with thick walls. These images demonstrate multiple simple appearing cysts of ovarian origin with associated free fluid which is more typical for theca-lutein cysts associated with ovarian hyperstimulation syndrome.
D: Iatrogenic form of theca-lutein cysts related to drug treatment for infertility. Typically present with multiple large bilateral cysts distributed throughout the ovaries which result in enlargement of the ovaries. Ovarian hyperstimulation can also be associated with significant amounts of free fluid.

A: An aortic valve stenosis has the same effect on the waveform as a stenosis anywhere proximal to the area of sampling and would include delayed systolic upstroke and decreased peak systolic velocities. Images demonstrate normal systolic upstroke and peak systolic velocities.
B: As with arterial venous malformations located throughout the body sampling proximal to AVM could produce increased peak systolic velocity and diastolic flow rather than the reversal of flow shown on these images.
C: Aortic valve incompetence if it is severe enough can result in reversal of diastolic flow and should affect the carotid system bilaterally.
D: A distal unilateral internal carotid artery (ICA) occlusion should result in increased velocities of the patent contralateral carotid system including the contralateral common carotid artery. In addition distal left ICA occlusion will result in a waveform that more closely resembles the left external carotid waveform with high resistance waveform but no reversed diastolic flow in the common carotid artery.

A: Submitted images particularly the lower uterine segment image confirm that the visualized pregnancy is intrauterine in position and is not an ectopic pregnancy.
B: Partial molar pregnancy by ultrasound will demonstrate a fetus (which is present) combined with an abnormally thickened and complex placenta. The placenta on these images is unremarkable in its visualized portions.
C: There is an intrauterine pregnancy in the right uterine horn with an empty uterine horn on the left. This could represent didelphis or bicornuate uterus based on the images. Physical exam confirmed two cervices consistent with didelphis uterus.
D: Intrauterine pregnancy is present with a separate "mass" to the left of the uterus. Although fibroids can be complex in appearance this "mass" contains what appears to be an endometrium which is most consistent with a separate uterine horn.

A: The sagittal and transverse ultrasound images of the right testis show a cluster of small cysts in the location of the rete testis. Seminomas can occur in this age group in fact the peak incidence is in the 4th and 5th decade of life. Seminomas can be bilateral. However on ultrasound seminomas appear as hypoechoic relatively homogeneous solid intratesticular mass so this answer is not correct.
B: Lymphoma is the most common testicular tumor in men over the age of 60 and is usually of the B cell type. It can be bilateral and appear as hypoechoic masses or diffuse heterogeneous enlargement of the testis. The age of the patient as well as the ultrasound appearance do not fit this diagnosis.
C: This ultrasound appearance of cluster of small cysts in the location of the rete testis is characteristic of cystic dilatation of the rete testis. This is an 'aunt Minnie' and should be recognized as a normal variant not to be confused with a neoplasm. Cystic dilatation of the rete testis is often but not always bilateral and can be associated with a spermatocele.
D: Orchitis is rarely isolated and usually associated with epididymitis. In this condition the testis is enlarged and hypervascular.

A: Because thrombolytic agents do not prevent formation of new thrombus systemic heparinization is often used during the course of the procedure and the desired PTT maintained by continuous heparin infusion.
B: Although the patient will likely have received a heparin bolus prior to or during the positioning of the catheter for thrombolysis and your starting dose will subsequently be adjusted depending upon the measured clotting factors 800 units of IV heparin per hour is not an unreasonable order to start with. You do want to keep the dose somewhat light when using tPA.
C: The problem here is that you used an unacceptable abbreviation. In 2004 the Joint Commission on Accreditation of Healthcare Organizations introduced the Do Not Use list of abbreviations in an effort to reduce medication errors. The reason U as an abbreviation for unit is dangerous is that the U too frequently has been mistaken for a zero. A patient infused 8000 units of heparin an hour would be given ten times more than the intended dose.
D: Correct.

A: Tc-99m sestamibi SPECT imaging is affected by soft tissue attenuation artifacts such as breast and diaphragmatic attenuation unless the data specifically undergoes some type of attenuation correction either by means of software correction of hardware correction such as the use of a hybrid SPECT-CT imaging device.
B: As in the case of Tc-99m sestamibi SPECT imaging the dual-isotope method is also subject to soft tissue attenuation artifacts unless specifically corrected. In fact because of the lower gamma photon energies used in thallium-201 chloride myocardial perfusion imaging the thallium images are even more prone to these artifacts than the images obtained using Tc-99m labeled radiopharmaceuticals.
C: There is attenuation correction in FDG PET images whether performed on a dedicated PET imaging device which uses external radioactive sources for attenuation correction or on a hybrid PET-CT imaging device. However FDG myocardial scintigraphy is used to assess myocardial glucose metabolism and is not a myocardial perfusion imaging study.
D: Rb-82 is a positron-emitting isotope with a short half-life of 5 seconds that is used for assessment of myocardial perfusion. It is a potassium analog and exhibits biochemical properties similar to those of Tl-201 chloride. In addition being a PET radiopharmaceutical the use of Rb-82 for myocardial perfusion imaging benefits from the image attenuation correction that is intrinsic to all PET and PET-CT studies.

A: The most common location for shunt stenosis is in the hepatic vein end of the shunt. Shunt stenosis can be identified by ultrasound by localized high velocity flow and turbulence. This associated with incomplete filling of the hepatic vein end of the shunt with color flow makes this the most likely diagnosis.

A: Incorrect. Diagnosis of a lipid rich adrenal adenoma is made on the non-contrast CT with HU B: Incorrect. Lipid poor adenoma can be diagnosed if % washout is > 60%. In this case the calculated % washout is 53%. Additionally the early enhanced phase image shows some heterogeneity of the lesion and washout calculations should be done only on homogeneous lesions.
C: Incorrect. Myelolipoma is diagnosed by identifying macroscopic fat within the mass
D: Correct. This nodule is indeterminant by CT washout criteria. A malignant neoplasm can't be excluded and followup or biopsy would be indicated. Additionally close inspection of the images shows there is heterogeneity in this mass rendering washout evaluation of questionable value. Approximately 3 years after this study the patient was found to have a very large adrenocortical carcinoma.

A: Correct. Several studies which used 4 and 16 detector row CT have shown consistently that at heart rates of greater than 70 beats a minute cardiac motion degrades the images.
B: Incorrect. Asthma is a contraindication to beta blockers. This is because many beta blockers are not cardioselective and block both B1 and B2 receptors. B1 receptors are found in the heart and B2 receptors are found in the airways smooth muscle. Blocking of B2 receptors causes bronchospasm in asthmatics. Even cardioselective beta blockers (such as metoprolol or atenolol) are a relative contraindication in asthmatics and should be avoided.
C: Incorrect. Verapamil can be used as an alternative to beta blockers such as in patients with asthma. It is usually given intravenously in cardiac CT.
D: Incorrect. Atrial fibrillation is not a contraindication to beta blocker use. Although the beta blocker slows the ventricular response rate it will not be effective in preventing atrial fibrillation. Atrial fibrillation (even with a slow ventricular response rate) is a relative contraindication to ECG gating.
References: (1) Choi HS Choi BW Choe KO Choi D Yoo KJ Kim MI Kim J. Pitfalls Artifacts and Remedies in Multi Detector Row CT Coronary Angiography. Radiographics 2004;24:787-800 (2) Kumar and Clark Clinical Medicine Fifth Edition Saunders 2002

A: Osteoid osteoma regression has been documented but only after many years of symptoms. Aspirin or other nonsteroidal anti-inflammatory medications frequently provide effective pain relief. Patients often describe night pain relieved by aspirin. Long-term therapy however may not control night pain and its resultant sleep deprivation and gastrointestinal complications can be serious. Articular or periarticular osteoid osteomas are particularly resistant to conservative therapy and more aggressive intervention is often necessary.
B: Surgical resection has been the treatment of choice for osteoid osteoma with success rates of 88%Ð97% for en bloc open resection. Resection however creates a bone defect predisposing to fracture. Internal fixation and bone grafting may be necessary in some cases. To minimize bone excision numerous methods of intraoperative localization were developed including needle localization of the nidus tetracycline labeling and intraoperative scintigraphy. Even with successful localization and resection the bone may still be prone to fracture. Incomplete surgical resection requires a second surgery. The location of some lesions may preclude surgical excision or increase the risk of injury to adjacent structures. The excision of articular and epiphyseal lesions may require arthrotomy with resultant impairment of bone growth joint mobility or both. Other postsurgical complications include hematoma and infection. The average postoperative hospital stay is 3Ð5 days. Weight-bearing activity is limited for 1Ð6 months after surgery and the use of crutches may be necessary in cases involving the lower limb. CT-guided percutaneous resection is a less-invasive alternative method of treatment that may allow a reduced hospital stay and earlier resumption of weight-bearing activity. However it is associated with postoperative complications similar to those of open surgical excision including hematoma osteomyelitis and fracture. The failure rate with this method of treatment in one patient series was 16%.
C: Percutaneous radiofrequency (RF) ablation is the use of thermal coagulation to induce necrosis and is a minimally invasive alternative to surgical resection of osteoid osteoma. The use of RF ablation to treat osteoid osteoma was first described in 1989 with initial results published in 1992. The procedure is safe effective widely available and should be considered the current treatment of choice. It is performed with CT guidance and with general spinal or propofol-induced anesthesia. Local anesthesia alone usually results in insufficient pain control particularly during entry into the nidus of the lesion. The average procedure can be performed in approximately 90 minutes. Daily activities may be resumed immediately without the use of a cast splint or other external support. Relative contraindications to RF ablation include the location of a lesion in the hand or the spine (D: The imaging findings are diagnostic of a benign osteoid osteoma. No aggressive features are present to suggest malignancy.

A: The Accreditation Council for Graduate Medical Education is responsible for the accreditation of post-MD medical training programs within the United States. Effective 7-1-07 it has become an ACGME common program requirement that the Sponsoring Institution must provide residents with fair reasonable and readily available policies and procedures for grievances. These policies and procedures must minimize conflict of interest by adjudicating parties.
B: This is accomplished at my institution by granting our residents the right under unusual circumstances to bring a grievance directly to the Office of Academic Affairs bypassing the Program Director and Department.'
C: The Accreditation Council for Graduate Medical Education is responsible for the accreditation of post-MD medical training programs within the United States. Effective 7-1-07 it has become an ACGME common program requirement that the Sponsoring Institution must provide residents with fair reasonable and readily available policies and procedures for grievances. These policies and procedures must minimize conflict of interest by adjudicating parties.
D: The Accreditation Council for Graduate Medical Education is responsible for the accreditation of post-MD medical training programs within the United States. Effective 7-1-07 it has become an ACGME common program requirement that the Sponsoring Institution must provide residents with fair reasonable and readily available policies and procedures for grievances. These policies and procedures must minimize conflict of interest by adjudicating parties.

A: The WH O defines osteoporosis as a T score -2.5.
B: This is the W O definition for osteoporosis although this finding may also be seen in osteomalacia. In addition many patients with T scores higher than -2.5 are deemed to be appropriate candidates for treatment of bone loss. The T score is derived by comparison with a young adult normal control group.
C: The score is derived from comparison with age sex and race-matched controls and is not a direct indicator of osteoporosis.
D: Again the T score rather than the score is used to define the presence of osteoporosis. A highly negative score indicates bone loss out of proportion to the patient's age sex and race.

Findings: WHO definition of osteoporosis is a bone mineral content measurement that is equal to or greater than 2.5 standard deviations below the expected measurement of a young normal control group (T score -2.5).

A: It is highly unlikely that a complete central placental previa will resolve. Therefore placental position will likely preclude vaginal delivery and require cesarean section.

A: Incorrect. The kidneys are often enlarged in adult polycystic kidney disease but the enlargement is due to innumerable renal cysts not fatty tumors. The masses in this case contain macroscopic fat as evidenced by the HU number of - 97 consistent with angiomyolipomas not cysts. Additionally there is no association of APCD with lung cysts.
B: Incorrect. Acquired cystic renal disease is a condition affecting patients with renal failure. The kidneys are typically small not enlarged as in this case. Multiple cysts develop often complicated by hemorrhage and calcification. Additionally there is increased risk for developing renal cell carcinomas that present as solid masses.
C: Correct. The renal masses in this case have macroscopic fat consistent with angiomyolipomas. 80% of patients with tuberous sclerosis have renal angiomyolipomas and 1% of patients with tuberous sclerosis have lung cysts indistinguishable from those found in lymphangiomyomatosis.
D: Incorrect. Renal cysts and renal cell carcinomas develop in patients with VHL but there is no association with angiomyolipomas. Additionally there is no association of VHL with lung cysts.