Intro To Radiology Lecture

MRI is a form of radiation that can NOT alter the patient's DNA.

Anaphylaxis is a contraindication to contrast, but the patient can be pretreated if a mild reaction had occurred previously. Can treat patient with benadryl 1 hr prior to scan.

Table 7-1

Motion is the number one cause of repeat films because when there is excessive movement during the imaging process, the resulting images may be blurry or distorted. This can make it difficult for the radiologist to accurately interpret the images and make a diagnosis. Repeat films are then necessary to obtain clear and high-quality images for a more accurate diagnosis.

The heart usually does not shift and the trachea remains midline.

When a pleural effusion is present, the accumulation of fluid in the pleural space causes compression on the surrounding structures. In this case, both the heart and the trachea shift away from the pleural effusion. The pressure from the fluid pushes these structures away, causing them to move in the opposite direction. This can be observed on imaging studies such as chest X-rays or CT scans.

In adults, the heart should be less than 50% of the internal diameter of the thoracic rib cage. This means that the heart should occupy less than half of the space inside the rib cage. In infants, the heart should be less than 65% of the internal diameter of the thoracic rib cage. This indicates that the heart can occupy a larger portion of the space inside the rib cage in infants compared to adults.

Chapter 6- pleural effusion

With right-sided atelectasis, the lung on the right side collapses or becomes partially blocked, causing a decrease in lung volume. As a result, the heart, which is located in the middle of the chest, will shift towards the collapsed lung to compensate for the empty space. Therefore, the heart shifts to the right in cases of right-sided atelectasis.

Gadolinium-based contrast agents are commonly used in MRI scans to enhance the visibility of certain tissues and organs. However, in patients with renal insufficiency, these agents can accumulate in the body and lead to the development of Nephrogenic Systemic Fibrosis (NSF). NSF is a rare but serious condition characterized by thickening and hardening of the skin, as well as potential involvement of internal organs. Therefore, MRI with gadolinium-based contrast should be avoided in patients with renal insufficiency to prevent the occurrence of NSF.

The right hemidiaphragm shifts upward and may disappear (silhouette sign).

PACS stands for "picture archiving and communication system". This system is commonly used for reading radiographs, which are useful for diagnosing trauma, such as fractures and bullets, as well as evaluating bone tumors and diagnosing bowel obstruction. However, radiographs are not the ideal imaging technique for examining soft tissue pathology, except for detecting foreign bodies and air.

Interstitial lung disease is characterized by "packets of disease separated by normal-appearing, aerated lung"

The lemon sign is a radiological finding associated with congenital diaphragmatic hernia (CDH), not pseudotumor. CDH is a condition where there is a hole in the diaphragm allowing abdominal organs to herniate into the chest cavity, compressing the lungs. The lemon sign refers to the appearance of the fetal head on ultrasound, resembling a lemon shape, due to the herniated organs pushing the diaphragm upwards. Therefore, the correct answer is not pseudotumor but CDH.

The possible routes of administration for CT contrast include oral, IV, and rectal. Oral administration involves taking the contrast agent by mouth, IV administration involves injecting the contrast agent into a vein, and rectal administration involves inserting the contrast agent into the rectum. These routes allow the contrast agent to reach the desired areas of the body for imaging purposes.

A CT scan with IV contrast is contraindicated when the patient's creatinine level (CR) is greater than 1.8. This is because IV contrast can potentially cause kidney damage, and patients with higher creatinine levels are at a higher risk for kidney problems. Therefore, it is important to avoid administering IV contrast in these cases to prevent further harm to the patient's kidneys.

Read 'take-home points' of Chapter 5 in the book