Imaging Modalities Flashcards
What are the four basic features of frontal radiographs?
Penetration
Rotation
Inspiration
Motion
How can you assess if there is proper penetration in chest radiography?
Proper penetration is present when there is faint visualisation of the intervertebral disk spaces of the thoracic spine and discrete branching vessels can be identified through the cardiac shadow.
How is rotation assessed in chest radiography?
Rotation is assessed by noting the relationship between the vertical line drawn midway between he medial cortical margins of the clavicular heads and one drawn vertically through the spinous process of the thoracic vertebrae.
Superimposition of these lines (the former midline anterior and the latter in the midline posterior) indicates a properly positioned, non rotated patient.
How to assessed if there is appropriate inspiration?
An appropriate deep inspiration in a normal individual is present when the apex of the right hemidiaphragm is visible below the 10th posterior rib.
The cardiac margin , diaphragm, and pulmonary vessels should be sharply marinated in complete still patients who has suspended respiration during radiographic exposure.
In AP chest radiograph, what happens to the cardiac diameter?
The apparent cardiac diameter increases by 15% to 20%, bringing the upper limit of normal for the cardiothoracic ratio from 50% on a PA radiograph to 57% on an AP radiograph.
As little as how many mL of fluid and mL of air can be demonstrated by the lateral decubitus view?
5 mL of fluid
15 mL of air
An expiratory radiograph obtained at residual volume (end maximal forced expiration) can detect what disease entity?
It can detect focal or diffuse air trapping and eases detection of small pneumothorax.
Chest fluoroscopy is used mainly to assess what disease process?
Assess chest dynamics on patients with suspected diaphragmatic paralysis.
What is a the routine setting fo CT display of mediastinal structures and lungs? (Window level and width?)
Mediastinal structures = WW 400 and WL 40
Lungs = WW 1500 and WL -700
What is HRCT?
HRCT, this section CT scan, technique involves incremental thinly collimated scans (1.0 to 1.5 mm) obtained at evenly spaced intervals through the thorax for the evaluation of diffuse bronchial or parenchyma disease.
Indications for thoracic CT scan?
- Evaluation of an abnormality identified on conventional radiographs
- Staging of lung cancer
- Detection of occult pulmonary metastases
- Detection of mediastinal nodes (lymphoma, metastases, infection)
- Distinction of emphysema from lung abscess (Contrast)
- Detection of pulmonary embolism
- Detection and evaluation of aortic disease; aneurysm, dissection, intramural hepatoma, aortitis, trauma
What are indications for thoracic HRCT?
- Solitary pulmonary nodule
- Detection of lung disease in a patient with pulmonary symptoms or pulmonary function studies and a normal or equivocal chest film
- Evaluation of diffusely abnormal chest film
- A baseline for evaluation of patients with chronic diffuse infiltrative lung disease for follow-up changes with therapy
- To determine approach (type or location) of biopsy
Indications for MR of the thorax
- Evaluation of aortic disease in stable patients: Dissection, aneurysm, intramural hematoma, aortitis
- Assessment of superior sulcus tumor
- Evaluation of mediastinal, vascular, and chest wall invasion of lung cancer
- Staging of lung cancer patients unable to receive intravenous iodinated contrast
- Evaluation of posterior mediastinal masses
MR is superior to CT in the diagnosis of what chest pathology?
In the diagnosis of chest wall or mediastinal invasion because of the high contrast between tumor and chest wall fat and musculature and mediastinal fat, respectively.
V/Q scanning is used almost exclusively for diagnosing what disease?
Pulmonary embolism.
Although quantitative V/Q imaging may be useful in the planning of bullectomy, lung volume reduction surgery for emphysema, and lung transplantation.
