Use Of CT Pulmonary Angiography Research Articles

THE IMPORTANCE OF ACCURATE PRETEST PROBABILITY DETERMINATION IN THE EVALUATION OF SUSPECTED PULMONARY EMBOLISM

PURPOSE: In our institution we have noted a recent substantial rise in the use of CT pulmonary angiography (CTPA) in the evaluation of atypical chest pain and other syndromes which could be caused by Pulmonary Emboli (PTE) but usually are not. Since there are good prediction rules (e.g. the Wells rules) which can quantitate the clinical risk of PTE, it seems that some of this definitive testing may be avoidable. The incidence of significant contrast reactions, combining anaphylactic/anaphylactoid and renal impairment is about 3%.

Female Breast Radiation Exposure During CT Pulmonary Angiography

The objective of our study was to estimate the effective radiation dose to the female breast during CT pulmonary angiography compared with other routine diagnostic imaging techniques. We retrospectively reviewed the demographic data of patients who underwent CT pulmonary angiography between May 2000 and December 2002, the diagnostic yield of those studies, and the estimated effective radiation dose to the breast incurred during CT. The estimated effective radiation dose was calculated using the ImPACT CT (Impact Performance Assessment of CT) dosimetry calculator and the CT dose index (CTDI) and was compared with the average glandular dose for two-view screening mammography. During the study period, 1,325 CT pulmonary angiograms were obtained. Sixty percent (797) of the scans were obtained on female patients. The mean age of scanned females was 52.5 years (range, 15-93 years). Of the studies performed in females, 401 (50.31%) were negative, 151 (18.95%) were nondiagnostic, and 245 (30.74%) were positive for pulmonary thromboembolism. The calculated effective minimum dose to the breast of an average 60-kg woman during CT was 2.0 rad (20 mGy) per breast compared with an average glandular dose of 0.300 rad (3 mGy) for standard two-view screening mammography. CT pulmonary angiography delivers a minimum radiation dose of 2.0 rad (20 mGy) to the breasts of an average-sized woman. This greatly exceeds the American College of Radiology recommendation of < or = 0.300 rad (3 mGy) or less for standard two-view mammography. The potential latent carcinogenic effects of such radiation exposure at this time remain unknown. We encourage the judicious use of CT pulmonary angiography and lower doses and nonionizing radiation alternatives when appropriate.

Pulmonary embolism in pregnant patients: a survey of practices and policies for CT pulmonary angiography.

We surveyed the practices and policies of the radiology departments of the Society of Thoracic Radiology members regarding the use of CT pulmonary angiography in pregnant patients suspected of having pulmonary embolism. Surveys were mailed electronically to the 403 members of the Society of Thoracic Radiology (403 addresses). Respondents were asked to send one response from each institution or department. Information gathered included use of CT angiography in relation to ventilation-perfusion imaging in pregnant patients, written policies, informed consent procedures, and modifications of standard protocols for dose reduction. Fifty-seven members responded; 43 (75%) reported that they perform CT angiography in pregnant patients suspected of having pulmonary embolism. Of the 43 respondents who perform CT angiography in pregnant patients, 23 (53%) generally perform CT angiography as the initial study rather than ventilation-perfusion scanning, 26 (60%) require informed consent from the patient, seven (16%) have a written policy concerning CT angiography in pregnant patients, and 17 (40%) modify standard imaging protocols for pregnant patients. The most common modification for dose reduction is decreasing the scanning area along the z-axis. Most respondents perform CT angiography in pregnant patients suspected of having pulmonary embolism, but their policies and practices vary considerably.