Israel Medical Association Journal

Background: The use of computed tomography in Israel has been growing rapidly during recent decades. The major drawback of this important technology is the exposure to ionizing radiation, especially among children, who have increased organ radiosensitivity and a long lifetime to potentially develop radiation-related cancer.

Objective: To estimate the number of excess lifetime cancer deaths related to annual CT scans performed in children in Israel.

Methods: We used CT scan utilization data from 1999 to 2003 obtained from the second largest health management organization in the country to project age and gender-specific CT scan use nationwide. Based on published organ doses for common CT examinations and radiation-related cancer mortality risk estimates from studies in survivors of the atomic bomb, we estimated the excess lifetime risks for cancer mortality attributed to use of CT in children and adolescents (up to 18 years old) in Israel.

Results: We estimated that 17,686 pediatric scans were conducted annually in Israel during 1999–2003. We project that 9.5 lifetime deaths would be associated with 1 year of pediatric CT scanning. This number represents an excess of 0.29% over the total number of patients who are eventually estimated to die from cancer in their lifetime.

Conclusions: Pediatric CT scans in Israel may result in a small but not negligible increased lifetime risk for cancer mortality. Because of the uncertainty regarding radiation effects at low doses, our estimates of CT-related cancer mortality should be considered with caution. Nevertheless, physicians, CT technologists, and health authorities should work together to minimize the radiation dose for children to as low as reasonably achievable and encourage responsible use of this essential diagnostic tool.
 

Background: Coronary heart disease and ischemic stroke are among the leading causes of morbidity and mortality in adults, and cerebrovascular disease is associated with the presence of symptomatic and asymptomatic CHD[1]. Several studies noted an association between coronary calcification and thoracic aorta calcification by several imaging techniques, but this association has not yet been examined in stable angina pectoris patients with the use of spiral computed tomography.

Objectives: To examine by spiral CT the association between the presence and severity of CC[2] and thoracic aorta calcification in patients with stable angina pectoris.

Methods: The patients were enrolled in ACTION (A Coronary Disease Trial Investigating Outcome with Nifedipine GITS) in Israel. The 432 patients (371 men and 61 women aged 40–89 years) underwent chest CT and were evaluated for CC and aortic calcification.

Results: CC was documented in 90% of the patients (n=392) and aortic calcification in 70% (n=303). A significant association (P < 0.05) was found between severity of CC and severity of aortic calcification (as measured by area, volume and slices of calcification). We also found an association between the number of coronary vessels calcified and the presence of aortic calcification: 90% of patients with triple-vessel disease (n=157) were also positive for aortic calcification (P < 0.05). Age also had an effect: 87% of patients ≥ 65 years (n=219) were positive for both coronary and aortic calcification (P = 0.005) while only 57% ≤ 65 (n=209) were positive for both (P = 0.081).

Conclusions: Our study demonstrates a strong association between the presence and severity of CC and the presence and severity of calcification of thoracic aorta in patients with stable angina pectoris as detected by spiral CT.

Multidetector-row computed tomography has been validated as a useful non-invasive diagnostic method in patients with various cardiac diseases.

Objectives: To investigate the spectrum of findings in 32 consecutive patients with chest pain who underwent CT coronary angiogram in order to determine the clinical situations that will benefit most from this new technique.

Methods: Thirty-two patients with chest pain were studied by MDCT[1] using 4 x 1 mm cross-sections, at 500 msec rotation with pitch 1–1.5, intravenous non-ionic contrast agent and a retrospectively ECG-gated reconstruction algorithm. The heart anatomy was evaluated using multi-planar reconstructions in the axial, long and short heart axes planes. Coronary arteries were evaluated using dedicated coronary software and the results were compared to those of the conventional coronary angiograms in 12 patients. The patients were divided into four groups according to the indication for the study: group A – patients with high probability for coronary disease; group B – patients after CCA[2] with undetermined diagnosis; group C – patients after cardiac surgery with possible anatomic derangement; and group D – symptomatic patients after coronary artery bypass graft, before considering conventional coronary angiography.

Results: Artifacts caused by coronary motion, heavy calcification and a lumen diameter smaller than 2 mm were the most frequent reasons for non-evaluable arteries. Assessment was satisfactory in 83% of all coronary segments. The overall sensitivity of 50% stenosis was 74% (85% for main vessels) with a specificity of 96%. Overall, the CTCA[3] results were critical for management in 18 patients.

Conclusions: Our preliminary experience suggests that CTCA is a reliable and promising technique for the detection of coronary artery stenosis as well as for a variety of additional cardiac and coronary structural abnormalities.

Objectives: To evaluate the accuracy of 16-slice multi-detector CT angiography in the diagnosis of coronary artery disease, and assess coronary bypass grafts and coronary anomalies.

Methods: We conducted a retrospective study of 223 patients who were examined at our medical center over a period of 2 years with a 16-slice CT angiography scanner and retrospective electrocardiographic gating.

Results: There were no significant complications, and good visualization of the coronary arteries was achieved in all but eight patients. A high correlation with the results of the invasive angiography was noted (sensitivity 85%, specificity 93%, negative predictive value 98%). Altogether, 131 bypass conduits were examined with excellent graft visualization. Several coronary anomalies were detected, as were significant extra-cardiac findings.

Conclusions: Multi-slice CT angiography is a reliable non-invasive diagnostic procedure for demonstration of the coronary arteries and bypass grafts. In the future it will probably replace part of the diagnostic invasive coronary angiography and, as a result, a large proportion of coronary angiography procedures will be therapeutic.