Assessment of deep venous thrombosis using routine pelvic CT.

OBJECTIVE: The purpose of this study was to assess routine pelvic CT both for accuracy in diagnosis of deep venous thrombosis and for frequency of detection of clinically unsuspected pelvic thrombi. MATERIALS AND METHODS: We reviewed the CT records of patients who had undergone pelvic CT during a 6-month period and cross-referenced these records to reports on lower extremity venous sonography to identify patients who had undergone this test within 1 week of pelvic CT. We compared the frequency and location of venous thrombosis revealed through these two tests. To identify unsuspected deep venous thrombosis detected on pelvic CT, we reviewed the charts of patients for whom a clot was reported to determine if it had been clinically suspected before CT. RESULTS: Among the 52 patients who underwent both CT and lower extremity venous sonography, the findings were in agreement for 49 (94%). The techniques disagreed for three patients; two patients had deep venous thrombosis detected on sonography but not on CT and the other had a clot detected on CT but not on sonography. The prevalence of unsuspected deep venous thrombosis detected by CT was 1.1%, and 73% of these patients underwent anticoagulation therapy without further confirmatory tests. CONCLUSION: Unsuspected deep venous thrombosis is commonly seen on routine pelvic CT and should be carefully sought during such examinations. CT appears to be relatively accurate in the detection of deep venous thrombosis. Thus, CT venography combined with pulmonary CT angiography may significantly increase the percentage of patients who are appropriately treated for thromboembolic disease because both deep venous thrombosis and pulmonary emboli can be identified by this combined test.

Smoking cessation following CT screening for early detection of lung cancer.

BACKGROUND: This study was conducted to assess the impact of lung cancer screening participation on smoking cessation. METHODS: Individuals (n = 134) who reported active smoking at the time of enrollment in our Early Lung Cancer Action Program (ELCAP) completed a brief, follow-up telephone interview assessing any changes in smoking patterns following lung cancer screening. Using logistic regression, we estimated the probability of decreasing or quitting smoking using each enrollee's background information and computed tomography (CT) scan results. RESULTS: Most survey respondents (74%) agreed that participation in the ELCAP increased their motivation for quitting smoking. In terms of self-reported changes in smoking behavior, 31 (23%) reported that they had quit and 35 (27%) decreased their smoking patterns. Several significant covariates of smoking cessation were identified: perceived benefit of quitting (OR 4.02), cancer anxiety (OR 2.49), younger age (OR 2.47), and abnormal CT finding (1.97). CONCLUSIONS: Our analyses suggest that low-dose helical CT scanning may serve as a strong catalyst for smoking cessation and that delivery of effective smoking cessation interventions along with CT scanning represents a potential opportunity to increase the overall cancer prevention benefit of lung cancer screening.

Optimization of combined CT pulmonary angiography with lower extremity CT venography.

OBJECTIVE: We wanted to determine the time delay for maximum enhancement of the deep venous system of the lower extremities after standard CT pulmonary angiography. SUBJECTS AND METHODS: In 20 patients who had undergone standard CT pulmonary angiography, we measured arterial and venous enhancement at the level of the greater trochanter. These measurements were obtained at 30-sec intervals immediately after completion of CT pulmonary angiography. Ten measurements were obtained in 5 min. Time-density curves were plotted. RESULTS: We found that the median and average peak venous enhancements were 92 and 95 H, respectively. Time to peak enhancement was variable. Because of the broad shape of the venous time-density curve, near peak enhancement could be achieved in most patients at 2 min after CT pulmonary angiography. CONCLUSION: CT of the deep venous system of the lower extremities after standard CT pulmonary angiography, performed with appropriate timing considerations, allows near maximal enhancement of the venous system in most patients without altering the optimum CT pulmonary angiography protocol.