Jeffrey Hellinger MD, PRESENTER: Nothing to Disclose

Abstract: HTML Purpose: When performing CTV following 2.5-5 mm single or dual detector CT Pulmonary Angiography (CTPA), previous authors have reported 3-10% of patients have deep venous thrombus (DVT) in the absence of pulmonary embolism (PE), resulting in a 14-36% increase of cases requiring thromboembolism (TE) management. We sought to determine the prevalence of positive DVT with negative CTPA, acquired using a thin-section MDCT, in order to assess the incremental clinical value of performing CTV. Methods and Materials: Over a 32 month period, 1240 consecutive CTPA-CTV examinations were performed for suspected pulmonary embolism in 1166 patients referred from the emergency department (49%), outpatient clinics (7.4%), inpatient wards (25.6%), or ICU (18%). CTPA images were acquired from lung bases to apices, on either 4 (n=418), 8 (n=728), or 16 (n=94) row MDCT, with average acquisition times of 30, 15, and 8 seconds, respectively. 120ml of contrast medium was injected at 4ml/sec, after a scan delay individualized by test-bolus or bolus trigger technique. Section thickness (1.25mm) and reconstruction interval (0.8) were identical on all exams. After a 3-minute delay, 5mm contiguous CTV images were obtained helically. Final reports were retrospectively reviewed for image quality and presence for PE and DVT. Reports reflected clinical practice of academic radiologists in a large tertiary setting. Results: 3% of our CTPA studies were technically inadequate, while 7% were inconclusive. 252 exams (20%) revealed PE, with the most proximal extent as follows: main=15%, lobar=27%, segmental=41%, subsegmental=17%. 115 studies (9%) revealed a DVT. Of these 115, 100 demonstrated PE (40% of positive PE studies, 87% of positive DVT studies), while 9 showed no PE, resulting in a positive DVT / negative PE prevalence rate of 0.7%, and a 3.4% increase in patients necessitating TE management. 1 non-diagnostic study and 5 inconclusive studies identified DVT, resulting in 15 cases (1.2%) total for positive DVT but no documented PE and a combined increase in TE management by 5.6%. Referral for these 15 patients was 47% ICU, 27% inpatient, 20% ER, and 7% outpatient. Conclusion: Our retrospective study found a 0.7% prevalence for positive DVT / negative PE, with CTPA acquired using thin-section MDCT technique. Including all studies of positive DVT, but no demonstrable PE, the incremental value of performing CTV was a 5.6% increase in TE management, a benefit less than previously reported in studies using single or dual-detector CTPA techniques.       Questions about this event email: jchellinger@yahoo.com

Hellinger MD, J, Multidetector Row CT (MDCT) Assessment of Thromboembolic Disease: Incremental Value of CT Venography (CTV) in 1240 Consecutive Exams.  Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL. http://archive.rsna.org/2003/3102237.html