Diana Litmanovich MD, Presenter: Nothing to Disclose

Phillip M. Boiselle MD, Abstract Co-Author: Nothing to Disclose

Vassilios D. Raptopoulos MD, Abstract Co-Author: Research grant, Toshiba Corporation, Tustin, CA Research grant, E-Z-EM, Inc, Lake Success, NY

To compare image quality using a reduced-dose 64-row MDCT angiography protocol for pregnant patients with standard-dose CTA images in a control population.

Between July 2006 and April 2007, all pregnant patients referred to radiology for suspected pulmonary embolus underwent chest CTA with a reduced-dose protocol: mA 200, kV 100, aortic arch to diaphragm. A control population was retrospectively identified consisting of 15 non-pregnant women scanned during the same time interval with a standard-dose technique: mA 400, kVp 120, entire thorax. Vessel attenuation of pulmonary arteries was measured by obtaining ROI at predetermined points. For each case, 2 radiologists independently and blindly interpreted scan quality for assessment of acute pulmonary or aortic disease using a 5-point scale (1= non-diagnostic to 5= excellent quality). DPL and CTDI values were measured using software on the CT scanner in a subset of patients.

Study population of 15 pregnant women, 21-40 years (28±6) and 5-38 weeks gestation (17±8). Control population of 15 non-pregnant women, 21-40 years (32±6). MDCT pulmonary angiography was technically diagnostic at the level of segmental pulmonary arteries in all patients and at the level of subsegmental arteries (score 4 or 5) in 12 (80%) pregnant patients, compared to 13 (87%) controls. Median ranks of confidence for excluding PE in segmental and subsegmental pulmonary arteries were 5 and 4 (quartiles 4.75-5 and 4-5, respectively) compared to 5 and 5 respectively for controls, p>0.05. Mean main and lobar pulmonary enhancement were 327± 58 and 307±87 HU respectively with no significant difference from matched controls (330±42, 320±55 HU respectively). Mean DLP in pregnant patients was 161±59 mGy-cm compared to 598 ± 32 mGy-cm in matched controls (p < 0.001), thus decreased by a factor of 4. There was increased image noise with the reduced-dose technique.

Reduced-dose CTA protocol for pregnant patients can provide diagnostic quality similar to a conventional dose CTA.

Reduced-dose chest CTPA with 64-MDCT is a suitable technique to evaluate pregnant patients with chest pain and suspected PE

Litmanovich, D, Boiselle, P, Raptopoulos, V, CTA of Pregnant Patients with Suspected PE: Comparison of Image Quality Between Reduced-Dose Protocol and Standard-Dose Protocols.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5014771.html