Kaushik S. Shahir MD, Presenter: Nothing to Disclose

Luis Antonio Sosa MD, Abstract Co-Author: Nothing to Disclose

Jonathan Michael McCrea MD, Abstract Co-Author: Nothing to Disclose

Lawrence R. Goodman MD, Abstract Co-Author: Nothing to Disclose

To evaluate the feasibility for applying reduced z axis coverage in CTPA in pregnant women. Were important diagnoses missed? What dose reduction resulted?

In this IRB-approved retrospective study, 84 pregnant patients underwent CTPA for pulmonary embolism during 2004-2012. New axial, sagittal and coronal series were created with a reduced anatomic coverage extending from aortic arch to the base of the heart. These were read individually by 2 experienced blinded readers on the PACS workstation. The scans were evaluated for PE, incidental and pertinent findings. The readers had access to most recent chest radiograph. These results were compared with original report by the 3rd reader. In case of missed abnormality, 3rd reader checked whether the finding was a known abnormality or whether it influenced the clinical outcome. Additionally, we estimated dose length product (along z axis) for 40 patients as a quality control project.

Two out of 84 patients had PE and were successfully identified by both readers. 32 patients had normal exams. Rest of the patients had 57 pertinent and 20 incidental findings. 4 incidental findings including 3 benign thyroid nodules and one benign splenic calcification were missed. One pertinent but a benign lung nodule was missed, but this was a known abnormality based on prior CT. None of these missed findings affected further clinical outcome or management. Radiation dose was reduced by a mean of 69%.

No PE or any important diagnosis are missed using the reduced anatomic coverage CTPA for PE in pregnant women. The radiation dose is reduced by approximately 69%. Hence we highly recommend this technique in pregnant women.

The study helps solve any doubts as regards to using a reduced z-axis CTPA technique for PE in pregnant women.

Shahir, K, Sosa, L, McCrea, J, Goodman, L, Reduced Z Axis CTPA in Pregnant Women for Pulmonary Embolism – Do We Really Miss Any Important Diagnoses? How Much Is the Resultant Dose Reduction?.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13015594.html