Edward Lin MD, Presenter: Nothing to Disclose

Shweta Bhatt MBBS, Abstract Co-Author: Nothing to Disclose

Deborah J. Rubens MD, Abstract Co-Author: Nothing to Disclose

Vikram Singh Dogra MD, Abstract Co-Author: Nothing to Disclose

During the ultrasound evaluation of deep venous thrombosis (DVT) of lower extremities, monophasic wave forms are often encountered particularly in the common femoral vein (CFV). The objective of the study is to assess the significance of these monophasic waveforms encountered in CFV during DVT study.

A retrospective review of the lower extremity color flow Doppler ultrasound (CFD) studies, performed from 1 September 2000 through 1 September 2005, was conducted. All satisfactory CFD studies, which were in compliance with the American college of Radiology standard protocol, were evaluated for the presence of monophasic waveforms, and correlated with computed tomography (CT) of the abdomen and pelvis. Studies were further reviewed to evaluate for the etiology of the monophasic waveforms. Patients less than the age of 17 were excluded from the study.

A total of 2963 CFD examinations were reviewed. 124/2963 demonstrated monophasic waveforms, of which 89/124 had additional CT examinations within 1 week, 19/124 within 2 months, and 16/124 with no additional exams. One patient was further evaluated with an MRV and 2 patients underwent a venogram during inferior vena cava (IVC) filter placement. 47/124 cases revealed DVT above the level of the common femoral vein, of which 23/47 were identified by CFD. 26/124 were due to extrinsic compression, such as pregnancy, lymphocele and hematoma. 6/124 demonstrated a hypoplastic or stenosed common iliac vein and the remaining 45/124 patients had no apparent cause for monophasic waveforms.

Since nearly two fifths of the cases with monophasic waveforms demonstrated a DVT above the level of the common femoral veins, and nearly fifty percent of those DVT’s were detected by CFD, we recommend that CFD of the external iliac vein be a part of the standard evaluation in patients who exhibit monophasic waveforms.

Discovery of monophasic wave form in CFV should not be ignored, as it has strong correlation with an iliac vein thrombus or mass compressing the iliac veins. This warrants further investigation of the external iliac vein by CFD or other imaging modalities.

Lin, E, Bhatt, S, Rubens, D, Dogra, V, Monophasic Venous Waveforms: What Do They Mean?.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4428766.html