Role of B-color and Resolution Sonography Presets for the Diagnosis of Lower Extremity Deep Vein Thrombosis

摘要

Sonography is an accurate and commonly used method of determining the presence, location, and acuity of deep vein thrombosis (DVT). A retrospective data analysis of 284 venous examinations was performed to determine if imaging presets increase the ability to detect an acute DVT. There were no significant differences between the outcomes of three modalities of sonographic imaging. If a patient had a prior DVT, the likelihood of observing another DVT using only two-dimensional imaging, resolution presets, or the B-color option was approximately nine times greater than for a patient who did not have a prior DVT. Sex, age, body mass index, ethnicity, and comorbidities of diabetes and/or hypertension were not significant predictors of observing a DVT. Using a resolution-enhancing preset that increases the overall frequency range to reduce artifacts and improve border definition and/or using the B-color preset to tint the overall image did not improve the likelihood of detecting an acute DVT during a lower extremity venous duplex sonogram. A deep venous thrombosis (DVT) is a blood clot that forms within the lumen of one of the deep veins of the body. Sonographically, a DVT presents as an echogenic soft tissue mass within the lumen of the deep vessel. In the setting of an acute DVT, the vessel lumen diameter typically will also be enlarged compared to the normal resting lumen diameter. The accurate diagnosis of a DVT is vitally important since, if untreated, a DVT can lead to pulmonary embolism and death or chronically cause damage to venous valves, leading to venous reflux. In the presence of an undetected acute DVT, the development of a pulmonary embolism is the most serious complication. Several limitations of lower extremity venous duplex sonography include patient obesity, soft tissue edema, swelling, extrinsic pressure from an abscess or mass limiting full compression of a vein or extrinsically compressing the vein already, and duplication of femoral veins. False positive results for DVT can be the result of inaccurate gain settings or slow flowing blood mimicking a thrombus. Despite these limitations, sonographic assessment for lower extremity DVT has an overall accuracy and sensitivity of 95% and specificity of 98%.