Case 3853 Colour-coded duplex and contrast medium enhanced ultrasonography in deep venous thrombosis in emergency patients

Transcription

1 Case 3853 Colour-coded duplex and contrast medium enhanced ultrasonography in deep venous thrombosis in emergency patients A.Kotis Radiologist M.D, L.Guindaglia Radiologist M.D. Radiology Department General Hospital of Rhodes General Hospital of Rhodes Section: Cardiovascular Published: 2006, Apr. 11 Patient: 50 year(s), female Clinical History Emergency Department (ED) patients with suspected deep vein thrombosis (DVT) require an imaging method such as ultrasound (US ) to confirm the diagnosis of DVT of lower deep venous system prior to treatment. Imaging Findings A prospective, study was performed on a sufficient sample of patients presenting to an ED with lower extremity symptoms and signs suggestive of DVT. Patients with a history of DVT in the symptomatic extremity were included. We evaluated the ability of color coded duplex ultrasonography performed by radiologists, to diagnose proximal DVT performed in our Ultrasound Department (Aspen Acuson scanner and 5-7linear array transducer). Long and short axis images were obtained.there were 65 patients who completed the study, and 20 patients (25%) were diagnosed with DVT, duplex US was positive in 16, negative in 2, and indeterminate in 2. Among 45 patients diagnosed without DVT by duplex US, there were 5 false-positive and indeterminate in 5.In all, duplex US was indeterminate in 7 patients. Color duplex ultrasonography had a sensitivity of 80% ( 95% C.I %) and specificity of 69% (55-70). Negative predictive value was 90% (80-90) performed in our ultrasound department. The inability to compress the common femoral vein, superficial femoral vein or popliteal vein, DVT was diagnosed in compression US, Was considered indeterminate the examination if the veins could not be clearly identified or

2 compressibility was equivocal. In those cases where ED compression Ultrasonography was discordant with color doppler Ultrasonography, we reviewed the US findings with additional injection of echo-enhancing agent (L-vist 16ml in concentration 200mg/ml bolus injection). The echo-enhanced color-coded duplex sonography showed a significant increase in detection of the thrombus in comparison with non-enhanced color-coded duplex sonography (p<0.01). Discussion The veins of the lower extremities are divided into deep and superficial veins. The deep veins follow the arteries. In the lower leg the deep system consists of the deep plantar veins of the foot and six paired veins in the calf. Emergency Department (ED) patients with suspected deep vein thrombosis (DVT) require an objective vascular study such as ultrasound (US) to confirm the diagnosis prior to treatment or disposition. A simple compression US test of the common femoral vein and popliteal vein reliably detects proximal DVT in symptomatic patients. Ultrasonography is currently the principal imaging technique used for detecting venous thrombosis. Thrombus within the venous system is hypoechoic, during the first few days after its formation, but with time the thrombus becomes more echogenic. The thrombus is divided in acute subacute and chronic. Acute thrombus means recently formed thrombus (days to 1-2 weeks old) generates low level echoes. Small and non occlusive thrombi may be difficult to visualize, but flow void and lack of vein compressibility indicate thrombus presence. As thrombus ages during the course of several days or weeks, echogenicity increases, but the intensity of the echoes generally remains less than that of the surrounding muscle. Resistance from surrounding musculoskeletal structures may prevent adequate compression of the vein and may result in false-positive diagnoses. Blood flow persists in veins that are incompletely filled with acute thrombus and even the vein lumen is filled, tiny residual channels adjacent to the vein wall within the thrombus. The recently thrombosed vein is generally distended to an abnormal large size. Venous distension is a significant finding, because it helps to differentiate between recently formed thrombus and older thrombus (months to years). Another reliable finding for differentiating between thrombosed and normal veins is the loss of compressibility of the vein. Thrombus can be excluded when compression causes the vein to disappear completely. Resistance from surrounding musculoskeletal structures may prevent adequate compression of the vein and may result in false-positive diagnoses. Final Diagnosis Enhanced ultrasonography provides significant diagnostic information in DVT emergecy patients. Figures Figure 1 Long axis image:deep Venous Thombosis of Popliteal Vein Distal

3 Figure 2 Long and short axis image:lack of compressibility Deep Venous Thrombosis Popliteal Vein Distal Long axis image:recanalization of Rt Common Femoral Vein enhanced with L-Vist injection Figure 3 Long Axis Image:DVT POPV PROX after L-Vist injection

4 Long Axis Image:DVT POPV PROX after L-Vist injection Figure 4 DVT LT POPV PROX :With color duplex sonography blood flow is seen -to tricklearound the thrombus DVT LT POPV PROX:There is no difference with the additional injection of echo-enhancing agent(l-vist) Figure 5 DVT LT POPV PROX:There is no difference with the additional injection of echo-enhancing agent(l-vist)

5 DVT LT POPV PROX:There is no difference with the additional injection of echo-enhancing agent(l-vist) Figure 6 Recanalization.Almost complete restoration of blood flow of superficial Femoral Vein is visible in this thrombus Recanalization.Almost complete restoration of blood flow of superficial Femoral Vein is visible in this thrombus Figure 7 Long axis image:recanalization of Rt Common Femoral Vein enhanced with L-Vist injection Long axis image:recanalization of Rt Common Femoral Vein enhanced with L-Vist

6 injection Figure 8 Long axis image:deep Venous Thrombosis(DVT) of Right Common Femoral Vein Long axis image:deep Venous Thrombosis(DVT) of Right Common Femoral Vein Figure 9 Short axis Image:Lack of Compressibility Deep Venous Thrombosis Popliteal Vein Proximal Short axis Image:Lack of Compressibility Deep Venous Thrombosis Popliteal Vein Proximal Figure 10 Post-Thrombotic syndrome of Lt superficial Femoral Vein

7 Post-Thrombotic syndrome of Lt superficial Femoral Vein Figure 11 Long Axis Image:DVT POPV DISTAL Long Axis Image:DVT POPV DISTAL Figure 12 Long and short axis image:lack of compressibility Deep Venous Thrombosis Popliteal Vein Distal Long and short axis image:lack of compressibility Deep Venous Thrombosis Popliteal Vein Distal Figure 13 Long axis image:partial recanalization of superficial femoral vein. Deep femoral vein patent

8 Long axis image:partial recanalization of superficial femoral vein. Deep femoral vein patent MeSH Diagnostic Imaging [E ] Any visual display of structural or functional patterns of organs or tissues for diagnostic evaluation. It includes measuring physiologic and metabolic responses to physical and chemical stimuli, as well as ultramicroscopy. Ultrasonography, Doppler, Color [E ] Ultrasonography applying the Doppler effect, with the superposition of flow information as colors on a gray scale in a real-time image. This type of ultrasonography is well-suited to identifying the location of high-velocity flow (such as in a stenosis) or of mapping the extent of flow in a certain region. References [1] W.J.Zweibel Introduction to Vascular Ultrasonography 4th Ed.Ch 23 & Ch 24 [2] Puls R, Hosten N, Bock JS, Oellinger JH, Lemke AJ, Gutberlet M, Holz K, Felix R. Signal-enhanced color Doppler sonography of deep venous thrombosis in the lower limbs and pelvis. J Ultrasound Med Mar;18(3): [3] Bradley MJ, Spencer PA, Alexander L, Milner GR. Colour flow mapping in the diagnosis of the calf deep vein thrombosis. Clin Radiol Jun;47(6): [4] Schott U, Laniado M, Duda SH, Seitz D, Claussen CD. Echo contrast agents for the color Doppler sonographic diagnosis of deep femoral venous thrombosis. Rofo Mar;162(3): [5] Schweizer J, Oehmichen F, Brandl HG, Altmann E. Color-coded duplex ultrasound and contrast medium enhanced duplex ultrasound in deep venous thrombosis. Vasa. 1993;22(1):22-5. Citation A.Kotis Radiologist M.D, L.Guindaglia Radiologist M.D. Radiology Department General Hospital

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