Colour Doppler ultrasound in deep venous thrombosis: a comparison with venography

Colour Doppler ultrasound is a new technical development allowing simultaneous grey scale imaging and a dynamic colour flow vascular image. To date, many real time ultrasonic studies have been assessed in the diagnosis of lower limb venous thrombosis and have been shown to be accurate in the femoral and popliteal segments. A double blind prospective study comparing colour Doppler with contrast venography in the diagnosis of lower limb thrombosis was performed in a group of 40 patients. Of the study group, 26 venograms were negative and 27 ultrasound examinations were negative. Of the 14 positive venograms there was one false negative colour doppler scan which missed a calf and lower popliteal thrombosis. Two cases of isolated calf vein thrombosis were successfully detected by colour Doppler. Overall, the sensitivity and specificity for detection of lower limb venous thrombosis, including calf vein assessment, were 93% and 100% respectively. Colour Doppler is easy to perform; the average scanning time being 15 minutes for complete assessment of a unilateral lower limb venous system. Spontaneous flow is evident in the femoropopliteal segment, whilst proximal calf vein flow can only be appreciated with the aid of distal compression. Eccentric thrombus and partially recanalized thrombus can be shown. Although the number of isolated calf vein thromboses was small, early experience suggests colour Doppler may be useful in the assessment of proximal calf vein patency.     

Colour flow imaging of calf vein thrombosis.

Ultrasound and more recently colour Doppler ultrasound has been successfully used in the diagnosis of lower limb venous occlusive disease. Colour Doppler ultrasound has shown promise in the diagnosis of calf vein thrombosis but to date there has been no prospective trial to specifically evaluate its potential. In view of this, we carried out a prospective trial of 50 patients comparing the accuracy of colour Doppler ultrasound with venography in the diagnosis of deep venous thrombosis both above and below knee but in particular with respect to the detection of calf vein clot. Of the 50 patients studied, 10 had only one imaging modality performed as there were eight venographic failures and two ultrasonic failures. Comparison was only thus possible in 40 cases. As in previous studies, colour Doppler ultrasound was shown to be accurate in the diagnosis of thrombosis within the femoro-popliteal veins and had a sensitivity and specificity of 100% respectively. With respect to calf vein lesions, there was one false negative scan using the ultrasonic technique giving a sensitivity of 95%, specificity of 100% and accuracy of 97.5%. We feel colour Doppler ultrasound can and should be used as a first line alternative to venography and can be employed for the exclusion of both above and below knee deep venous thrombosis. Venography should now be reserved for those patients who are unsuitable for ultrasound examination or who have an equivocal ultrasound scan.     

Deep veins of the calf: assessment with color Doppler flow imaging

The authors studied the ability of real-time ultrasound aided by color Doppler flow imaging to demonstrate the deep veins of the calf in ten healthy subjects and 49 patients (91 limbs) with suspected deep venous thrombosis. Posterior tibial and peroneal veins demonstrated flow accentuation in 98% (74 of 75) and 96% (72 of 75), respectively, of the limbs without thrombosis and in all 20 normal limbs. Sixteen legs were involved with deep venous thrombosis. Peroneal veins could not be seen in three legs with marked calf swelling due to proximal thrombosis. There were two cases of thrombosis limited to the calf, nine of popliteal thrombosis (seven with contiguous spread of thrombus), and five of thrombosis limited to above the knee (four with sparing of the deep veins of the calf). Visualization of anterior tibial veins, achieved in 65% of all legs, did not correlate with thrombosis. The authors conclude that color Doppler flow imaging can demonstrate patency of posterior tibial and peroneal veins in most patients without deep venous thrombosis and aid in detection of below-the-knee thrombosis.     

彩色多普勒超声在急性孤立性小腿深静脉血栓中应用价值

目的探讨彩色多普勒超声在急性孤立性小腿深静脉血栓诊断中的临床应用价值。方法选取2016年1-12月收治的急性下肢深静脉主干血栓患者38例作为A组,急性孤立性小腿深静脉血栓患者38例作为B组。两组患者均给予彩色多普勒超声检查,比较两组超声诊断准确率。结果两组超声诊断准确率均较高,差异无统计学意义(P>0.05)。结论应用彩色多普勒超声诊断急性孤立性小腿深静脉血栓准确率高,值得在临床检查诊断工作中推广应用。     

Color Doppler ultrasound imaging of lower-extremity venous disease

A color Doppler ultrasound imaging device was used to evaluate 475 patients with suspected lower-extremity venous thrombosis. Occlusive and nonocclusive femoral and popliteal thrombi were detected in 200 studies (42%). In phase 1 of the study (240 examinations), peripheral augmentation with the use of periodic calf compression was required to show color flow throughout the femoropopliteal venous segment. In phase 2 (235 examinations), with a software upgrade to enhance detectability of slow flow, spontaneous flow could be appreciated in the normal, partly thrombosed, and recanalized femoral popliteal veins without augmentation. Augmentation was often necessary to view tibioperoneal veins. Of the total study group, conventional venography was performed for correlation in 47 patients. In the other patients, clinicians relied on the color Doppler test for the definitive diagnosis of the presence or absence of femoral popliteal venous thrombosis and treated these patients on the basis of the color Doppler test result. In the femoral veins, color Doppler studies and venography agreed in all 12 positive and 35 negative cases. In the popliteal veins, there was agreement in five isolated popliteal thromboses and in 10 femoral popliteal thromboses; there were two false-negative color Doppler studies of isolated popliteal thromboses. In four patients, Doppler studies detected nonocclusive thrombus not evident on venography. Color Doppler imaging is easy to perform and does not require augmentation to view color flow in the femoropopliteal venous segment. Eccentric thrombus and partially canalized thrombus can be shown. Initial experience suggests color Doppler imaging may be useful in the detection of tibioperoneal venous thrombosis.     

Real-time ultrasound diagnosis of deep vein thrombosis: a comparison with venography

A prospective study comparing real-time ultrasound scanning with contrast venography in the diagnosis of deep venous thrombosis of the lower limb was performed in a group of 46 patients. The sensitivity of ultrasound scanning for thrombus within the iliofemoral segment, femoral vein, and popliteal vein was 94% with a specificity of 100%. Additional information obtained by ultrasound included the diagnosis of popliteal cysts, pelvic and inguinal lymphadenopathy, popliteal haematoma, and traumatic arterial aneurysm. Real-time ultrasound scanning is a rapid and non-invasive alternative to contrast venography in the diagnosis of lower limb deep venous thrombosis.     

经皮导管抽吸去栓术治疗急性下肢深静脉血栓形成

目的：探讨经皮导管抽吸去栓术在急性下肢深静脉血栓形成（deep venous thrombosis,DVT）综合介入治疗术中的临床应用价值。方法：34例左侧急性下肢DVT,均经右侧股静脉穿刺置入下腔静脉滤器,随后经左侧股静脉或胭静脉穿刺插管,行导管抽吸去栓,最后对左侧髂总静脉进行球囊血管成形术。结果：31例血栓一次性清除,3例部分清除;所有病例均存在左髂静脉受压综合征;左下肢水肿完全消退30例,部分消退4例;未出现肺栓塞或其它并发症,随访6～52个月,临床治愈者元复发。结论：经皮导管抽吸去栓术治疗急性下肢DVT是一种快捷、有效的方法,值得临床推广。     

Stent Placement on Fresh Venous Thrombosis

Purpose: To report on the efficacy of fixing fresh venous thrombus to the venous wall by stent placement. Methods: Seven patients underwent stenting to treat acute venous thrombosis. In two patients, the hemodialysis fistula was thrombosed with the thrombus extending into the brachial veins. In three patients, the hemodialysis fistula was patent but massive swelling of the ipsilateral arm was caused by proximal venous thrombosis. Two patients presented with iliac venous thrombosis within stented pelvic veins. Stent placement was preceded by other mechanical thrombectomy methods in all cases. Results: Attachment of thrombus to the venous wall was successful in all cases treated. Acute rethrombosis did not occur. Follow-up patency in dialysis patients was 7.2 ± 2.1 months. One patient had rethrombosis of the dialysis graft 3 months after primary treatment. Three patients developed restenosis within a mean period of 7.7 months. One shunt remained patent for 10 months with no event of reobstruction during follow-up. In both patients with iliac stent placement, the vein remained patent over a follow-up period of 8 and 12 months respectively. Conclusion: Stenting fresh venous thrombus can achieve immediate venous patency. It may be used as an alternative approach when all other percutaneous methods fail. Frequent restenosis within stented veins limits its use to very selected cases. Received: 0/00/00/Accepted: 0/00/00     

Combined MR direct thrombus imaging and non-contrast magnetic resonance venography reveal the evolution of deep vein thrombosis: a feasibility study

Objectives

Lower limb deep venous thrombosis (DVT) is a common condition with high morbidity and mortality. The aim of the study was to investigate the temporal evolution of the acute thrombus by magnetic resonance imaging (MRI) and its relationship to venous recanalization in patients with recurrent DVTs.

Methods

Thirteen patients with newly diagnosed lower limb DVTs underwent MRI with non-contrast MR venography (NC-MRV) and MR direct thrombus imaging (MR-DTI), an inversion-recovery water-selective fast gradient-echo acquisition. Imaging was performed within 7 days of the acute thrombotic event, then at 3 and 6 months.

Results

By 3 months from the thrombotic event a third of the thrombi had resolved and by 6 months about half of the cases had resolved on the basis of vein recanalisation using NC-MRV. On the initial MR-DTI acute thrombus was clearly depicted by hyperintense signal, while the remaining thrombi were predominantly low signal at 3 and 6 months. Some residual thrombi contained small and fragmented persisting hyperintense areas at 3 months, clearing almost completely by 6 months.

Conclusions

Our study suggests that synergistic venous assessment with combined NC-MRV and MR-DTI is able to distinguish acute venous thrombosis from the established (old) or evolving DVT detected by ultrasound.

Key Points

? MRI can distinguish between acute and evolving or chronic lower limb DVT ? Two advanced MRI techniques can follow the evolution of lower limb DVT ? MRI could be used to avoid an incorrect diagnosis of recurrent DVT ? MRI could help avoid the risks and complications of lifelong anticoagulation therapy

     

Synovial rupture of the knee joint: confusion with deep vein thrombosis

Four patients were admitted to hospital with a provisional diagnosis of deep vein thrombosis. Arthrography of the knee joint subsequently demonstrated the presence of synovial cysts in all four patients with rupture into the tissues of the calf in two cases. These conditions are difficult to distinguish clincally and radiological investigation may be required to provide the correct diagnosis. Synovial rupture should be suspected in patients with knee effusions who develop acute pain and swelling of the calf, particularly if the patient has rheumatoid arthritis.     

Deep venous thrombosis in pregnancy: noninvasive diagnosis

In pregnant patients, venous thrombosis usually affects the left-side iliofemoral deep vein. Vascular ultrasound (US) offers distinct advantages in confirming the clinical suspicion of disease or suggesting the need for further tests. The authors encountered three consecutive cases of antepartum proximal vein thrombosis during a 6-month period (0.6 case per 1,000 deliveries). Lack of venous flow accentuation and lack of diameter change at the common femoral vein during the Valsalva maneuver are indications for iliac venography and suggest the diagnosis of iliac vein thrombosis. In distal iliac and proximal femoral vein thrombosis, noncompressibility of the vein and the presence of echogenic material within are indicative of acute thrombus.     

Efficacy of noninvasive modalities of diagnosis of thrombophlebitis

In a blind prospective study of 158 limbs, Doppler ultrasound, pneumoplethysmography, and radionuclide venography (RNV) using 99mTc-MAA were compared to phlebography as methods of detecting thrombophlebitis. All three noninvasive modalities were very insensitive to isolated thrombus below the knee. In patients with extension of thrombus above the knee and isolated thrombus in the deep veins of the upper limb, Doppler ultrasound had a sensitivity of 81% and RNV had a sensitivity of 77%. All of the noninvasive modalities were found to be dependent on venous occlusion. Overall, pneumoplethysmography had a sensitivity of 28% and specificity of 96%, compared with 56% and 91%, respectively, for Doppler ultrasound and 51% and 84% for RNV. Based on these findings, phlebography would still seem to be the modality of choice in the diagnosis of thrombophlebitis.     

Nontraumatic vascular emergencies: imaging and intervention in acute venous occlusion

Risk factors for acute venous occlusion range from prolonged immobilization to hypercoagulability syndromes, trauma, and malignancy. The aim of this review article is to illustrate the different imaging options for the diagnosis of acute venous occlusion and to assess the value of interventional strategies for venous thrombosis treatment in an emergency setting. First, diagnosis and treatment of the most common form of venous occlusion, at the level of the lower extremities, is presented, followed by pelvic vein and inferior vena cava occlusion, mesenteric venous thrombosis, upper extremity occlusion, acute cerebral vein thrombosis, and finally acute venous occlusion of hemodialysis access. In acute venous occlusion of the lower extremity phlebography is still the reference gold standard. Presently, duplex ultrasound with manual compression is the most sensitive and specific noninvasive test. Limitations of ultrasonography include isolated distal calf vein occlusion, obesity, and patients with lower extremity edema. If sonography is nondiagnostic, venography should be considered. Magnetic resonance venography can differentiate an acute occlusion from chronic thrombus, but because of its high cost and limited availability, it is not yet used for the routine diagnosis of lower extremity venous occlusion only. Regarding interventional treatment, catheter-directed thrombolysis can be applied to dissolve thrombus in charily selected patients with symptomatic occlusion and no contraindications to therapy. Acute occlusion of the pelvic veins and the inferior vena cava, often due to extension from the femoropopliteal system, represents a major risk for pulmonary embolism. Color flow Doppler imaging is often limited owing to obesity and bowel gas. Venography has long been considered the gold standard for identifying proximal venous occlusion. Both CT scanning and MR imaging, however, can even more accurately diagnose acute pelvis vein or inferior vena cava occlusion. MRI is preferred because it is noninvasive, does not require contrast agent, carries no exposure to ionizing radiation, and is highly accurate and reproducible. Apart from catheter-directed thrombolysis, mechanical thrombectomy has proven to be a quick and safe treatment modality by enabling the recanalization of thrombotic occlusions in conjunction with minimal invasiveness and a low bleeding risk. Mechanical thrombectomy devices should only be used in conjunction with a temporary cava filter. Contrast-enhanced CT is at present considered the examination of choice for acute mesenteric vein occlusion which has mortality rates as high as 80%. Patients with proven acute mesenteric venous occlusion and contraindications to surgical therapy and no identified bleeding disposition without looming bowel ischemia or infarction are possible contenders to the less invasive percutaneous approach either by (in)direct thrombolysis or mechanical means. Ultrasonography is the primary imaging modality for the diagnosis of upper extremity thrombosis. Computed tomography and MRI are in addition helpful in diagnosing central chest vein occlusions. The interventionalist is rarely involved in the treatment of this entity. Catheter-directed thrombolysis is known to improve lysis rates. Together with balloon angioplasty good results have been obtained. If stenosis or thrombus remains after thrombolysis and angioplasty, stent placement should follow. Within the first two weeks, thrombosed dural sinus and cerebral venous vessels are typically hyperdense on CT compared with brain parenchyma; after the course of 2 weeks, the thrombus will become isodense. In MRI an axial fluid-attenuated inversion recovery sequence, an axial diffusion-weighted MRI, coronal T1-weighted spin-echo and T2-weighted turbo-spin-echo sequences, a coronal gradient-echo and a 3D phase-contrast venous angiogram should be performed. Local thrombolysis is needed only when patients have an exacerbation of clinical symptoms or imaging signs of worsening disease despite sufficient anticoagulation therapy. Acute occlusions of dialysis grafts and fistulae are a frequently encountered complication. Among the various methods described for acute occlusion screening, ultrasonography and MRI have been proven to be accurate and noninvasive; however, if immediate treatment can be anticipated, imaging should be performed directly by digital subtraction angiography before the percutaneous intervention. Initial percutaneous thrombectomy is very effective with success rates and patency rates comparable to those of surgical thrombectomy. A short thrombosis can be treated with balloon angioplasty alone, whereas an extensive thrombosis requires a combination of mechanical devices and/or thrombolytic agents with adjunctive balloon angioplasty. Electronic Publication     

Pulmonary embolism from a venous thrombosis distal to the popliteal vein

A case of pulmonary embolism from a venous thrombosis distal to the popliteal vein is reported. This occurred despite venographic and ultrasound verification that the thrombus had not extended to the popliteal vein. The medical literature supports expectant treatment of "calf-only" venous thrombi. Our case clearly demonstrates that clinically significant pulmonary emboli can arise from calf vein thrombi without popliteal involvement.     

Diagnosis of deep venous thrombosis by duplex sonography

In a prospective study 90 patients with clinically suggested lower limb deep venous thrombosis (DVT) were examined with duplex ultrasonography (US) prior to venography. No attempts were made to examine the calf veins. Five ultrasound examinations were inconclusive. Thirty-four patients had DVT diagnosed at US with a sensitivity of 97 per cent and a specificity of 96 per cent. Compressibility of the vein as assessed by the real-time image was in the acute phase an easy and fast test for DVT, whereas the Doppler data failed to add to the diagnostic accuracy. Twenty-seven patients with DVT were followed during anticoagulant treatment, but only 16 regained fully compressible veins within the observation period of 3 to 6 months. Duplex sonography was useful in monitoring the changes in vein patency during anticoagulant treatment.     

Computer assisted strain-gauge plethysmography is a practical method of excluding deep venous thrombosis

AIM: To evaluate a computed strain-gauge plethysmograph (CSGP) as a screening tool to exclude above knee deep venous thrombosis (DVT). METHODS: The first phase took place in the Radiology department. One hundred and forty-nine patients had both Doppler ultrasound and CSGP performed. Discordant results were resolved by venography where possible. The second phase took place in an acute medical admissions ward using a modified protocol. A further 173 patients had both studies performed. The results were collated and analysed. RESULTS: Phase 1. The predictive value of a negative CSGP study was 98%. There were two false-negative CSGP results (false-negative rate 5%), including one equivocal CSGP study which had deep venous thrombosis on ultrasound examination. Two patients thought to have thrombus on ultrasound proved not to have acute thrombus on venography. Phase 2. The negative predictive value of CSGP using a modified protocol was 97%. There were two definite and one possible false-negative studies (false-negative rate 4-7%). CONCLUSION: Computer strain-gauge plethysmograph can provide a simple, cheap and effective method of excluding lower limb DVT. However, its use should be rigorously assessed in each hospital in which it is used. Goddard, A. J. P., Chakraverty, S. & Wright, J. (2001). Clinical Radiology56, 30-34.     

Distribution of thrombi in acute lower extremity deep venous thrombosis: implications for sonography and CT and MR venography

OBJECTIVE: Our objective was to determine the typical distribution of thrombi in acute lower extremity deep venous thrombosis as a means of evaluating the validity of imaging techniques that only include the common femoral and popliteal veins, but not the superficial femoral vein. MATERIALS AND METHODS: The results of 2704 lower extremity venous sonograms, obtained in 2026 consecutive patients over a 4-year interval, were reviewed retrospectively. The distribution of acute deep venous thromboses across various lower extremity venous segments was analyzed for this population, which consisted of both symptomatic and asymptomatic patients. RESULTS: Of 2704 lower extremities studied with duplex sonography, acute deep venous thrombosis was identified in 269 (9.9%). Of these 269 cases, acute deep venous thrombosis was isolated to the superficial femoral vein in 60 (22.3%). The remaining 209 cases (77.7%) showed thrombus that extended into the common femoral or popliteal veins (or both). CONClUSION: An abbreviated imaging study that evaluates only the common femoral and popliteal veins would fail to identify more than 20% of lower extremity acute deep venous thromboses in a population like ours. Although evaluation of the superficial femoral vein requires additional time and resources, evaluation of this segment may prevent a substantial number of thrombi from being missed.     

临时性腔静脉滤器在静脉血栓溶栓治疗中的应用

目的：探讨临时性腔静脉滤器置入在外周静脉血栓患者溶栓治疗中预防异位栓塞的应用价值。方法：10例下肢静脉血栓及1例永存动脉干合并右颈内静脉血栓的患者,分别经静脉置入临时性腔静脉滤器后,用大量尿激酶顺行或全身静脉溶栓治疗。结果：11例患者经7－15d的治疗后症状消失,血栓完全或部分溶解,血管开通,取出临时性腔静脉滤器,未出现并发症及异位栓塞。结论：置入临时性腔静脉滤器在外周静脉血栓患者溶栓治疗中是预防静脉血栓脱落导致异位栓塞的有效方法。     

320排CT血管造影和超声诊断下肢深静脉血栓价值比较

目的：探讨320排容积 CT 静脉造影(CTV)和超声(US)对下肢深静脉血栓(DVT)的诊断价值。方法回顾性分析经DSA 证实为下肢 DVT 的患者51例,对比直接法 CTV 及 US 对下肢不同部位栓子的检出率。结果51例患者中,CTV 共诊断DVT 48例,发现栓子124处,US 诊断静脉血栓46例,发现栓子86处。其中盆腔 DVT CTV 检出34处,US 检出10处,胫腓静脉血栓 CTV 检出25处,US 检出5处,CTV 检出股深静脉血栓2处,US 检出11处。结论直接法 CTV 及 US 对下肢 DVT 的诊断均具有较高的临床应用价值,而前者对盆腔 DVT 及胫腓静脉血栓的检出率更高,而对股深静脉血栓的显示不及后者。     

军训致急性下肢深静脉血栓的微创治疗

目的 探讨多种介入方法 相互配合对军训致急性下肢深静脉血栓(DVT)的疗效.方法 对军训致25例急性DVT患者均行Fogarty导管取栓术.其中单纯取栓3例;取栓联合球囊导管血管成形6例;血管成形联合血管腔内超声消融11例;血管成形和(或)血管腔内超声消融联合支架置入5例.对其疗效进行总结. 结果 髂股段静脉完全开通24例,术中造影示管腔直径≥71%;左髂总静脉开口未能开通1例.25例均行术后随访,平均时间34个月.其中24例完全恢复正常或基本正常,可从事正常军事训练;1例髂静脉未开通者训练后仍感肢体肿胀. 结论 多种外科介入技术相互配合可明显提高军训致DVT的疗效.