Superior vena cava syndrome and bilateral subclavian vein thrombosis. CT and radionuclide venography correlation

Radionuclide venography (RNV) and CT with contrast infusion were performed in a patient with superior vena cava (SVC) syndrome and upper extremity swelling due to SVC and bilateral subclavian vein thrombosis resulting from infection of a Le Veen peritoneovenous shunt. Although CT was suggestive of thrombosis and excluded extrinsic compression by a mass, obstruction of the SVC and deliniation of collateral venous channels were best demonstrated by RNV.     

Radionuclide venography: imaging monitor in deep-vein thrombosis of the pelvis and lower extremities

Seventy-four adults with documented deep-vein thrombosis of the pelvis and/or lower extremities had baseline and follow-up radionuclide venography (RNV), giving a total of 171 studies. Fifty-nine of the patients had unilateral venous thrombosis, of which 36 (61.0%) involved the left side and 23 (39.0%) the right. The higher incidence in the left side was attributed to the longer and more horizontal course of the left common iliac vein, as well as to compression by the right iliac artery and inguinal ligament. In 13 patients bilateral involvement was noted. "Normalisation" of the venous circulatory pattern was characterised by recanalisation and partial or significant disappearance of abnormal collaterals. This occurred in 43/74 patients. In 24 cases, no change was recorded during the interval, while seven patients deteriorated.     

平衡法核素显像诊断下肢深静脉血栓

目的：建立诊断下肢深静脉血栓的平衡期核素检查方法。方法：上肢静脉给药，体内法９９ｍＴｃ标记ＲＢＣ，３０分钟后先做平衡期静脉显像，然后用放射性核素体积描记术（ＲＰＧ）做血流测量。获得双下肢深静脉影像、ＲＰＧ曲线、深静脉回流血量和回流速度。结果：３５０例病人接受检查，其中回流正常者７８例，单侧梗阻１３３例，双侧病变１０８例，深静脉功能不全３１例。５０例病人同时做核素深静脉显像（ＲＮＶ），１０例同时做Ｘ线静脉造影，结果与核素平衡法的符合率均为９０％。结论：核素平衡法可用于临床常规检查，并可取代ＲＮＶ。     

放射性核素显像诊断下肢深静脉血栓形成的临床研究

目的 探讨放射性核素显像诊断下肢深静脉血栓形成(DVT)的价值.方法 利用SPECT对177例可疑下肢DVT患者进行~(99)Tc~m-大颗粒聚合白蛋白(~(99)Tc~m-MAA)核素静脉显像(RNV).结果 RNV对下肢DVT诊断的灵敏度、特异度和准确度分别为92.1%(129/140)、83.7%(31/37)、90.3%(160/177),DV工具有较为典型的RNV影像表现.结论 RNV安全无创、简便易行,灵敏度、特异度及准确度较高.能较准确反映DVT后深浅静脉功能状态,是一种可靠的诊断下肢DVT方法.     

放射性核素显像诊断下肢深静脉血栓形成的临床研究

目的 探讨放射性核素显像诊断下肢深静脉血栓形成(DVT)的价值。方法 利用SPECT对177例可疑下肢DVT患者进行99Tcm-大颗粒聚合白蛋白(99Tcm-MAA)核素静脉显像(RNV)。结果 RNV对下肢DVT诊断的灵敏度、特异度和准确度分别为92.1%(129/140)、83.7%(31/37)、90.3%(160/177),DV工具有较为典型的RNV影像表现。结论 RNV安全无创、简便易行,灵敏度、特异度及准确度较高。能较准确反映DVT后深浅静脉功能状态,是一种可靠的诊断下肢DVT方法。     

99Tcm-大颗粒聚合白蛋白显像在下肢深静脉血栓中的诊断价值

目的 探讨99Tcm-大颗粒聚合白蛋白( 99Tcm-M AA)核素深静脉显像(RNV)对下肢深静脉血栓(DVT)的诊断价值.方法 临床疑似下肢DVT的患者45例,均行99Tcm-MAA双下肢RNV,并与临床最终诊断结果进行对照.结果 43例共51条患肢经临床确诊,51条血栓性患肢中,左下肢36条、右下肢15条,左下患...     

Radionuclide venography in the management of proximal venous occlusion. A comparison with X-ray contrast venography.

Ascending contrast venography often fails to show the proximal venous system when there is co-existing occlusion of femoral or iliac veins. Retrograde and pertrochanteric venography both have severe limitations in terms of invasiveness and reliability. Radionuclide venography (RNV) is suggested as a less invasive alternative. 100 patients were investigated by both RNV and X-ray contrast venography (XRV). There was a 72% overall correlation between two methods of investigation. The proximal definition of XRV was limited in those cases with femoral obstruction. RNV, however gave progressively better views as imaging became more proximal and this was accentuated in the presence of femoral or iliac occlusion. RNV is simple and easy to perform and less invasive than XRV. The definition at calf level is such that it cannot at this stage replace XRV as the standard diagnostic procedure. However, in patients with proximal occlusions it gives more reliable information than that obtainable by ascending contrast venography.     

Radionuclide venography and uptake imaging using 99Tcm-fibrinogen in the detection of venous thrombosis and its correlation with contrast venography

Thirty-eight patients (76 legs) with suspected deep vein thrombosis were examined with 99Tcm-fibrinogen study (Tc-F), which consists of three parts: (1) radionuclide venography (RNV) of both legs after injection of 150 MBq of 99Tcm-fibrinogen into the dorsal veins of each foot, (2) blood pool imaging (BPI) at 5 to 20 min and (3) uptake imaging (UI) at 4 to 6 and 17 to 26 h. The clinical diagnosis was deep vein thrombosis in 27 legs. Twenty-nine patients (with 18 thrombi) were also studied with contrast venography (CV). Comparison of RNV with BPI suggests that the time-consuming and laborious RNV could, without affecting the diagnosis, be substituted by BPI, which is possible to perform after a single antecubital injection. When all patients were taken into consideration the sensitivity of Tc-F to detect fresh thrombosis was 100% but the specificity was lower (73%) because of the false positive findings in RNV/BPI. However, the specificity of UI was 100%. Previous anticoagulation did not prevent the uptake of fibrinogen within thrombi. There was good agreement of RNV/BPI and CV in the popliteal, femoral and iliac veins but the calf veins were better delineated in CV. Seventeen of the 18 thrombi examined both with Tc-F and CV were positive with RNV/BPI, 14 with UI and 13 with CV. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value (%) were with RNV/BPI: 83, 73, 86, 90, 83, with UI: 78, 100, 86, 100, 74 and with CV: 73, 100, 83, 100, 69. Our results suggest that Tc-F could be used not only as a screening test but also instead of CV in the detection of venous thrombosis.     

Multimodality imaging of early heterotopic bone formation

An atypical heterotopic bone formation that was difficult to diagnose presented in a young paraplegic patient as an acute deep vein thrombosis. A number of imaging methods, including contrast venography, ultrasonography, conventional radiography, bone scanning, leukocyte scanning, computed tomography, and magnetic resonance imaging, were used to arrive eventually at the final diagnosis. Early bone scanning remains a sensitive and effective method of diagnosis. Computed tomography can be useful in difficult cases, but the role of other imaging studies appears limited.     

The effect of varying tourniquet applications on the flow pattern of lower extremity radionuclide venography

Radionuclide venography (RNV) is an accepted, reliable, and simple method for detecting thrombi of the deep venous system of the lower extremity. No universal agreement, however, has been established regarding specific techniques for tourniquet applications. In fact, present data reflect a general consensus that tourniquet use and location other than above the ankles has no appreciable or recognizable effect on study outcome. A prospective study was performed on 20 consecutive patients referred for RNV with the clinical impression of deep venous thrombosis (DVT). Each patient was studied initially with tourniquets above the knee and ankle, then with tourniquets above the ankle only, and finally without tourniquets. On the basis of standard criteria for DVT, 8 out of 20 patients were positive for DVT when the study was performed with tourniquets only above the ankle. Four of the eight positive studies became negative, however, when additional tourniquets were placed above the knees (20% false-positive rate). It is concluded that the routine application of additional tourniquets above the knees would eliminate a significant number of false-positive studies and should be part of an established routine protocol.     

Deep venous thrombosis with suspected pulmonary embolism: detection with combined CT venography and pulmonary angiography

PURPOSE: To determine the frequency and location of deep venous thrombosis at computed tomographic (CT) venography after CT pulmonary angiography in a large series of patients clinically suspected of having pulmonary embolism and to compare the accuracy of CT venography with lower-extremity venous sonography. MATERIALS AND METHODS: Venous phase images were acquired from the diaphragm to the upper calves after completion of CT pulmonary angiography in 650 patients (373 women, 277 men; age range, 18-99 years; mean age, 63 years) to determine the presence and location of deep venous thrombosis. Results of CT venography were compared with those of bilateral lower-extremity venous sonography in 308 patients. RESULTS: A total of 116 patients had pulmonary embolism and/or deep venous thrombosis, including 27 patients with pulmonary embolism alone, 31 patients with deep venous thrombosis alone, and 58 patients with both. Among 89 patients with deep venous thrombosis, thrombosis was bilateral in 26, involved the abdominal or pelvic veins in 11, and was isolated to the abdominal or pelvic veins in four. In patients in whom sonographic correlation was available, CT venography had a sensitivity of 97% and a specificity of 100% for femoropopliteal deep venous thrombosis. CONCLUSION: Combined CT venography and pulmonary angiography can accurately depict the femoropopliteal deep veins, permitting concurrent testing for venous thrombosis and pulmonary embolism. CT venography also defines pelvic or abdominal thrombus, which was seen in 17% of patients with deep venous thrombosis.     

Evaluation of the lower extremity veins in patients with suspected pulmonary embolism: a retrospective comparison of helical CT venography and sonography. 2000 ARRS Executive Council Award I. American Roentgen Ray Society

OBJECTIVE: In patients undergoing a combined CT angiographic and CT venographic protocol, the accuracy of helical CT venography for the detection of deep venous thrombosis was compared with that of lower extremity sonography. MATERIALS AND METHODS: Patients who had undergone a combined CT angiographic and CT venographic protocol and sonography of the lower extremities within 1 week were identified. The final reports were evaluated for the presence or absence of deep venous thrombosis. Statistical measures for the identification of deep venous thrombosis with helical CT venography were calculated. In each true-positive case, the location of the thrombus identified with both techniques was compared. All false-positive and false-negative cases were reviewed to identify the reasons for the discrepancies. RESULTS: Seventy-four patients were included. There were eight patients (11%) with true-positive findings, 61 patients (82%) with true-negative findings, four patients (5%) with false-positive findings, and one patient (1%) with a false-negative finding. When comparing helical CT venography with sonography for the detection of lower extremity deep venous thrombosis, the sensitivity measured 89%; specificity, 94%; positive predictive value, 67%; negative predictive value, 98%; and accuracy, 93%. Of the eight true-positive cases, five had sites of thrombus that were in agreement on both CT venography and sonography. Of the five discordant cases, four were false-positives and one was a false-negative. Possible explanations for all discrepancies were identified. CONCLUSION: Compared with sonography, CT venography had a 93% accuracy in identifying deep venous thrombosis. However, the positive predictive value of only 67% for CT venography suggests that sonography should be used to confirm the presence of isolated deep venous thrombosis before anticoagulation is initiated. In addition, interpretation of CT venography should be performed with knowledge of certain pitfalls.     

Role of CT Venography in the Diagnosis and Treatment of Benign Thoracic Central Venous Obstruction

Objective

To evaluate the role of CT venography in the diagnosis and treatment of benign thoracic central venous obstruction.

Materials and Methods

Eighteen patients who had undergone both CT venography and digital subtraction venography were prospectively enrolled in this study. The following features were analyzed by two observers: the cause, degree, and extent of venous obstruction; associated thrombosis; and implications for the planning of treatment. CT venography and digital subtraction venography were compared in defined venous segments, and the degree of obstruction, and correlation was expressed using Spearman''s rank correlation coefficient.

Results

In all patients, CT venography depicted the causes of obstruction, including extrinsic compression of the left brachiocephalic vein, and mediastinal inflammatory pseudotumor. Interobserver agreement regarding classification of the degree of obstruction was judged as good for CT venography (κ=0.864), and in evaluating this, there was significant correlation between CT venography and digital subtraction venography (reader 1: Rs = 0.58, p < 0.01; reader 2: Rs = 0.56, p < 0.01). In evaluating the status of central veins proximal to long segmental obstruction, and associated thrombosis, CT venography was superior to digital subtraction venography. In half of all patients, the findings of CT venography led to changes in the treatment plan.

Conclusion

The findings of CT venography correlated closely with those of digital subtraction venography, and the former accurately depicted the degree and extent of benign venous obstruction.     

Thromboembolic disease: comparison of combined CT pulmonary angiography and venography with bilateral leg sonography in 70 patients

OBJECTIVE. The purpose of this study was to compare combined CT pulmonary angiography and venography with leg sonography for accuracy and relative efficacy in diagnosis of deep venous thrombosis from the popliteal vein to the common femoral vein. SUBJECTS AND METHODS. Seventy consecutive patients with clinically suspected pulmonary embolism underwent both combined CT pulmonary angiography and venography and bilateral leg sonography within 24 hr. CT venograms were analyzed independently in a blinded fashion for quality of venous opacification and patency by two observers. CT venography was compared with sonography for femoropopliteal vein thrombosis, and the final assessment based on multiple subjective and objective clinical and imaging criteria was recorded in three categories: 1, CT venography better than sonography; 2, CT venography equivalent to sonography; and 3, sonography better than CT venography. RESULTS. Sixty-eight patients (97%) had a satisfactory or good quality CT venography examination. Two CT venography studies had false-positive findings due to flow artifacts. Both CT venography and sonography had positive findings for deep venous thrombosis in five patients, and both had negative findings in 63 patients (100% sensitivity, 97% specificity, 100% negative predictive value, and 71% positive predictive value). CT venography was better and more efficacious than sonography (category 1) in 25 patients (36%). CT venography was equivalent to sonography (category 2) in 26 patients (37%), and sonography was better than CT venography (category 3) in 19 patients (27%). CONCLUSION. Compared with sonography, CT venography in addition to CT pulmonary angiography is a relatively accurate method for evaluation of femoropopliteal venous thrombosis. Combined CT pulmonary angiography and CT venography may be more efficacious than sonography or two separate examinations in selected patients.     

Venous compression syndromes: clinical features,imaging findings and management

Extrinsic venous compression is caused by compression of the veins in tight anatomic spaces by adjacent structures, and is seen in a number of locations. Venous compression syndromes, including Paget–Schroetter syndrome, Nutcracker syndrome, May–Thurner syndrome and popliteal venous compression will be discussed. These syndromes are usually seen in young, otherwise healthy individuals, and can lead to significant overall morbidity. Aside from clinical findings and physical examination, diagnosis can be made with ultrasound, CT, or MR conventional venography. Symptoms and haemodynamic significance of the compression determine the ideal treatment method.Extrinsic venous compression occurs by adjacent arterial, ligamentous, muscular or osseous structures in tight anatomic spaces [1]. Despite its relative infrequency, venous compression is most commonly seen in otherwise healthy and young individuals and may cause significant haemodynamic alterations that may lead to clinical symptoms and significant associated morbidity. Venous compression usually becomes clinically significant when there is a change in the flow direction or increased venous pressure, which lead to the formation of venous collaterals, varicosities and/or chronic venous insufficiency [2]. Repetitive endothelial injury at the site of extrinsic compression predisposes to acute or chronic venous thrombosis, which in turn may aggravate venous hypertension downstream [2].Diagnosis of venous compression is based on a combination of clinical and imaging features. A wide range of signs and symptoms may be seen, including pain, swelling, venous thrombosis, varicosities and haematuria [1,2]. External venous compression incidentally demonstrated by imaging may not be of clinical significance on its own; therefore, imaging should be used for confirmation of the cause of the symptoms. Ultrasound with Doppler, contrast-enhanced CT, CT venography (CTV), contrast-enhanced MRI and MR venography (MRV) are helpful in the diagnosis of venous compression syndromes [3].Ultrasound has been utilised to identify deep venous thrombosis (DVT) within the vein affected by the compression and allows for evaluation of the flow direction and dynamic examinations of the area of interest. Although MRV is more expensive than CTV, there has been an increasing use of MRV since the introduction of blood pool contrast agents and owing to concerns regarding radiation exposure with CTV. Variations in venous haemodynamics from patient to patient make the timing of CTV challenging in obtaining the appropriate venous phase for optimal visualisation of the venous system. MRI provides flow directionality with flow sensitive sequences that could be very valuable in evaluating the haemodynamic significance of the compression. MRV with blood pool contrast agents, such as gadofoveset trisodium, allows for evaluation of the vasculature (arterial and venous) during the steady-state phase. Isotropic high-resolution images can be obtained by allowing multiplanar reformats for better visualisation of compression, characterisation of acute vs chronic clot and venous mapping for procedure planning.Ultimate diagnostic confirmation is obtained by conventional venography, demonstrating pressure gradients across the compressions, flow alteration and/or thrombus within the compressed vein. Several management options unique to the location of venous compression have been described, including conservative, endovascular and surgical treatment options.In this review, we discuss the underlying anatomy, pathophysiology, diagnostic methods and management options of various venous compression syndromes namely May–Thurner syndrome (MTS), Paget–Schroetter syndrome (PSS), Nutcraker syndrome (NCS) and popliteal venous compression (PVC).     

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.     

Ultrasonographic diagnosis of iliac vein compression (May-Thurner) syndrome

Iliac vein compression syndrome (IVCS), also known as May-Thurner syndrome, is the result of compression of the left common iliac vein between the right common iliac artery and overlying vertebrae. The most common clinical presentation is left lower extremity deep vein thrombosis. Rarely, a patient with IVCS can present with obstruction of venous outflow, without deep vein thrombosis. Iliac vein compression, with or without thrombosis, should be treated if symptomatic. We present a patient with IVCS that was initially diagnosed with transabdominal ultrasonography (US), and then confirmed with computed tomography and venography with pressure measurements. We believe this is the first report of an IVCS patient diagnosed with US.     

MR venography using an intravascular contrast agent: results from a multicenter phase 2 study of dosage

OBJECTIVE: The objective of this study was to determine the optimal dose of the iron oxide contrast agent feruglose for contrast-enhanced MR venography of the abdominopelvic and lower extremity veins and to evaluate its safety and tolerability in patients with deep venous thrombosis. SUBJECTS AND METHODS: We enrolled in our study a total of 45 patients at six centers who had lower extremity deep venous thrombosis documented on radiographic venography. Forty-four patients received the study drug; 39 completed the study. Each patient received three sequential IV injections of feruglose at doses of 0.75, 1.25, and 3.0 mg Fe/kg body weight. MR venography at 1.5 T was repeated at three levels after each dose. Safety was evaluated. RESULTS: The agreement between contrast-enhanced MR venography and radiographic venography with regard to deep venous thrombosis above the knee was zero at the lowest dose (0.75 mg Fe/kg body weight), 43% at the dose 2.0 mg Fe/kg body weight, and 49% at the dose 5.0 mg Fe/kg body weight. No significant difference was seen between the two highest doses. The highest cumulative dose provided the greatest diagnostic usefulness score. No serious adverse events occurred. CONCLUSION: The two highest doses of feruglose showed the best agreement between contrast-enhanced MR venography and radiographic venography for deep venous thrombosis above the knee. The safety and tolerability of feruglose were confirmed.     

双向多层螺旋CT下肢静脉造影法的研究和应用

目的探讨双向多层螺旋CT静脉造影(Bi-directionalMSCTV)对诊断下肢深静脉血栓(DVT)的临床应用价值。方法收集8人次超声难以显示的下肢肿胀病人行Bi-directiorralMSCTV检查,检查后经最大密度投影(MIP),表面遮盖法(SSD)及容积再现法(VR)重建。结果双向多层螺旋CT下肢静脉造影技术较常规静脉造影和常规单向CT静脉造影更清晰显示盆腔静脉血栓,尚能显示小腿等超声难以显示的血栓。结论双向多层螺旋CT下肢静脉造影法可作为诊断下肢静脉血栓性病变的最佳方法。     

Deep venous thrombosis: comparison of indirect multidetector CT venography and sonography of lower extremities in 26 patients

OBJECTIVE: To compare the accuracy of indirect mutidetector row computed tomographic (MDCT) venography with lower extremity venous sonography for the diagnosis of femoropopliteal deep venous thrombosis (DVT), and to determine the frequency and location of DVT at MDCT venography. MATERIALS AND METHODS: Twenty-six consecutive patients suspected of having pulmonary embolism (PE) underwent both combined MDCT venography and MDCT pulmonary angiography and lower extremity venous sonography. Indirect MDCT venography was acquired from the upper calves to the mid-abdomen following MDCT pulmonary angiography. The CT venographic findings were compared with those of sonography for the diagnosis of femoropopliteal DVT. All CT scans were also reviewed for the frequency and location of DVT. RESULTS: Indirect MDCT venography disclosed DVT in 19 patients, and 12 of whom also had PE. Seventeen patients with thrombosis in the femoropopliteal veins were identified in both indirect MDCT venography and sonography. The sensitivity and specificity of indirect MDCT venography for femoropopliteal DVT, as compared with sonography, were both 100%. In one patient DVT in the superficial femoral vein was detected using only indirect MDCT venography. MDCT venography also showed superior extension of femoropopliteal DVT to the inferior vena cava and iliac veins in four patients and thrombosis isolated to the inferior vena cava and common iliac vein thrombosis in one patient. CONCLUSIONS: Indirect MDCT venography is as accurate as sonography in the diagnosis of femoropopliteal DVT. MDCT venography can further reveal thrombus in large pelvis veins and the inferior vena cava, an important advantage over sonographic screening for DVT.