Subcutaneous whole-body radionuclide venography using Tc-99m in vivo tagged red blood cells

PURPOSE: The accurate diagnosis of deep vein thrombosis (DVT) is essential to prevent its complications and to initiate appropriate treatment. Doppler ultrasound (DUS), contrast venography, and intravenous radionuclide venography have been used for many years to detect DVT. However, obtaining venous access in the foot for injection of contrast agent can be difficult. METHODS: The authors introduce the technique of subcutaneous radionuclide venography using Tc-99m in vivo tagged red blood cells and compare it with DUS, a widely used method. Sixty patients (120 lower extremities) underwent subcutaneous radionuclide venography and DUS. RESULTS: The concordance rate was 94% in the femoral veins and 95% in the popliteal veins. Subcutaneous radionuclide venography revealed 10 iliac vein thromboses and 2 inferior vena cava thromboses that were not detected by DUS. CONCLUSIONS: Subcutaneous radionuclide venography is a useful alternative method for detecting DVT. It is particularly valuable for evaluating DVT in the iliac veins and in the inferior vena cava.     

Deep venous thrombosis: diagnosis by using venous enhanced subtracted peak arterial MR venography versus conventional venography

PURPOSE: To assess diagnostic accuracy and interobserver variability at venous enhanced subtracted peak arterial (VESPA) magnetic resonance (MR) venography compared with those at conventional venography for the diagnosis of femoral and iliac deep venous thrombosis (DVT). MATERIALS AND METHODS: A single anteroposterior maximum intensity projection (MIP) venogram of the femoral and iliac veins was constructed by using VESPA MR venography in 55 symptomatic patients suspected of having lower limb DVT. All patients also underwent conventional venography, results of which were used as the standard of reference. VESPA MR venograms were interpreted by two independent reviewers (reviewers A and B) who were unaware of other results. Sensitivity and specificity of VESPA MR venography for the diagnosis of thrombus in the femoral and iliac veins were calculated. Interobserver variability was calculated for these observations by using weighted kappa with equally spaced weights for positive, nondiagnostic, and negative studies. Nondiagnostic studies were reinterpreted separately by reviewer A on the basis of source data. RESULTS: Sensitivity of VESPA MR venography for the femoral veins (20 of 20) and iliac veins (seven of seven) was 100% for both reviewers. Specificity was 100% (39 of 39 for reviewer A, 40 of 40 for reviewer B) for the iliac veins and 97% (31 of 32) for the femoral veins for both reviewers. Segments in which the VESPA MR venograms were nondiagnostic were excluded from this analysis. Interobserver variability as calculated by using weighted kappa for positive, negative, and nondiagnostic studies was 0.85 for femoral veins and 0.97 for iliac veins. Interpretation of the source data led to correct diagnosis in six of six cases in which the VESPA MR venograms were nondiagnostic. CONCLUSION: VESPA MR venography yielded MIP venograms that were highly accurate for the diagnosis of DVT in femoral and iliac veins. Interpretation of the studies was also highly reproducible.     

Comparison of MS-325- and gadodiamide-enhanced MR venography of iliocaval veins

PURPOSE: To compare conventional extracellular and blood-pool magnetic resonance (MR) contrast agents in "indirect" contrast-enhanced three-dimensional (3D) MR venography of the iliocaval veins. MATERIALS AND METHODS: Twenty-nine gadodiamide-enhanced 3D MR (Gd-MR) angiography studies and 12 MS-325-enhanced 3D MR (MS-325-MR) angiography studies were reviewed retrospectively. Abnormalities of the inferior vena cava (IVC) or iliac veins were not suspected before MR imaging. The MR angiography studies were reviewed with and without subtraction. Diagnostic conspicuity and subjective contrast of the various iliocaval venous segments (suprarenal IVC, infrarenal IVC, and iliac veins) and the presence of artifacts were subjectively scored by two blinded observers. RESULTS: In the Gd-MR angiography group, the infrarenal IVC and iliac veins were visualized with good conspicuity in only 55% of segments compared to 92%-100% of segments in the MS-325-MR angiography group. Although subtraction improved subjective conspicuity and contrast relative to background in the Gd-MR angiography group, it resulted in increased artifacts and luminal blurring. Subtraction offered little diagnostic advantage in the MS-325-MR angiography group. CONCLUSION: Indirect contrast-enhanced 3D MR venography with use of MS-325 offered significantly improved diagnostic conspicuity and contrast in iliocaval venous opacification compared to gadodiamide-enhanced studies.     

Cerebral venography with MR

The authors describe a two-dimensional time-of-flight magnetic resonance (MR) angiography technique to create projection venograms of the head. The technique was applied to 27 healthy volunteers and 39 patients. The superior sagittal and straight sinuses, the internal cerebral veins, and the Galen vein were visualized in all the volunteers. Other veins were seen in a high percentage of subjects. Systematic comparison of digital subtraction angiography (DSA) after intraarterial contrast medium injection and MR venography in patients showed good correlation between the two techniques. MR venography proved helpful in identifying thrombosis or patency of cerebral veins and sinuses and showed collateral venous drainage and venous drainage from arteriovenous malformations. There was good correlation between conventional contrast angiography and MR venography. In conclusion, MR venography is considered reliable for showing the cerebral venous system and provides information additional to that of conventional spin-echo imaging.     

Deep venous thrombosis evaluation with limited-flip-angle, gradient- refocused MR imaging: preliminary experience

Sixteen patients (17 lower extremities) were prospectively examined with venography and limited-flip-angle, gradient-refocused magnetic resonance (MR) imaging for the presence or absence of deep venous thrombosis. Thrombosed vessels showed decreased-to-absent signal intensity, while patent vessels had high signal intensity. In 16 of 17 extremities, MR images allowed accurate detection and localization of the thrombi found with venography. In the remaining extremity, MR imaging allowed correct identification of thrombus in the iliac and femoral veins but incorrectly demonstrated clot in the calf and popliteal veins. MR imaging with limited-flip-angle, gradient-refocused pulse sequences appears to be a sensitive, noninvasive means of detecting deep venous thrombosis.     

Intraosseous venography with carbon dioxide contrast agent in percutaneous vertebroplasty

OBJECTIVE: Our objectives were to ascertain whether CO2 can be used as a contrast agent in venography during percutaneous vertebroplasty and to evaluate whether it might be capable of replacing nonionic iodinated contrast agents. CONCLUSION: Intraosseous venography with CO2 contrast agent was slightly inferior to iodine venography in terms of its ability to visualize the vertebral bodies and perivertebral veins, but it remains a useful technique because no interference with optimal visualization of bone cement occurs during the cement injection when CO2 remains within the fracture cleft.     

Radionuclide venography in iliac and inferior vena caval obstruction

Thirteen cases are presented to demonstrate normal and various abnormal radionuclide venographic patterns following obstruction of the inferior vena cava or common iliac veins. In these patients, obstruction was due to surgery, thrombosis, or neoplasm. Contrast venography was also performed in seven patients to confirm the radionuclide findings. Radionuclide venograms did not visualize the same collateral patterns that contrast venograms did. Most notably, the anterior parietal vessels were seen in many cases with radionuclide venography, and the paraspinal veins were seen more commonly with contrast venography.     

Non-contrast enhanced MR venography using 3D fresh blood imaging (FBI): initial experience.

OBJECTIVE: This study examined the efficacy of 3D-fresh blood imaging (FBI) in patients with venous disease in the iliac region to lower extremity. MATERIALS AND METHODS: Fourteen patients with venous disease were examined [8 deep venous thrombosis (DVT) and 6 varix] by 3D-FBI and 2D-TOF MRA. All FBI images and 2D-TOF images were evaluated in terms of visualization of the disease and compared with conventional X-ray venography (CV). RESULTS: The total scan time of 3D-FBI ranged from 3 min 24 sec to 4 min 52 sec. 3D-FBI was positive in all 23 anatomical levels in which DVT was diagnosed by CV (100% sensitivity) as well as 2D-TOF. The delineation of collateral veins was superior or equal to that of 2D-TOF. 3D-FBI allowed depiction of varices in five of six cases; however, in one case, the evaluation was limited because the separation of arteries from veins was difficult. CONCLUSION: The 3D-FBI technique, which allows iliac to peripheral MR venography without contrast medium within a short acquisition time, is considered clinically useful.     

Simultaneous acquisition of MR angiography and venography (MRAV).

A dual-echo pulse sequence for simultaneous acquisition of MR angiography and venography (MRAV) is developed. Data acquisition of the second echo for susceptibility-weighted imaging-based MR venography is added to the conventional three-dimensional (3D) time-of-flight (TOF) MRA pulse sequence. Using this dual-echo acquisition approach, the venography data can be acquired without increasing the repetition time, and, therefore, the scan duration of routine TOF MRA scans is maintained. The feasibility of simultaneous acquisition of MRAV is presented in brain scans at different spatial resolutions. The effect of spatial resolution on vein-to-background contrast is also demonstrated. Venous contrast is improved in high-resolution (0.52 x 0.52 x 1.6 mm(3)) images compared to that in standard-resolution (0.78 x 0.78 x 1.6 mm(3)) images. This MRAV technique enables the acquisition of MR venography without the need of an extra scan or injection of contrast agent in routine clinical brain exams at 3T.     

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.     

MR portal venography: preliminary results of fast acquisition without contrast material or breath holding

RATIONALE AND OBJECTIVES: The authors performed this study to evaluate the feasibility of using the steady-state free precession (SSFP) sequence to perform magnetic resonance (MR) venography of the portal venous system without the use of contrast material or breath holding. MATERIALS AND METHODS: Eleven patients underwent MR venography with the SSFP technique. Coronal three-dimensional images were obtained with respiratory triggering. Contrast material and respiratory suspension were not used. All patients had recently undergone at least one other imaging study (conventional angiography, transhepatic portal venography, ultrasound, or contrast-enhanced computed tomography), and these findings were correlated with those from MR venography. The structures evaluated were the main portal vein, right portal vein, left portal vein, superior mesenteric vein, and splenic vein. RESULTS: MR venography with SSFP accurately depicted the status of these veins in all cases except one. In this patient, MR venography depicted portal vein thrombus but could not indicate that it was tumor thrombus. CONCLUSION: MR venography with SSFP accurately depicted the portal venous system in 10 of 11 patients without the use of respiratory suspension or contrast material.     

直接三维增强MRV技术在下肢静脉血管造影中的应用

目的探讨直接三维增强MRV技术在下肢静脉血管造影中的应用。方法使用GE公司S igna 1.0T磁共振成像系统,对15例经手术、DSA或超声多普勒证实的下肢静脉疾病患者行MRV检查,观察直接三维增强MRV对下肢静脉病变的显示。结果15例患者均获得轮廓清晰、伪影少、信号强,且直观完整三维立体下腹、盆腔和下肢的深、浅静脉图像。结论直接三维增强MRV技术为一种良好的下肢静脉造影方法。     

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.     

Acute iliofemoral deep vein thrombosis: evaluation of underlying anatomic abnormalities by spiral CT venography

PURPOSE: To evaluate the spectrum of underlying anatomic abnormalities in iliofemoral deep vein thrombosis (DVT) by spiral computed tomographic (CT) venography. MATERIALS AND METHODS: During the past 4 years, 56 patients with acute iliofemoral DVT have been evaluated by CT venography at our institution. Forty-four patients had left-sided DVT, nine had right-sided DVT, and the remaining three had DVT in both extremities. CT venography was performed with use of 2.5-3.2-mm x-ray beam collimation and a 1.25-2.0-mm reconstruction interval. Spiral scans were initiated 5 minutes after intravenous contrast medium injection. The CT venograms were correlated with catheter venograms. In addition, with use of axial sections and their three-dimensional reconstructions, including multiplanar reformation and volume rendering, the presence or absence of central obstructing lesions and their causes were evaluated. RESULTS: Among 44 patients with left-sided DVT, 37 had significant anatomic abnormalities in their iliofemoral veins or inferior vena cava (IVC). The most common lesion was left common iliac vein compression by the right common iliac artery (n = 27; exaggerated by a bony spur in nine and associated with extrinsic compression by the left internal iliac artery in two). Of the nine patients with right-sided DVT, six had significant anatomic abnormalities including encasement or extrinsic compression of their iliac veins by various causes (n = 3) and venous stricture without extrinsic lesions (n = 3). Among three patients with DVT in both extremities, two had anatomic abnormalities in the IVC. Therefore, 45 of 56 patients had anatomic abnormalities central to the thrombosed deep veins. CONCLUSION: The majority of patients with acute iliofemoral DVT had underlying anatomic abnormalities. The presence of central stenosis or obstruction and their causes can be evaluated by spiral CT venography.     

64层螺旋CT直接法静脉造影对下肢深静脉血栓的临床应用价值初步研究

目的 探讨64层螺旋CT直接法静脉造影在下肢深静脉血栓(DVT)中的诊断价值. 资料与方法 19例临床怀疑DVT患者行64层螺旋CT直接法下肢深静脉造影检查,着重分析DVT的CT征象,探讨影响其诊断准确性的因素.结果 64层螺旋CT直接法静脉造影对DVT显示较好,在15例患者中共发现DVT 25处,分别位于髂静脉(4)、股静脉(7)、胭静脉(9)和腓静脉(5).结论 64层螺旋CT直接法下肢深静脉造影结合多种后处理技术可以清楚显示DVT,具有较高的临床应用价值.     

Pelvic and lower extremity veins: contrast-enhanced three-dimensional MR venography with a dedicated vascular coil-initial experience

PURPOSE: To assess the performance of three-dimensional (3D) magnetic resonance (MR) venography of the pelvis and lower extremities in patients without acute deep venous thrombosis by using a lower extremity vascular coil and pedal injection of paramagnetic contrast material. MATERIALS AND METHODS: Conventional and MR venography were performed in 35 legs in 25 patients referred for evaluation of varicosities (n = 8) and postthrombotic changes (n = 7) and assessment of the great saphenous veins prior to bypass surgery (n = 10). Injection of 120 mL of diluted (1:15) gadopentetate dimeglumine into a pedal vein was performed manually at a rate of 1 mL/sec, and 3D gradient-recalled echo data sets of the upper and lower veins were collected. Conventional and MR venographic images were analyzed separately in a blinded fashion. RESULTS: MR image quality was comparable to that of conventional venograms. Varicose changes of the great and small saphenous veins (sensitivity, 94% [44 of 47]; specificity, 96% [89 of 93]) were assessed as reliably as their status before bypass surgery (sensitivity, 98% [53 of 54]; specificity, 92% [47 of 51]). Postthrombotic changes were diagnosed with a sensitivity of 100% [13 of 13] and a specificity of 98% [88 of 90]. CONCLUSION: Direct 3D MR venography comprehensively displays the lower extremity venous system and permits assessment of postthrombotic and varicose changes and the bypass suitability of the saphenous vein.     

下肢血管病变的16层螺旋CT血管造影

本文通过对16层螺旋CT下肢血管造影的扫描参数、造影计划和重建方式的选择,系统阐述了其最佳的成像技术规范,提出了直接CT静脉造影技术诊断髂静脉受压综合征并获得良好效果;同时也介绍了常见下肢动、静脉病变CTA的应用价值.     

Combined CT venography and pulmonary angiography: how much venous enhancement is routinely obtained?

OBJECTIVE: Combined CT venography and helical pulmonary angiography is a new diagnostic test that permits radiologists to check both the pulmonary arteries for embolism and the deep veins of the abdomen, pelvis, and legs for thrombosis in a single examination. The purpose of this study was to determine the degree of venous enhancement routinely obtained using this combined CT examination. MATERIALS AND METHODS: We identified all patients at a single institution who, during a 29-month period, had symptoms suggestive of pulmonary embolism and who underwent CT venography and helical pulmonary angiography. The examinations were performed after the patients received a rapid (3--5 mL/sec) IV injection of 150 mL of nonionic contrast medium (240 mg I/mL). CT venography of the abdomen, pelvis, and lower extremities was performed as follows: Beginning 3 min after the start of contrast medium infusion for helical CT pulmonary angiography, 1-cm axial images obtained at 5-cm intervals were acquired from an area ranging from the diaphragm to the calves. Patients who had evidence of deep venous thrombosis on CT scans were excluded from further analysis. The venous portions of the remaining 429 examinations were retrospectively reviewed at a CT console or workstation by one of two radiologists, and Hounsfield unit measurements were recorded from the inferior vena cava as well as from the right and left external or internal iliac, common femoral, superficial femoral, and popliteal veins. A single Hounsfield unit measurement was obtained from the center of each vessel using a region of interest that was approximately half the diameter of the vessel. Mean Hounsfield unit measurements were then calculated for these venous stations. RESULTS: Mean Hounsfield unit measurements at the inferior vena cava and at the right and left external or internal iliac veins were 97, 95, and 95 H, respectively. Mean measurements at the common femoral veins were 95 H for both the right and left; the mean measurements at the superficial femoral veins were 91 H for both the right and left, and those at the popliteal veins were 97 H for the right and 94 H for the left. CONCLUSION: CT venography of the abdomen, pelvis, and lower extremities begun 3 min after the start of contrast medium infusion for helical CT pulmonary angiography routinely produced high mean levels of venous enhancement.     

Double inferior vena cava or iliac vein occlusion? A diagnostic problem in radionuclide venograms.

Radionuclide venography in two patients with suspected deep venous disease revealed double channel drainage with cross-pelvic collateral circulation. Contrast inferior venacavograms revealed that one patient had persistent right and left supracardinal veins (double inferior vena cava) and the other had iliac vein occlusion with ascending lumbar collateral circulation. The similarity of radionuclide venographic findings in these two patients emphasizes the importance of contrast venacavography in patients with this appearance on radionuclide venography.     

Abdominal Magnetic Resonance Venography

With the refinement of fast gradient-echo imaging, it is now possible to perform abdominal magnetic resonance venography completely noninvasively, without the use of oral or injected contrast agents. In this paper, we emphasize two-dimensional, time-of-flight angiographic techniques, as applied to the study of patency and flow in the veins of the abdomen. Magnetic resonance venography is routinely applicable to patients with portal disease, or suspected occlusion of the inferior vena cava, iliac veins or renal veins. Sequential, single-slice venographic images, acquired during breath holding, can be postprocessed to form projected venograms. Hemodyanmic information is derived using presaturation schemes, bolus-tracking or phase imaging. These techniques can also be used to establish the integrity of surgical portosystemic shunts.