Multidetector Computed Tomography Venography Research Articles

Trans-abdominal Color Doppler US versus Direct Multi-detector Computed Tomography Venography in the Diagnosis of May-Thurner Syndrome

Trans-abdominal Color Doppler US versus Direct Multi-detector Computed Tomography Venography in the Diagnosis of May-Thurner Syndrome

Multidetector Computed Tomography Venography versus Magnetic Resonance Venography in Cerebral Venous Thrombosis: A Cross-sectional Study

Introduction: Cerebral Venous Thrombosis (CVT) is a relatively uncommon condition whose presentation is varied. The diagnostic imaging features can be subtle. The correct diagnosis of CVT relies on neuroimaging Non Contrast Computed Tomography (NCCT), CT Venography (CTV), Magnetic Resonance Imaging (MRI), MR Venography (MRV). Aim: To compare 128 slice Multidetector Computed Tomography (MDCT) venography and MRV in CVT, taking MRV as gold standard. Materials and Methods: This cross-sectional study was conducted in the Department of Radiodiagnosis, Gandhi Medical College, Secunderabad, Telangana, India, from October 2017 to September 2019. The study constituted of 56 patients, with clinical signs and symptoms of CVT who underwent MDCT venography and MRV. NCCT with MDCT venography was carried out on HITACHI 128 slice CT machine and MR imaging was performed in 1.5 tesla SIEMENS AVANTO systems. Imaging findings analysed on NCCT were hyperdense cord sign, delta sign, and multiple parenchymal hypodense lesions in bilateral parasagittal location, bilateral thalamic hypodensities, and isolated temporal bleed and on CTV signs like empty delta / empty triangle sign. Plain MRI was assessed for involved sinuses with thrombus showing loss of expected flow void with hyperintensity on T1-Weighted (T1W) and blooming on Gradient Recalled Echo (GRE). Parenchymal changes were assessed for presence of cytotoxic oedema, vasogenic oedema and haemorrhagic infarct. MRV was assessed for nonvisualisation of involved sinus or lack of normal flow related enhancement. Results: Among the total 56 study subjects evaluated, 48 were diagnosed to have CVT on both CTV and MRV. On CTV, 147 sinuses were found to be involved, while MRV showed involvement of 142 sinuses. One case was found to be negative for thrombus on CTV but positive on TOF (Time of Flight) MRV. Both CTV and MRV were negative for CVT in seven patients. The sensitivity and specificity of NCCT in diagnosing CVT was found to be 60% and 87% respectively. Conclusion: The parenchymal changes in CVT were better evaluated on MRI. Venous abnormalities were better depicted in MRI as loss of flow voids in T1, T2 and with dark signal on GRE. Haemorrhagic bleeds were easily evaluated on MRI with 100% sensitivity of GRE sequence. CTV was easier to interpret, showed better and faster depiction of sinuses, with thin section reformatted images and showed higher spatial resolution compared to MRV.

Doppler ultrasound and contrast-enhanced ultrasound in detection of stent stenosis after iliac vein stenting

BackgroundTo compare the diagnostic accuracy of Doppler ultrasound (DUS) with contrast-enhanced ultrasound (CEUS) for detection of iliac vein stent stenosis using multidetector computed tomography venography (MDCTV) as the reference method.MethodsPatients with iliac vein obstructive disease treated with nitinol stents (Smart Control, Cordis, USA) between January 2016 and December 2017 were consecutively included in this study. DUS, CEUS, and MDCTV were carried out in all patients within one week of each other at 1 year post stenting to investigate the presence of stent compression and in-stent restenosis (ISR).ResultsThe study included 139 patients (87 females; mean age 58 ± 15 years). For detecting stent compression, the kappa coefficient between the ultrasound modality of gray-scale imaging and MDCTV was 0.901, indicating very good agreement between these two modalities. ISR was detected in 50, 61, and 65 patients by DUS, CEUS, and MDCTV, respectively. DUS and CEUS (kappa = 0.449) and DUS and MDCTV (kappa = 0.516) had moderate agreement for ISR diagnosis, while for which CEUS and MDCTV (kappa 0.884) had very good agreement. The sensitivity and specificity of DUS and CEUS for diagnosing ISR were 63.1% and 90.8%, 87.8% and 97.3%, respectively.ConclusionsCEUS is probably superior to DUS in terms of diagnostic accuracy for the follow-up of patients with iliac vein stent stenosis.

Assessment of the Inferior Petrosal Sinus on T1-Weighted Contrast-Enhanced Magnetic Resonance Imaging.

Context:Skull base venous anatomy.Aims:While prior studies have focused on the efficacy of conventional fluoroscopic venography and multidetector computed tomography venography to evaluate the inferior petrosal sinus (IPS) before image-guided intervention (such as dural venous sinus sampling), we believe that routine magnetic resonance imaging (MRI) may provide reliable structural information helpful for planning without the need for further imaging.Settings and Design:Retrospective review of brain MRI.Materials and Methods:Retrospective analysis was carried out on IPSs on contrast-enhanced T1-weighted MR images. Qualitative measurements were made regarding the grade of patency of the IPS, variation in IPS drainage pattern, and grading of the ipsilateral transverse and sigmoid sinuses (TS and SS).Statistical Analysis Used:Pearson's product-moment correlation.Results:Evaluation of a total of 148 IPSs revealed that 91% of cases were grade 3 or grade 2 (either fully or mostly visualized), with 65% of cases demonstrating “typical” (type A) drainage directly into the internal jugular vein and no statistically significant correlation between the patency of the IPS and the dominance of the ipsilateral TS/SS. A bilateral concordance rate of 77% was also observed.Conclusions:Our analysis indicates that routine thin-slice contrast-enhanced T1-weighted MRI can provide sufficient anatomic detail to identify typical drainage pattern of the IPS in a majority of cases. In cases where routine drainage was not identified, spatial resolution was not sufficient to further delineate complex drainage anatomy. No correlation was observed between the TS/SS dominance and patency of the ipsilateral IPS.

Recent Updates of the Diagnosis and Prevention of Venous Thromboembolism in Patients with a Hip Fracture.

Venous thromboembolism (VTE) is a potentially fatal complication that is relatively common after hip surgery. Since patients with a hip fracture have a higher risk of preoperative VTE due to an inability to ambulate after injury and aggravation of underlying age-related conditions, it may be difficult to effectively prevent VTE using only conventional approaches. Very few studies have been published reporting on the prevalence and prevention of VTE in patients with a hip fracture compared to those with hip arthroplasty. For this reason, we aimed to share recent updates on the diagnosis and prevention of VTE in patients with a hip fracture. Preoperative screening tests to diagnose VTE need to be performed more actively following hip fracture and indirect multidetector computed tomography venography is considered the most effective test for this purpose. As the risk of VTE appears to increase with time following a hip fracture, preventive measures should be taken as soon as possible in patients with a hip fracture. A wide variety of mechanical and pharmacological options are available for prophylaxis. When considering patient compliance and preventive impact, intermittent pneumatic compression devices and foot pumps are recommended as mechanical modalities. Of the available preventive medications for patients with a hip fracture, low molecular weight heparin seems to be the most appropriate option because of its short half-life and fast onset of action. Surgery should be performed as soon as possible in patients with hip fractures, and we recommend mechanical and pharmacological methods as active interventions immediately after injury to prevent VTE.

Fibrin sheath formation and intimal thickening after catheter placement in dog model: role of hemodynamic wall shear stress.

To investigate the role of wall shear stress in aspects of the formation of fibrin sheath and intimal thickening in a dog model. Tunneled silicone 14.5-F catheters were inserted into the left internal jugular vein in eight dogs. The dogs were separated into two groups according to catheter indwelling time of 14 and 28 days. All dogs underwent extracorporeal circulation three times a week. Multidetector computed tomography venography (MDCTV) examination was used to examine the catheter tip thrombus. After the animals were sacrificed, histological and immunohistochemistry evaluations were performed to confirm specific cell populations. We used computer modeling to generate wall shear stress profiles for the blood flow through the catheter. Catheter-related sheaths were identified in all catheter specimens, but there was no fibrin sheath around the catheter tip. There were also differences in wall shear stress between the different venous wall sites. Differences in vein wall thickening at different sites have been found at both 14 days (intima to media (I/M) ratio S1 vs S2: p = 0.01, S3 vs S4: p<0.01) and 28 days (I/M ratio S1 vs S2: p<0.01, S3 vs S4: p<0.05). After catheter placement, fibrin sheath formation partially covered the catheter. Meanwhile, focal areas of intimal thickening were also seen in the venous wall adjacent to the sites of high wall shear stress. These findings indicate an important role of wall shear stress profiles in fibrin sheath formation and intimal thickening.

Thoracic central venous evaluation: comparison of first-pass direct versus delayed-phase indirect multidetector CT venography

PurposeThe purpose was to compare first-pass and delayed-phase thoracic computed tomography (CT) venography for the evaluation of suspected central thoracic venous pathology. Material and methodsCT images and medical records of all patients who underwent thoracic CT venography over a 5-year period were retrospectively reviewed. Both first-pass (18s) and delayed-phase (60s) venous images were obtained in all patients. The images were reviewed in random order by three readers using a semiquantitative visual grading scheme for image quality, including artifacts and the uniformity of venous enhancement. In addition, enhancement was quantitatively evaluated. The presence and type of venous pathology, and overall diagnostic confidence were recorded and compared. Reference verification was performed when available. ResultsEighteen patients formed the study group, mean age 49.5years and 28% male. Dual-arm injection was successful in 72% of exams. All readers reported more streak artifacts on first-pass imaging than delayed imaging (72%–94% vs. 27%–44%, respectively; P<.05). First-pass imaging had significantly higher measured enhancement across all central venous segments than delayed imaging (mean HU range 212–906 HU vs. 173–414 HU; P<.05) but also had significantly more heterogeneous enhancement (mean S.D. range 75–1058 HU vs. 67–378 HU; P<.05). For overall diagnosis, reader agreement, accuracy, and confidence levels were higher for delayed-phase images (P<.05). ConclusionIndirect thoracic CT venography using delayed-phase imaging alone may be sufficient for evaluating clinically suspected central venous abnormality.

The incidence of pulmonary embolism and deep vein thrombosis and their predictive risk factors after lower extremity arthroplasty: a retrospective analysis based on diagnosis using multidetector CT.

The true incidence of venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE) events, and the predictive risk factors are not well-defined in patients who undergo major lower extremity arthroplasty such as total hip arthroplasty (THA) or total or partial knee arthroplasty (TPKA). Using multidetector computed tomography (MDCT), pulmonary angiography (CTA), and MDCT venography (CTV), we investigated the prevalence of VTE and its predictive risk factors in patients for whom the guideline recommends prophylaxis. The electronic records of patients who underwent elective THA or TPKA at our institution from April 2010 through July 2013 were surveyed. We examined a total of 1,163 patient records for 986 patients who had undergone MDCT seven days after THA or TPKA. No PE-related deaths occurred in this study, though arterial embolization was needed for major bleeding in two cases. CTA-CTV revealed VTE in 51 (4.4%) patients, PE in 20 (1.7%), and DVT in 43 (3.3%). Five of 51 patients had symptoms suggestive of DVT. In the logistic regression model, the type of surgery (TPKA>THA), patient age, and body mass index (BMI) were identified as predictive risk factors for VTE. This observational study showed that the overall incidence of VTE after THA and TPKA is 4.4% in patients receiving recommended antithrombotic prophylaxis. TPKA is associated with a higher incidence of VTE than of THA, and greater BMI and older patient age are also independent risk factors.

Three-dimensional contrast-enhanced magnetic resonance venography for detection of renal vein thrombosis: comparison with multidetector CT venography

Renal vein thrombosis is not uncommon, however, there have been few reports on the diagnostic accuracy of three-dimensional contrast-enhanced magnetic resonance venography (3D-CE-MRV) in the detection of renal vein thrombosis (RVT). To evaluate the value of 3D-CE-MRV for detecting RVT with multidetector computed tomography (CT) venography as reference standard. Thirty-two patients with nephrotic syndrome underwent renal CT venography and gradient echo pulse sequence (FLASH 3D) 3D-CE-MRV in a clinical 3-T whole-body MR scanner for suspected RVT with time interval of 0-5 days. RVT was recorded on a per-patient and per-vessel (left renal vein, right renal vein, and inferior vena cava) basis. The diagnostic accuracy of 3D-CE-MRV for detection of RVT was calculated with CT venography as reference standard. Inter-reader agreement for RVT detection was evaluated using Kappa statistics. Of 32 patients, CT venography detected 22 vessels with thrombosis in 17 patients, including five in right renal veins, 14 in left renal veins, and three in inferior vena cava, while 15 patients had no RVT. 3D-CE-MRV detected 21 vessels (21/96, 21.9%) with thrombosis in 16 patients (6/32, 50%), including five in right renal veins, 13 in left renal veins, and three in inferior vena cava, while 16 patients (16/32, 50%) had no RVT. With CT venography as reference standard, the sensitivities and specificities of 3D-CE-MRV for RVT detection were 94.1%, 100%; 95.5%, 100% on a per-patient and a per-vessel basis, respectively. Excellent inter-reader agreement (Kappa value = 0.969, P < 0.001) was observed for RVT detection. 3D-CE-MRV has a high diagnostic accuracy in the detection of RVT, which is optimal alternative imaging modality in the detection of RVT.

Underlying deep venous abnormalities in patients with unilateral chronic venous disease

To report our initial experience using direct multidetector computed tomography venography (MDCT-V) for imaging lower limb deep veins. CT findings in limbs with chronic venous disease (CVD) were compared with contralateral healthy limbs. MDCT-V with bilateral direct pedal injection of contrast was used to image the deep veins in both lower limbs. Eight patients with unilateral lower limb CVD of varying severity (according to the Clinico-Etiological-Anatomical and Pathological classification [CEAP] class 2-6) were studied. Five patients had primary CVD, while three patients had CVD secondary to previous deep vein thrombosis. Deep venous obstruction (>50%) or occlusion was identified in all CVD limbs and was not seen in contralateral healthy limbs. These lesions were not only iliac, were not exclusively present in advanced CVD and were independent of the presence or absence of deep venous reflux. Morphologically significant lesions could be underlying in patients with clinically significant CVD. Direct MDCT-V provides clear reconstructable cross-sectional images of the whole deep venous tree, including infrainguinal areas, beyond the reach of intravascular ultrasound. Utilization of new venous imaging modalities may uncover previously undiagnosed and potentially treatable venous pathology in patients with CVD.

A comparison of multidetector computed tomography direct venography with color Doppler ultrasound in the diagnosis of lower limb and inferior vena cava deep venous thrombosis

Background: This study aims to compare the diagnostic value of the multidetector computed tomography (MDCT) direct venography and color Doppler ultrasound (CDUS) in detection of lower limb deep venous thrombosis (DVT). Methods: Color Doppler ultrasound and MDCT direct venography examinations were performed in 30 patients (21 males, 9 females; mean age 48 years; range 21 to 80 years) with clinical suspicion of DVT. The MDCT direct venography was performed within 24 hours, after the CDUS examination. Results: Color Doppler ultrasound was diagnostic in all of the lower limb veins (240 venous segments), while non-diagnostic in 68 out of 150 venous segments at the pelvic region. Color Doppler ultrasound identified DVT in 13 segments, and MDCT direct venography identified DVT in 21 venous segments at the pelvic region. All of the lower limb DVT&#8217;s were depicted both by CDUS and direct MDCT venography, except for one calf muscular vein thrombosis which was detected by CDUS. Multidetector computed tomography direct venography showed false positive thrombosis in five venous segments (4 femoral vein, 1 popliteal vein) and a pseudotrombosis appearance due to the flow phenomenon in one venous segment (common iliac vein). Partially recanalized low flow in chronic DVT patients could also be demonstrated on MDCT direct venography. Conclusion: Multidetector computed tomography direct venography is more reliable than color Doppler US in diagnosis of DVT of the iliac veins and inferior vena cava. However, false positive thrombosis on MDCT direct venography can be seen distal to an occluded venous segment similar to the conventional venography.

Multi-Detector Computed Tomography Venography in the Assessment of Dysfunction of Tunneled Hemodialysis Central Vein Catheters

To assess the value of multi-detector computed tomography venography (MDCTV) in the assessment of tunneled hemodialysis central vein catheters (CVCs) dysfunction. Twenty-five patients who had tunneled CVC dysfunction without abnormality found by x-ray and ultrasound were enrolled. Anti-platelet agents, anticoagulants, and thrombolytic therapy with urokinase failed to resume normal catheter function. MDCTV was performed to observe the position of catheters and to detect central venous stenosis, thrombosis, and fibrin sheath formation. Correct intervention was given according to MDCTV results. MDCTV revealed that the catheter was malpositioned in 10 cases; there were five cases of central venous stenosis, four cases of central venous thrombosis, one case of fibrin sheath formation, and the other five had no abnormalities found. Blood flow on hemodialysis had reached over 300 mL/min after correct intervention. MDCTV provided a new possible way to assess dysfunction of tunneled hemodialysis central venous catheters.

MDCT venography in the evaluation of inferior vena cava in Budd-Chiari syndrome

To assess the role of multidetector computed tomography (MDCT) venography in the evaluation of the inferior vena cava (IVC) in Budd-Chiari syndrome (BCS), its accuracy as compared to digital subtraction venography (DSV) and the potential of this technique to replace venography for the definitive diagnosis of BCS. Twenty-five suspected cases of BCS were prospectively enrolled in this study and underwent both MDCT venography and DSV. Two observers independently evaluated and graded both the axial and reformatted MDCT images for the presence, site, degree and length of IVC narrowing. The collateral pathways and the hepatic veins were also assessed in all cases. The degree of correlation between MDCT venography and DSV was expressed using Spearman's rank correlation coefficient (Rs). There was excellent correlation between MDCT venography and DSV in predicting the presence of stenosis and in grading the degree and length of IVC stenosis (Rs=0.58, p<0.05). Four patients had presence of a web within the IVC and the reconstructed MDCT venography images detected the flap of the membrane in all of them. In three cases of complete obstruction the cranial extent of the obstruction could be determined on the reconstructed MDCT venography images, while double catheter access through the femoral and jugular routes was needed to determine the same on DSV. MDCT venography was significantly more informative in depicting the presence and site of both intrahepatic and extrahepatic collaterals as compared to DSV. MDCT venography, in the present study, accurately provided information of both conventional CT and IVCgraphy, in the evaluation of the IVC in a non-invasive way. It helped overcome the shortcomings of CT in the evaluation of IVC and was better than DSV for the evaluation of collaterals, calcification and complete IVC obstruction. We suggest that CT venography can be used as a frontline investigation for the diagnosis of IVC obstruction and for planning surgery or percutaneous endovascular intervention.

MDCT venography in the evaluation of inferior vena cava in Budd-Chiari syndrome: a road less travelled

Indian J Gastroenterol 2009: 28(Jan–Feb):3–4 Budd-Chiari syndrome is characterized by hepatic venous outfl ow obstruction, with or without involvement of the inferior vena cava (IVC), and can be due either to venous thrombosis or to membranous occlusion, often leading to chronic liver disease. It is a well known clinical entity in the Far East, the Middle East, India and Africa. 1 The site, extent, and rapidity of hepatic venous occlusion can be highly variable. Information on these aspects of venous obstruction is important for planning appropriate treatment for patients with BCS. Thus, imaging of the hepatic veins and IVC plays a crucial role in the management of patients with BCS. Several non-invasive diagnostic imaging techniques like color Doppler (CD), multidetector computed tomography (MDCT) and, more recently, magnetic resonance imaging (MRI) have all been used in patients with BCS. Because of wide variations in clinical presentations and venous anatomy, and availability of a variety of imaging modalities, patients with BCS need an individualized imaging strategy to obtain a complete evaluation of venous abnormalities and deciding an appropriate treatment plan. Since the clinical condition of patients with BCS can deteriorate rapidly, an early correct diagnosis and evaluation is important. Ultrasonography combined with CD has a diagnostic sensitivity of more than 75% to diagnose venous obstruction. It is also cheap, quick, non-invasive and widely available. Because of these advantages, it is usually the fi rst line of investigation to diagnose hepatic venous outfl ow obstruction in patients with liver disease. 2,3 Normal hepatic veins exhibit characteristic triphasic Doppler signal when patent. Classic fi ndings that suggest involvement of hepatic vein(s) in BCS are non-visualization of the vein(s), replacement of the vein with a fi brous cord-like structure, presence of a thrombus in the vein lumen and venous stenosis at the confl uence of the hepatic vein with the IVC. Demonstration of a caudate lobe vein equal to or larger than 3 mm in diameter is a specifi c sign of BCS, provided the patient does not have heart failure. 4 However, CD evaluation of hepatic veins in a swollen liver in BCS is often diffi cult and inaccurate, because the compressed hepatic veins may not be visible even though these they may be patent. In addition, it is sometimes diffi cult to detect occlusion of the left and middle hepatic veins using CD as cardiac pulsations are in close proximity with the left lobe of the liver. 4 Thus, though CD appears to be a good screening tool in the initial

New techniques for the evaluation and therapeutic planning of patients with Klippel–Trénaunay syndrome

Klippel-Trénaunay syndrome (KTS) is a well-known eponym for a capillary-lymphatic-venous malformation which is associated with soft tissue and skeletal hypertrophy, usually of one or more limbs. Plain films, sonograms, conventional venograms, and arteriograms have been employed for the evaluation of the disease. To demonstrate the usefulness of multidetector computed tomography (MDCT) and fast 3-dimensional magnetic resonance imaging (3D-MR) venography for the assessment and therapeutic planning of patients with KTS. A prospective study in 16 consecutive patients with KTS using MDCT and 3D-MR venography, performed between January 2004 and January 2006 in a university hospital in Pamplona, Spain. In nearly all patients, persistent embryologic veins were observed, and in one subject aplasia/atresia of the whole deep venous system of the affected extremity was seen. In four individuals hypoplasia of the femoral vein was observed; one subject had duplication of the femoral vein, and in three patients aplasia/atresia of this vein was found. Only half of the patients had normal popliteal veins. In one patient, aneurysmal dilatation of the popliteal vein was detected, and in six subjects, aplasia of this vein was observed. The presence of geographic stains was suggestive of hypoplasia and/or aplasia of femoral and popliteal veins. The small size of the group of patients with KTS, which is related to low incidence of the disease. MDCT and 3D-MR venography are extremely helpful for the global evaluation of patients with KTS. Information regarding soft tissue and bony anatomy as well as information about superficial and deep venous systems may be obtained with a single exam.

Cerebral Venous Thrombosis and Multidetector CT Angiography: Tips and Tricks

Because of the great diversity of clinical features, its unforeseeable evolution, and a small proportion of cases that will worsen in the acute phase, cerebral venous thrombosis must be diagnosed as early as possible so that specific treatment can be started, typically transcatheter thrombolysis or systemic anticoagulation. Unenhanced computed tomography (CT) is usually the first imaging study performed on an emergency basis. Unenhanced CT allows detection of ischemic changes related to venous insufficiency and sometimes demonstrates a hyperattenuating thrombosed dural sinus or vein. Helical multidetector CT venography with bolus power injection of contrast material and combined use of two-dimensional and three-dimensional reformations (maximum intensity projection, integral display, and volume rendering) provides exquisite anatomic detail of the deep and superficial intracranial venous system and can demonstrate filling defects. However, common variants of the sinovenous system should not be mistaken for sinus thrombosis. A comprehensive diagnostic approach facilitates imaging of cerebral venous thrombosis with multidetector CT.