3D Magnetic Resonance Venography Research Articles

VARIANT ANATOMY IN MR VENOGRAPHY OF BRAIN

Introduction:Identifying the variations in cerebral dural venous sinus anatomy on magnetic resonance (MR) venography is important for the adequate diagnosis of cerebral venous sinus thrombosis (CVST). There is limited documentation available on gender differences in cerebral dural venous sinus anatomical variants. Aims and Objectives:This study aimed to investigate gender-related variations as well as the typical variance of the cerebral venous system anatomy in asymptomatic individuals as shown by MR venography (3D). Material and Methods:This Hospital-based retrospective study was carried out over 24 months from December 2020 to November 2022 at the Department of Radiodiagnosis, Narayana medical college, Nellore. The study was done on 100 patients. All patients underwent 3D MR Venography on 3.0 Tesla (GE DISCOVERY 750W) MRI machine. Results: 1. Headache was the most prevalent clinical symptom for an MR venography (81%). 2. The most frequent anatomical variant was hypoplastic left transverse sinus (27%). 3. Males had a greater likelihood than females to have a hypoplastic left transverse sinus (12 versus 11). 4. Hypoplastic anterior one-third SSS was the most prevalent anatomical variant of the superior sagittal sinus (SSS). Conclusion:In the current research, the most frequent structural variant was found to be hypoplastic left transverse sinus, which was more prevalent in males than females. Other dural venous sinus structural differences did not show a significant difference between genders.

The Investigation of the Diagnostic Values of the T2WI Sequence in Cerebral Venous Sinuses Thrombosis in Comparison With 3D MRV

Cerebral venous sinus thrombosis is an important pathology with various clinical symptoms. Early detection of thrombosis is very important for the improvement of the prognosis. The aim of this study was to calculate the diagnostic value of T2-weighted sequences of magnetic resonance imaging (MRI) in detecting subacute thrombosis. All patients that were suspected of having subacute cerebral venous sinus thrombosis and were referred to the emergency center of Kashani hospital (between September 2018 and September 2019) were entered into the study. Magnetic resonance venography (MRV) and T2-weighted MRI were accomplished for each patient. The sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of MRI using MRV as the reference method were calculated. A total of 630 patients were entered into the study. A positive subacute venous sinus thrombosis was detected in the MRV of 53 patients; consequently, the sensitivity of 60%, the specificity of 80%, the PPV of 21%, and the NPV of 96% were calculated. MRI was highly specific for detecting the subacute thrombosis of superior sagittal sinus, transverse sinuses, sigmoid sinuses, and straight sinus (specificity>94%). A substantial agreement was detected between MRI and MRV in distinguishing thrombosis of superior sagittal sinus, transverse sinuses, sigmoid sinuses, and straight sinus (kappa>0.6). T2-weighted MRI is a specific method in detecting cerebral venous sinus thrombosis. In a patient with signs of thrombosis in the T2-weighted sequence, additional workups are highly suggested to rule out the pathology.

Magnetic resonance venography for 3-dimensional live guidance during venous sinus stenting

PurposeThe purpose of this study was to report the technique for intraprocedural guidance of endovascular Venous Sinus Stenting procedures using 3-Dimensional (3D) Magnetic Resonance Venography (MRV) as an overlay on live biplanar fluoroscopy.Materials and methodsVenous sinus stenting procedures performed between April and December, 2017 with 3D MRV fusion for live guidance were reviewed in this study. A thin-slice, contrast-enhanced MR Venogram was used to create 2 3D models – vessels and skull – for procedural guidance via augmented fluoroscopy (Vessel ASSIST, GE Healthcare, Chicago, IL). The skull model was used in the registration of the 3D overlay on both the frontal and lateral planes, which required 1–2 min of procedural time. The vessel model was used to mark landmarks such as the cortical vein ostia and stenosis on the 3D overlay fused with biplanar fluoroscopy.The retrospective imaging review was conducted by 3 neurointerventionalists and relied on a consensus confidence ranking on a 3-point Likert scale from 1- low confidence to 3- high confidence. The neurointerventionalists first reviewed the conventional 2-dimensional pre-stent deployment fluoroscopy images and then reviewed the corresponding images with the 3D MRV overlay. They ranked their confidence in their understanding of cortical venous anatomy for each group. Statistical analysis was performed using a Paired T Test at a 99% confidence interval.ResultsTen cases were included in the retrospective image review. Operator confidence regarding the location of cortical veins was significantly increased using 3D MRV fusion during venous sinus stenting procedures (1.9 vs 2.9, p = .001).Conclusion3-Dimensional MRV fusion is feasible and helpful in understanding the venous sinus anatomy and location of important cortical veins during venous sinus stenting procedures.

Three-dimensional visualization of intracranial tumors with cortical surface and vasculature from routine MR sequences.

The simultaneous three-dimensional (3D) visualization of intracranial tumors, brain structures, skull, and vessels is desired by neurosurgeons to create a clear mental picture of the anatomical orientation of the surgical field prior to the surgical intervention. Different anatomical and pathological components are usually visualized separately on different magnetic resonance (MR) sequences; however, during surgery, they are tackled simultaneously. Another problem is that most present day MR workstations enable review of two-dimensional (2D) slices only with limited postprocessing options. With recent software developments, a simultaneous 3D visualization simulating the real surgical field is possible using commercial or open source softwares. The authors have reviewed the important concepts and described a technique of interactive 3D visualization from routine 3D T1-weighted, MR angiography, and MR venography sequences using open source FSL (Functional MRI of the brain software library) and BrainSuite softwares.

Anatomical Variations of Cerebral MR Venography: Is Gender Matter?

PurposeKnowledge of variations in the cerebral dural venous sinus anatomy seen on magnetic resonance (MR) venography is essential to avoid over-diagnosis of cerebral venous sinus thrombosis (CVST). Very limited data is available on gender difference of the cerebral dural venous sinus anatomy variations.Materials and MethodsA retrospective study was conducted to study the normal anatomy of the intracranial venous system and its normal variation, as depicted by 3D MR venography, in normal adults and any gender-related differences.ResultsA total of 1654 patients (582 men, 1072 women, age range 19 to 86 years, mean age: 37.98±13.83 years) were included in the study. Most common indication for MR venography was headache (75.4%). Hypoplastic left transverse sinus was the most common anatomical variation in 352 (21.3%) patients. Left transverse sinus was hypoplastic in more commonly in male in comparison to female (24.9% versus 19.3%, p = 0.009). Most common variation of superior sagittal sinus (SSS) was atresia of anterior one third SSS (15, 0.9%). Except hypoplastic left transverse sinus, rest of anatomical variations of the transverse and other sinuses were not significantly differ among both genders.ConclusionHypoplastic left transverse sinus is the most common anatomical variation and more common in male compared to female in the present study. Other anatomical variations of dural venous sinuses are not significantly differ among both genders.

A Multicenter MRI Protocol for the Evaluation and Quantification of Deep Vein Thrombosis.

We evaluated a magnetic resonance venography (MRV) approach with gadofosveset to quantify total thrombus volume changes as the principal criterion for treatment efficacyin a multicenter randomized study comparing edoxaban monotherapy with a heparin/warfarin regimen for acute, symptomatic lower extremities deep vein thrombosis (DVT) treatment. We also used a direct thrombus imaging approach (DTHI, without the use of a contrast agent) to quantify fresh thrombus. We then sought to evaluate the reproducibility of the analysis methodology and applicability of using 3D magnetic resonance venography and direct thrombus imaging for the quantification of DVT in a multicenter trial setting. From 10 randomly selected subjects participating in the edoxaban Thrombus Reduction Imaging Study (eTRIS), total thrombus volume in the entire lower extremity deep venous system was quantified bilaterally. Subjects were imaged using 3D-T1W gradient echo sequences before (direct thrombus imaging, DTHI) and 5 min after injection of 0.03 mmol/kg of gadofosveset trisodium (magnetic resonance venography, MRV). The margins of the DVT on corresponding axial, curved multi-planar reformatted images were manually delineated by two observers to obtain volumetric measurements of the venous thrombi. MRV was used to compute total DVT volume, whereas DTHI was used to compute volume of fresh thrombus. Intra-class correlation (ICC) and Bland Altman analysis were performed to compare inter and intra-observer variability of the analysis. The ICC for inter and intra-observer variability was excellent (0.99 and 0.98, p <0.001, respectively) with no bias on Bland-Altman analysis for MRV images. For DTHI images, the results were slightly lower (ICC = 0.88 and 0.95 respectively, p <0.001), with bias for inter-observer results on Bland-Altman plots. This study showed feasibility of thrombus volume estimation in DVT using MRV with gadofosveset trisodium, with good intra- and inter-observer reproducibility in a multicenter setting.

Chronic cerebrospinal venous insufficiency: masked multimodal imaging assessment

Background: Chronic cerebrospinal venous insufficiency (CCSVI) was implicated in the pathophysiology of multiple sclerosis (MS). Objective: We evaluated neurosonography (NS), magnetic resonance venography (MRV), and transluminal venography (TLV) in subsets of MS patients drawn from a single-center, prospective, case-control study of 206 MS and 70 non-MS volunteers. Methods: As previously reported, findings on high-resolution B-mode NS imaging with color and spectral Doppler of the extracranial and intracranial venous drainage consistent with CCSVI were similar among MS and non-MS volunteers (3.88% vs 7.14%; p = 0.266). Ninety-nine MS participants consented to intravascular contrast-enhanced 3D MRV to assess their major systemic and intracranial venous circulation, and 40 advanced to TLV that included pressure measurements of the superior vena cava, internal jugular, brachiocephalic, and azygous veins. Results: NS findings and MRV patterns were discrepant for 26/98 evaluable subjects, including four with abnormal findings on NS that had normal venous anatomy by MRV. In no instance were TLV pressure gradients indicative of clinically significant functional stenosis encountered. The three imaging approaches provided generally consistent data with discrepancies referable to inherent technique properties. Conclusions: Our findings lend no support for altered venous outflow dynamics as common among MS patients, nor do they likely contribute to the disease process.

MR venography of the brain with enhanced vessel contrast using image‐domain high‐pass filtering of the susceptibility phase shift

To develop a postprocessing algorithm that enhances the visibility of intracranial venous vasculature and reduces the artifacts in the display of susceptibility-weighted images (SWI). Image-domain high-pass filters based on second-order phase difference were applied to the complex 3D SWI data to enhance the susceptibility phase shift of the veins and suppress background signal in SWI. A multivariant statistical parameter was used to suppress the noise in air. Magnetic resonance (MR) venography with enhanced susceptibility phase shift and reduced off-resonance artifacts was obtained using the proposed filters. The background signal in the 3D MR venography data was well suppressed. Venous vasculature in the peripheral regions of the brain was well depicted and the adverse effect of noise in air in the maximum-intensity projection display of the 3D SWI data was well suppressed. Image-domain high-pass filtering with second-order phase difference provides an alternative display of 3D SWI data with enhanced visibility of the venous vasculature and effective suppression of artifacts.

Real-time MR-guided Retrieval of Inferior Vena Cava Filters: An in Vitro and Animal Model Study

Purpose To develop interventional magnetic resonance (MR) guidance techniques for inferior vena cava (IVC) filter retrieval in vitro and demonstrate feasibility in vivo. Materials and Methods Three optional IVC filters and their retrieval systems were investigated. Experiments were performed on a 1.5-T MR system. Real-time MR imaging was optimized by using a custom-built IVC phantom. A three-dimensional (3D) contrast-enhanced MR venography sequence was optimized in vitro for improved detection of thrombus trapped within the filters. Filters were then retrieved in vitro and in vivo in a swine model under MR guidance. In-vivo retrieval procedure time was measured. Results The combination of one of the nitinol filters and a loop snare was suitable for real-time MR procedures. With a 90° flip angle, 3D MR venography allowed detection of simulated thrombus within the filter. A radial true fast imaging sequence with steady-state precession allowed visualization of the loop snare and IVC filter hook and successful retrieval of the filter in vivo and in vitro. In-vivo MR fluoroscopy time for retrieval was 97 seconds ± 51 (mean ± SD). Conclusions MR-guided retrieval of a nitinol-based IVC filter by using a loop snare is feasible with the use of optimized sequences and passive device tracking.

3-T contrast-enhanced MR angiography with parallel imaging in cerebral venous and sinus thrombosis

Contrast-enhanced (CE) 3D magnetic resonance venography (MRV) and CE 3D magnetization prepared rapid acquisition of gradient echo (MP-RAGE) sequences are increasingly commonly used methods for evaluation of the intracranial venous system. Our aim was to compare CE MRV, 2D time-of-flight (TOF) MRV and MP-RAGE sequences at 3 T for visualization of cerebral venous and sinus thrombosis. Patients with suspected or known cerebral venous thrombosis were examined prospectively by TOF MRV, CE MRV and MP-RAGE sequences. In 11 consecutive patients (all women; mean age, 42.5 years; age range, 25-70 years) with venous thrombosis, scores according to overall image quality, and presence or absence (score P) and differentiation (score D) of venous thrombosis were evaluated. By all measurements, overall image quality ranged from good to excellent. In 20 of 52 venous structures (38.5%), score P was the same on TOF MRV, CE MRV and MP-RAGE sequences. Venous thrombosis was definitely or almost definitely present or absent with TOF MRV in 20 of 52 (38.5%), with CE MRV in 97 of 99 (97.9%) and with MP-RAGE sequences in 86 of 99 (86.9%) venous structures. In all venous structures with uncertain diagnosis on TOF MRV, thrombosis was definitely or almost definitely present or absent on CE MRV and MP-RAGE sequences. Differentiation of thrombosis was better on CE MRV (score D: 3.33) than on MP-RAGE sequences (score D: 2.78), followed by TOF MRV (score D: 1.32). CE MRV was superior to TOF MRV and MP-RAGE sequences in visualizing cerebral venous and sinus thrombosis.

Comparison of Real-time Three-dimensional Gadolinium-enhanced Elliptic Centric-ordered MR Venography and Two-dimensional Time-of-flight MR Venography of the Intracranial Venous System

To compare 3-dimensional gadolinium-enhanced elliptic centric-ordered (3D GEC) magnetic resonance venography (MRV) with traditional 2-dimensional time-of-flight (2D TOF) MRV for imaging of the intracranial venous system. Fifty-three patients underwent 2D and 3D MRV, whereby venous structures were evaluated by 2 neuroradiologists. Of the 53 patients, 10 were diagnosed with dural venous sinus thrombosis and 12 with intracranial tumors. 3D GEC MRV displayed superior sensitivity/specificity (90.9%/96.8%) compared to 2D TOF MRV (63.6%/48.4%). Analysis of the areas under the receiver operating characteristic curves also showed superiority of 3D GEC (0.91) versus 2D TOF (0.53) MRV. Of the remaining 31 healthy patients, the rate of complete visibility of venous structures was also greater for 3D GEC (95.8%) than for 2D TOF (62.1%) MRV. 3D GEC MRV is superior to 2D TOF MRV for providing more detail of the intracranial venous system, and can lead to better diagnosis of venous conditions.

Comparative evaluation of 2D time‐of‐flight and 3D elliptic centric contrast‐enhanced MR venography in patients with presumptive cerebral venous and sinus thrombosis

We retrospectively evaluated an elliptic centric ordered 3D (ec 3D) magnetic resonance venography (MRV) technique in comparison to 2D time-of-flight (2D TOF) MRV in patients with presumptive cerebral venous sinus thrombosis (CVST). Twenty-five patients (mean age 40.6 +/- 16.5 years) with presumptive CVST underwent cerebral MRI including 2D TOF and ec 3D MRV. Radiologic findings and clinical outcome were correlated. MRV studies were evaluated by two neuroradiologists in a blinded manner for image quality, assessment of various sinus, internal cerebral veins (ICV), vein of Labbé and Galen (VL/VG) as well as for additional imaging procedures required. Sensitivity/specificity of ec 3D MRV amounted to 85.7%/97.2% as compared with 2D TOF 71.4%/55.6 %. Ec 3D MRV performed superior in terms of image quality as well as assessment of all sinus and veins except for the straight sinus. Additional imaging procedures were less often required in ec 3D MRV studies (28% vs. 66% for 2D TOF MRV; P < 0.001). Interobserver agreement was significantly increased by using ec 3D MRV (93.1% vs. 70.9% of readings). The results of our study provide additional evidence for the superiority of ec 3D compared with 2D TOF MR venography for the diagnosis or exclusion of acute CVST in daily clinical practice.

Cerebral Varix Simulating a Meningioma: Use of 3D Magnetic Resonance Venography for Diagnosis

A rare isolated cerebral varix of a superficial convexity cortical vein was described. On conventional magnetic resonance images, the varix was initially interpreted as a meningioma but a subsequent 3D magnetic resonance venography revealed the varix and the associated venous anatomy clearly.

Cerebral MR Venography in Children: Comparison of 2D Time-of-Flight and Gadolinium-enhanced 3D Gradient-Echo Techniques

To prospectively compare two-dimensional (2D) time-of-flight cerebral magnetic resonance (MR) venography with gadolinium-enhanced three-dimensional (3D) gradient-echo cerebral MR venography in children. This investigation had investigational review board approval and was Health Insurance Portability and Accountability Act compliant; parental informed consent was obtained. Thirty-seven patients (20 boys, 17 girls) who ranged in age from 4 days to 15 years underwent 2D and 3D MR venography. Two pediatric neuroradiologists compared the visibility of the superior sagittal, straight, transverse, and sigmoid sinuses and the internal jugular veins on images obtained with the two sequences. In 17 (46%) of the 37 patients, the sequences were equivalent in terms of their depiction of venous anatomy. In 19 (51%) of the 37 patients, 3D MR venography was superior to 2D MR venography. Suboptimal enhancement of veins occurred in one (3%) patient at 3D MR venography. Venous anomalies suggested at 2D MR venography but not present at 3D MR venography included flow gaps in the nondominant transverse sinuses of four patients, unilateral transverse sinus atresia in eight, and a narrowed superior sagittal sinus in two. Two-dimensional MR venography results failed to reveal a persistent falcine sinus associated with straight sinus atresia in one patient and suggested transverse sinus thrombosis in two patients in whom 3D MR venography results were normal. Additionally, the extent of dural thrombosis was overestimated at 2D MR venography in one patient. As compared with 3D MR venography, 2D MR venography failed to reveal sigmoid sinus stenosis in one patient and poorly depicted posterior fossa dural sinus anatomy in two patients with dural arteriovenous fistula. Three-dimensional MR venography is often superior to 2D MR venography in the delineation of major cerebral venous structures in children. Most of the artifactual loss of vascular signal seen with the use of 2D MR venography occurred in nondominant transverse sinuses.

Magnetic resonance venography in consecutive patients with suspected deep vein thrombosis of the upper extremity: initial experience.

To assess the feasibility and accuracy of two magnetic resonance (MR) venography methods in a consecutive series of patients with suspected deep vein thrombosis of the upper extremity (DVTUE). Consecutive in- and outpatients who were referred for imaging of suspected DVTUE in a large teaching hospital during the period April 2001 to October 2002 were eligible for inclusion. All patients were scheduled to undergo contrast venography with the intention to perform additional MR venography. Both time-of-flight and gadolinium-enhanced 3D MR venography were scheduled. All MR imaging were interpreted independently by consensus of two experienced radiologists, who were blinded for contrast venography outcome. Patients were managed based on contrast venography only. A total of 44 patients were eligible for inclusion. Thirteen patients were excluded (5 refused consent, 2 inability to gain venous access, 2 renal failure, 4 logistic reasons). Contrast venography was performed in 31 patients, and demonstrated DVTUE in 11 patients. MR imaging was not feasible in 10 patients (4 unable to lie flat, 3 claustrophobia, 1 too large for MR scanner, 1 osteosynthesis of shoulder, 1 pacemaker). The sensitivity and specificity of TOF MRV versus Gadolinium 3D MRV was 71% and 89% versus 50% and 80%, respectively. A high number of patients were unable to undergo MR venography in this setting. Contrast-enhanced MRV did not improve diagnostic accuracy. The clinical utility of MR venography in the setting of suspected DVTUE seems disappointing.

Comparison of MS-325- and Gadodiamide-enhanced MR Venography of Iliocaval Veins

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. 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. 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. 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.

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

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. 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. 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]. 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.

Three-dimensional gadolinium-enhanced MR venographic evaluation of patency of central veins in the thorax: initial experience.

To assess the usefulness of three-dimensional (3D) gadolinium-enhanced magnetic resonance (MR) venography for evaluation of thoracic central veins. A retrospective study included 15 patients who underwent 3D gadolinium-enhanced subtraction MR venography with a spoiled gradient-echo sequence before and at multiple times after intravenous administration of 30-40 mL of contrast material. Maximum intensity projection and multiplanar reconstruction images were used to categorize central veins as patent, occluded, or narrowed. Results were compared with findings (in 12 patients) at conventional venography (n = 3), attempted central venous catheter placement (n = 3), or surgery (n = 6). Medical records were retrospectively reviewed to determine if patient care was affected by MR venographic findings. By using MR venograms, an appropriate vessel could be identified for successful placement of a catheter, indwelling venous access device, or arteriovenous hemodialysis graft in all nine patients in whom placement was attempted. MR venography also was predictive of unsuccessful hemodialysis catheter placement in one patient. Conventional venographic findings confirmed MR venographic findings in three patients; in a fourth patient, conventional venography was unsuccessful due to inadequate access. MR venographic findings influenced treatment in 14 patients. On the basis of these initial results, 3D gadolinium-enhanced MR venography may facilitate comprehensive evaluation of abnormalities of the central veins in the thorax, particularly with regard to selection of venous access sites.