Assessment of deep venous thrombosis in the lower extremity in Behçet's syndrome: MR venography versus Doppler ultrasonography.

Lower extremity venous thrombosis (DVT) is the most common vascular manifestation of Behçet's syndrome (BS). Currently, Doppler ultrasonography (USG) is the most commonly preferred imaging modality in the diagnosis and follow-up of patients with acute and chronic DVT. Magnetic resonance (MR) venography, a quick and a non-invasive imaging modality, is successfully used to detect DVT in various settings. We had been unaware of studies with MR venography in BS. The aim of this study is to compare the diagnostic value of true fast imaging with steady-state precession magnetic resonance (True-FISP MR) venography and Doppler USG in the assessment of chronic DVT among patients with BS. 28 BS patients with chronic lower extremity DVT were studied. Common femoral (CFV) and femoral vein (FV) on both right and left sides were examined for the presence of thrombosis, recanalisation, collaterals and reflux. There are findings of chronic DVT in all Doppler USG images of 28 patients (45 of 56 FV and 35 of 56 CFV), while MR venography detects chronic thrombotic changes in 26/28 (93%) patients (43 of 52 FV and 28 of 52 CFV). Collateral veins are detected in 19 patients (19/28) with MR venography, whereas they are present in only 7 (7/28) with USG (P = 0.003). Furthermore, patients with severe post-thrombotic syndrome are more likely to have collateral formation on the MR compared to those without (12/14 vs 7/14; P = 0.043). Among patients with BS, MR venography might be an alternative or additional method to detect chronic thrombosis in the lower extremities.

A robust multi-scale approach to quantitative susceptibility mapping.

Quantitative Susceptibility Mapping (QSM), best known as a surrogate for tissue iron content, is becoming a highly relevant MRI contrast for monitoring cellular and vascular status in aging, addiction, traumatic brain injury and, in general, a wide range of neurological disorders. In this study we present a new Bayesian QSM algorithm, named Multi-Scale Dipole Inversion (MSDI), which builds on the nonlinear Morphology-Enabled Dipole Inversion (nMEDI) framework, incorporating three additional features: (i) improved implementation of Laplace's equation to reduce the influence of background fields through variable harmonic filtering and subsequent deconvolution, (ii) improved error control through dynamic phase-reliability compensation across spatial scales, and (iii) scalewise use of the morphological prior. More generally, this new pre-conditioned QSM formalism aims to reduce the impact of dipole-incompatible fields and measurement errors such as flow effects, poor signal-to-noise ratio or other data inconsistencies that can lead to streaking and shadowing artefacts. In terms of performance, MSDI is the first algorithm to rank in the top-10 for all metrics evaluated in the 2016 QSM Reconstruction Challenge. It also demonstrated lower variance than nMEDI and more stable behaviour in scan-rescan reproducibility experiments for different MRI acquisitions at 3 and 7 Tesla. In the present work, we also explored new forms of susceptibility MRI contrast making explicit use of the differential information across spatial scales. Specifically, we show MSDI-derived examples of: (i) enhanced anatomical detail with susceptibility inversions from short-range dipole fields (hereby referred to as High-Pass Susceptibility Mapping or HPSM), (ii) high specificity to venous-blood susceptibilities for highly regularised HPSM (making a case for MSDI-based Venography or VenoMSDI), (iii) improved tissue specificity (and possibly statistical conditioning) for Macroscopic-Vessel Suppressed Susceptibility Mapping (MVSSM), and (iv) high spatial specificity and definition for HPSM-based Susceptibility-Weighted Imaging (HPSM-SWI) and related intensity projections.

Cerebral venous sinus thrombosis after vestibular schwannoma surgery: a call for evidence-based management guidelines.

OBJECTIVE Postoperative cerebral venous sinus thrombosis (CVST) is an uncommon complication of posterior fossa surgery. The true incidence of and optimal management strategy for this entity are largely unknown. Herein, the authors report their institutional incidence and management experience of postoperative CVST after vestibular schwannoma surgery. METHODS The authors undertook a retrospective review of all vestibular schwannoma cases that had been treated with microsurgical resection at a single institution from December 2011 to September 2017. Patient and tumor characteristics, risk factors, length of stay, surgical approaches, sinus characteristics, CVST management, complications, and follow-up were analyzed. RESULTS A total of 116 patients underwent resection of vestibular schwannoma. The incidence of postoperative CVST was 6.0% (7 patients). All 7 patients developed lateral CVST ipsilateral to the lesion. Four cases occurred after translabyrinthine approaches, 3 occurred after retrosigmoid approaches, and none occurred following middle cranial fossa approaches. Patients were managed with anticoagulation or antiplatelet therapy. Although patients were generally asymptomatic, one patient experienced intraparenchymal hemorrhage, epidural hemorrhage, and obstructive hydrocephalus, likely as a result of the anticoagulation therapy. However, all 7 patients had a modified Rankin scale score of 1 at the last follow-up. CONCLUSIONS Postoperative CVST is an infrequent complication, with an incidence of 6.0% among 116 patients who had undergone vestibular schwannoma surgery at one institution. Moreover, the management of postoperative CVST with anticoagulation therapy poses a serious dilemma to neurosurgeons. Given the paucity of reports in the literature and the low incidence of CVST, additional studies are needed to better understand the cause of thrombus formation and help to establish evidence-based guidelines for CVST management and prevention.

Creating normograms of dural sinuses in healthy persons using computer-assisted detection for analysis and comparison of cross-section dural sinuses in the brain.

Dural sinuses vary in size and shape in many pathological conditions with abnormal intracranial pressure. Size and shape normograms of dural brain sinuses are not available. The creation of such normograms may enable computer-assisted comparison to pathologic exams and facilitate diagnoses. The purpose of this study was to quantitatively evaluate normal magnetic resonance venography (MRV) studies in order to create normograms of dural sinuses using a computerized algorithm for vessel cross-sectional analysis. This was a retrospective analysis of MRV studies of 30 healthy persons. Data were analyzed using a specially developed Matlab algorithm for vessel cross-sectional analysis. The cross-sectional area and shape measurements were evaluated to create normograms. Mean cross-sectional size was 53.27±13.31 for the right transverse sinus (TS), 46.87+12.57 for the left TS (p=0.089) and 36.65+12.38 for the superior sagittal sinus. Normograms were created. The distribution of cross-sectional areas along the vessels showed distinct patterns and a parallel course for the median, 25th, 50th and 75th percentiles. In conclusion, using a novel computerized method for vessel cross-sectional analysis we were able to quantitatively characterize dural sinuses of healthy persons and create normograms.

Catheter venography for the assessment of internal jugular veins and azygous vein: position statement by expert panel of the International Society for Neurovascular Disease.

This document by an expert panel of the International Society for Neurovascular Disease is aimed at presenting current technique and interpretation of catheter venography of the internal jugular veins, azygous vein and other veins draining the central nervous system. Although interventionalists agree on general rules, significant differences exist in terms of details of venographic technique and interpretations of angiographic pictures. It is also suggested that debatable findings should be investigated using multimodal diagnostics. Finally, the authors recommend that any publication on chronic cerebrospinal venous insufficiency should include detailed description of venographic technique used, to facilitate a comparison of published results in this area.

The role of colour Doppler sonography in the diagnosis of lower limb Klippel-Trénaunay syndrome.

AIM: To investigate the accuracy of colour Doppler sonography as compared to phlebography in patients with Klippel-Trénaunay syndrome (KTS). MATERIALS AND METHODS: From September 2004 to May 2012, 59 consecutive patients seen in Shandong medical imaging research institute with a clinical suggestion of KTS were included. Thirty-four were female and 25 were male, with a mean age of 28.4 years. Colour Doppler sonography was used to assess the lower limb veins. The main sonographic criteria for a positive diagnosis were visualization of the lateral vein or sciatic vein, capillary haemangioma, and abnormality of the deep veins. These data were compared with phlebography findings. The κ statistic was used to determine the level of agreement. The sensitivity, specificity, positive and negative predictive values, and accuracy of colour Doppler sonography as a diagnostic test were assessed. RESULTS: Colour Doppler sonography findings were positive in 21 of 59 patients with a clinical suggestion of KTS. The diagnosis was confirmed using phlebography in 22 patients. There were two false-positive results and one false-negative result by colour Doppler sonography. The κ-value was 0.892. Sensitivity, specificity, positive and negative predictive values, and accuracy for colour Doppler sonography were 95.4, 94.6, 91.3, 97.2, and 94.9%, respectively. CONCLUSION: Colour Doppler sonography is an accurate, reliable, and non-invasive investigation in the assessment of patients with suspected KTS.

Computed tomography (CT) colonography with CT arteriography and venography for the workup of intestinal transplant candidates.

Prior to intestinal transplantation, prospective candidates must undergo a series of radiologic examinations to address a variety of clinical issues. To date, little literature exists to guide physicians in this preoperative assessment. Multiple imaging studies can provide overlapping information. We have developed a simple two- or three-test protocol to streamline the workup. Sixteen adult patients presented as potential intestinal transplant candidates to Georgetown University Hospital. All but two patients underwent the full protocol of a biphasic IV contrast-enhanced computed tomography (CT) scan of the chest, abdomen, and pelvis with rectal carbon dioxide, an upper gastrointestinal study with small bowel follow through, and fistulogram when appropriate. Three-dimensional (3-D) reconstructions of the vascular anatomy as well as the colon were also generated. A telephone survey to other transplant centers was additionally conducted to compare radiographic evaluations. Overall, 15 of the 16 scans were diagnostic. One patient required a barium enema. Mean examinations per patient was 2.4. Only one of seven other centers was performing CT colonography in prospective intestinal transplant candidates. Our protocol provided all the necessary anatomic information needed to evaluate prospective transplant candidates. CT colonography with angiography is a suitable alternative to more time-consuming radiological studies.

Diagnostic accuracy of current sonographic criteria for the detection of outflow abnormalities in the internal jugular veins.

OBJECTIVES: This study was aimed at evaluation of the diagnostic value of Doppler sonography for the assessment of abnormalities in the internal jugular veins (IJVs). METHOD: One hundred and sixteen IJVs were assessed in 58 patients with associated multiple sclerosis. Findings of Doppler sonography were compared with results of the reference test: catheter venography. RESULTS: At least one positive extracranial sonographic criterion suggesting venous abnormality was found in 92.2% of the assessed veins. Yet, sensitivity, specificity, positive and negative predictive values of sonography were low: 93.4%, 12.0%, 79.4% and 33.3% for at least one positive criterion, and for at least two positive criteria: 29.3%, 75.0%, 81.8% and 21.7%, respectively. CONCLUSIONS: Our research has shown that currently used extracranial sonographic criteria for the detection of obstructive venous abnormalities in the IJVs are of limited diagnostic value. For the time being, diagnosis of this vascular pathology should be given using catheter venography.

Sensitivity and specificity for screening of chronic cerebrospinal venous insufficiency using a multimodal non-invasive imaging approach in patients with multiple sclerosis.

The aim of this study was to investigate whether a combination of Doppler sonography (DS) and magnetic resonance venography (MRV) on 3T MRI increases specificity for detection of chronic cerebrospinal venous insufficiency (CCSVI) in 171 (113 relapsing-remitting, 47 secondary-progressive, 11 primary progressive) patients with multiple sclerosis (MS) and 79 age- and sex matched healthy controls (HCs). One hundred ten (64.3%) MS patients and 30 (38%) HCs presented ≥2 venous hemodynamic CCSVI criteria (p<.0001). Both DS and MRV showed relatively high specificity but lower sensitivity for determining a CCSVI diagnosis in patients with MS vs HCs and between MS subgroups. In MS patients this diagnostic specificity increased to over 90% by combining internal jugular vein and vertebral vein abnormal DS and MRV findings, reflux in deep cerebral veins and MRV findings of >1 collateral veins. This study suggests that a multimodal non-invasive approach (DS and MRV) increases the specificity for a diagnosis of CCSVI in patients with MS.

ESPR uroradiology task force and ESUR paediatric working group: imaging and procedural recommendations in paediatric uroradiology, part III. Minutes of the ESPR uroradiology task force minisymposium on intravenous urography, uro-CT and MR-urography in childhood.

The ESPR working groups have addressed intravenous urography (IVU), uro-CT and MR-urography (MRU) in childhood as the last in the series of recommendations for paediatric uroradiology. The aim of this process was again to standardise paediatric uroradiologic imaging and to reduce invasiveness and radiation dose. As for the existing recommendations, the new proposals are consensus-based because evidence is lacking, use and indications have changed, or approaches on how to perform the examination in children differ in the literature (MRU). As in the previous recommendations, a thorough review of the literature and existing guidelines and recommendations has been performed. The proposals were discussed within the group and with non-member experts and colleagues from other partner disciplines. These recommendations aim to serve as a quality measure in order to standardise the procedures and thus grant comparable good quality results throughout different institutions.

Multiple spinal dural arteriovenous fistulae and deterioration post lumbar puncture.

We report a 73-year-old man presenting with bilateral leg numbness and weakness. Three spinal dural arteriovenous fistulae (SDAVF) were found after clinical deterioration post lumbar puncture (LP). This patient highlights the difficulties in the diagnosis and management of SDAVF, and the risks of LP.

Cerebral venous thrombosis: diagnostic accuracy of combined, dynamic and static, contrast-enhanced 4D MR venography.

BACKGROUND AND PURPOSE: MR including MRV is an established method to diagnose CVT. However, it remains unsettled which MR imaging modalities offer the highest diagnostic accuracy. We evaluated the accuracy of a combined, dynamic (1.5 seconds per dataset) and static (voxel size, 1.1 x 0.9 x 1.5 mm), contrast-enhanced MRV method (combo-4D MRV) relative to other established MR/MRV modalities. MATERIALS AND METHODS: A total of 39 patients with CVT (n = 20) and control subjects (n = 19) underwent combo-4D MRV, 2D TOF MRV, GRE imaging, and T2W imaging. For these modalities, diagnostic accuracy (ROCs) for CVT affecting 53 out of 234 predefined venous segments was determined. Sensitivity and specificity were separately calculated for different stages of CVT (acute/subacute/chronic). RESULTS: Combo-4D MRV showed the highest accuracy (AUC, 0.99 [95% CI, 0.97-1.0]; sensitivity, 97% [84%-100%]) for thrombosed dural sinuses. For all thrombosed segments including cortical veins, its sensitivity was best (76% [64%-84%]; AUC, 0.92 [0.88-0.96]), followed by TOF MRV (72% [59%-81%]; AUC, 0.93 [0.88-0.97]). Even for chronic CVT, it showed a relatively high sensitivity of 67% (30%-90%). For thrombosed cortical veins alone, GRE images achieved the highest sensitivity (66% [46%-81%]; AUC, 0.88 [0.78-0.97]). Specificities of all modalities ranged from 96% to 99%. CONCLUSIONS: Combo-4D MRV showed an excellent accuracy for the diagnosis of dural sinus thrombosis. The analysis of dynamic patterns of contrast enhancement in dural sinuses appeared useful to identify chronic thrombosis. To diagnose thrombosed cortical veins, GRE images should primarily be analyzed.

[Pre-test and post-test probabilities. Who cares?]. / Vortest-Wahrscheinlichkeit - Bildgebung - Nachtest-Wahrscheinlichkeit: Wen kümmert das?

The accuracy of a diagnostic test, i.e. abdomen ultrasound in patients with suspected acute appendicitis, is described in the terms of sensitivity and specificity. According to eminent textbooks physicians should use the values of the sensitivity and specificity of a test in their diagnostic reasoning. Physician's estimate, after taking the history, the pretest-probability of the suspected illness, order one or more tests and then calculate the respective posttest-probability. In practice physicians almost never follow this line of thinking. The main reasons are; to estimate concrete illness probabilities is difficult, the values for the sensitivity and specificity of a test are most often not known by physicians and calculations during daily practice are intricate. Helpful for busy physicians are trustworthy expert recommendations which test to apply in which clinical situation.

CT angiography of the superior vena cava: normative values and implications for central venous catheter position.

PURPOSE: To determine normative data for radiographic landmarks of the superior vena cava (SVC) and the location of the junction of the SVC with the right atrium for use in the placement of central venous catheters. MATERIALS AND METHODS: The authors retrospectively reviewed 112 pulmonary computed tomographic (CT) angiograms obtained in seven men and seven women from each decade of life between the ages of 20 and 99 years. For each patient, the length of the SVC was measured from its origin to the cavoatrial junction. The distances from the carina and right tracheobronchial angle to the cavoatrial junction and the origin of the SVC were also measured. Interobserver variation in choosing the location of the carina and tracheobronchial angle was analyzed. RESULTS: The mean length (+/-standard deviation) of the SVC was 70.7 mm +/- 14.1. The mean distance from the superior margin of the SVC to the carina was 30.4 mm +/- 11.2, from the carina to the cavoatrial junction 40.3 mm +/- 13.6, from the superior margin of the SVC to the right tracheobronchial angle 21.7 mm +/- 10.8, and from the right tracheobronchial angle to the cavoatrial junction 49.0 mm +/- 13.6. There was a statistically significant difference in interobserver variation in selecting the location of the right tracheobronchial angle as compared to choosing the carina. CONCLUSION: Placement of the central venous catheter tip at or just below the level of the carina during inspiration ensures placement in the SVC. Placement of the central venous catheter tip approximately 4 cm below the carina will result in placement near the cavoatrial junction.

Comparison of sonography with venography in the diagnosis of deep venous thrombosis.

OBJECTIVE: To compare the findings of venous sonography with contrast venography in the detection of deep venous thrombosis (DVT) of the lower limbs. DESIGN: Prospective study. SETTING: The Kenyatta National Hospital, a teaching and referral hospital in Nairobi. SUBJECTS: Fifty five limbs in 44 patients with clinical suspicion of DVT were evaluated during the seven months study period (October 2002-April 2003). The ethics committee in the institution granted approval for the study and participants gave written informed consent. INTERVENTION: Venous sonography in which a three step protocol involving B-mode gray scale compression sonography, colour and colour Doppler sonography was obtained after contrast venography in patients with clinical suspicion of DVT. The ultrasound examination was done within 24 hours of the contrast venogram. RESULTS: The overall sensitivity of venous sonography was 88.9%, specificity 91.8% and accuracy 90.9%. Considering only DVT above the calf, the sensitivity improved to 100%. An alternative diagnosis was found by ultrasound in 48.6% of the negative for DVT cases. CONCLUSION: The accuracy of venous sonography as done locally is high and comparable to that in developed countries. We recommend that for patients with clinical suspicion of DVT, venous sonography be done as the initial imaging investigation and venography be reserved for those patients with equivocal or inadequate sonography results.

Interobserver agreement for the diagnosis of venous thromboembolism on computed tomography chest angiography and indirect venography of the lower extremities in emergency department patients.

OBJECTIVES: To determine interobserver agreement between radiologists for computed tomography (CT) angiography and venography. CT venography of the lower extremities combined with standard CT angiography of the chest may result in an increased overall diagnosis rate of venous thromboembolism (pulmonary embolism or deep venous thrombosis). METHODS: The study had a retrospective cohort design. The population consisted of emergency department patients who were evaluated for suspected pulmonary embolism. A random sample of 50 patients diagnosed and treated for venous thromboembolism and 50 age- and gender-matched patients whose CT angiograms and venograms were read as negative were enrolled. The original reading (R1) was compared with readings of two study radiologists: R2, a general radiologist, and R3, a radiologist with fellowship training in cross-sectional imaging. All readers were blinded to each other. RESULTS: Both R2 and R3 found both CT angiogram and venogram components technically adequate in 95% (95% CI = 89% to 98%) and 86% (95% CI = 78% to 92%) of studies, respectively. The agreement was very good for CT angiography (lowest agreement = 92%; lowest kappa = 0.83) and was good for CT venography (85%, kappa = 0.65). In nine cases, R1 read the CT angiogram as negative but the venogram as positive for DVT, whereas both R2 and R3 read both components as negative in four of these nine, suggesting a false-positive isolated DVT rate of 44% (95% CI = 19% to 73%). In no case did R1 read both scan components as negative when R2 and R3 agreed on presence of pulmonary embolism or DVT. CONCLUSIONS: Diagnosis of pulmonary embolism on CT angiography is more reliable than diagnosis of isolated DVT on CT venography.