Management of anastomotic biliary stricture through utilizing percutaneous transhepatic cholangioscopy

AIM

Occurrence of anastomotic biliary stricture (AS) remains an essential issue following hepatobiliary surgeries, and percutaneous transhepatic cholangioscopy (PTCS) has great therapeutic significance in handling refractory AS for patients with altered gastrointestinal anatomy after cholangio-jejunostomy. This present study aimed to investigate feasibility of PTCS procedures in AS patients for therapeutic indications.

MATERIALS AND METHODS

This study was a single-center, retrospective cohort study with a total number of 124 consecutive patients who received therapeutic PTCS due to AS. Clinical success rate, required number, and adverse events of therapeutic PTCS procedures as well as patients survival state were reviewed.

RESULTS

These 124 patients previously underwent choledochojejunostomy or hepatico-jejunostomy, and there was post-surgical altered gastrointestinal anatomy. Overall, 366 therapeutic PTCS procedures were performed for these patients through applying rigid choledochoscope, and the median time of PTCS procedures was 3 (1-11). Among these patients, there were 34 cases (27.32%) accompanied by biliary strictures and 100 cases (80.65%) were also combined with biliary calculi. After therapeutic PTCS, most patients presented with relieved clinical manifestations and improved liver functions. The median time of follow-up was 26 months (2-86 months), and AS was successfully managed through PTCS procedures in 104 patients (83.87%). During the follow-up period, adverse events occurred in 81 cases (65.32%), most of which were tackled through supportive treatment.

CONCLUSION

PTCS was a feasible, safe and effective therapeutic modality for refractory AS, which may be a promising alternative approach in clinical cases where the gastrointestinal anatomy was changed after cholangio-jejunostomy.

Differentiation Between the Low and High Trans-Stenotic Pressure Gradient in Patients With Idiopathic Intracranial Hypertension Using 4D Flow MRI-Derived Hemodynamic Parameters

BACKGROUND

Trans-stenotic pressure gradient (TPG) measurement is essential for idiopathic intracranial hypertension (IIH) patients with transverse sinus (TS) stenosis. Four-D flow MRI may provide a noninvasive imaging method for differentiation of IIH patients with different TPG.

PURPOSE

To investigate the associations between 4D flow parameters and TPG, and to evaluate the diagnostic performance of 4D flow parameters in differentiating patients with high TPG (GroupHP) from low TPG (GroupLP).

STUDY TYPE

Prospective.

POPULATION

31 IIH patients with TS stenosis (age, 38 ± 12 years; 23 females) and 5 healthy volunteers (age, 25 ± 1 years; 2 females).

FIELD STRENGTH/SEQUENCE

3T, 3D phase contrast MR venography, and gradient recalled echo 4D flow sequences.

ASSESSMENT

Scan-rescan reproducibility of 4D flow parameters were performed. The correlation between TPG and flow parameters was analyzed. The netflow and velocity difference between inflow plane, outflow plane, and the stenosis plane were calculated and compared between GroupHP and GroupLP.

STATISTICAL TESTS

Pearson's correlation or Spearman's rank correlation coefficient, Independent samples t-test or Wilcoxon rank-sum test, Intra-class correlation coefficient (ICC), Bland-Altman analyses, Receiver operating characteristic curves. A P value <0.05 was considered significant.

RESULTS

Significant correlations were found between TPG and netflow parameters including Favg,out-s, Favg,in-s, Fmax,out-s, and Fmax,in-s (r = 0.525-0.565). Significant differences were found in Favg,out-s, Fmax,out-s, Favg,in-s, and Fmax,in-s between GroupHP and GroupLP. Using the cut-off value of 2.19 mL/sec, the Favg,out-s showed good estimate performance in distinguishing GroupHP from GroupLP (AUC = 0.856). The ICC (ranged 0.905-0.948) and Bland-Altman plots indicated good scan-rescan reproducibility.

DATA CONCLUSIONS

4D flow MRI derived flow parameters showed good correlations with TPG in IIH patients with TS stenosis. Netflow difference between outflow and stenosis location at TS shows the good performance in differentiating GroupHP and GroupLP cases.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 2.

Predictive role of ureteral wall thickness and patient characteristics in endoscopic treatment outcomes for ureteral stricture disease following stone surgery

PURPOSE

To evaluate the role of certain radiological parameters and patient characteristics in predicting the success of endoscopic treatment in ureteral stricture disease.

METHODS

Fifty one adult patients with ureteral stricture disease (< 1 cm) after developing due to upper ureteral stones with ureteroscopic laser disintegration were included and in addition to stone and patient parameters, radiological parameters including ureteral wall thickness (UWT) at the impacted stone site were also measured on computed tomography (CT) images. Patients were divided into two groups: Group 1: Patients with endoscopic treatment success and Group 2: Patients with endoscopic treatment failure. The possible relationship between the UWT values and other radiological parameter was comparatively evaluated.

RESULTS

Mean UWT value assessed at the treated stone site was significantly higher in cases unresponsive to endoscopic treatment with values of 2.77 ± 1.03 mm and 4.25 ± 1.32 mm in Group 1 and 2 respectively. A cut off value 3.55 mm for UWT was found to be highly predictive for endoscopic treatment failure.

CONCLUSIONS

Our current results indicated that assessment of UWT value at the obstructing stone could be helpful enough to predict the likelihood of failure following endoscopic management of strictures with high sensitivity and specificity. Evaluation of this particular parameter could let the endourologists to look for more rational treatment alternatives with necessary measures taken on time.

Intravascular ultrasound characteristics of different types of stenosis in idiopathic intracranial hypertension with venous sinus stenosis

BACKGROUND

In this study, we analyzed the characteristics of different stenosis types in idiopathic intracranial hypertension (IIH) patients with venous sinus stenosis (VSS) using intravascular ultrasound (IVUS).

METHODS

We retrospectively reviewed data from patients who underwent IVUS evaluation during venography or stenting procedures between January 2014 and February 2022.

RESULTS

Among the 80 patients with intrinsic lesions, 47 cases were identified, including 41 single lesions and 6 multiple lesions. Single lesions consisted of 36 cases of AG, 3 cases of brain herniation, and 2 cases of septation. Multiple intrinsic lesions were found in 6 patients, with AG observed in the transverse sinus and sigmoid sinus. IVUS features varied depending on the anatomical variations of intrinsic stenosis. Additionally, among the 33 cases of extrinsic stenosis, two types were observed: unilateral compression (22 cases) and bilateral compression (11 cases), primarily affecting the transverse sinus.

CONCLUSION

IVUS effectively differentiated intrinsic and extrinsic types of stenosis and identified intraluminal and mural components of intrinsic stenosis.

Contributions of endoscopic ultrasonography-guided tissue acquisition (EUS-TA) to the diagnostics of biliary stricture and gallbladder lesions

Endoscopic ultrasonography (EUS) provides high spatial resolution and more detailed images than other diagnostic modalities. Furthermore, EUS-guided tissue acquisition (EUS-TA), such as EUS-guided fine needle aspiration or biopsy (EUS-FNA/FNB), is an indispensable tool in pancreaticobiliary disease diagnostics, supporting a conclusive pathological diagnosis. In this review, we evaluate the current status and the usefulness of EUS-TA for the diagnostics of the following biliary tract diseases: (A) biliary stricture diagnostics, (B) biliary tract cancer (BTC) itself, and (C) staging of advanced BTC. Previous reports have shown that EUS-FNA for biliary lesions is a safe procedure that is useful in differentiating biliary cancer from benign lesions and in the staging of BTC. On the other hand, the diagnostic performance of EUS-TA for bile duct lesions is reported to be similar to that of transpapillary biopsy. Overall, EUS-TA for biliary lesions may be a safe and effective method, but it should be performed with an understanding of the risk of serious adverse events such as bile leakage and peritoneal dissemination of cancer. It is recommended for distal biliary stricture lesions for which endoscopic retrograde cholangiopancreatography cannot confirm the diagnosis or gallbladder lesions if they do not require the needle to pass through the biliary lumen.

Foundations of the Diagnosis and Management of Idiopathic Intracranial Hypertension and Pulsatile Tinnitus

Venous sinus stenosis has garnered increasing academic attention as a potential etiology of idiopathic intracranial hypertension (IIH) and pulsatile tinnitus (PT). The complex anatomy of the cerebral venous sinuses and veins plays a crucial role in the pathophysiology of these conditions. Venous sinus stenosis, often found in the superior sagittal or transverse sinus, can lead to elevated intracranial pressure (ICP) and characteristic IIH symptoms. Stenosis, variations in dural venous anatomy, and flow dominance patterns contribute to aberrant flow and subsequent PT. Accurate imaging plays a vital role in diagnosis, and magnetic resonance (MR) venography is particularly useful for detecting stenosis. Management strategies for IIH and PT focus on treating the underlying disease, weight management, medical interventions, and, in severe cases, surgical or endovascular procedures. Recently, venous sinus stenting has gained interest as a minimally invasive treatment option for IIH and PT. Stenting addresses venous sinus stenosis, breaking the feedback loop between elevated ICP and stenosis, thus reducing ICP and promoting cerebrospinal fluid outflow. The correction and resolution of flow aberrances can also mitigate or resolve PT symptoms. While venous sinus stenting remains an emerging field, initial results are promising. Further research is needed to refine patient selection criteria and evaluate the long-term efficacy of stenting as compared to traditional treatments.

Systematic review: Defining, diagnosing and monitoring small bowel strictures in Crohn's disease on intestinal ultrasound

BACKGROUND

Stricturing Crohn's disease (CD) occurs most commonly in the terminal ileum and poses a clinical problem. Cross-sectional imaging modalities such as intestinal ultrasound (IUS), computed tomography enterography (CTE), and magnetic resonance enterography (MRE) allow for assessment of the entire bowel wall and associated peri-enteric findings. Radiologic definitions of strictures have been developed for CTE and MRE; their reliability and responsiveness are being evaluated in index development programs. A comprehensive assessment strategy for strictures using IUS is needed.

AIMS

To provide a detailed summary of definitions, diagnosis and monitoring of strictures on IUS as well as technical aspects of image acquisition.

METHODS

We searched four databases up to 6 January 2024. Two-stage screening was done in duplicate. We assessed risk of bias using QUADAS-2.

RESULTS

There were 56 studies eligible for inclusion. Definitions for strictures on IUS are heterogeneous, but the overall accuracy for diagnosis of strictures is high. The capability of IUS for characterising inflammation versus fibrosis in strictures is not accurate enough to be used in clinical practice or trials. We summarise definitions for improvement of strictures on IUS, and discuss parameters for image acquisition and standardisation.

CONCLUSIONS

This systematic review is the first step for a structured program to develop a stricture IUS index for CD.

Contemporary Imaging Assessment of Strictures and Fibrosis in Crohn Disease, With Focus on Quantitative Biomarkers: From the AJR Special Series on Imaging of Fibrosis

Patients with Crohn disease commonly have bowel strictures develop, which exhibit varying degrees of inflammation and fibrosis. Differentiation of the distinct inflammatory and fibrotic components of strictures is key for the optimization of therapeutic management and for the development of antifibrotic drugs. Cross-sectional imaging techniques, including ultrasound, CT, and MRI, allow evaluation of the full thickness of the bowel wall as well as extramural complications and associated mesenteric abnormalities. Although promising data have been reported for a range of novel imaging biomarkers for detection of fibrosis and quantification of the degree of fibrosis, these biomarkers lack sufficient validation and standardization for clinical use. Additional methods, including PET with emerging radiotracers, artificial intelligence, and radiomics, are also under investigation for stricture characterization. In this review, we highlight the clinical relevance of identifying fibrosis in Crohn disease, review the histopathologic aspects of strictures in Crohn disease, summarize the morphologic imaging findings of strictures, and explore contemporary developments in the use of cross-sectional imaging techniques for detecting and characterizing intestinal strictures, with attention given to emerging quantitative biomarkers.

Challenges in the use of Venous Sinus Stenting in the Treatment of Idiopathic Intracranial Hypertension and Pulsatile Tinnitus

Although numerous case series and meta-analyses have shown the efficacy of venous sinus stenting (VSS) in the treatment of idiopathic intracranial hypertension and idiopathic intracranial hypertension-associated pulsatile tinnitus, there remain numerous challenges to be resolved. There is no widespread agreement on candidacy; pressure gradient and failed medical treatment are common indications, but not all clinicians require medical refractoriness as a criterion. Venous manometry, venography, and cerebral angiography are essential tools for patient assessment, but again disagreements exist regarding the best, or most appropriate, diagnostic imaging choice. Challenges with the VSS technique also exist, such as stent choice and deployment. There are considerations regarding postprocedural balloon angioplasty and pharmacologic treatment, but there is insufficient evidence to formalize postoperative decision making. Although complications of VSS are relatively rare, they include in-stent stenosis, hemorrhage, and subdural hematoma, and the learning curve for VSS presents specific challenges in navigating venous anatomy, emphasizing the need for wider availability of high-quality training. Recurrence of symptoms, particularly stent-adjacent stenosis, poses challenges, and although restenting and cerebrospinal fluid-diverting procedures are options, there is a need for clearer criteria for retreatment strategies. Despite these challenges, when comparing VSS with traditional cerebrospinal fluid-diverting procedures, VSS emerges as a favorable option, with strong clinical outcomes, lower complication rates, and cost-effectiveness. Further research is necessary to refine techniques and indications and address specific aspects of VSS to overcome these challenges.

Endoscopic Ultrasound Can Differentiate High-Grade Pancreatic Intraepithelial Neoplasia, Small Pancreatic Ductal Adenocarcinoma, and Benign Stenosis

Background/Aims

High-grade pancreatic intraepithelial neoplasia and invasive pancreatic ductal adenocarcinoma ≤10 mm are targets for early detection of pancreatic cancer. However, their imaging characteristics are unknown. We aimed to identify endoscopic ultrasound findings for the detection of these lesions.

Methods

Patients diagnosed with high-grade pancreatic intraepithelial neoplasia (n=29), pancreatic ductal adenocarcinoma ≤10 mm (n=11) (who underwent surgical resection), or benign main pancreatic duct stenosis (n=20) between January 2014 and January 2021 were retrospectively included. Six features differentiating these lesions were examined by endoscopic ultrasonography: main pancreatic duct stenosis, upstream main pancreatic duct dilation, hypoechoic areas surrounding the main pancreatic duct irregularities (mottled areas without demarcation or round areas with demarcation), branch duct dilation, prominent lobular segmentation, and atrophy. Interobserver agreement was assessed by two independent observers.

Results

Hypoechoic areas surrounding the main pancreatic duct irregularities were observed more frequently in high-grade pancreatic intraepithelial neoplasia (82.8%) and pancreatic ductal adenocarcinoma ≤10 mm (90.9%) than in benign stenosis (15.0%) (p<0.001). High-grade pancreatic intraepithelial neoplasia exhibited mottled hypoechoic areas more frequently (79.3% vs 18.9%, p<0.001), and round hypoechoic areas less frequently (3.4% vs 72.7%, p<0.001), than pancreatic ductal adenocarcinoma ≤10 mm. The sensitivity and specificity of hypoechoic areas for differentiating high-grade pancreatic intraepithelial neoplasia, pancreatic ductal adenocarcinoma ≤10 mm, and benign stenosis were both 85.0%, with moderate interobserver agreement.

Conclusions

The hypoechoic areas surrounding main pancreatic duct irregularities on endoscopic ultrasound may differentiate between high-grade pancreatic intraepithelial neoplasia, pancreatic ductal adenocarcinoma ≤10 mm, and benign stenosis (Trial Registration: UMIN Clinical Trials Registry (UMIN000044789).

High jugular bulb in patients with non-thrombotic internal jugular venous and transverse sinus stenosis: Clues to pathogenesis

AIMS

Conventional theories for jugular bulb (JB) formation are insufficient to explain the high proportion of high JB in adult patients. We aimed to study features of high JB in patients with non-thrombotic internal jugular venous stenosis (IJVS) and/or transverse sinus stenosis (TSS) to explore the pathogenesis of high JB formation.

METHODS

We retrospectively enrolled consecutive patients with the diagnosis of non-thrombotic IJVS and/or TSS. The relationship between IJVS and/or TSS and high JB was explored. Logistic regression analysis was performed to identify potential independent risk factors for high JB.

RESULTS

A total of 228 patients were included in the final analyses. The proportions of IJVS, dominant-side IJVS, and non-TSS in dominant-side high JB subgroup were higher than those in nondominant-side high JB subgroup (83.3% vs. 62.5%, p < 0.001; 72.2% vs. 18.3%, p < 0.001; 43.5% vs. 29.2%, p = 0.02). Heights of JBs on dominant sides in IJVS subgroup and non-TSS subgroup were higher than those in non-IJVS subgroup and TSS subgroup (12.93 ± 2.57 mm vs. 11.21 ± 2.76 mm, p < 0.001; 12.66 ± 2.71 mm vs. 11.34 ± 2.73 mm, p = 0.003). Multivariate logistic regression indicated an independent association between dominant-side IJVS and dominant-side high JB (odds ratio, 29.40; 95% confidence interval, 11.04-78.30; p < 0.001).

CONCLUSION

IJVS and asymmetric transverse sinus were independently and positively associated with high JB, especially dominant-side IJVS with dominant-side high JB, indicating a potential hemodynamic relationship between IJVS and high JB formation. Conversely, TTS might impede high JB formation.

Flow-induced high frequency vascular wall vibrations in an arteriovenous fistula: a specific stimulus for stenosis development?

Hemodialysis is the lifeline for nearly three million end stage renal disease patients worldwide. Native arteriovenous fistula (AVF) is the preferred vascular access, but 40% fail within 1 year. We recently demonstrated that AVFs harbour transitional flows and the goal of the present study was to investigate whether the associated high-frequency pressure fluctuations could promote vibrations within the vascular wall. We acquired MRI images and flow rates immediately after surgery in one patient and generated a 3D patient-specific model. High-fidelity fluid structure interaction simulations revealed the presence of wall vibrations in distinct frequency bands up to 200 Hz and amplitude of 200 μm. A sensitivity analysis to assess the impact of flow rates, and vascular wall stiffness and thickness, changes that typically occur during AVF maturation, confirmed the robustness of the results. Interestingly, the vibrations were always predominant at the anastomosis floor and on the inner venous side, which correlates with typical stenotic regions. As studies seeking to correlate aberrant stresses and vascular remodelling have been largely inconclusive, the focal colocalization between vibrations and stenosis may suggest an unknown mechanobiological process between high-frequency mechanical stresses within the vascular wall and adverse vascular remodelling.

Ureteral stricture formation after endoscopic removal of obstructing stones: could it be predicted with well-assessed radiological parameters?

The possible role of well-assessed radiological parameters in the prediction of ureteral stricture formation in cases with impacted obstructive ureteral calculi has been evaluated. 46 adult patients with or without ureteral stricture formation after ureteroscopic stone management were included. In addition to stone size and some certain radiological parameters including ureteral wall thickness (UWT) of the involved ureter at the impacted stone site was also measured and noted on computed tomography (CT) images. Parameters were evaluated in two subgroups of cases, namely: Group 1: patients in whom a ureteral stricture formed after endoscopic stone removal and Group 2: patients normal ureteral anatomy without any stricture formation. The possible relationship between the UWT values and degree of hydronephrosis (HN) with subsequent stricture formation was comparatively evaluated. All of the stones were proximal ureteral calculi in both groups. Both the degree of HN and proximal ureteral diameter (PUD) parenchymal was higher in cases with stricture formation. In addition, mean parenchymal thickness was lower and mean values of UWT measurements at the stone site were 3.70 ± 0.97 mm and 2.17 ± 0.26 mm in Groups 1 and 2, respectively. A cutoff value 2.49 mm for UWT was found to be highly predictive for stricture formation. UWT value calculated at the obstructing stone site was found to be predictive enough for the likelihood of ureteral stricture formation with high sensitivity and specificity . This evaluation along with some other radiological parameters may enable the urologists to follow such cases on this aspect with necessary measures taken.

Differential Assessment of Internal Jugular Vein Stenosis in Patients Undergoing CT and MRI with Contrast

OBJECTIVE

Internal Jugular Vein Stenosis (IJVS) is hypothesized to play a role in the pathogenesis of diverse neurological diseases. We sought to evaluate differences in IJVS assessment between CT and MRI in a retrospective patient cohort.

METHODS

We included consecutive patients who had both MRI of the brain and CT of the head and neck with contrast from 1 June 2021 to 30 June 2022 within the same admission. The degree of IJVS was categorized into five grades (0-IV).

RESULTS

A total of 35 patients with a total of 70 internal jugular (IJ) veins were included in our analysis. There was fair intermodality agreement in stenosis grades (κ = 0.220, 95% C.I. = [0.029, 0.410]), though categorical stenosis grades were significantly discordant between imaging modalities, with higher grades more frequent in MRI (χ2 = 27.378, p = 0.002). On CT-based imaging, Grade III or IV stenoses were noted in 17/70 (24.2%) IJs, whereas on MRI-based imaging, Grade III or IV stenoses were found in 40/70 (57.1%) IJs. Among veins with Grade I-IV IJVS, MRI stenosis estimates were significantly higher than CT stenosis estimates (77.0%, 95% C.I. [35.9-55.2%] vs. 45.6%, 95% C.I. [35.9-55.2%], p < 0.001).

CONCLUSION

MRI with contrast overestimates the degree of IJVS compared to CT with contrast. Consideration of this discrepancy should be considered in diagnosis and treatment planning in patients with potential IJVS-related symptoms.

Preliminary findings on diagnostic performance of computed tomography perfusion images for intracranial arterial stenosis: a retrospective study

OBJECTIVES

Computed tomographic perfusion (CTP) can play an auxiliary role in the selection of patients with acute ischemic stroke for endovascular treatment. However, data on CTP in non-stroke patients with intracranial arterial stenosis are scarce. We aimed to investigate images in patients with asymptomatic intracranial arterial stenosis to determine the detection accuracy and interpretation time of large/medium-artery stenosis or occlusion when combining computed tomographic angiography (CTA) and CTP images.

METHODS

We retrospectively reviewed 39 patients with asymptomatic intracranial arterial stenosis from our hospital database from January 2021 to August 2023 who underwent head CTP, head CTA, and digital subtraction angiography (DSA). Head CTA images were generated from the CTP data, and the diagnostic performance for each artery was assessed. Two readers independently interpreted the CTA images before and after CTP, and the results were analyzed.

RESULTS

After adding CTP maps, the accuracy (area under the curve) of diagnosing internal carotid artery (R1: 0.847 vs. 0.907, R2: 0.776 vs. 0.887), middle cerebral artery (R1: 0.934 vs. 0.933, R2: 0.927 vs. 0.981), anterior cerebral artery (R1: 0.625 vs. 0.750, R2: 0.609 vs. 0.750), vertebral artery (R1: 0.743 vs. 0.764, R2: 0.748 vs. 0.846), and posterior cerebral artery (R1: 0.390 vs. 0.575, R2: 0.390 vs. 0.585) occlusions increased for both readers (p < 0.05). Mean interpretation time (R1: 72.4 ± 6.1 s vs. 67.7 ± 6.4 s, R2: 77.7 ± 3.8 s vs. 72.6 ± 4.7 s) decreased when using a combination of both images both readers (p < 0.001).

CONCLUSIONS

The addition of CTP images improved the accuracy of interpreting CTA images and reduced the interpretation time in asymptomatic intracranial arterial stenosis. These findings support the use of CTP imaging in patients with asymptomatic intracranial arterial stenosis.

Emergent Large Vessel Occlusion due to Intracranial Stenosis: Identification, Management, Challenges, and Future Directions

This comprehensive literature review focuses on acute stroke related to intracranial atherosclerotic stenosis (ICAS), with an emphasis on ICAS-large vessel occlusion. ICAS is the leading cause of stroke globally, with high recurrence risk, especially in Asian, Black, and Hispanic populations. Various risk factors, including hypertension, diabetes, hyperlipidemia, smoking, and advanced age lead to ICAS, which in turn results in stroke through different mechanisms. Recurrent stroke risk in patients with ICAS with hemodynamic failure is particularly high, even with aggressive medical management. Developments in advanced imaging have improved our understanding of ICAS and ability to identify high-risk patients who could benefit from intervention. Herein, we focus on current management strategies for ICAS-large vessel occlusion discussed, including the use of perfusion imaging, endovascular therapy, and stenting. In addition, we focus on strategies that aim at identifying subjects at higher risk for early recurrent risk who could benefit from early endovascular intervention The review underscores the need for further research to optimize ICAS-large vessel occlusion treatment strategies, a traditionally understudied topic.

Bow Hunter Syndrome: An Illustrative Case and Operative Management

The differential for vertebrobasilar insufficiency is wide and can be caused by posterior circulation infarcts, steal-type phenomena, or other systemic causes. In the absence of imaging findings explaining symptomology, the utility of appropriate history gathering and dynamic angiography cannot be understated in identifying Bow Hunter's syndrome, a rare cause of dynamic vertebrobasilar insufficiency. We present a case of a 69-year-old man who complained of presyncope and severe dizziness when turning his head towards the right. On examination he had no radiculopathy but did have objective evidence of myelopathy. Computed tomography imaging and dynamic angiography demonstrated C3-C4 right uncovertebral joint hypertrophy and near complete stenosis of the right vertebral artery with dynamic head position towards the right. Given vertebrobasilar insufficiency and myelopathy, he was taken to the operating room for C3-C4 anterior cervical discectomy and fusion with vertebral artery decompression (Video 1). The patient provided consent for the procedure. Standard anterior cervical neck dissection was undertaken with additional platysmal undermining to facilitate exposure of the right uncovertebral joint and transverse processes. The vertebral artery was first decompressed above and below the area of most significant stenosis at the respective transverse foramina before the hypertrophied uncovertebral joint was removed. Next, discectomy and posterior osteophyte removal were completed in typical fashion followed by graft, plate, and screw placement. Postoperatively the patient had immediate resolution of symptoms and continued so at eight month follow-up. Imaging demonstrated return to normal caliber of the right vertebral artery and successful decompression.

Long-term recurrence of ischemic events in patients with intracranial atherosclerotic stenosis stratified by symptoms and pathogenesis

BACKGROUND

Intracranial atherosclerotic stenosis (ICAS) can cause either transient ischemic attack (TIA) or acute ischemic stroke (AIS). Pathogenesis of ICAS-AIS can be divided into artery-to-artery embolism(A-A), hypoperfusion(HP), and parent-artery atherosclerosis occluding penetrating artery(POPA). However, the prognosis of each type remains uncertain. Our study aimed to investigate potential disparities in the recurrent risk among these four subtypes of symptomatic ICAS.

METHODS

From a prospective, single-center cohort study of acute cerebrovascular diseases from January 2017 to November 2021, we recruited 120 ICAS patients and classified them into four groups based on diffusion weighted imaging. Patients were retrospectively followed up for recurrence in December 2022. The primary outcome was recurrent cerebral vascular events (RCVE) in the same territory.

RESULTS

Among 120 recruited patients, POPA(33%) was the most common subtype, followed by A-A(32%), HP(29%), and TIA(6%). Cumulative recurrent rate was 31.2% with median months of follow-up as 27(20-45.5). There was no significant difference in the risk of RCVE in the same territory among four subgroups within three months. However, when considering the risk after three months, TIA(57%) had the highest risk of RCVE, followed by A-A(26%), while HP(4%) and POPA(8%) had lower risks (P = 0.001). Cox regression model indicated that symptom and pathogenesis was an independent risk factor for RCVE in long-term prognosis (P = 0.022), after adjusting for a history of hypertension and cerebral infarction.

CONCLUSIONS

Distinctive symptoms and pathogenesis of ICAS exhibit varying risks of RCVE in long-term prognosis. The differentiation in recurrent risk may provide valuable insights for guiding secondary prevention strategies.

CASMatching strategy for automated detection and quantification of carotid artery stenosis based on digital subtraction angiography

BACKGROUND AND OBJECTIVE

Automated detection and quantification of carotid artery stenosis is a crucial task in establishing a computer-aided diagnostic system for brain diseases. Digital subtraction angiography (DSA) is known as the "gold standard" for carotid stenosis diagnosis. It is commonly used to identify carotid artery stenosis and measure morphological indices of the stenosis. However, using deep learning to detect stenosis based on DSA images and further quantitatively predicting the morphological indices remain a challenge due the absence of prior work. In this paper, we propose a quantitative method for predicting morphological indices of carotid stenosis.

METHODS

Our method adopts a two-stage pipeline, first locating regions suitable for predicting morphological indices by object detection model, and then using a regression model to predict indices. A novel Carotid Artery Stenosis Matching (CASMatching) strategy is introduced into the object detection to model the matching relationship between a stenosis and multiple normal vessel segments. The proposed Match-ness branch predicts a Match-ness score for each normal vessel segment to indicate the degree of matching to the stenosis. A novel Direction Distance-IoU (2DIoU) loss based on the Distance-IoU loss is proposed to make the model focused more on the bounding box regression in the direction of vessel extension. After detection, the normal vessel segment with the highest Match-ness score and the stenosis are intercepted from the original image, then fed into a regression model to predict morphological indices and calculate the degree of stenosis.

RESULTS

Our method is trained and evaluated on a dataset collected from three different manufacturers' monoplane X-ray systems. The results show that the proposed components in the object detector substantially improve the detection performance of normal vascular segments. For the prediction of morphological indices, our model achieves Mean Absolute Error of 0.378, 0.221, 4.9 on reference vessel diameter (RVD), minimum lumen diameter (MLD) and stenosis degree.

CONCLUSIONS

Our method can precisely localize the carotid stenosis and the normal vessel segment suitable for predicting RVD of the stenosis, and further achieve accurate quantification, providing a novel solution for the quantification of carotid artery stenosis.

Long-term efficacy of venous sinus stenting in the treatment of idiopathic intracranial hypertension

BACKGROUNDS

Previous studies have suggested that cerebral dural sinus stenosis could be a possible underlying cause of idiopathic intracranial hypertension (IIH). Venous sinus stenting (VSS) has emerged as a potential alternative for treating IIH related to dural sinus stenosis. However, most of the documented studies have been conducted in Western countries. In this study, we present the results of 16 Chinese IIH patients who underwent VSS treatment in our single center.

METHODS

We prospectively collected angiographic and manometric data from IIH patients who underwent angioplasty/stenting. All patients had confirmed dural sinus stenosis and had failed maximal medical therapy (MMT). Demographic, clinical, and radiological presentation, as well as long-term follow-up outcomes were collected retrospectively.

RESULTS

A total of 16 patients who underwent VSS were enrolled in the present study. Demographic data revealed a mean age of 40 (range 20-55), with 69% (11/16) being female, and a mean body mass index (BMI) of 27.05 (range 19.18-38.04) kg/m2 . All patients presented with papilledema and visual disturbances. During a median follow-up period of 47.5 months, 93.75% (15/16) of patients reported improvement in symptoms, although only 37.5% (6/16) experienced complete resolution. Headaches, blurred vision, and amaurosis related to increased pressure improved in 100% (8/8), 81.25% (13/16), and 75% (3/4) of patients, respectively. However, one patient suffered cerebral infarction and secondary epilepsy soon after VSS, and another patient had recurrence of symptoms due to stent wall thrombosis 2 years later.

CONCLUSIONS

The significance of venous sinus stenosis in the development of IIH may be undervalued. Our study, based on a Chinese case series, affirms the long-term safety and effectiveness of VSS in treating IIH patients with relatively lower BMI than those from Western countries.

Differentiation of malignant from benign ampullary strictures: A prediction nomogram based on MR imaging and clinical findings

PURPOSE

To construct a predictive nomogram based on contrast-enhanced magnetic resonance imaging (MRI) and clinical findings for differentiating malignant from benign ampullary strictures.

METHOD

In this retrospective study, 76 patients with ampullary strictures (51 benign and 25 malignant) who underwent contrast-enhanced MRI were enrolled. Imaging findings were evaluated independently by two abdominal radiologists who reached consensus. Clinical findings were also collected. Significant findings for malignant ampullary strictures were assessed by univariable and multivariable logistic regression analyses. Based on the results of multivariable analysis, a nomogram to differentiate malignant from benign ampullary strictures was developed and internally validated.

RESULTS

In multivariable analysis, presence of an ampullary mass (odds ratio [OR]: 8.42, p = 0.047), bulging ampulla (OR: 8.32, p = 0.033), diffusion restriction of the ampulla (OR: 42.76, p = 0.004) on MRI, and jaundice (OR: 12.41, p = 0.019) were significant predictors of malignant ampullary strictures. A predictive nomogram was constructed using these findings. Among them, diffusion restriction of the ampulla showed the highest OR and predictor score on the nomogram. The calibration plots for internal validation achieved strong agreement between the predicted probabilities and the actual rates of malignant ampullary strictures.

CONCLUSION

A combination of significant contrast-enhanced MRI and clinical findings of ampullary mass, bulging ampulla, diffusion restriction of the ampulla, and jaundice may be useful in the prediction of malignant ampullary stricture.

Celiac trunk thrombosis in a patient with antiphospholipid syndrome induced by median arcuate ligament compression: a case presentation and literature review

Median arcuate ligament syndrome (MALS) is a rare disorder caused by the compression of the celiac axis by the fibrous structure of the diaphragm called the median arcuate ligament. Patients with MALS are usually undiagnosed unless characteristic symptoms such as nausea and vomiting, postprandial pain, and weight loss are presented. We report a case of a 29-year-old patient diagnosed with MALS and secondary antiphospholipid syndrome (APS) that developed celiac trunk, common hepatic artery and splenic artery thrombosis. There is not enough information on MALS as a trigger of thrombosis in predisposed patients such as those with APS. However, the case gives rise to suspicion and highlights the diagnostic processes, especially for patients with APS presenting postprandial abdominal pain and weight loss. This review likewise aims at the importance of Doppler ultrasonography as a screening tool and computer tomography (CT) or magnetic resonance (MR) both in the angiography variant, especially to diagnose confirmation and underlying treatment options.

The diagnosis of intracranial artery stenosis in patients with stroke by transcranial Doppler ultrasound: A meta-analysis

BACKGROUND

Strokes are the most common cause of death and the leading cause of acquired disability in adults worldwide.

OBJECTIVE

The present study aimed to investigate the value of transcranial Doppler ultrasound (TCD) in the diagnosis of intracranial vascular stenosis in patients with a history of stroke.

METHODS

This is a meta-analysis study of diagnostic tests. PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Wanfang, and VIP databases were systematically searched. Diagnostic tests using TCD or transcranial colour Doppler ultrasound (TCCD) for detecting intracranial arterial stenosis in patients with a history of stroke were included, with reference standards of intracranial angiography, computed tomography angiography (CTA), or magnetic resonance angiography. The risk bias map was drawn by Revman v5.3, the sensitivity and specificity forest plot was drawn by Stata v16.0, the receiver operating characteristic curve was drawn, and the area under the curve (AUC) was calculated.

RESULTS

A total of 812 patients with stroke in 12 studies were included in the meta-analysis. The estimated sensitivity of TCD or TCCD for the detection of intracranial vascular stenosis was 0.77-1.00, and the combined sensitivity was 0.96 (95% confidence interval [CI]: 0.88-0.99); the estimated specificity was 0.32-1.00, and the combined specificity was 0.94 (95% CI: 0.82-0.98); the positive likelihood ratio was 15.8 (95% CI: 5.1-48.6); and the negative likelihood ratio was 0.04 (95% CI: 0.01-0.14). The AUC was 0.99 (95% CI: 0.97-0.99).

CONCLUSION

Doppler ultrasound has good consistency with conventional methods for the diagnosis of intracranial artery stenosis in patients with a history of stroke. Different reference standards may affect sensitivity and specificity; when CTA was used as the reference standard, the consistency of the TCD in the diagnosis of intracranial artery stenosis in stroke patients was relatively good.

Prediction of Venous Trans-Stenotic Pressure Gradient Using Shape Features Derived From Magnetic Resonance Venography in Idiopathic Intracranial Hypertension Patients

OBJECTIVE

Idiopathic intracranial hypertension (IIH) is a condition of unknown etiology associated with venous sinus stenosis. This study aimed to develop a magnetic resonance venography (MRV)-based radiomics model for predicting a high trans-stenotic pressure gradient (TPG) in IIH patients diagnosed with venous sinus stenosis.

MATERIALS AND METHODS

This retrospective study included 105 IIH patients (median age [interquartile range], 35 years [27-42 years]; female:male, 82:23) who underwent MRV and catheter venography complemented by venous manometry. Contrast enhanced-MRV was conducted under 1.5 Tesla system, and the images were reconstructed using a standard algorithm. Shape features were derived from MRV images via the PyRadiomics package and selected by utilizing the least absolute shrinkage and selection operator (LASSO) method. A radiomics score for predicting high TPG (≥ 8 mmHg) in IIH patients was formulated using multivariable logistic regression; its discrimination performance was assessed using the area under the receiver operating characteristic curve (AUROC). A nomogram was constructed by incorporating the radiomics scores and clinical features.

RESULTS

Data from 105 patients were randomly divided into two distinct datasets for model training (n = 73; 50 and 23 with and without high TPG, respectively) and testing (n = 32; 22 and 10 with and without high TPG, respectively). Three informative shape features were identified in the training datasets: least axis length, sphericity, and maximum three-dimensional diameter. The radiomics score for predicting high TPG in IIH patients demonstrated an AUROC of 0.906 (95% confidence interval, 0.836-0.976) in the training dataset and 0.877 (95% confidence interval, 0.755-0.999) in the test dataset. The nomogram showed good calibration.

CONCLUSION

Our study presents the feasibility of a novel model for predicting high TPG in IIH patients using radiomics analysis of noninvasive MRV-based shape features. This information may aid clinicians in identifying patients who may benefit from stenting.

Angioarchitecture of the hemorrhagic developmental venous anomaly with stenosis of the collecting vein and cavernous malformation: a case report

We herein report a case of developmental venous anomaly (DVA) with venous congestion caused by stenosis of the collecting vein that presented with intracerebral hemorrhage (ICH). A 74-year-old woman was referred to our hospital a few days after the onset of motor aphasia. Computed tomography (CT) and magnetic resonance imaging (MRI) showed ICH in the left frontal lobe. Angiography revealed DVA in the left frontal lobe in the late venous phase. Stenosis of the collecting vein of DVA at the entrance to the superior sagittal sinus was detected and accompanied by cavernous malformation (CM) beside DVA. Cone-beam CT revealed the absence of the left septal vein and hypoplastic transverse caudate veins. The patient was treated by blood pressure management and no additional neurological symptoms were detected. DVA develops to compensate for the absence of pial or deep venous systems, and generally benign and clinically asymptomatic. However, the outflow restriction of DVA causes chronic venous hypertension and the formation of CM. These abnormalities are considered to occur during post-natal life and may result in ICH. The risk of hemorrhage needs to be considered in cases of DVA with restricted venous outflow or CM.

Intracranial arterial stenosis and recurrence in stroke patients with different risk stratifications by Essen stroke risk score

OBJECTIVES

We sought to investigate whether the prognostic value of intracranial arterial stenosis (ICAS) is consistent across different risk stratifications using the Essen Stroke Risk score (ESRS).

METHODS

We derived data from the Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events trial. Patients without complete baseline brain imaging data were excluded. Participants were categorized into different risk groups based on ESRS (low risk, 0-2, and high risk ≥ 3). The main outcome was stroke recurrence within 3 and 12 months. Hazard ratios (HRs) and 95% confidence intervals (95%CIs) of ICAS, and other factors associated with stroke recurrence within 3 and 12 months were estimated using the Cox regression method.

RESULTS

During the 3-month follow-up, 54 patients (7.9%) had recurrent stroke in the low-risk group, and 39 patients (9.6%) had recurrent stroke in the high-risk group. ICAS was associated with a higher risk of stroke within 3 months (HR = 2.761; 95%CI = 1.538-4.957; P < 0.001) in the low-risk group, but not in the high-risk group (HR = 1.501; 95%CI = 0.701-3.213; P = 0.296). ICAS was independently associated with higher recurrent risk in the low-risk group (HR = 2.540; 95%CI = 1.472-4.381; P < 0.001), but not in the high-risk group (HR = 1.951; 95%CI = 0.977-3.893; P = 0.058) within 12 months.

CONCLUSION

ICAS was an independent predictor of both 3- and 12-month stroke recurrence in low-risk but not high-risk patients with minor ischemic stroke or transient ischemic attack according to ESRS stratification.

Does tumoral cavernous carotid stenosis predict an increased risk of future stroke in skull base meningiomas?

OBJECTIVE

Skull base meningiomas (SBMs) involving the cavernous sinus encase the internal carotid artery (ICA) and may lead to stenosis of the vessel. Although ischemic stroke has been reported in the literature, there are to the authors' knowledge no reported studies quantifying the risk of stroke in these patients. The authors aimed to determine the frequency of arterial stenosis in patients with SBMs that encase the cavernous ICA and to estimate the risk of ischemic stroke in these patients.

METHODS

Records of all patients with SBM encasing the ICA whose cases were managed by the skull base multidisciplinary team at Salford Royal Hospital between 2011 and 2017 were reviewed using a two-stage approach: 1) clinical and radiological strokes were identified from electronic patient records, and 2) cases were reviewed to examine the correlation between ICA stenosis associated with SBM encasement and anatomically related stroke. Strokes that were caused by another pathology or did not occur in the perfusion territory were excluded.

RESULTS

In the review of patient records the authors identified 118 patients with SBMs encasing the ICA. Of these, 62 SBMs caused stenosis. The median age at diagnosis was 70 (IQR 24) years, and 70% of the patients were female. The median follow-up was 97 (IQR 101) months. A total of 13 strokes were identified in these patients; however, only 1 case of stroke was associated with SBM encasement, which occurred in the perfusion territory of a patient without stenosis. Risk of acute stroke during the follow-up period for the entire cohort was 0.85%.

CONCLUSIONS

Acute stroke in patients with ICA encasement by SBMs is rare despite the propensity of these tumors to stenose the ICA. Patients with ICA stenosis secondary to their SBM did not have a higher incidence of stroke than those with ICA encasement without stenosis. The results of this study demonstrate that prophylactic intervention to prevent stroke is not necessary in ICA stenosis secondary to SBM.

Duodenal stenosis surgical treatment in Crohn's disease

We present the case of a 34-year-old man with daily vomiting and 20% weight loss in a year. A gastroduodenoscopy was performed, noticing 2nd and 3rd duodenal portion dilatation and inflammatory involvement of the 3rd and 4th portion, causing luminal stenosis. These findings are the same than in the magnetic resonance . The biopsy proves the histological diagnosis of Crohn's disease. At the beginning the patient was treated with Prednisone, Adalimumab and Ustekinumab. After 9 months, surgery was decided because the disease was refractory to treatment and there was corticosteroid dependence. A partial resection of 3rd and 4th portion of the duodenum and the first loop of jejunum was performed, with duodenojejunal anastomosis. The patient presents good postoperative evolution and after 1 year he remained asymptomatic under treatment with Ustekinumab.

Unravelling the pathogenesis of foramen magnum stenosis in patients with severe achondroplasia: a CT-based comparison with age-matched controls and FGFR3 craniosynostosis syndromes

OBJECTIVE

Foramen magnum(FM) stenosis can be responsible for acute and chronic damage to the cervicomedullary junction in children with achondroplasia. The bony anatomy and patterns of suture fusion of the FM in this context are incompletely understood, yet becoming increasingly important in the light of novel medical therapies for achondroplasia. The objective of this study was to describe and quantify bony anatomy and fusion patterns of FM stenosis in patients with achondroplasia using CT scans, comparing them to age-matched controls and other FGFR3 craniosynostosis patients.

METHODS

Patients with achondroplasia and severe FM stenosis, classified as achondroplasia foramen magnum score(AFMS) grades 3 and 4, were identified from a departmental operative database. All had pre-operative CT scans of the craniocervical junction. Measurements obtained comprised sagittal diameter (SD), transverse diameter (TD), foramen magnum area, and opisthion thickness. Anterior and posterior interoccipital synchondroses (AIOS and PIOS) were graded by the extent of fusion. These measurements were then compared with CT scans from 3 age-matched groups: the normal control group, children with Muenke syndrome, and children with Crouzon syndrome with acanthosis nigricans (CSAN).

RESULTS

CT scans were reviewed in 23 cases of patients with achondroplasia, 23 normal controls, 20 Muenke, and 15 CSAN. Children with achondroplasia had significantly smaller sagittal diameter (mean 16.2 ± 2.4 mm) compared to other groups (control 31.7 ± 2.4 mm, p < 0.0001; Muenke 31.7 ± 3.5 mm, p < 0.0001; and CSAN 23.1 ± 3.4 mm, p < 0.0001) and transverse diameters (mean 14.3 ± 1.8 mm) compared with other groups (control 26.5 ± 3.2 mm, p < 0.0001; Muenke 24.1 ± 2.6 mm, p < 0.0001; CSAN 19.1 ± 2.6 mm, p < 0.0001). This translated into a surface area which was 3.4 times smaller in the achondroplasia group compared with the control group. The median grade of the AIOS fusion achondroplasia group was 3.0 (IQR 3.0-5.0), which was significantly higher compared with the control group (1.0, IQR 1.0-1.0, p < 0.0001), Muenke group (1.0, IQR 1.0-1.0, p < 0.0001), and CSAN (2.0, IQR 1.0-2.0, p < 0.0002). Median PIOS fusion grade was also highest in the achondroplasia group (5.0, IQR 4.0-5.0) compared with control (1.0, IQR 1.0-1.0, p < 0.0001), Muenke (2.5, IQR 1.3-3.0, p < 0.0001), and CSAN (4.0, IQR 4.0-4.0, p = 0.2). Distinct bony opisthion spurs projecting into the foramen magnum were seen in achondroplasia patients but not others, resulting in characteristic crescent and cloverleaf shapes.

CONCLUSION

Patients with AFMS stages 3 and 4 have significantly reduced FM diameters, with surface area 3.4 times smaller than age-matched controls. This is associated with premature fusion of the AIOS and PIOS in comparison with controls and other FGFR3-related conditions. The presence of thickened opisthion bony spurs contributes to stenosis in achondroplasia. Understanding and quantifying bony changes at the FM of patients with achondroplasia will be important in the future quantitative evaluation of emerging medical therapies.

Endovascular stenting to treat an acute stroke caused by severe stenosis of the duplicated middle cerebral artery

BACKGROUND

The duplicated middle cerebral artery (DMCA), a rare anatomical variant of the middle cerebral artery, arises between the anterior choroidal artery and the distal end of the internal carotid artery. We present the case of a patient who had an acute progressive stroke caused by severe stenosis in the initial segment of the DMCA and was successfully treated with endovascular stenting.

CASE PRESENTATION

A 57-year-old man was admitted to our hospital with sudden left extremity weakness for three days. Cranial magnetic resonance imaging revealed multiple fresh infarcts in the right basal ganglia and temporal lobe. Cerebrovascular imaging revealed severe stenosis of the right DMCA's initial segment. However, despite standard medical therapy, the patient's limb weakness worsened. Based on the clinical and imaging findings, we speculated that severely stenotic DMCA is responsible for the acute progressive stroke. On the basis of the best medical treatment, the patient successfully underwent endovascular stent implantation under general anesthesia two weeks after the onset. The patient's condition was stable after interventional therapy, and his postoperative follow-up prognosis was favorable.

CONCLUSIONS

Endovascular stenting may be a feasible treatment for symptomatic severe stenosis of the DMCA in cases of poor control with standard medications.

Extreme lateral infracondylar approach for internal jugular vein compression syndrome: A case series with preliminary clinical outcomes

BACKGROUND AND OBJECTIVES

Internal jugular vein (IJV) stenosis is associated with several neurological disorders including idiopathic intracranial hypertension (IIH) and pulsatile tinnitus. In cases of extreme bony compression causing stenosis in the infracondylar region, surgical decompression might be necessary. We aim to examine the safety and efficacy of surgical IJV decompression.

METHODS

We retrospectively reviewed patients who received surgical IJV decompression via the extreme lateral infracondylar (ELI) approach between July 2020 and February 2022.

RESULTS

Fourteen patients with IJV stenosis were identified, all with persistent headache and/or tinnitus. Six patients were diagnosed with IIH, three of whom failed previous treatment. Of the eight remaining patients, two failed previous treatment. All underwent surgical IJV decompression via styloidectomy, release of soft tissue, and removal of the C1 transverse process (TP). Follow-up imaging showed significant improvement of IJV stenosis in eleven patients and mild improvement in three. Eight patients had significant improvement in their presenting symptoms, and three had partial improvement. Two patients received IJV stenting after a lack of initial improvement. Two patients experienced cranial nerve paresis, and one developed a superficial wound infection.

CONCLUSION

The ELI approach for IJV decompression appears to be safe for patients who are not ideal endovascular candidates due to bony anatomy. Confirming long-term efficacy in relieving debilitating clinical symptoms requires longer follow-up and a larger patient cohort. Carefully selected patients with symptomatic bony IJV compression for whom there are no effective medical or endovascular options may benefit from surgical IJV decompression.

Quantitative hemodynamic assessment of stenotic below-the-knee arteries using spatio-temporal bolus tracking on 4D-CT angiography

BACKGROUND

Peripheral arterial disease (PAD) is a chronic occlusive disease that restricts blood flow in the lower limbs, causing partial or complete blockages of the blood flow. While digital subtraction angiography (DSA) has traditionally been the preferred method for assessing blood flow in the lower limbs, advancements in wide beam Computed Tomography (CT), allowing successive acquisition at high frame rate, might enable hemodynamic measurements.

PURPOSE

To quantify the arterial blood flow in stenotic below-the-knee (BTK) arteries. To this end, we propose a novel method for contrast bolus tracking and assessment of quantitative hemodynamic parameters in stenotic arteries using 4D-CT.

METHODS

Fifty patients with suspected PAD underwent 4D-CT angiography in addition to the clinical run-off computed tomography angiography (CTA). From these dynamic acquisitions, the BTK arteries were segmented and the region of maximum blood flow was extracted. Time attenuation curves (TAC) were estimated using 2D spatio-temporal B-spline regression, enforcing both spatial and temporal smoothness. From these curves, quantitative hemodynamic parameters, describing the shape of the propagating contrast bolus were automatically extracted. We evaluated the robustness of the proposed TAC fitting method with respect to interphase delay and imaging noise and compared it to commonly used approaches. Finally, to illustrate the potential value of 4D-CT, we assessed the correlation between the obtained hemodynamic parameters and the presence of PAD.

RESULTS

280 out of 292 arteries were successfully segmented, with failures mainly due to a delayed contrast arrival. The proposed method led to physiologically plausible hemodynamic parameters and was significantly more robust compared to 1D temporal regression. A significant correlation between the presence of proximal stenoses and several hemodynamic parameters was found.

CONCLUSIONS

The proposed method based on spatio-temporal bolus tracking was shown to lead to stable and physiologically plausible estimation of quantitative hemodynamic parameters, even in the case of stenotic arteries. These parameters may provide valuable information in the evaluation of PAD and contribute to its diagnosis.

4Dflow-VP-Net: A deep convolutional neural network for noninvasive estimation of relative pressures in stenotic flows from 4D flow MRI

PURPOSE

To estimate relative transvalvular pressure gradient (TVPG) noninvasively from 4D flow MRI.

METHODS

A novel deep learning-based approach is proposed to estimate pressure gradient across stenosis from four-dimensional flow MRI (4D flow MRI) velocities. A deep neural network 4D flow Velocity-to-Presure Network (4Dflow-VP-Net) was trained to learn the spatiotemporal relationship between velocities and pressure in stenotic vessels. Training data were simulated by computational fluid dynamics (CFD) for different pulsatile flow conditions under an aortic flow waveform. The network was tested to predict pressure from CFD-simulated velocity data, in vitro 4D flow MRI data, and in vivo 4D flow MRI data of patients with both moderate and severe aortic stenosis. TVPG derived from 4Dflow-VP-Net was compared to catheter-based pressure measurements for available flow rates, in vitro and Doppler echocardiography-based pressure measurement, in vivo.

RESULTS

Relative pressures calculated by 4Dflow-VP-Net and in vitro pressure catheterization revealed strong correlation (r2  = 0.91). Correlations analysis of TVPG from reference CFD and 4Dflow-VP-Net for 450 simulated flow conditions showed strong correlation (r2  = 0.99). TVPG from in vitro MRI had a correlation coefficient of r2  = 0.98 with reference CFD. 4Dflow-VP-Net, applied to 4D flow MRI in 16 patients, showed comparable TVPG measurement with Doppler echocardiography (r2  = 0.85). Bland-Altman analysis of TVPG measurements showed mean bias and limits of agreement of -0.20 ± 2.07 mmHg and 0.19 ± 0.45 mmHg for CFD-simulated velocities and in vitro 4D flow velocities. In patients, overestimation of Doppler echocardiography relative to TVPG from 4Dflow-VP-Net (10.99 ± 6.77 mmHg) was observed.

CONCLUSION

The proposed approach can predict relative pressure in both in vitro and in vivo 4D flow MRI of aortic stenotic patients with high fidelity.

Does the Severity of Foraminal Stenosis Impact Outcomes of Lumbar Decompression Surgery?

OBJECTIVE

To establish the relationship between the magnitude of foraminal stenosis and 1) improvement in patient-reported outcomes, 2) improvement in motor function after lumbar decompression surgery, and 3) difference in surgical outcomes.

METHODS

Patients who underwent one-level posterior lumbar decompression for radiculopathy were retrospectively identified. Patient demographics and surgical characteristics were collected through a query search and manual chart review of the electronic medical records. Foraminal stenosis was determined on magnetic resonance imaging and graded using Lee et al.'s validated methodology as none, mild, moderate, or severe. Surgical outcomes, motor function, and patient-reported outcome measures (PROMs) were compared based on the amount of stenosis (mild vs. moderate vs. severe). Bivariant and multivariant analyses were performed.

RESULTS

Severe stenosis demonstrated more 90-day readmissions (0.00% vs. 0.00% vs. 8.57%, respectively, P = 0.019), though this effect did not remain significant on multivariate analysis (P = 0.068). There was no association between stenosis severity and the degree of functional impairment or PROMs preoperatively. Patients with moderate or severe preoperative foraminal stenosis showed improvement in all PROMs after surgery (P < 0.05) except the mental component of the Short Form 12 survey. Notably, central stenosis grade was insignificantly different between groups (P = 0.358). Multivariable logistic regression analysis did not identify any significant independent predictors of surgical outcomes or changes in PROMs.

CONCLUSIONS

We demonstrated that regardless of foraminal stenosis severity preoperatively, patients have a similar improvement in PROMs, surgical outcomes, and restoration of motor function after lumbar decompression surgery for radiculopathy.

Angiographic tapering sign as a surrogate marker for large vessel occlusion due to intracranial atherosclerotic stenosis and its clinical implication: a retrospective matched case-control study

BACKGROUND

The purpose of this study was to investigate whether the initial DSA appearance of the occlusion during mechanical thrombectomy (MT) can help distinguish the nature of the underlying lesion and predict radiological and clinical outcomes.

METHODS

We retrospectively reviewed cases of patients with acute ischemic stroke who underwent MT for anterior circulation occlusion between March 2017 and February 2020. Underlying intracranial atherosclerotic stenosis (ICAS) was determined based on the presence of fixed stenosis after endovascular treatment. Patients were categorized based on the appearance of the occlusion observed in the initial DSA as tapering sign (+) or (-) groups. We performed 1:2 propensity score matching to establish a proper control group among the tapering sign (-) group. We analyzed and compared baseline characteristics and clinical outcomes between the two groups.

RESULTS

A total of 293 patients (tapering sign (+), n=47; tapering sign (-), n=246) were included in the analysis. The procedure time of MT was significantly longer for the tapering sign (+) group, and the successful recanalization rate after MT was significantly lower in the tapering sign (+) group than in the tapering sign (-) group. Logistic regression showed that ICAS-related occlusion was strongly associated with a positive angiographic tapering sign, and the angiographic tapering sign was a negative factor for the first-pass effect during MT. However, a 3-month good functional outcome was not significantly associated with the angiographic tapering sign.

CONCLUSIONS

The tapering sign on the initial DSA could be a surrogate marker for ICAS-related occlusion and procedural difficulty. However, its clinical significance remains unclear.

Radiopathologic predictors of 1- and 2-year frontal sinusotomy outcomes in a southeast Asian chronic rhinosinusitis population

BACKGROUND

The frontal sinus and its drainage pathway are difficult spaces to navigate surgically. The complexity of the frontal recess anatomy as well as inflammatory factors may influence outcomes of endoscopic frontal sinusotomy. It is not clear which factors are more important in determining post-operative frontal ostium patency.

OBJECTIVE

The objective is to investigate whether the distribution of fronto-ethmoidal cells, frontal recess dimensions and sinonasal inflammation predict frontal ostium patency at 1- and 2-years after endoscopic frontal sinusotomy.

METHODS

A retrospective review of 94 chronic rhinosinusitis patients (185 sides) who had undergone endoscopic frontal sinusotomies between 2015 and 2019 was conducted. Computed tomography was used to evaluate the type of fronto-ethmoidal cells present and determine the dimensions of the frontal recess. The International Classification of the Radiological Complexity of frontal recess and frontal sinus was used to grade the complexity of frontal recess anatomy. Mucosal inflammation was graded according to a structured histopathology report. Frontal ostium patency at 1- and 2-years post-operatively was recorded.

RESULTS

The frontal ostium patency rates were 80.9% and 73.4% at 1- and 2-years respectively. Eosinophilic predominance (adjusted OR 3.5, 95% CI 1.6-8.0, p = 0.003) and mucosal ulceration on histology (adjusted OR 4.5, 95% CI 1.1-17.9, p = 0.033) predicted ostial stenosis at 1 year. Smoking (adjusted OR 7.6, 95% CI 2.4-24.7, p = 0.001), aspirin exacerbated respiratory disease (AERD) (adjusted OR 7.6, 95% CI 1.9-30.1, p = 0.004) and histological findings of severe inflammation (adjusted OR 8.9, 95% CI 1.9-41.2, p = 0.005) were independent predictors of ostial stenosis at 2 years. Frontal cell patterns, frontal recess dimensions and frontal recess complexity did not predict frontal ostium stenosis at both 1- and 2-years post-operatively.

CONCLUSION

Post-operative control of sinonasal inflammation is important in maintaining frontal ostium patency, regardless of frontal cell patterns or frontal recess dimensions.

Magnetic resonance cholangiography in the diagnosis of dominant strictures in pediatric-onset primary sclerosing cholangitis

BACKGROUND

Magnetic resonance cholangiopancreaticography (MRCP) has become the primary imaging modality in primary sclerosing cholangitis (PSC). Endoscopic retrograde cholangiopancreaticography (ERCP) is recommended when a dominant stricture (DS) of bile ducts is suspected in MRCP. However, MRCP criteria for DS are lacking.

AIMS

To evaluate the diagnostic accuracy of MRCP in the diagnosis of DS in patients with pediatric-onset PSC.

METHODS

ERCP and MRCP images of patients with pediatric-onset PSC (n=36) were evaluated for the presence of DS applying the diameter-based ERCP criteria. The diagnostic accuracy of MRCP in detecting DS was calculated using ERCP as the gold standard.

RESULTS

The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and accuracy of MRCP for detecting DS were 62%, 89%, 5.6, 0.43, and 81%. Most common reasons for incongruent ERCP/MRCP assessment were (1) MRCP stenosis not fulfilling the diameter criteria of ERCP, resulting in false negative MRCP evaluation, and (2) lack of filling pressure in MRCP, resulting in false positive MRCP evaluation.

CONCLUSION

The high positive likelihood ratio of MRCP in detecting DS suggests that MRCP is a useful tool in the follow-up of PSC. However, diameter limits of DS should probably be less strict in MRCP than in ERCP.

Serial Changes in Intestinal Stenotic Stiffness in Patients with Crohn's Disease Treated with Biologics: A Pilot Study Using Ultrasound Shear Wave Elastography

BACKGROUND/AIMS

Intestinal strictures represent an important serious complication of Crohn's disease. Shear wave elastography is a promising noninvasive ultrasound technique for assessing tissue stiffness. This study aimed to evaluate stiffness in the areas of intestinal stricture in patients with Crohn's disease using shear wave elastography and the changes in stiffness after biologics.

MATERIALS AND METHODS

We enrolled 21 Crohn's disease patients having intestinal stricture. The patients consisted of 3 groups, which were the infliximab naïve (n = 6) group, the ustekinumab naïve (n = 8), and the bio-switch from infliximab to ustekinumab (n = 7) group. Bowell wall thickness was examined by ultrasound sonography, and the stiffness of Crohn's disease stricture lesions was evaluated using Shear wave speed before and 1 year after anti-tumor necrosis factor-alpha antibody infliximab, anti-interleukin 12/23 antibody ustekinumab, and bio-switch from infliximab to ustekinumab.

RESULTS

Bowell wall thickness was significantly improved after infliximab, ustekinumab, and the bio-switch. However, shear wave speed indices only in the ustekinumab group significantly decreased after treatment (P = .028), but not in the other group.

CONCLUSIONS

Shear wave elastography might be a useful method to evaluate stiffness in the areas of intestinal stricture in patients with Crohn's disease treated with biologics. However, a prospective randomized study evaluating the development of obstruction after biological treatment is needed to validate the study findings.

[Characteristics of SPECT/CT-derived pulmonary perfusion imaging in chronic pulmonary vascular stenosis with different etiologies]

Objective: To explore the characteristics of pulmonary blood flow perfusion imaging of single photo emission computer tomography/computer tomography (SPECT/CT) in chronic pulmonary vascular Stenosis (CPVS) caused by different etiological factors. Methods: This is a retropective study. Present study screened 50 consecutive cases diagnosed with chronic pulmonary vascular stenosis from January 2019 to January 2020 in the department of cardiology of Gansu Provincial Hospital and underwent SPECT/CT pulmonary blood flow perfusion examination. Thirteen patients were excluded because of pulmonary vascular lesions with a disease course of less than 3 months and poor image quality. According to the etiology, patients were divided into fibrosing mediastinitis (FM) group, Takyasu's arteritis (PTA) group, and chronic thromboembolic pulmonary hypertension/chronic thromboembolic pulmonary disease (CTEPH/CTED) group. The severity of pulmonary blood flow perfusion was evaluated in accordance with the Begic scoring principle in the three groups. The overall Begic score, lung lobe scores among three groups were compared. CT signs of lung SPECT/CT, such as enlargement of hilar lymph node, atelectasis, bronchial stenosis, were also analyzed in three groups. Results: A total of 37 patients with chronic pulmonary vascular stenosis were finally enrolled (18 in the FM group, 5 in the PTA group, and 14 in the CTEPH/CTED group). The total Begic score of pulmonary perfusions was similar among the three groups (F=0.657,P>0.05). There was a statistically significant difference in the left upper lobe Begic score among the three groups (H=4.081, P<0.05). The left upper lobe Begic score was higher in the FM group than in the PTA group (3.44±2.50 vs. 1.60±0.55, P<0.05). As compared to other two groups, patients in FM group were featured with CT signs of higher percent of hilar enlargement (FM group vs. PTA group: 16/18 vs. 1/5, P=0.008; FM group vs. CTEPH/CTED group: 16/18 vs. 3/14, P=0.000 2), enlargement of the pulmonary hilum lymph nodes (FM group vs. PTA group: 14/18 vs. 1/5, P=0.033; FM group vs. CTEPH/CTED group: 14/18 vs. 2/14, P=0.001), and calcification of mediastinal soft tissue (FM group vs. PTA group: 11/18 to 0/5, P=0.037; FM group vs. CTEPH/CTED group: 11/18 vs. 1/14, P=0.003). The proportion of CT signs of bronchial stenosis (9/18 vs. 0/14, P=0.002) and atelectasis (9/18 vs. 1/14, P=0.002) was also higher in the FM group than in the CTEPH/CTED group. In case of abnormal pulmonary blood flow perfusion, the diagnostic accuracy of CT signs hilar enlargement, hilar lymph node enlargement, mediastinal soft tissue calcification, bronchial stenosis, and atelectasis for the diagnosis of FM were 81.1%, 83.8%, 78.4%, 75.7%, and 73.0%, respectively. Conclusion: There is no significant difference in the Begic score of SPECT/CT pulmonary blood flow perfusion imagines among the three groups of patients. Impaired pulmonary blood flow perfusion combined with typical CT signs is useful for identifying patients with FM.

Combined Conduit Score in Contrast-Enhanced Magnetic Resonance Venography in Patients with Idiopathic Intracranial Hypertension : Neuro-interventionalists' vs. Radiologists' Assessment

BACKGROUND

Based on increased understanding of the idiopathic intracranial hypertension (IIH) pathophysiology, venous sinus stenting (VSS) has emerged as an effective treatment for patients with transverse sinus stenosis (TSS). The presence of a reliable TSS screening tool is warranted. The combined conduit score (CCS) is the most widely used score for evaluation of the cerebral sinovenous stenosis in contrast-enhanced magnetic resonance venography (CE-MRV).

PURPOSE OF THE STUDY

To evaluate the interobserver agreement between neuro-interventionalists and radiologists with respect to the CCS in evaluation of transverse sinus stenosis in patients with idiopathic intracranial hypertension using CE-MRV.

METHODS

A retrospective study was conducted on 26 consecutive patients diagnosed with IIH and underwent CE-MRV. The 2 neuro-interventionalists and 2 radiologists separately evaluated the cerebral venous sinuses using the CCS.

RESULTS

The mean CCS was significantly different between the neuro-interventionalists and radiologists (p < 0.001), higher for the radiologists. The inter-rater reliability was excellent (ICC = 0.954, 95% CI: 0.898-0.979) between the 2 neuro-interventionalists, good between the 2 radiologists (ICC = 0.805, 95% CI: 0.418-0.921), but was not acceptable between the neuro-interventionalists and the radiologists (ICC 0.47 95% CI:-2.2-0.782).

CONCLUSION

Despite the excellent agreement between the neuro-interventionists and the good agreement between the radiologists, there was no agreement between the neuro-interventionists and the radiologists. Our finding suggests that there is a gap between the 2 specialties but does not favor any of them. Factors related to the observers, the venous sinus system, the MRV or the CCS score may have resulted in this discrepancy. Automatic or semi-automatic feature extractions to produce quantifiable biomarkers for IIH are warranted. The clinical decisions should not depend only on strongly observer-dependent scores with training and/or experience-dependent influences.

Efficacy of modified time of flight magnetic resonance venography in diagnosis of iliac vein compression syndrome

OBJECTIVE

We investigated the diagnostic efficacy of modified time of flight magnetic resonance venography (mTOF-MRV) for iliac vein compression syndrome diagnosis by optimizing the scanning parameters and improving image quality.

METHODS

A retrospective study was conducted on 69 patients who underwent routine time of flight magnetic resonance venography (TOF-MRV) and 85 patients who received mTOF-MRV. Assessment of image quality of the two methods was performed by two radiologists using a four-point method. The sensitivity, specificity, positive and negative predictive values of TOF-MRV and mTOF-MRV in the diagnosis of significant iliac vein compression (stenosis >50%) were analyzed by calculating the iliac vein stenosis rates of the two methods and using digital subtraction angiography (DSA) as the gold standard.

RESULTS

Inter-observer assessment of objective data measurement revealed excellent agreement {ICC [95% confidence interval (CI)]: 0.972 (0.953 to 0.983) for TOF-MRV and 0.979 (0.965 to 0.988) for m-TOF MRV, 0.976 (0.960 to 0.986) for DSA}. The mean error of stenosis rate of mTOF-MRV was markedly smaller than that of TOF-MRV (p < 0.05). Sensitivity, specificity, positive and negative predictive values of TOF-MRV in the diagnosis of significant stenosis were 100%, 95%, 67% and 100%, respectively. The sensitivity, specificity, positive and negative predictive values of mTOF-MRV were 100%. The mean image score for the mTOF-MRV was 3.63 ± 0.59, which was significantly higher compared with that of TOF-MRV (2.19 ± 0.42).

CONCLUSION

mTOF-MRV has better image quality and can accurately diagnose venous stenosis. Therefore, it can be used for the detection of iliac vein compression syndrome and further assessment after endovascular interventions.

Association Between Low-Density Lipoprotein-Cholesterol Level and Risk of Intracranial Atherosclerotic Stenosis: Results From the APAC Study

BACKGROUND

It is unknown whether plasma low-density lipoprotein-cholesterol level (LDL-C) can predict the occurrence of intracranial atherosclerotic stenosis (ICAS), especially asymptomatic (A)ICAS. This study investigated whether LDL-C level is independently associated with AICAS.

METHODS

The Asymptomatic Polyvascular Abnormalities Community study is an ongoing community-based, prospective, long-term follow-up observational study with 3387 participants. AICAS was diagnosed by transcranial Doppler ultrasonography. The participants were divided into 3 groups based on LDL-C level. Cox regression was used to evaluate the association between LDL-C level and incidence of AICAS.

RESULTS

During 2 years of follow-up, 9.98% of participants were diagnosed with AICAS. The incidence of AICAS (person-years with 95% CI) was 4.99% (4.48%-5.50%). AICAS incidence did not increase with increasing LDL-C level. Compared with the <2.6 mmol/l subgroup, the incidence of asymptomatic ICAS was not significantly higher in the 2.6 to 3.4 and >3.4 mmol/l subgroups after adjusting for confounding factors (hazard ratio=0.95, 95% CI: 0.86-1.03 and hazard ratio=0.96, 95% CI: 0.84-1.10, respectively).

CONCLUSIONS

LDL-C is not an independent predictor of AICAS incidence in the Chinese population.

Comparing non-invasive diagnostic methods for arteriovenous fistula stenosis: a prospective study

PURPOSE

International guidelines recommend screening for arteriovenous fistula (AVF) stenosis using various non-invasive methods. We evaluate different non-invasive AVF flow measurements for detecting AVF stenosis.

METHODS

Twenty-three haemodialysis patients with suspected AVF stenosis are enrolled based on abnormal physical signs or high venous pressure during dialysis. Ultrasound dilution, urea dilution, Doppler ultrasonography, and fistulography are performed on all patients. The accuracy of three non-invasive methods is compared.

RESULTS

Fistulography reveals AVF stenosis in 18 patients, 12 of whom have severe stenosis (greater than 50% stenosis in diameter). Concerning the location of the stenosis lesions, eight are at the inflow site, six at the outflow site, and four on both sites. Receiver operating characteristic curve analysis shows that Doppler ultrasonography has a high discriminative ability and the averaged areas under the curves are 0.933 (95% confidence interval [CI]; 0.81 to 0.99) for stenosis and 0.929 (95% CI 0.82-0.99) for severe stenosis. The sensitivity of each method for the prediction of access stenosis using ultrasound dilution, urea dilution, and Doppler ultrasonography is 73%, 73%, and 80%, respectively. The respective specificity of each method is 40%, 80%, and 100%, respectively. Physical examination (PE) shows an 80% sensitivity and 80% specificity in the detection of AVF stenosis. The combination of Doppler ultrasound with PE produces the highest sensitivity (93%) for detecting AVF stenosis.

CONCLUSIONS

Doppler ultrasound combined with physical examination is more accurate than other non-invasive methods for detecting AVF stenosis.

Improved fluoroscopy-guided biopsies in the diagnosis of indeterminate biliary strictures: a multi-center retrospective study

To evaluate the diagnostic accuracy of improved fluoroscopy-guided biopsies for indeterminate biliary strictures (IBDS). A multi-center retrospective study was performed. Patients with IBDS who underwent digital single-operator cholangioscopy (DSOC) and improved fluoroscopy-guided biopsies procedures were included. The individual sensitivity, specificity, and accuracy were analyzed. A total of 67 patients were enrolled in this multi-center retrospective study. The DSOC and improved fluoroscopy-guided biopsies procedures were successfully performed in all cases (100%). The sensitivity, specificity, and accuracy values were 83.3%, 89.5%, and 85.1% for DSOC visual impression; 95.8%, 94.7%, and 95.5% for improved fluoroscopy-guided biopsies procedures, respectively. The sensitivity and accuracy of improved fluoroscopy-guided biopsies were significantly higher compared with DSOC visual impression. Four patients (6.0%, 4/67) occurred adverse events after the procedures. Improved fluoroscopy-guided biopsies had a high diagnostic accuracy of IBDS diagnosis.

Comparison of single coronal thick-slab minimum intensity projection with flexible bronchoscopy for airway compression in children with lymphobronchial tuberculosis

AIM

To generate standardised coronal minimum intensity projection (MinIP) computed tomography (CT) reconstructions, and compare these with flexible bronchoscopy in children with lymphobronchial tuberculosis (LBTB).

MATERIALS AND METHODS

Standardised coronal MinIP reconstructions were performed from CT images in children with LBTB and the findings of three readers were compared with the reference standard, flexible bronchoscopy (FB), regarding airway narrowing. Intraluminal lesions, the site of the stenosis, and the degree of stenosis were also evaluated. The length of stenosis was evaluated by CT MinIP only.

RESULTS

Sixty-five children (38 males; 58.5% and 27 females; 41.5%), with ages ranging from 2.5 to 144 months were evaluated. Coronal CT MinIP demonstrated a sensitivity of 96% and specificity of 89% against FB. The most common site of stenosis was the bronchus intermedius (91%), followed by the left main bronchus (85%), the right upper lobe bronchus RUL (66%), and the trachea (60%).

CONCLUSION

Coronal CT MinIP reconstruction is useful in demonstrating airway stenosis in children with lymphobronchial TB, with high sensitivity and specificity. CT MinIP had additional advantages over FB in that it allowed objective measurement of the diameter of stenosis, measurement of the length of stenosis, and evaluation of post-stenotic segments of the airways and lung parenchymal abnormalities.