Endovascular Management of Post-Irradiated Carotid Blowout Syndrome in Patients with Lower Neck Cancers.

OBJECTIVE: Lower neck cancers (LNCs) include specific tumour types and have some different vascular supply or collaterals from other head and neck cancers. This prospective study evaluated the outcome of endovascular management of post-irradiated carotid blowout syndrome (PCBS) in patients with LNC by comparing reconstructive management (RE) and deconstructive management (DE). METHODS: This was a single centre, prospective cohort study. Patients with LNC complicated by PCBS between 2015 and 2021 were enrolled for RE or DE. RE was performed by stent graft placement covering the pathological lesion and preventive external carotid artery (ECA) embolisation without balloon test occlusion (BTO). DE was performed after successful BTO by permanent coil or adhesive agent embolisation of the internal carotid artery (ICA) and ECA to common carotid artery, or ICA occlusion alone if the pathological lesion was ICA only. Cross occlusion included the proximal and distal ends of the pathological lesion in all patients. Re-bleeding events, haemostatic period, and neurological complications were evaluated. RESULTS: Fifty-nine patients (mean age 58.5 years; 56 male) were enrolled, including 28 patients undergoing RE and 31 patients undergoing DE. Three patients originally grouped to DE were transferred to RE owing to failed BTO. The results of RE vs. DE were as follows: rebleeding events, 13/28 (46%) vs. 10/31 (32%) (p = .27); haemostatic period, 9.4 ± 14.0 months vs. 14.2 ± 27.8 months (p = .59); neurological complication, 4/28 (14%) vs. 5/31 (16%) (p = .84); and survival time, 11.8 ± 14.6 months vs. 15.1 ± 27.5 months (p = .61). CONCLUSION: No difference in rebleeding risk or neurological complications was observed between the DE and RE groups. RE could be used as a potential routine treatment for PCBS in patients with LNC.

Percutaneous transluminal angioplasty and stenting of post-irradiated stenosis of subclavian artery: A matched case-control study.

BACKGROUND: Although radiotherapy is common for head/neck and chest cancers (HNCC), it can result in post-irradiation stenosis of the subclavian artery (PISSA). The efficacy of percutaneous transluminal angioplasty and stenting (PTAS) to treat severe PISSA is not well-clarified. AIMS: To compare the technical safety and outcomes of PTAS between patients with severe PISSA (RT group) and radiation-naïve counterparts (non-RT group). METHODS: During 2000 and 2021, we retrospectively enrolled patients with severe symptomatic stenosis (>60%) of the subclavian artery who underwent PTAS. The rate of new recent vertebrobasilar ischaemic lesions (NRVBIL), diagnosed on diffusion-weight imaging (DWI) within 24 h of postprocedural brain MRI; symptom relief; and long-term stent patency were compared between the two groups. RESULTS: Technical success was achieved in all 61 patients in the two groups. Compared with the non-RT group (44 cases, 44 lesions), the RT group (17 cases, 18 lesions) had longer stenoses (22.1 vs 11.1 mm, P = 0.003), more ulcerative plaques (38.9% vs 9.1%, P = 0.010), and more medial- or distal-segment stenoses (44.4% vs 9.1%, P<0.001). The technical safety and outcome between the non-RT group and the RT group were NRVBIL on DWI of periprocedural brain MRI 30.0% vs 23.1%, P = 0.727; symptom recurrence rate (mean follow-up 67.1 ± 50.0 months) 2.3% vs 11.8%, P = 0.185; and significant in-stent restenosis rate (>50%) 2.3% vs 11.1%, P = 0.200. CONCLUSION: The technical safety and outcome of PTAS for PISSA were not inferior to those of radiation-naïve counterparts. PTAS for PISSA is an effective treatment for medically refractory ischaemic symptoms of HNCC patients with PISSA.

Clinical and imaging findings for the evaluation of large Rathke's cleft cysts and cystic craniopharyngiomas.

PURPOSE: Large Rathke's cleft cysts (LRCCs) and cystic craniopharyngiomas (CCPs) arise from the same embryological origin and may have similar MR presentations. However, the two tumors have different management strategies and outcomes. This study was designed to evaluate the clinical and imaging findings of LRCCs and CCPs, aiming to evaluate their pretreatment diagnosis and outcomes. METHODS: We retrospectively enrolled 20 patients with LRCCs and 25 patients with CCPs. Both tumors had a maximal diameter of more than 20 mm. We evaluated the patients' clinical and MR imaging findings, including symptoms, management strategies, outcomes, anatomic growth patterns and signal changes. RESULTS: The age of onset for LRCCs versus CCPs was 49.0 ± 16.8 versus 34.2 ± 22.2 years (p = .022); the following outcomes were observed for LRCCs versus CCPs: (1) postoperative diabetes insipidus: 6/20 (30%) versus 17/25 (68%) (p = .006); and (2) posttreatment recurrence: 2/20 (10%) versus 10/25 (40%) (p = .025). The following MR findings were observed for LRCCs versus CCPs: (1) solid component: 7/20 (35%) versus 21/25 (84%) (p = .001); (2) thick cyst wall: 2/20 (10%) versus 12/25 (48%) (p = .009); (3) intracystic septation: 1/20 (5%) versus 8/25 (32%) (p = .030); (4) snowman shape: 18/20 (90%) versus 1/25 (4%) (p < .001); (5) off-midline extension: 0/0 (0%) versus 10/25 (40%) (p = .001); and (6) oblique angle of the sagittal long axis of the tumor: 89.9° versus 107.1° (p = .001). CONCLUSIONS: LRCCs can be differentiated from CCPs based on their clinical and imaging findings, especially their specific anatomical growth patterns. We suggest using the pretreatment diagnosis to select the appropriate surgical approach and thus improve the clinical outcome.

Percutaneous transluminal angioplasty and stenting of post-irradiation stenosis of the vertebral artery.

BACKGROUND: The outcomes of percutaneous transluminal angioplasty and stenting (PTAS) in patients with medically refractory post-irradiation stenosis of the vertebral artery (PISVA) have not been clarified. AIM: This retrospective study evaluated the safety and outcomes of PTAS in patients with severe PISVA compared with their radiation-naïve counterparts (non-RT group). METHODS: Patients with medically refractory severe symptomatic vertebral artery stenosis and undergoing PTAS between 2000 and 2021 were classified as the PISVA group or the non-RT group. The periprocedural neurological complications, periprocedural brain magnetic resonance imaging, the extent of symptom relief, and long-term stent patency were compared. RESULTS: As compared with the non-RT group (22 cases, 24 lesions), the PISVA group (10 cases, 10 lesions) was younger (62.0 ± 8.6 vs 72.4 ± 9.7 years, P = 0.006) and less frequently had hypertension (40.0% vs 86.4%, P = 0.013) and diabetes mellitus (10.0% vs 54.6%, P = 0.024). Periprocedural embolic infarction was not significantly different between the non-RT group and the PISVA group (37.5% vs 35.7%, P = 1.000). At a mean follow-up of 72.1 ± 58.7 (3-244) months, there was no significant between-group differences in the symptom recurrence rate (0.00% vs 4.55%, P = 1.000) and in-stent restenosis rate (10.0% vs 12.5%, P = 1.000). CONCLUSION: PTAS of severe medically refractory PISVA is effective in the management of vertebrobasilar ischemic symptoms in head and neck cancer patients. Technical safety and outcome of the procedure were like those features in radiation-naïve patients.

Influence of angioplasty and stenting on intracranial artery stenosis: preliminary results of high-resolution vessel wall imaging evaluation.

OBJECTIVES: To investigate whether the imaging changes on high-resolution vessel wall imaging (HR-VWI) in patients before and after percutaneous transluminal angioplasty and stenting (PTAS) contribute to predicting the clinical outcome. METHODS: The study included 24 severe intracranial artery stenosis (SICAS) patients undergoing PTAS with Wingspan Stent between 2018 and 2020 and had a 1-year follow-up. Three HR-VWI sessions (preprocedural, early [within 24 h], and delayed postprocedural [134.7 ± 27.1 days)]) in each subject were performed with 3-Tesla MRI. We evaluated periprocedural HR-VWI changes in patients with and without recurrent cerebral ischemic symptoms (RCIS) within 1-year follow-up. RESULTS: On CE-T1WI of the patients without RCIS, a significant decrease in enhanced area was observed on early postprocedural (0.04 ± 0.02 cm2, p = 0.001) and delayed postprocedural (0.04 ± 0.02 cm2; p = 0.001) HR-VWI compared to preprocedural (0.07 ± 0.02 cm2) HR-VWI. Patients with RCIS demonstrated no significant loss of enhanced area on CE-T1WI of early postprocedural HR-VWI (p = 0.180). Significant decreases in calibrated T1 signals were observed in both presence (1.77 ± 0.70 vs. 0.79 ± 0.52; p = 0.018) and absence (1.42 ± 0.62 vs. 0.83 ± 0.40; p = 0.001) of RCIS in early postprocedural HR-VWI. CONCLUSION: The preliminary results showed the presence of reduced contrast enhancement immediately after PTAS may indicate less recurrent stroke events within 1 year. Further studies are necessary to confirm the phenomena in a longer observation period. KEY POINTS: • Early postprocedural high-resolution vessel imaging (HR-VWI) within 24 h can effectively predict a 1-year outcome following intracranial stenting. • For stenotic lesions after stenting without reduced contrast enhancement on HR-VWI within 24 h may need closer clinical surveillance for potentially higher risk of stroke events within 1 year.

Shortened cerebral circulation time correlates with seizures in brain arteriovenous malformation: a cross-sectional quantitative digital subtraction angiography study.

OBJECTIVE: Seizure is the most common clinical presentation in patients with nonhemorrhagic brain arteriovenous malformations (BAVMs) and it influences their quality of life. Angioarchitectural analysis of the seizure risk for BAVMs is subjective and does not consider hemodynamics. This study aimed to investigate the angioarchitectural and hemodynamic factors that may be associated with seizure in patients with BAVMs. METHODS: From 2011 to 2019, 104 patients with supratentorial BAVMs without previous hemorrhage or treatment were included and grouped according to the initial presentation of seizure. Their angiograms and MRI results were analyzed for morphological characteristics and quantitative digital subtraction angiography (QDSA) parameters. Modified cerebral circulation time (mCCT) was defined as the difference between the bolus arrival time of the ipsilateral cavernous internal carotid artery and the parietal vein on lateral DSA. Logistic regression analysis was performed to estimate the odds ratio (OR) for BAVMs presenting with seizure. RESULTS: The seizure group had shorter mCCT (1.98 s vs. 2.44 s, p = 0.005) and more BAVMs with temporal location (45% vs. 30.8%, p = 0.013), neoangiogenesis (55% vs. 33%, p = 0.03), and long draining veins (95% vs. 72%, p = 0.004) than did the nonseizure group. Shorter mCCT (OR: 3.4, p = 0.02), temporal location (OR: 13.4, p < 0.001), and neoangiogenesis (OR: 4.7, p = 0.013) were independently associated with higher risks of seizure, after adjustments for age, gender, BAVM volume, and long draining vein. CONCLUSIONS: Shorter mCCT, temporal location, and neoangiogenesis were associated with epileptic BAVMs. QDSA can objectively evaluate hemodynamic changes in epileptic BAVMs. KEY POINTS: • Quantitative digital subtraction angiography may be used to evaluate the hemodynamic differences between brain arteriovenous malformations presenting with and without seizure. • BAVMs with temporal location, neoangiogenesis, and shortened cerebral circulation time were more likely to present with seizure.

Quantitative diagnosis of carotid blowout syndrome with CT perfusion: Carotid blowout syndrome CTP quantitative diagnosis.

BACKGROUND AND PURPOSE: Carotid blowout syndrome (CBS) is a potentially fatal disease. The CBS diagnosis mainly relies on subjective observations and the quantitative diagnotic method was not well established. This study aimed to diagnose CBS severity by computed tomography perfusion (CTP) parameters with different region-of-interest (ROI) models. MATERIALS AND METHOD: We prospectively recruited CBS patients between February 1, 2018 and July 31, 2023 in a tertiary medical center, and CTP was performed using the same 128-detector CT machine. Digital subtraction angiography (DSA) and elective endovascular intervention were performed within 3 days post-CTP for diagnosis confirmation and treatments. CBS severity was classified into ongoing (threatened + impending) or acute CBS based on DSA findings and clinical features. Pericarotid soft-tissue (PCST) CTP parameters, including blood flow (BF), blood volume (BV), mean transit time (MTT) and flow extraction product (FEP), were evaluated and correlated on DSA. We depicted models A, B and C for the small focal lesion in 1 cm of PCST, 1 cm around PCST and the whole PCST respectively. RESULTS: CTP images of 110 patients (77 ongoing (45 threatened + 32 impending); 33 acute) were analyzed. Pericarotid BV (1.8 ± 1.2vs.3.5 ± 2.0; p < 0.001) in Model A and BF in Model B (42.6 ± 11.0vs.50.9 ± 20.4; p = 0.031) were lower in acute-CBS than in ongoing-CBS patients. Subgroup analysis demonstrated lower BV in acute (1.8 ± 1.2) compared with threatened (3.7 ± 2.3; p < 0.001; p < 0.001) and impending (3.2 ± 1.6; p = 0.009) CBS patients in Model A. CONCLUSION: CBS severity can be quantitatively diagnosed by pericarotid soft-tissue CTP parameters. In Model A (small focus), BV was capable of differentiating acute CBS from other subtypes, demonstrating its potential role as a CBS imaging biomarker.

Percutaneous transluminal angioplasty and stenting for severe stenosis of the intracranial carotid artery and its branches: Comparison of the Wingspan stent vs the Credo stent.

BACKGROUND: Despite the widespread use of the Wingspan stent system for treating severe medically refractory intracranial artery stenosis (SMR-ICAS), a new Credo stent system was approved because it could integrate stent delivery within the balloon catheter. However, the therapeutic outcomes of these two systems have not been compared. This preliminary study aimed to compare the results of percutaneous angioplasty and stenting (PTAS) in SMR-ICAS patients treated with either Wingspan or Credo stents within the anterior cerebral circulation. METHODS: SMR-ICAS patients with >70% stenosis in the anterior circulation who underwent PTAS using either the Wingspan or Credo stent system were retrospectively analyzed. We evaluated the technical success, safety, and outcomes of the two-stent systems. RESULTS: A total of 29 patients were analyzed, including 17 patients treated with Wingspan stents and 12 with Credo stents. The outcomes of the Wingspan stent vs Credo stent were as follows: technical success (16/17 [94%] vs 11/12 [92%], p = 1.00); periprocedural intracranial hemorrhage (2/17 [12%] vs 0/12 [0%], p = 0.50); silent embolic ischemic lesions on periprocedural magnetic resonance imaging (MRI) (13/17 [76%] vs 7/12 [58%], p = 0.42); and significant (>50%) in-stent restenosis in 1 year (4/17 [24%] vs 2/12 [17%], p = 1.00). No recurrent stroke or mortality was noted within 30 days after the procedures or during the 1-year follow-up period. CONCLUSION: The technical success, safety, and outcomes of the Credo stent system were comparable to those of the Wingspan stent system in the management of SMR-ICAS patients. Further large-scale studies are warranted to substantiate these findings.

Early Improvement in Interstitial Fluid Flow in Patients With Severe Carotid Stenosis After Angioplasty and Stenting.

BACKGROUND AND PURPOSE: This study aimed to investigate early changes in interstitial fluid (ISF) flow in patients with severe carotid stenosis after carotid angioplasty and stenting (CAS). METHODS: We prospectively recruited participants with carotid stenosis ≥80% undergoing CAS at our institute between October 2019 and March 2023. Magnetic resonance imaging (MRI), including diffusion tensor imaging (DTI), and the Mini-Mental State Examination (MMSE) were performed 3 days before CAS. MRI with DTI and MMSE were conducted within 24 hours and 2 months after CAS, respectively. The diffusion tensor image analysis along the perivascular space (DTI-ALPS) index was calculated from the DTI data to determine the ISF status. Increments were defined as the ratio of the difference between post- and preprocedural values to preprocedural values. RESULTS: In total, 102 participants (age: 67.1±8.9 years; stenosis: 89.5%±5.7%) with longitudinal data were evaluated. The DTI-ALPS index increased after CAS (0.85±0.15; 0.85 [0.22] vs. 0.86±0.14; 0.86 [0.21]; P=0.022), as did the MMSE score (25.9±3.7; 24.0 [4.0] vs. 26.9±3.4; 26.0 [3.0]; P<0.001). Positive correlations between increments in the DTI-ALPS index and MMSE score were found in all patients (rs=0.468; P<0.001). CONCLUSION: An increased 24-hour post-CAS DTI-ALPS index suggests early improvement in ISF flow efficiency. The positive correlation between the 24-hour DTI-ALPS index and 2-month MMSE score increments suggests that early ISF flow improvement may contribute to long-term cognitive improvement after CAS.

Endovascular management of intracranial carotid blowout syndrome in patients with head and neck cancer.

BACKGROUND: Carotid blowout syndrome is a serious complication of head and neck cancer (HNC) that may involve the intracranial or extracranial internal carotid artery (ICA). Although parent artery occlusion (PAO) is the major endovascular treatment for intracranial carotid blowout syndrome (iCBS), the efficacy of using a balloon-expandable coronary stent-graft (BES) remains unclear. METHODS: This was a quasi-randomized trial, prospective study that included patients with iCBS treated by BES or PAO between 2018 and 2024. Patients were allocated to either group based on the last digit of their chart number; even numbers went to the BES group and odd numbers to the PAO group. The inclusion criteria of iCBS included the pathological process of CBS involving petrous and/or cavernous ICA detected by both imaging and clinical features. The primary outcome was defined as rebleeding events after intervention. The secondary outcome was defined as neurological complication after intervention. RESULTS: Fifty-nine patients with 61 iCBS lesions were enrolled. Thirty-three iCBS lesions were treated with BES and 28 underwent PAO. The results for the BES group versus the PAO group, respectively, were: rebleeding events, 5/33 (15.1%) vs 5/28 (17.8%) (p=0.78); neurological complication, 5/33 (15.1%) vs 5/28 (17.8%) (p=0.78); median hemostatic time (months), 10.0 vs 11.5 (p=0.22); and median survival time (months), 10.0 vs 11.5 (p=0.39). CONCLUSIONS: No significant difference in rebleeding risk or neurological complication was observed between the BES and PAO groups. Our study confirmed the safety and effectiveness of applying BES for iCBS in HNC patients.

Length and location of post-PIRCS predict percutaneous transluminal angioplasty and stenting-related restenosis in nasopharyngeal cancer.

PURPOSE: Post-irradiated carotid stenosis (PIRCS) commonly occurs in patients with nasopharyngeal cancer (NPC) after receiving radiotherapy. A high in-stent restenosis (ISR) is observed in these patients after percutaneous transluminal angioplasty and stenting (PTAS) for PIRCS. Risk factors for ISR in these patients remain unclear. METHODS: Data were retrospectively analyzed from 68 NPC patients with 70 lesions treated with PTAS for PIRCS. The median follow-up was 40 months (range: 4-120). Evaluations of demographic and clinical characteristics included stenotic severity, stenotic lesion length (SLL), stenotic lesion location, and ISR-related stroke during follow-up. The risk for ISR was evaluated using multiple Cox regression analysis. RESULTS: The median age of the patients was 61 (35-80) years and 94.1% were male. The median stenosis was 80% (60-99%) and the median SLL was 2.6 cm (0.6-12.0 cm) before PTAS. Compared to those without ISR, patients with longer SLL were at significantly greater risk of developing significant ISR, defined as > 50% after PTAS (hazard ratio [HR] and 95% confidence interval [CI]: 2.06 [1.30-3.28]). PTAS for lesions from the internal carotid artery (ICA) to common carotid artery (CCA) was associated with a significantly greater risk of ISR than lesions located only in the ICA (HR: 9.58 [1.79-51.34]). The baseline cut-off value for SLL that best predicted significant ISR was 1.6 cm (area under the curve 0.700, sensitivity 83.3% and specificity 62.5%). CONCLUSION: Stenotic lesions located from the ICA to CCA with longer SLL at baseline appear to predict ISR in NPC patients with PIRCS after PTAS. Intensive post-procedural follow-up is advised for this patient population.

Prevention of in-stent restenosis with drug-eluting balloons in patients with postirradiated carotid stenosis accepting percutaneous angioplasty and stenting.

OBJECTIVE: To investigate the technical safety and outcome of in-stent restenosis (ISR) prevention with drug-eluting balloon (DEB) in patients with postirradiated carotid stenosis (PIRCS) undergoing percutaneous angioplasty and stenting (PTAS). METHODS: Between 2017 and 2021, we prospectively recruited patients with severe PIRCS for PTAS. They were randomly separated into two groups based on endovascular techniques performed with and without DEB. Preprocedural and early postprocedural (within 24 hours) MRI, short-term ultrasonography (6 months after PTAS), and long-term CT angiography (CTA)/MR angiography (MRA), 12 months after PTAS, were performed. Technical safety was evaluated based on periprocedural neurological complications and the number of recent embolic ischemic lesions (REIL) in the treated brain territory on diffusion-weighted imaging of early postprocedural MRI. RESULTS: Sixty-six (30 with and 36 without DEB) subjects were enrolled, with one failure in techniques. For 65 patients in the DEB versus conventional groups, technical neurological symptoms within 1 month (1/29 (3.4%) vs 0/36; P=0.197) and REIL numbers within 24 hours (1.0±2.1 vs 1.3±1.5; P=0.592) after PTAS showed no differences. Peak systolic velocity (PSVs) on short-term ultrasonography was significantly higher in the conventional group (104.13±42.76 vs .81.95±31.35; P=0.023). The degree of in-stent stenosis (45.93±20.86 vs 26.58±8.75; P<0.001) was higher, and there were more subjects (n=8, 38.9% vs 1, 3.4%; P=0.029) with significant ISR (≥ 50%) in the conventional group than in the DEB group on long-term CTA/MRA. CONCLUSIONS: We observed similar technical safety of carotid PTAS with and without DEBs. The number of cases of significant ISR were fewer and the degree of stenosis of ISR was less in primary DEB-PTAS of PIRCS than for conventional PTAS in the 12-month follow-up.

Iatrogenic retroperitoneal hematoma as an access-site complication of neurointervention.

BACKGROUND: To evaluate the clinical and imaging presentation, management, and outcome of iatrogenic retroperitoneal hematomas (IRPHs) during a series of neurointerventional procedures (NIPs). METHODS: Six IRPH patients with complications, including five renal subcapsular hematomas (RSH) and one retroperitoneal hemorrhage, were observed among 2290 NIPs performed at our hospital from 2000 through 2020. The medical records, neurointerventional techniques, imaging data, and management of these six IRPH patients were retrospectively reviewed. All six patients received preprocedural dual antiplatelet medication and intraprocedural heparinization. RESULTS: All patients underwent right femoral access. The guidewires were not handled under full course fluoroscopy monitoring. The most common symptom of IRPH was periprocedural flank/abdominal pain (6/6, 100%), including five on the left side (83.3%). Hypotension or shock was observed in three patients (50%). Two patients (33%) were diagnosed intraoperatively by sonogram and received on-site treatment, whereas the other four were diagnosed by postprocedural abdominal computed tomography. Active extravasation from a renal artery was diagnosed by angiogram in the five patients with RSH and was successfully treated with embolization. Multiple bleeders in the branches of the renal artery were noted in three RSH patients (60%). The patient with retroperitoneal hematoma was treated conservatively. CONCLUSION: Unexplained periprocedural or postprocedural abdominal/flank pain, especially contralateral to the femoral access side of the NIPs, should raise the possibility of IRPH. To prevent IRPH, the authors suggest using full visual fluoroscopic monitoring for guidewire navigation during femoral catheterization of NIPs.

Stagnant venous outflow in ruptured arteriovenous malformations revealed by delayed quantitative digital subtraction angiography.

PURPOSE: To investigate the reproducibility of quantitative digital subtraction angiography (QDSA) measurements and their associations with brain arteriovenous malformation (BAVM) hemorrhage. METHODS: From 2011-2019, 37 patients with BAVMs who had undergone both diagnostic and stereotactic DSA were divided into hemorrhagic and nonhemorrhagic groups. QDSA analysis was performed on the 2 DSA exams. The inter-exam reliabilities of QDSA measurements across the diagnostic and stereotactic DSA were tested using intraclass correlation coefficients (ICCs). Demographics, BAVM characteristics, and QDSA results for the hemorrhagic and nonhemorrhagic groups were compared. RESULTS: Fifteen of 37 (40.5 %) patients presented with hemorrhage were associated with smaller BAVM volume and the presence of intranidal aneurysm and exclusive deep venous drainage. The median interval between the diagnostic and stereotactic DSA was 49 days and did not differ between the groups. In both groups, the inter-exam QDSA measurements were more reliable for drainage veins and transnidal time (ICCs ranged from 0.38-0.93) than for feeding arteries (ICCs ranged from 0.01-0.74). Among the venous parameters, the hemorrhagic group had lower peak density, area under the curve, inflow gradient, and outflow gradient on both DSA exams and larger full width at half maximum and stasis index on the stereotactic DSA exam than the nonhemorrhagic group. CONCLUSIONS: In BAVMs, the QDSA measurements for veins are more reliable than those for arteries. QDSA analysis reflecting stagnant venous drainage is associated with BAVM hemorrhage, but may be confounded by the acute hemodynamic change after hemorrhage.

Stagnant Venous Outflow Predicts Brain Arteriovenous Malformation Obliteration After Gamma Knife Radiosurgery Without Prior Intervention.

BACKGROUND: Gamma Knife radiosurgery (GKRS) obliterates 65% to 82% of brain arteriovenous malformations (BAVMs). OBJECTIVE: To explore the impact of hemodynamics on GKRS outcomes. METHODS: We retrospectively (2011-2017) included 98 patients with BAVMs who had received GKRS alone. Two evaluators, blinded to the outcomes, analyzed the pre-GKRS angiography and magnetic resonance images to obtain the morphological characteristics and quantitative digital subtraction angiography (QDSA) parameters. The venous stasis index was defined as the inflow gradient divided by the absolute value of the outflow gradient. Patients' follow-up magnetic resonance or digital subtraction angiography images were evaluated for the presence of complete obliteration (CO). Cox regression and Kaplan-Meier analyses were conducted to determine the correlations between the parameters and outcomes. RESULTS: Among the 98 patients, 63 (63.4%) achieved CO after GKRS at a median latency period of 31 mo. In multivariable analyses with adjustments for age and sex, increased BAVM volume (hazard ratio (HR) 0.949, P = .022) was an independent characteristic predictor, and venous stenosis (HR 2.595, P = .009), venous rerouting (HR 0.375, P = .022), and larger stasis index (HR 1.227, P = .025) were independent angiographic predictors of CO. BAVMs with a stasis index of >1.71 had a higher 36-mo probability of CO than those with a stasis index of ≤1.71 (61.1% vs 26.7%, P < .001). CONCLUSION: BAVMs with a larger stasis index, indicating more stagnant venous outflow, may predict obliteration after GKRS. QDSA analysis may help in predicting BAVM treatment outcomes and making therapeutic decisions.

Stasis index from hemodynamic analysis using quantitative DSA correlates with hemorrhage of supratentorial arteriovenous malformation: a cross-sectional study.

OBJECTIVE: Assessments of hemorrhage risk based on angioarchitecture have yielded inconsistent results, and quantitative hemodynamic studies have been limited to small numbers of patients. The authors examined whether cerebral hemodynamic analysis using quantitative digital subtraction angiography (QDSA) can outperform conventional DSA angioarchitecture analysis in evaluating the risk of hemorrhage associated with supratentorial arteriovenous malformations (AVMs). METHODS: A cross-sectional study was performed by retrospectively reviewing adult supratentorial AVM patients who had undergone both DSA and MRI studies between 2011 and 2017. Angioarchitecture characteristics, DSA parameters, age, sex, and nidus volume were analyzed using univariate and multivariate logistic regression, and QDSA software analysis was performed on DSA images. Based on the QDSA analysis, a stasis index, defined as the inflow gradient divided by the absolute value of the outflow gradient, was determined. The receiver operating characteristic (ROC) curve was used to compare diagnostic performances of conventional DSA angioarchitecture analysis and analysis using hemodynamic parameters based on QDSA. RESULTS: A total of 119 supratentorial AVM patients were included. After adjustment for age at diagnosis, sex, and nidus volume, the exclusive deep venous drainage (p < 0.01), observed through conventional angioarchitecture examination using DSA, and the stasis index of the most dominant drainage vein (p = 0.02), measured with QDSA hemodynamic analysis, were independent risk factors for hemorrhage. The areas under the ROC curves for the conventional DSA method (0.75) and QDSA hemodynamics analysis (0.73) were similar. A venous stasis index greater than 2.18 discriminated the hemorrhage group with a sensitivity of 52.6% and a specificity of 81.5%. CONCLUSIONS: In QDSA, a higher stasis index of the most dominant drainage vein is an objective warning sign associated with supratentorial AVM rupture. Risk assessments of AVMs using QDSA and conventional DSA angioarchitecture were equivalent. Because QDSA is a complementary noninvasive approach without extra radiation or contrast media, comprehensive hemorrhagic risk assessment of cerebral AVMs should include both DSA angioarchitecture and QDSA analyses.

Effects of RF pulse profile and intra-voxel phase dispersion on MR fingerprinting with balanced SSFP readout.

PURPOSE: To investigate possible errors in T1 and T2 quantification via MR fingerprinting with balanced steady-state free precession readout in the presence of intra-voxel phase dispersion and RF pulse profile imperfections, using computer simulations based on Bloch equations. MATERIALS AND METHODS: A pulse sequence with TR changing in a Perlin noise pattern and a nearly sinusoidal pattern of flip angle following an initial 180-degree inversion pulse was employed. Gaussian distributions of off-resonance frequency were assumed for intra-voxel phase dispersion effects. Slice profiles of sinc-shaped RF pulses were computed to investigate flip angle profile influences. Following identification of the best fit between the acquisition signals and those established in the dictionary based on known parameters, estimation errors were reported. In vivo experiments were performed at 3T to examine the results. RESULTS: Slight intra-voxel phase dispersion with standard deviations from 1 to 3Hz resulted in prominent T2 under-estimations, particularly at large T2 values. T1 and off-resonance frequencies were relatively unaffected. Slice profile imperfections led to under-estimations of T1, which became greater as regional off-resonance frequencies increased, but could be corrected by including slice profile effects in the dictionary. Results from brain imaging experiments in vivo agreed with the simulation results qualitatively. CONCLUSION: MR fingerprinting using balanced SSFP readout in the presence of intra-voxel phase dispersion and imperfect slice profile leads to inaccuracies in quantitative estimations of the relaxation times.

Clinical applications of correlational vestibular autorotation test.

CONCLUSION: The correlational vestibular autorotation test (VAT) system has the advantages of good test-retest reliability and calibrations of absolute degrees of eye movement are unnecessary when acquiring a cross correlation coefficient (CCC). The approach is able to efficiently detect peripheral vestibulopathies. OBJECTIVE: A VAT has some drawbacks including poor test-retest reliability and slippage of sensor. This study aimed to develop a correlational VAT system and to evaluate the reliability and applicability of this system. METHODS: Twenty healthy participants and 10 vertiginous patients were enrolled. Vertical and horizontal autorotations from 0 to 3 Hz with either closed or open eyes were performed. A small sensor and a wireless transmission technique were used to acquire the electro-ocular graph and head velocity signals. The two signals were analyzed using CCCs to assess the functioning of the vestibular ocular reflex (VOR). RESULTS: The results showed a significantly greater CCC for open-eye versus closed-eye of head autorotations. The CCCs also increased significantly with head rotational frequencies. Moreover, the CCCs significantly correlated with the VOR gains at autorotation frequencies ≥1.0 Hz. The test-retest reliability was good (intraclass correlation coefficients ≥0.85). The vertiginous participants had significantly lower individual CCCs and overall average CCC than age- and-gender matched controls.