Chien-Hung Chang

Background: Collateral circulation plays a supportive role in stroke recovery, particularly among patients undergoing endovascular thrombectomy (EVT). While multiphase computed tomography angiography (mCTA)-based visual collateral scoring (vCS-mCTA) is widely used, its subjectivity and interobserver variability limit consistency. This preliminary study aimed to evaluate whether the mean fractal dimension ratio (mFD), derived from single-phase CTA (sCTA)-equivalent images, could serve as an objective and reproducible biomarker for collateral status assessment. Materials and Methods: This study retrospectively analyzed 54 patients with acute ischemic stroke who underwent EVT. The mFD was calculated using semi-automated fractal analysis of segmented vessels from the first phase of mCTA images. Collateral status was assessed using both sCTA and mCTA Menon visual scoring systems. The primary outcome was favorable 90-day functional status (modified Rankin Scale ≤ 2). Results: The sCTA-based visual collateral score (vCS-sCTA) was not significantly associated with clinical outcome. In contrast, higher mFD were significantly associated with favorable outcomes and demonstrated concordance with vCS-mCTA. In multivariable analysis, mFD remained an independent predictor after adjusting for clinical covariates. Its predictive performance was comparable to vCS-mCTA and superior to single-phase visual scoring. Conclusion: The mFD derived from sCTA-equivalent images may offer a practical and reproducible imaging biomarker for collateral assessment, offering predictive performance comparable to vCS-mCTA. As it does not rely on multiphase acquisition or subjective interpretation, mFD may enhance thrombectomy candidate selection, particularly in resource-limited or time-constrained settings.

Background: Acute ischemic stroke (AIS) remains a leading cause of mortality and disability worldwide. Accurate evaluation of collateral circulation is essential for predicting outcomes following endovascular thrombectomy (EVT). However, conventional visual collateral scoring (vCS) based on multiphase CT angiography (mCTA) is limited by subjectivity and inter-observer variability. This preliminary study introduces the multiphase quantitative collateral score (mqCS), a novel imaging biomarker designed to provide an objective and reproducible assessment of both the morphological extent and temporal dynamics of collateral flow. Methods: In this exploratory study, 54 AIS patients treated with EVT were retrospectively analyzed. Collateral status was evaluated using both vCS (graded by two blinded neuroradiologists) and mqCS, derived from mCTA-based fractal dimension (FD) and delay indicator (DI) metrics. Logistic regression and receiver operating characteristic (ROC) analyses were performed to assess the predictive value of each scoring system for favorable 90-day functional outcomes (modified Rankin scale, mRS ≤ 2). Results: The mqCS was significantly associated with favorable outcomes. Patients with mqCS ≥ 0.8674 had significantly higher odds of achieving favorable outcomes (adjusted OR = 5.98, 95% CI: 1.38–25.93, p = 0.017; AUC = 0.80). In comparison, the visual collateral score (vCS) showed a lower adjusted predictive value (adjusted OR = 2.84, 95% CI: 1.17–6.89, p = 0.02; AUC = 0.79). Patients in the highest mqCS quartiles (Q3–Q4) exhibited significantly better recovery rates (69%, p < 0.01). Conclusions: This proof-of-concept study suggests that mqCS provides a potentially more objective and robust alternative to visual scoring for collateral assessment in AIS. By integrating structural and temporal characteristics, mqCS enhances outcome prediction and may inform EVT decision-making, particularly in borderline cases. These preliminary findings warrant validation in larger, prospective cohorts and support its potential integration into automated imaging platforms.

Non-infectious cerebral venous thrombosis (CVT) is an uncommon type of cerebrovascular disease that usually affects young patients. It occurs frequently in female patients, probably due to the association of sex-specific risk factors for coagulopathies. Currently, the prognostic factors of CVT remain unclear. We retrospectively reviewed the clinical characteristics among 260 CVT patients, including 147 females and 113 males. A favorable clinical outcome was defined by the scores of the modified Rankin Scale (mRS) ≤ 2 at hospital discharge, while a poor clinical outcome was defined by an mRS score of 3 to 6. A headache (28.5%) was the most frequent presentation. The most commonly affected sinus was the transverse-sigmoid sinus (59.6%). Most of the cases (78.5%) were treated with anticoagulants. One hundred and fifty-seven patients (60.4%) were discharged with favorable clinical outcomes. Consciousness disturbance (odds ratio: 5.01, p < 0.001) was associated with a poor clinical outcome. Patients with poor clinical outcomes demonstrated higher D-dimer levels on admission (4137.76 ± 3317.07 vs. 2476.74 ± 2330.87 ng/mL FEU, p = 0.029) and longer hospitalization days (31.81 ± 26.29 vs. 13.96 ± 8.82 days, p < 0.001) compared with favorable clinical outcomes. These findings provide important information of clinical characteristics and prognosis for CVT. Aggressive monitoring and treatment should be considered in CVT patients with poor prognostic factors.

Background and purpose: to investigate the frequency of cervical–cranial vascular complications soon after radiation therapy (RT) and identify differences among patients with various types of head and neck cancer (HNC). Methods: We enrolled 496 patients with HNC who had received their final RT dose in our hospital. These patients underwent carotid duplex ultrasound (CDU) for monitoring significant carotid artery stenosis (CAS). Brain imaging were reviewed to detect vertebral, intracranial artery stenosis, or preexisted CAS before RT. Primary outcome was significant CAS at the internal or common carotid artery within first 5 years after RT. We categorized the patients into nasopharyngeal carcinoma (NPC) and non-NPC groups and compared the cumulative occurrence of significant CAS between the groups using Kaplan–Meier and Cox-regression analyses. Results: Compared to the NPC group, the non-NPC group had a higher frequency of significant CAS (12.7% vs. 2.0%) and were more commonly associated with significant CAS after adjusting the covariates (Adjusted hazard ratio: 0.17, 95% confident interval: 0.05–0.57) during the follow-up period. All the non-NPC subtypes (oral cancer/oropharyngeal, hypopharyngeal, and laryngeal cancers) were associated with higher risks of significant CAS than the NPC group (p < 0.001 respectively). Conclusion: Significant CAS was more frequently noted within 5 years of RT among the patients with non-NPC HNC than among the patients with NPC. Scheduled carotid artery surveillance and vascular risk monitoring should be commenced earlier for patients with non-NPC HNC. By contrast, vascular surveillance could be deferred to 5 years after RT completion in NPC patients.

Background: Tailored rehabilitation programs for stroke patients cannot be made without knowledge of their recovery potential. The aim of this study is to characterize the functional recovery patterns of ischemic stroke (IS) and intracerebral hemorrhage (ICH) patients under post-acute care stroke rehabilitation. Methods: This retrospective study analyzed the data of patients enrolled in the Post-Acute Care-Cerebrovascular Disease (PAC-CVD) rehabilitation program, which provides an individualized 1- to 3-hour intensive physical, occupational, and speech and language therapy for post-acute stroke patients in Taoyuan Chang Gung Memorial hospital in Taiwan. Our primary endpoint measure was Barthel Index (BI), and secondary endpoint measures included other 12 functional measures. Results: A total of 489 patients were included for analysis. Patients with stroke history had less BI improvement than those who suffered their first-ever stroke. In first-ever stroke patients who had completed 6 to 12 weeks of PAC-CVD program, subcortical ICH patients had greater BI, quality of life, sensation, and balance improvements, and had greater late-phase recovery than their IS counterparts. In IS patients, those with age > 75 had less BI improvement; those with National Institute of Health Stroke Scale (NIHSS) score 1– 5 had greater Motor Activity Log quality of use (MAL-quality) improvement than those with NIHSS score > 5; those with Mini-Mental State Examination (MMSE) score ≥ 24 had greater BI and instrumental activities of daily living (IADL) improvement. Using the general linear model, previous stroke (ß: − 6.148, p=0.01) and subcortical ICH (ß: 5.04, p=0.03) were factors associated with BI improvement. Conclusion: Subcortical ICH patients have greater functional improvement and greater late-phase recovery than their IS counterparts following PAC rehabilitation. More studies are needed to validate our findings and unravel the underlying mechanisms of stroke recovery to optimize the treatment strategy following a stroke.

Introduction: The multiphase computed tomography angiography (mCTA) is superior to the noncontrast computed tomography (NCCT) in selecting patients that would benefit from mechanical thrombectomy following an acute ischemic stroke (AIS). It remains unclear whether the longer examination time of mCTA worsens outcomes of intravenous recombinant tissue plasminogen activator (IV r-tPA) or increases the risk of hemorrhagic transformation (HT) compared to NCCT in Asian stroke patients. Methods: Between January 2011 and December 2017, 199 AIS patients receiving IV r-tPA with initial National Institute of Health Stroke Scale (NIHSS) scores between 6 and 25 were enrolled in a single medical center. Onset-to-needle time (ONT), door-to-needle time (DNT), and creatinine levels before and after thrombolysis were recorded. We evaluated NIHSS scores 2, 24 h after treatment, and at discharge, the modified Rankin Scale (mRS) at discharge, and mortality rate. The presence of HT was reviewed within 7 days after thrombolysis. Results: DNT, perithrombolysis creatinine levels, NIHSS, and mRS scores at the emergency room were similar between the NCCT and mCTA groups. ONT was shorter in the mCTA group. AIS patients got more significant neurologic improvement (NIHSS decrease ≥4) after thrombolysis and physically independent (mRS ≤2) at discharge in the mCTA group. Mortality rates, symptomatic, and total HT rates were similar between the NCCT and mCTA groups. Conclusion: Comparing to NCCT, mCTA-based IV r-tPA would not delay DNT nor worsen the outcome. Furthermore, mCTA provides more information for early identification of candidates for mechanical thrombectomy in Asian AIS patients.