Preoperative 11 C-Methionine PET-MRI in Pediatric Infratentorial Tumors.

PURPOSE: MRI is the main imaging modality for pediatric brain tumors, but amino acid PET can provide additional information. Simultaneous PET-MRI acquisition allows to fully assess the tumor and lower the radiation exposure. Although symptomatic posterior fossa tumors are typically resected, the patient management is evolving and will benefit from an improved preoperative tumor characterization. We aimed to explore, in children with newly diagnosed posterior fossa tumor, the complementarity of the information provided by amino acid PET and MRI parameters and the correlation to histopathological results. PATIENTS AND METHODS: Children with a newly diagnosed posterior fossa tumor prospectively underwent a preoperative 11 C-methionine (MET) PET-MRI. Images were assessed visually and semiquantitatively. Using correlation, minimum apparent diffusion coefficient (ADC min ) and contrast enhancement were compared with MET SUV max . The diameter of the enhancing lesions was compared with metabolic tumoral volume. Lesions were classified according to the 2021 World Health Organization (WHO) classification. RESULTS: Ten children were included 4 pilocytic astrocytomas, 2 medulloblastomas, 1 ganglioglioma, 1 central nervous system embryonal tumor, and 1 schwannoma. All lesions showed visually increased MET uptake. A negative moderate correlation was found between ADC min and SUV max values ( r = -0.39). Mean SUV max was 3.8 (range, 3.3-4.2) in WHO grade 4 versus 2.5 (range, 1.7-3.0) in WHO grade 1 lesions. A positive moderate correlation was found between metabolic tumoral volume and diameter values ( r = 0.34). There was no correlation between SUV max and contrast enhancement intensity ( r = -0.15). CONCLUSIONS: Preoperative 11 C-MET PET and MRI could provide complementary information to characterize pediatric infratentorial tumors.

Analysis of Changes in KPS Scores and Imaging Signs in Deep Brain Gliomas by DWI Combined with Intraoperative Ultrasound Resection.

Objective: This study investigates the efficacy of DWI combined with intraoperative ultrasound for deep brain glioma treatment, analyzing changes in Karnofsky performance status (KPS) scores and imaging signs. Objectives include elucidating the approach's advantages, addressing knowledge gaps, and contributing insights into its effectiveness for enhancing deep brain glioma management. Methods: In this retrospective study, we analyzed a total of 346 patients with deep brain glioma who underwent surgical treatment at our hospital from July 2015 to January 2022. After applying inclusion and exclusion criteria, 310 patients were selected and categorized into a control group (n = 150) and an observation group (n = 160) based on different auxiliary techniques of surgical treatment. The degree of resection and Karnofsky performance status (KPS) scores were assessed at 1 day preoperatively, 1 week, and 1 month postoperatively for both groups. Additionally, we conducted a comprehensive analysis of DWI and ultrasound imaging signs among patients with different grades of deep brain glioma. The study duration covered the specified period, and statistical analyses were performed to evaluate the outcomes. Results: In our study, the observation group demonstrated significantly improved resection degrees, with a total resection rate of 82.50% compared to the control group's 65.33%. Preoperative Karnofsky performance status scores showed no significant difference between groups (P > .05), but postoperative scores at 1 week and 1 month were significantly higher in the observation group (P < .05). Intraoperative ultrasound and DWI revealed distinct imaging signs differentiating low-grade and high-grade patients. These results highlight the efficacy of DWI combined with intraoperative ultrasound resection in enhancing resection outcomes and influencing postoperative Karnofsky performance status. Conclusions: DWI combined with intraoperative ultrasonic resection in deep brain glioma has a significant effect, with specific imaging signs, which can effectively improve the total resection rate and KPS score, and is worthy of clinical promotion. DWI combined with intraoperative ultrasound has important clinical significance in the resection of deep brain gliomas. The better resection results and improved postoperative Karnofsky performance-status score that we observed suggest a possible benefit in patient outcomes, which could influence treatment strategies. The precise imaging signs identified by this method provide valuable guidance for targeted and effective tumor resection.

ADC Values for Detecting Bowel Inflammation and Biologic Therapy Response in Patients With Crohn Disease: A Post Hoc Prospective Trial Analysis.

BACKGROUND. New biologic agents for Crohn disease (CD) create a need for noninvasive disease markers. DWI may assess bowel inflammation without contrast agents. OBJECTIVE. The purpose of this study was to evaluate ADC values for identifying bowel inflammation and therapeutic response in patients with CD treated with biologic therapy. METHODS. This study entailed post hoc analysis of prospective trial data. Analysis included 89 patients (median age, 37 years; 49 women, 40 men) with CD treated by biologic therapy who underwent MR enterography (MRE) at baseline and 46 weeks after therapy, from March 2013 to April 2021; 43 patients underwent ileocolonoscopy at both time points. Analysis was conducted at the level of small-bowel and colorectal segments (586 segments analyzed). MR index of activity (MaRIA) score and presence of endoscopic ulcers were determined at both time points. One observer measured bowel wall ADC. Diagnostic performance was evaluated. Dichotomous ADC assessments used a threshold of 1301 × 10-6 mm2/s based on initial ROC analysis; dichotomous MaRIA score assessments used a threshold of 11 (moderate to severe inflammation). A second observer repeated ADC measurements in 15 patients. RESULTS. At baseline, ADC had AUC of 0.92, sensitivity of 78.6%, specificity of 91.4%, and accuracy of 88.2% for detecting segments with MaRIA score 11 or greater. At baseline, AUC for detecting endoscopic ulcers was 0.96 for MaRIA score versus 0.87 for ADC (p < .001); sensitivity, specificity, and accuracy were 70.8%, 90.2%, and 85.1% for ADC and 86.2%, 96.2%, and 93.6% for MaRIA score. At follow-up, ADC had AUC of 0.87, sensitivity of 75.4%, specificity of 83.6%, and accuracy of 80.0% for detecting improvement in MaRIA score to less than 11. At follow-up, AUC for detecting endoscopic ulcer healing was 0.94 for MaRIA score versus 0.84 for ADC (p = .01); sensitivity, specificity, and accuracy were 70.7%, 95.8%, and 84.4% for ADC and 90.2%, 100.0%, and 95.6% for MaRIA score. Interobserver agreement for ADC, based on intraclass correlation coefficient, was 0.70 at baseline and 0.65 at follow-up. CONCLUSION. The findings do not support use of ADC rather than MaRIA scores for detecting biologic therapy response. CLINICAL IMPACT. ADC may have an adjunct role in assessing bowel inflammation in CD, but showed limited performance for detecting biologic therapy response.

Imaging findings of intraventricular pilocytic astrocytoma.

OBJECTIVE: The aim of this study is to present the clinical and imaging findings of 16 patients with intraventricular pilocytic astrocytomas (PAs). METHODS: 16 patients with histopathological diagnosis of intraventricular PA between February 2016 and January 2022 were evaluated retrospectively. Imaging and clinical findings of the patients, as well as apparent diffusion coefficient (ADC) measurements were analyzed. RESULTS: Of 16 patients, 8 (%50) were male and 8 (%50) were female. The mean age of the patients was 20.8 years (2-44 years range). The most common symptoms in the patients were headache and ataxia. The mean long-axis size of lesions was found to be 48.19 ± 21.59 (range, 15-92 mm). 9 out of 16 lesions (56.2%) were located in the fourth ventricle. The majority of the lesions were iso-hypointense in T1W and hyperintense in T2W images. The mean ADC value of PAs was 1.57 × 10-3 ± 0.2 mm2/s, while the mean thalamic ADC and white matter ADC values were found to be 0.78 × 10-3 ± 0.04 and 0.76 × 10-3 ± 0.06 mm2/s, respectively. There was a statistically significant difference between the ADC values obtained from the solid components of the lesions and the thalami/white matter (p < 0.001). CONCLUSION: PAs often originate from midline structures, however, they can also be located intraventricularly. Although intraventricular PAs are frequently seen in pediatric population, it should be kept in mind that they can also be seen in adults, albeit rarely. ADVANCES IN KNOWLEDGE: PA should be considered in the differential diagnosis of intraventricular neoplasms in case of high ADC values.

Field-of-view optimized and constrained undistorted single-shot study of intravoxel incoherent motion and diffusion-weighted imaging of the uterus during the menstrual cycle: a prospective study.

PURPOSE: This study aimed to compare the variability of the uterus during the menses phase (MP), follicular phase (FP), and luteal phase (LP) of the menstrual cycle using intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI). METHODS: This prospective study was conducted at the Guangdong Provincial Hospital of Traditional Chinese Medicine between January 2022 and January 2023. Women of childbearing age (18-45 years) with appropriate progesterone levels were included in this study. Conventional magnetic resonance imaging and IVIM-DWI scans were performed during the MP, FP, and LP. The differences in IVIM-DWI-derived parameters between these phases were then compared, and the overlap was quantitatively described. RESULTS: The apparent diffusion coefficient (ADC) and pure molecular diffusion coefficient (D) values from the endometrium, uterine junctional zone (UJZ), and myometrium indicated statistical differences between the MP and FP and the MP and LP (ADC: endometrium, both P < 0.001; UJZ, P = 0.008 and P < 0.001, respectively; myometrium, P = 0.033 and P = 0.006, respectively; D: endometrium, both P < 0.001; UJZ, P = 0.008 and P = 0.006, respectively; myometrium, P = 0.041 and P = 0.045, respectively). The perfusion-related diffusion coefficient (D*) values from the myometrium indicated statistical differences between the FP and MP and the FP and LP (D*: myometrium, P = 0.049 and P = 0.009, respectively). The overlapping endometrium ratios between the MP and FP or LP were lower than 50% in the ADC and D values (ADC: overlapping of MP and FP: 33.33%, overlapping of MP and LP: 23.33%; D: overlapping of MP and FP: 40.00%, overlapping of MP and LP: 43.33%). CONCLUSION: The ADC and IVIM-derived parameters indicated differences in the uterus in diverse phases of the menstrual cycle, especially in the endometrium in relation to ADC and D values.

Diffusion-weighted imaging measurements of central smell regions in COVID-19 patients: insular gyrus, corpus amygdala, and thalamus.

OBJECTIVE: The aim of this study was to investigate central smell centers with cranial magnetic resonance imaging (MRI) diffusion-weighted imaging (DWI) in COVID-19. PATIENTS AND METHODS: This retrospective study evaluated cranial MRI images of 54 adults. The experimental group (Group 1), consisting of 27 patients with positive COVID-19 real-time polymerase chain reaction (RT-PCR) assays, was compared to the control group (Group 2), comprising 27  healthy controls without COVID-19. The apparent diffusion coefficient (ADC) values were measured in the corpus amygdala, thalamus, and insular gyrus in both groups. RESULTS: Thalamus ADC values of the COVID-19 group were significantly lower compared to the control group bilaterally. However, no differences were found in the insular gyrus and corpus amygdala ADC values between the two groups. Positive correlations were observed between the insular gyrus and corpus amygdala ADC values and the thalamus ADC values. Insular gyrus ADC values (right) were higher in females. Left insular gyrus and corpus amygdala ADC values were higher in COVID-19 patients with smell loss. Right insular gyrus and left corpus amygdala ADC values were lower in COVID-19 patients with lymphopenia. CONCLUSIONS: Diffusion restriction in olfactory areas can be considered an obvious indicator that the COVID-19 virus affects and damages the immune system at the neuronal level. Given the urgency and lethality of the current pandemic, acute onset odor loss should be considered a high suspicion-adhesive index for patients with SARS-CoV-2 infection. Therefore, the sense of smell should be considered and evaluated simultaneously with other neurological symptoms. DWI should be widely used as an early imaging method for central nervous system (CNS) infections, especially in relation to COVID-19.

Patient preparation for prostate MRI: A scoping review.

PURPOSE: To perform a scoping review of the literature evaluating patient preparation for prostate MRI. METHODS: We conducted a search of English language literature, between 1989 and 2022 using MEDLINE and EMBASE for key terms: diet, enema, gel, catheter and anti-spasmodic agents linked to prostate MRI. Studies were reviewed for: level of evidence (LOE), study design and key results. Knowledge gaps were identified. RESULTS: Three studies evaluated dietary modification in 655 patients. LOE was 3. All studies showed improved DWI and T2W image quality (IQ) and reduced DWI artifact. Nine studies evaluated enema use in 1551 patients. Mean LOE was 2.8 (range 2-3). Six studies reported IQ; DWI and T2W IQ were significantly improved with enema in 5/6 and 4/6 studies respectively. Only one study evaluated DWI/T2W lesion visibility which was improved with enema. One study evaluated impact of enema on eventual prostate cancer diagnosis, showing no benefit in false negative reduction. One study (LOE = 2, 150 patients) evaluated rectal gel; however, in combination with enema showing improved DWI and T2W IQ, lesion visibility and PI-QUAL compared to no preparation. Two studies evaluated use of rectal catheter in 396 patients. LOE was 3. One study showed improved DWI and T2W IQ and artifact compared to no preparation; however, the other showed inferior results comparing rectal catheter to enema. Six studies evaluated anti-spasmodic agent use in 888 patients. Mean LOE was 2.8 (range 2-3). Benefit of anti-spasmodic agent use on image quality and artifact on DWI and T2W are conflicting with no clear benefit. CONCLUSION: Data evaluating patient preparation for prostate MRI is limited by level of evidence, study design and conflicting results. The majority of published studies do not evaluate impact of patient preparation on eventual prostate cancer diagnosis.

Magnetic resonance differential analysis for different hormone receptor expression status in HER-2-positive breast cancer. / HER-2é˜³æ€§ä¹³è ºç™Œä¸­ä¸åŒæ¿€ç´ å—ä½“è¡¨è¾¾çŠ¶æ€çš„ç£å ±æŒ¯é‰´åˆ«.

OBJECTIVES: Currently, it is difficult to assess the expression status of hormone receptor (HR) in breast malignant tumors with human epidermal growth factor receptor 2 (HER-2)-positive in the early preoperative stage, and it is difficult to predict whether it is non-invasively. This study aims to explore the value of MRI on the different HR expression status (HR+/HR-) in HER-2 positive breast cancer. METHODS: Thirty patients with HR+ HER-2-positive breast cancer (HR+ group) and 23 patients with HR-HER-2-positive breast cancer (HR- group) from the First Hospital of Hunan University of Traditional Chinese Medicine between January 7, 2015 and November 26, 2021 were selected as subjects, and all the patients were examined by MRI and all were confirmed by surgery or pathological biopsy puncture. The immunohistochemical staining results were used as the gold standard to analyze the basic clinical conditions, peri-lesion conditions and MRI sign characteristics in the 2 groups. RESULTS: There were all significant differences in terms of mass margins, internal reinforcement features, and apparent diffusion coefficient (ADC) values between the HR+ group and the HR- group (all P<0.05). The logistic multivariate regression model showed that: when the lesion presented as a mass-type breast cancer on MRI, the internal enhancement features of the lesion were an independent predictor for differentiation in the 2 types of breast cancer [odds ratio (OR)=5.95, 95% CI: 1.223 to 28.951, P<0.05], and the mass margin (OR=0.386, 95% CI: 0.137 to 1.082, P>0.05) and ADC value (OR=0.234, 95% CI: 0.001 to 105.293, P>0.05) were not the independent predictors in distinguishing the 2 types of breast cancer. CONCLUSIONS: Multiparametric MRI has good diagnostic value for HR expression status in HER-2-positive breast cancer. Combined logistic regression analysis to construct a predictive model may be helpful to the identical diagnosis.

The effect of mindfulness-based intervention on neurobehavioural functioning and its association with white-matter microstructural changes in preterm young adolescents.

Very preterm (VPT) young adolescents are at high risk of executive, behavioural and socio-emotional difficulties. Previous research has shown significant evidence of the benefits of mindfulness-based intervention (MBI) on these abilities. This study aims to assess the association between the effects of MBI on neurobehavioral functioning and changes in white-matter microstructure in VPT young adolescents who completed an 8-week MBI program. Neurobehavioural assessments (i.e., neuropsychological testing, parents- and self-reported questionnaires) and multi-shell diffusion MRI were performed before and after MBI in 32 VPT young adolescents. Combined diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) measures were extracted on well-defined white matter tracts (TractSeg). A multivariate data-driven approach (partial least squares correlation) was used to explore associations between MBI-related changes on neurobehavioural measures and microstructural changes. The results showed an enhancement of global executive functioning using parent-reported questionnaire after MBI that was associated with a general pattern of increase in fractional anisotropy (FA) and decrease in axonal dispersion (ODI) in white-matter tracts involved in executive processes. Young VPT adolescents with lower gestational age at birth showed the greatest gain in white-matter microstructural changes after MBI.

Accurately quantified plasma free glycine concentration as a biomarker in patients with acute ischemic stroke.

We developed a hollow fiber centrifugal ultrafiltration (HFCF-UF) method to study the change of plasma levels of free glycine (Gly) in patients with acute ischemic stroke (AIS). Twenty-four patients with AIS confirmed by diffusion-weighted imaging (DWI) were enrolled. During the study period, the patients did not receive any supplemental amino acids therapy that could affect the obtained results. Our results showed that although AIS patients adopted different methods of treatment (thrombolytic and non-thrombolytic), the clinical NIHSS score of AIS showed a downward trend whereas Gly concentration showed increased trend. Moreover, plasma free Gly concentration was positively correlated with ASPECTS score. The correlation between Gly levels and infarct volume showed a statistical significance. That is to say, higher Gly level predicted smaller infarct size. Thus, the change of free Gly level in plasma could be considered as a potential biomarker of AIS.

Magnetic resonance differential analysis for different hormone receptor expression status in HER-2-positive breast cancer / 中南大学学报(医学版)

OBJECTIVES@#Currently, it is difficult to assess the expression status of hormone receptor (HR) in breast malignant tumors with human epidermal growth factor receptor 2 (HER-2)-positive in the early preoperative stage, and it is difficult to predict whether it is non-invasively. This study aims to explore the value of MRI on the different HR expression status (HR+/HR-) in HER-2 positive breast cancer.@*METHODS@#Thirty patients with HR+ HER-2-positive breast cancer (HR+ group) and 23 patients with HR-HER-2-positive breast cancer (HR- group) from the First Hospital of Hunan University of Traditional Chinese Medicine between January 7, 2015 and November 26, 2021 were selected as subjects, and all the patients were examined by MRI and all were confirmed by surgery or pathological biopsy puncture. The immunohistochemical staining results were used as the gold standard to analyze the basic clinical conditions, peri-lesion conditions and MRI sign characteristics in the 2 groups.@*RESULTS@#There were all significant differences in terms of mass margins, internal reinforcement features, and apparent diffusion coefficient (ADC) values between the HR+ group and the HR- group (all P<0.05). The logistic multivariate regression model showed that: when the lesion presented as a mass-type breast cancer on MRI, the internal enhancement features of the lesion were an independent predictor for differentiation in the 2 types of breast cancer [odds ratio (OR)=5.95, 95% CI: 1.223 to 28.951, P<0.05], and the mass margin (OR=0.386, 95% CI: 0.137 to 1.082, P>0.05) and ADC value (OR=0.234, 95% CI: 0.001 to 105.293, P>0.05) were not the independent predictors in distinguishing the 2 types of breast cancer.@*CONCLUSIONS@#Multiparametric MRI has good diagnostic value for HR expression status in HER-2-positive breast cancer. Combined logistic regression analysis to construct a predictive model may be helpful to the identical diagnosis.

STEAM-DWI as a robust alternative to EPI-DWI: Evaluation in pediatric brain MRI.

PURPOSE: Diffusion-weighted imaging (DWI) is an essential element of almost every brain MRI examination. The most widely applied DWI technique, a single-shot echo-planar imaging DWI (EPI-DWI) sequence, suffers from a high sensitivity to magnetic field inhomogeneities. As an alternative, a single-shot stimulated echo acquisition mode diffusion-weighted MRI (STEAM-DWI) has recently been re-introduced after it became significantly faster. The aim of the study was to investigate the applicability of STEAM-DWI as a substitute to EPI-DWI in a daily routine of pediatric radiology. METHODS: Retrospectively, brain MRI examinations of 208 children with both EPI-DWI and STEAM-DWI were assessed. Visual resolution and diagnostic confidence were evaluated, the extent of susceptibility artifacts was quantified, and contrast-to-noise ratio was calculated in case of diffusion restriction. Furthermore, the correlation of apparent diffusion coefficient values between STEAM-DWI and EPI-DWI was tested. RESULTS: STEAM-DWI was inferior to EPI-DWI in visual resolution but with higher diagnostic confidence and lower artifact size. The apparent diffusion coefficient values of both sequences demonstrated excellent correlation. The contrast-to-noise ratio of STEAM-DWI was only half of that of EPI-DWI (58% resp. 112%). CONCLUSION: STEAM-DWI is a robust alternative to EPI-DWI when increased susceptibility artifacts are to be expected. Drawbacks are a lower contrast-to-noise ratio and poorer visual resolution.

PET/MR in recurrent glioblastoma patients treated with regorafenib: [18F]FET and DWI-ADC for response assessment and survival prediction.

OBJECTIVE: The use of regorafenib in recurrent glioblastoma patients has been recently approved by the Italian Medicines Agency (AIFA) and added to the National Comprehensive Cancer Network (NCCN) 2020 guidelines as a preferred regimen. Given its complex effects at the molecular level, the most appropriate imaging tools to assess early response to treatment is still a matter of debate. Diffusion-weighted imaging and O-(2-18F-fluoroethyl)-L-tyrosine positron emission tomography ([18F]FET PET) are promising methodologies providing additional information to the currently used RANO criteria. The aim of this study was to evaluate the variations in diffusion-weighted imaging/apparent diffusion coefficient (ADC) and [18F]FET PET-derived parameters in patients who underwent PET/MR at both baseline and after starting regorafenib. METHODS: We retrospectively reviewed 16 consecutive GBM patients who underwent [18F]FET PET/MR before and after two cycles of regorafenib. Patients were sorted into stable (SD) or progressive disease (PD) categories in accordance with RANO criteria. We were also able to analyze four SD patients who underwent a third PET/MR after another four cycles of regorafenib. [18F]FET uptake greater than 1.6 times the mean background activity was used to define an area to be superimposed on an ADC map at baseline and after treatment. Several metrics were then derived and compared. Log-rank test was applied for overall survival analysis. RESULTS: Percentage difference in FET volumes correlates with the corresponding percentage difference in ADC (R = 0.54). Patients with a twofold increase in FET after regorafenib showed a significantly higher increase in ADC pathological volume than the remaining subjects (p = 0.0023). Kaplan-Meier analysis, performed to compare the performance in overall survival prediction, revealed that the percentage variations of FET- and ADC-derived metrics performed at least as well as RANO criteria (p = 0.02, p = 0.024 and p = 0.04 respectively) and in some cases even better. TBR Max and TBR mean are not able to accurately predict overall survival. CONCLUSION: In recurrent glioblastoma patients treated with regorafenib, [18F]FET and ADC metrics, are able to predict overall survival and being obtained from completely different measures as compared to RANO, could serve as semi-quantitative independent biomarkers of response to treatment. ADVANCES IN KNOWLEDGE: Simultaneous evaluation of [18F]FET and ADC metrics using PET/MR allows an early and reliable identification of response to treatment and predict overall survival.

Novel Diffusion-Weighted Imaging Score Showed Good Prognostic Value for Acute Basilar Artery Occlusion Following Endovascular Treatment: The Pons-Midbrain and Thalamus Score.

BACKGROUND AND PURPOSE: Prognostic factors for outcome of endovascular treatment remains to be investigated in patients with acute basilar artery occlusion. We aimed to assess the prognostic value of a novel pretreatment diffusion-weighted imaging score: The Pons-Midbrain and Thalamus (PMT) score. METHODS: Eligible patients who underwent endovascular treatment due to acute basilar artery occlusion were reviewed. The PMT score was a diffusion-weighted imaging-based semiquantitative scale in which the infarctions of pons, midbrain, and thalamus were fully considered. The PMT score was assessed as well as the posterior circulation Acute Stroke Prognosis Early Computed Tomography Score and Brain Stem Score. Good outcomes were defined as a modified Rankin Scale score of ≤3 at 90-day and successful reperfusion as Thrombolysis in Cerebral Infarction grades 2b/3. The associations between baseline clinical parameters and good outcomes were evaluated with logistic regression. RESULTS: A total of 107 patients with pretreatment magnetic resonance imaging were included in this cohort. The baseline PMT score (median [interquartile range], 3 [1-5] versus 7 [5-9]; P<0.001) and Brain Stem Score (median [interquartile range], 2 [1-4] versus 3 [2-5]; P=0.001) were significantly lower in good outcome group; the posterior circulation Acute Stroke Prognosis Early Computed Tomography Score was higher in good outcome group without statistical significance. As a result of receiver operating characteristic curve analyses, the posterior circulation Acute Stroke Prognosis Early Computed Tomography Score showed poor prognostic accuracy for good outcome (area under the curve, 0.60 [95% CI, 0.49-0.71]; P=0.081); The baseline PMT score showed significantly better prognostic accuracy for 90-day good outcome than the Brain Stem Score and National Institutes of Health Stroke Scale (area under the curve, 0.80 versus 0.68 versus 0.78, P=0.003). In addition, favorable PMT score <7 (odds ratio, 22.0 [95% CI, 6.0-80.8], P<0.001), Brain Stem Score <3 (odds ratio, 4.65 [95% CI, 2.05-10.55], P<0.001) and baseline National Institutes of Health Stroke Scale <23 (odds ratio, 8.0 [95% CI, 2.5-25.6], P<0.001) were associated with improved good outcome. CONCLUSIONS: In patients with acute basilar artery occlusion following endovascular treatment, the pretreatment diffusion-weighted imaging based PMT score showed good prognostic value for clinical outcome.

Isolated acute pseudobulbar palsy with infarction of artery of percheron: case report and literature review.

INTRODUCTION: Pseudobulbar palsy (PBP) is characterized by supranuclear lesions in the corticobulbar pathway. Neoplasia, inflammatory, demyelinating, and stroke are possible etiologies of this disorder. CASE REPORT: We report an elderly female who presented with dysarthria. She was dysarthric with a hypernasal voice, no apraxia or aphasia was observed. Tongue movements were slow with limited amplitude. Her soft palate dropped bilaterally; gag reflex was present. Also, she reported swallowing difficulty and choking with her saliva. Bilateral vertical and horizontal gaze were intact to either voluntary or oculocephalic movements. A cranial CT scan was suggestive of artery of Percheron (AOP) infarction. Brain magnetic resonance imaging showed hypersignal on diffusion-weighted and T2-weighted images and hyposignal on apparent diffusion coefficient in both thalami. CT angiography scan revealed an AOP originating from the left posterior cerebral artery. The swallowing study with a videofluoroscopic demonstrated oral and pharyngeal phases with severe dysfunction. CONCLUSION: To the authors' knowledge, there are two cases of individuals with artery of Percheron infarction who developed PBP associated with other clinical syndromes. Still, isolated PBP following infarction of Percheron's artery was not reported. We hypothesized that the PBP may have occurred because of the existence of vascular territory variations in the perforating arteries that arise from the AOP.

Characterizing Diaschisis-Related Thalamic Perfusion and Diffusion After Middle Cerebral Artery Infarction.

Background and Purpose: Ipsilateral thalamic diaschisis (ITD) initially describes functional depression of the thalamus ipsilateral to a supratentorial lesion, but accumulating evidence has shown morphological changes also occur. Therefore, we aimed to characterize thalamic perfusion and diffusion related to ITD over time and their inter-relationships after middle cerebral artery infarction. Methods: Eighty-five patients with middle cerebral artery infarction who underwent diffusion kurtosis imaging and arterial spin labeling were retrospectively included. ITD was diagnosed as ipsilateral thalamic hypoperfusion present on ≥2 cerebral blood flow maps. The thalamic asymmetrical index was calculated as (ipsilateral value−contralateral value)/contralateral value×100%. Finally, the inter-relationships of thalamic perfusion and diffusion were analyzed. Results: ITD was present in 56/85 patients (65.9%, ITD+). In ITD+ patients, larger abnormal perfusion volume, higher perfusion-infarct mismatch and lower rates of focal hyperperfusion were observed than ITD− patients. Infarction affecting the corona radiata were more frequent among ITD+ patients. Mean kurtosis were slightly but significantly increased within the ipsilateral thalamus compared with the contralateral one in ITD+ patients of subacute and chronic groups, while fractional anisotropy was significantly increased in subacute group but decreased in chronic group for both ITD+ and ITD− patients. Mean diffusivity was significantly increased in ITD+ patients of chronic group. Furthermore, the AICBF was negatively and significantly correlated with AIMK and AIFA in ITD+ patients in subacute group, and AIMD, even after adjustment for abnormal perfusion volume and days from symptoms onset, in chronic group. ITD+ patients had significantly higher National Institutes of Health Stroke Scale and modified Rankin Scale scores at admission and discharge and also showed a trend to independent association with clinical outcome at discharge. Conclusions: The combination of arterial spin labeling and diffusion kurtosis imaging can reveal early, time-specific thalamic perfusion and diffusion changes after middle cerebral artery infarction. ITD-related hypoperfusion was significantly correlated with underlying microstructural alterations.

Methylene tetrahydrofolate reductase A1298C polymorphisms influence the adult sequelae of chemotherapy in childhood-leukemia survivors.

This retrospective correlation study investigated the putative link between methylene tetrahydrofolate reductase (MTHFR) A1298C mutations and chemotherapy-related brain function changes in adult childhood-leukemia survivors. To this end, we determined the relationship between the particular MTHFR1298 genotype (AA, AC or CC) of 31 adult childhood-leukemia survivors, and (1) their CSF Tau and phosphorylated Tau (pTau) levels at the time of treatment, (2) their adult performance intelligence quotient (PIQ), and (3) their regional brain connectivity using diffusion magnetic resonance imaging (dMRI) and resting-state functional MRI (rsfMRI). We confirmed that neuropathology markers Tau and pTau significantly increased in CSF of children after intrathecal methotrexate administration. Highest concentrations of these toxicity markers were found during the induction phase of the therapy. Moreover, CSF concentrations of Tau and pTau during treatment were influenced by the children's particular MTHFR1298 genotype. CSF Tau (but not pTau) levels significantly dropped after folinic acid supplementation. At adult age (on average 13.1 years since the end of their treatment), their particular MTHFR1298 genotype (AA, AC or CC) influenced the changes in PIQ and cortical connectivity that we found to be related to their childhood exposure to chemotherapeutics. In summary, we suggest that homozygous MTHFR1298CC individuals are more vulnerable to the adult sequelae of antifolate chemotherapy.

Structural alterations in cortical and thalamocortical white matter tracts after recovery from prefrontal cortex lesions in macaques.

Unilateral damage to the frontoparietal network typically impairs saccade target selection within the contralesional visual hemifield. Severity of deficits and the degree of recovery have been associated with widespread network dysfunction, yet it is not clear how these behavioural and functional brain changes relate with the underlying structural white matter tracts. Here, we investigated whether recovery after unilateral prefrontal cortex (PFC) lesions was associated with changes in white matter microstructure across large-scale frontoparietal cortical and thalamocortical networks. Diffusion-weighted imaging was acquired in four male rhesus macaques at pre-lesion, week 1, and week 8-16 post-lesion when target selection deficits largely recovered. Probabilistic tractography was used to reconstruct cortical frontoparietal fiber tracts, including the superior longitudinal fasciculus (SLF) and transcallosal fibers connecting the PFC or posterior parietal cortex (PPC), as well as thalamocortical fiber tracts connecting the PFC and PPC to thalamic nuclei. We found that the two animals with small PFC lesions showed increased fractional anisotropy in both cortical and thalamocortical fiber tracts when behaviour had recovered. However, we found that fractional anisotropy decreased in cortical frontoparietal tracts after larger PFC lesions yet increased in some thalamocortical tracts at the time of behavioural recovery. These findings indicate that behavioural recovery after small PFC lesions may be supported by both cortical and subcortical areas, whereas larger PFC lesions may have induced widespread structural damage and hindered compensatory remodeling in the cortical frontoparietal network.

Displaying the autonomic processing network in humans - a global tractography approach.

Regulation of the internal homeostasis is modulated by the central autonomic system. So far, the view of this system is determined by animal and human research focusing on cortical and subcortical grey substance regions. To provide an overview based on white matter architecture, we used a global tractography approach to reconstruct a network of tracts interconnecting brain regions that are known to be involved in autonomic processing. Diffusion weighted imaging data were obtained from subjects of the human connectome project (HCP) database. Resulting tracts are in good agreement with previous studies assuming a division of the central autonomic system into a cortical (CAN) and a subcortical network (SAN): the CAN consist of three subsystems that encompass all cerebral lobes and overlap within the insular cortex: a parieto-anterior-temporal pathway (PATP), an occipito-posterior-temporo-frontal pathway (OPTFP) and a limbic pathway. The SAN on the other hand connects the hypothalamus to the periaqueductal grey and locus coeruleus, before it branches into a dorsal and a lateral part that target autonomic nuclei in the rostral medulla oblongata. Our approach furthermore reveals how the CAN and SAN are interconnected: the hypothalamus can be considered as the interface-structure of the SAN, whereas the insula is the central hub of the CAN. The hypothalamus receives input from prefrontal cortical fields but is also connected to the ventral apex of the insular cortex. Thus, a holistic view of the central autonomic system could be created that may promote the understanding of autonomic signaling under physiological and pathophysiological conditions.

Discriminating subcortical ischemic vascular disease and Alzheimer's disease by diffusion kurtosis imaging in segregated thalamic regions.

Differentiating between subcortical ischemic vascular disease (SIVD), Alzheimer's disease (AD), and normal cognition (NC) remains a challenge, and reliable neuroimaging biomarkers are needed. The current study, therefore, investigated the discriminative ability of diffusion kurtosis imaging (DKI) metrics in segregated thalamic regions and compare with diffusion tensor imaging (DTI) metrics. Twenty-three SIVD patients, 30 AD patients, and 24 NC participants underwent brain magnetic resonance imaging. The DKI metrics including mean kurtosis (MK), axial kurtosis (Kaxial ) and radial kurtosis (Kradial ) and the DTI metrics including diffusivity and fractional anisotropy (FA) were measured within the whole thalamus and segregated thalamic subregions. Strategic correlations by group, thalamo-frontal connectivity, and canonical discriminant analysis (CDA) were used to demonstrate the discriminative ability of DKI for SIVD, AD, and NC. Whole and segregated thalamus analysis suggested that DKI metrics are less affected by white matter hyperintensities compared to DTI metrics. Segregated thalamic analysis showed that MK and Kradial were notably different between SIVD and AD/NC. The correlation analysis between Kaxial and MK showed a nonsignificant relationship in SIVD group, a trend of negative relationship in AD group, and a significant positive relationship in NC group. A wider spatial distribution of thalamo-frontal connectivity differences across groups was shown by MK compared to FA. CDA showed a discriminant power of 97.4% correct classification using all DKI metrics. Our findings support that DKI metrics could be more sensitive than DTI metrics to reflect microstructural changes within the gray matter, hence providing complementary information for currently outlined pathogenesis of SIVD and AD.