Relevance of antinuclear antibody in diagnosis and characteristics of multiple sclerosis.

BACKGROUND: Criteria for multiple sclerosis (MS) diagnosis rely upon clinical and paraclinical data that are supportive of MS in the absence of a better explanation. Patients referred for consideration of a MS diagnosis often undergo an extensive serologic workup including antinuclear antibody (ANA) testing, even when an individual already meets diagnostic criteria for MS. It is unclear whether ANA serostatus is associated with clinical outcomes in MS. The present study aims to determine if ANA seropositivity in those referred with concern for MS differs in those who meet 2017 revised McDonald criteria compared to those who did not receive a diagnosis of MS. Associations between ANA seropositivity and clinical or radiological phenotype of MS patients are also explored. METHODS: The cohort included people at least 18 years old, referred to our tertiary care MS center with concern for MS (regardless of prior diagnosis) who had an ANA test with known titer completed within one year of first evaluation. Electronic health record (EHR) charts were manually reviewed, and MRIs underwent blinded review by a radiologist with training in neuroradiology. Diagnosis of MS was determined by a neuroimmunologist and was based on 2017 revised McDonald Criteria. Results are reported as odds ratios from multivariable logistic regression analyses adjusted for age, sex at birth, race, smoking history, personal history of comorbid autoimmune conditions, and family history of autoimmunity. Within the MS cohort, similar analytical models were performed to assess association between ANA and clinical and radiological characteristics. RESULTS: A final cohort of 258 patients was analyzed (out of 542 referrals): 106 nonMS and 152 with MS. There was no association between MS (vs. nonMS) diagnosis and ANA status (ANA positive n = 74) in the multivariable models (OR 1.5, 95 % CI 0.82, 2.72, p = 0.20). Among those with MS, there was no association of ANA seropositivity with the odds of atypical brain MRI features, number of cardinal MRI areas involved, location of MRI lesions, or of having an atypical presentation of first demyelinating event. Black race (OR 2.8, 95 % CI 1.27, 6.26, p = 0.01) and family history of autoimmunity (OR 2.1, 95 % CI 1.09, 3.98, p = 0.03) were independently associated with increased odds of ANA positivity. Within the MS cohort analysis, progressive MS (PMS; vs relapsing-remitting MS), a covariate in the model, appeared to be at higher odds of being ANA positive (OR 3.6, 95 % CI 1.03, 13.05, p = 0.046) but only when assessing mean area of cardinal MS locations. CONCLUSIONS: While ANA testing does not appear to be useful in distinguishing MS from non-MS, it remains less clear as to whether it may be associated with differences in the clinical course of MS (relapsing-remitting vs progressive). Future studies should aim to systematically evaluate whether those who are ANA positive are more likely, in well-designed and representative prospective cohorts, to be diagnosed with or develop progressive MS. Whether a positive ANA early in MS is associated with increased risk over time of developing or diagnosing another systemic autoimmune disease would also be of interest.

Infectious Diseases of the Brain and Spine: Parasitic and Other Atypical Transmissible Diseases.

Atypical infections of the brain and spine caused by parasites occur in immunocompetent and immunosuppressed hosts, related to exposure and more prevalently in endemic regions. In the United States, the most common parasitic infections that lead to central nervous system manifestations include cysticercosis, echinococcosis, and toxoplasmosis, with toxoplasmosis being the most common opportunistic infection affecting patients with advanced HIV/AIDS. Another rare but devastating transmittable disease is prion disease, which causes rapidly progressive spongiform encephalopathies. Familiarity and understanding of various infectious agents are a crucial aspect of diagnostic neuroradiology, and recognition of unique features can aid timely diagnosis and treatment.

Infectious Diseases of the Brain and Spine: Fungal Diseases.

Advances in treatments of autoimmune diseases, acquired immunodeficiency syndrome, organ transplantation, and the use of long-term devices have increased the rates of atypical infections due to prolonged immune suppression. There is a significant overlap in imaging findings of various fungal infections affecting the central nervous system (CNS), often mimicking those seen in neoplastic and noninfectious inflammatory conditions. Nonetheless, there are imaging characteristics that can aid in distinguishing certain atypical infections. Hence, familiarity with a wide range of infectious agents is an important part of diagnostic neuroradiology. In this article, an in-depth review of fungal diseases of the CNS is provided.

Brain AVM compactness score in children with hereditary hemorrhagic telangiectasia.

OBJECTIVE: The brain arteriovenous malformation (BAVM) nidus compactness score (CS), determined on angiography, predicts BAVM recurrence after surgical resection among children with sporadic BAVMs. We measured the angiographic CS for BAVMs among children with hereditary hemorrhagic telangiectasia (HHT) to determine CS characteristics in this population. METHODS: A pediatric interventional neuroradiologist reviewed angiograms to determine the CS of BAVMs in children with HHT recruited to the BVMC. CS is based on overall nidus and perinidal anomalous vessel compactness. CS categories included 1 = diffuse nidus, 2 = intermediate nidus, and 3 = compact nidus. RESULTS: Forty-eight of 78 children (61.5%) with HHT and brain vascular malformations had a conventional angiogram; 47 (97.9%) angiograms were available. Fifty-four BAVMs were identified in 40 of these 47 children (85.1%). Of 54 BAVMs in children with HHT, CS was 1 in 7 (13%), 2 in 29 (53.7%), and 3 in 18 BAVMs (33.3%) compared with CS of 1 in six (26.1%), 2 in 15 (65.2%), and 3 in 2 BAVMs (8.7%) among 23 previously reported children with sporadic BAVMs, p = 0.045 (Fisher's exact). Seven children with HHT had intracranial hemorrhage: 4 had CS = 3, 1 had CS = 2, and 2 had CS = 1. CONCLUSIONS: A range of CSs exists across HHT BAVMs, suggesting it may be an angiographic measure of interest for future studies of BAVM recurrence and hemorrhage risk. Children with HHT may have more compact niduses compared to children with sporadic BAVMs. Additional research should determine whether CS affects hemorrhage risk or post-surgical recurrence risk in HHT-associated BAVMs, which could be used to direct BAVM treatment.

Velocity-Selective Arterial Spin Labeling Perfusion in Monitoring High Grade Gliomas Following Therapy: Clinical Feasibility at 1.5T and Comparison with Dynamic Susceptibility Contrast Perfusion.

MR perfusion imaging is important in the clinical evaluation of primary brain tumors, particularly in differentiating between true progression and treatment-induced change. The utility of velocity-selective ASL (VSASL) compared to the more commonly utilized DSC perfusion technique was assessed in routine clinical surveillance MR exams of 28 patients with high-grade gliomas at 1.5T. Using RANO criteria, patients were assigned to two groups, one with detectable residual/recurrent tumor ("RT", n = 9), and the other with no detectable residual/recurrent tumor ("NRT", n = 19). An ROI was drawn to encompass the largest dimension of the lesion with measures normalized against normal gray matter to yield rCBF and tSNR from VSASL, as well as rCBF and leakage-corrected relative CBV (lc-rCBV) from DSC. VSASL (rCBF and tSNR) and DSC (rCBF and lc-rCBV) metrics were significantly higher in the RT group than the NRT group allowing adequate discrimination (p < 0.05, Mann-Whitney test). Lin's concordance analyses showed moderate to excellent concordance between the two methods, with a stronger, moderate correlation between VSASL rCBF and DSC lc-rCBV (r = 0.57, p = 0.002; Pearson's correlation). These results suggest that VSASL is clinically feasible at 1.5T and has the potential to offer a noninvasive alternative to DSC perfusion in monitoring high-grade gliomas following therapy.

Brain Frontal-Lobe Misery Perfusion in COVID-19 ICU Survivors: An MRI Pilot Study.

Post-acute COVID-19 syndrome (PCS) is highly prevalent. Critically ill patients requiring intensive care unit (ICU) admission are at a higher risk of developing PCS. The mechanisms underlying PCS are still under investigation and may involve microvascular damage in the brain. Cerebral misery perfusion, characterized by reduced cerebral blood flow (CBF) and elevated oxygen extraction fraction (OEF) in affected brain areas, has been demonstrated in cerebrovascular diseases such as carotid occlusion and stroke. This pilot study aimed to examine whether COVID-19 ICU survivors exhibited regional misery perfusion, indicating cerebral microvascular damage. In total, 7 COVID-19 ICU survivors (4 female, 20-77 years old) and 19 age- and sex-matched healthy controls (12 female, 22-77 years old) were studied. The average interval between ICU admission and the MRI scan was 118.6 ± 30.3 days. The regional OEF was measured using a recently developed technique, accelerated T2-relaxation-under-phase-contrast MRI, while the regional CBF was assessed using pseudo-continuous arterial spin labeling. COVID-19 ICU survivors exhibited elevated OEF (ß = 5.21 ± 2.48%, p = 0.047) and reduced relative CBF (ß = -0.083 ± 0.025, p = 0.003) in the frontal lobe compared to healthy controls. In conclusion, misery perfusion was observed in the frontal lobe of COVID-19 ICU survivors, suggesting microvascular damage in this critical brain area for high-level cognitive functions that are known to manifest deficits in PCS. Physiological biomarkers such as OEF and CBF may provide new tools to improve the understanding and treatment of PCS.

Clinical and ocular abnormalities in DEGCAGS syndrome-Developmental delay with gastrointestinal, cardiovascular, genitourinary, and skeletal abnormalities.

PURPOSE: To describe clinical and ocular abnormalities in a case of Developmental Delay with Gastrointestinal, Cardiovascular, Genitourinary, and Skeletal Abnormalities (DEGCAGS syndrome). METHODS: A clinical report. CASE DESCRIPTION: An infant born to a consanguineous Middle Eastern family who was delivered by cesarean section because of in utero growth restriction, premature labor, and breech presentation. Post-partum medical problems included hypotension, generalized hypotonia, bradycardia, apnea requiring resuscitation and positive pressure ventilation, facial dysmorphia, skeletal malformations, and disorders of the gastrointestinal, immune, urinary, respiratory, cardiac, and visual systems. The family reported that a previous child had severe hypotonia at birth and was given the diagnosis of hypoxic ischemic encephalopathy; that child remains on a ventilator in a chronic care facility. Our patient was found to be homozygous for a novel pathogenic missense variant in theZNF699 zinc finger gene on chromosome 19p13 causing a syndrome known as Developmental Delay with Gastrointestinal, Cardiovascular, Genitourinary, and Skeletal Abnormalities (DEGCAGS syndrome). We review this variable syndrome, including abnormalities of the visual system not described previously. CONCLUSIONS: We describe the 15th child to be presumably identified with the DEGCAGS syndrome and the first individual with homozygous missense variants in the ZNF699 gene who had complete clinical examination and detailed retinal imaging.

Simultaneous perfusion, diffusion, T2 *, and T1 mapping with MR fingerprinting.

PURPOSE: Quantitative mapping of brain perfusion, diffusion, T2 *, and T1 has important applications in cerebrovascular diseases. At present, these sequences are performed separately. This study aims to develop a novel MRI technique to simultaneously estimate these parameters. METHODS: This sequence to measure perfusion, diffusion, T2 *, and T1 mapping with magnetic resonance fingerprinting (MRF) was based on a previously reported MRF-arterial spin labeling (ASL) sequence, but the acquisition module was modified to include different TEs and presence/absence of bipolar diffusion-weighting gradients. We compared parameters derived from the proposed method to those derived from reference methods (i.e., separate sequences of MRF-ASL, conventional spin-echo DWI, and T2 * mapping). Test-retest repeatability and initial clinical application in two patients with stroke were evaluated. RESULTS: The scan time of our proposed method was 24% shorter than the sum of the reference methods. Parametric maps obtained from the proposed method revealed excellent image quality. Their quantitative values were strongly correlated with those from reference methods and were generally in agreement with values reported in the literature. Repeatability assessment revealed that ADC, T2 *, T1 , and B1 + estimation was highly reliable, with voxelwise coefficient of variation (CoV) <5%. The CoV for arterial transit time and cerebral blood flow was 16% ± 3% and 25% ± 9%, respectively. The results from the two patients with stroke demonstrated that parametric maps derived from the proposed method can detect both ischemic and hemorrhagic stroke. CONCLUSION: The proposed method is a promising technique for multi-parametric mapping and has potential use in patients with stroke.

Tinnitus sound amplification and masking therapy: Treatment and outcomes at the University of North Carolina at Chapel Hill.

BACKGROUND: Tinnitus is burdensome to many patients. Sound amplification and masking therapy has been useful for some patients. METHOD: Retrospective chart review of patients treated for tinnitus at a single academic medical center over a 12-month period. Information on treatment course and outcomes was collected and analyzed. Statistical comparisons were made using a t-test for paired means. RESULTS: In 2021, 141 patients were evaluated for tinnitus sound amplification and masking therapy at our medical center. Average age at presentation was 55.2. Average onset was 6-7 years before presentation. Tinnitus perception was decreased in patients who received a trial of amplification and masking therapy, from 9.2 out of 20 at baseline to 6.1 with amplification and 3.2 with amplification and masking at the initial visit. The difference in each of these values is statistically significant. Nine patients recorded a Tinnitus Handicap Index (THI), which measures tinnitus burden, before and after being treated with amplification and masking therapy. These nine patients saw a decrease in THI from 39.6/100 to 19.1/100, which was also statistically significant. LIMITATIONS: This study has several limitations. Our data are from a single clinic over one year with limited follow up information, and it is a retrospective study. CONCLUSION: Our data showed benefit in sound amplification and masking therapy for the treatment of tinnitus. Patients treated with amplification and masking therapy showed a statistically significant decrease in perception of their tinnitus during their in-office demonstration. Long term data are still needed. Our data contribute to the broader discussion on the proper treatment course of tinnitus and the most effective measures.

A Facilitated Peer Mentoring Program With a Dedicated Curriculum to Foster Career Advancement of Academic Hospitalists.

Introduction: In the field of hospital medicine, there is both a limited pool of senior faculty to mentor the rapidly growing number of junior faculty and a lack of career development curricula focused on scholarly activities specific to the needs of the hospitalist. These deficits have resulted in a disproportionately low number of academic hospitalists being promoted to associate and full professor. We implemented a facilitated peer mentoring program with a dedicated curriculum to foster career advancement of academic hospitalists. Methods: We recruited 29 academic hospitalists and divided them into five small groups, each guided by one senior faculty. Peer members participated in a 9-month curriculum consisting of alternating large- and small-group sessions that reviewed topics important for academic advancement. Quantitative analysis assessed feasibility of the program, as measured by participation and knowledge improvement on curriculum topics, with pre- and postprogram surveys. Results: Results demonstrated feasibility of the large-group sessions as measured through participation. Small-group participation was more variable. Pre- and postsurvey results showed significant knowledge improvement (p < .05) in nearly all of the curriculum topics. Discussion: Currently, there is a gap in both mentorship and scholarly skills of academic hospitalists. Our facilitated peer mentoring program with a dedicated curriculum can be used as a framework for other hospitalist programs to support career development.

Blood-brain barrier breakdown in COVID-19 ICU survivors: an MRI pilot study.

Objectives: Coronavirus disease 2019 (COVID-19) results in severe inflammation at the acute stage. Chronic neuroinflammation and abnormal immunological response have been suggested to be the contributors to neuro-long-COVID, but direct evidence has been scarce. This study aims to determine the integrity of the blood-brain barrier (BBB) in COVID-19 intensive care unit (ICU) survivors using a novel MRI technique. Methods: COVID-19 ICU survivors (n=7) and age and sex-matched control participants (n=17) were recruited from June 2021 to March 2023. None of the control participants were hospitalized due to COVID-19 infection. The COVID-19 ICU survivors were studied at 98.6 ± 14.9 days after their discharge from ICU. A non-invasive MRI technique was used to assess the BBB permeability to water molecules, in terms of permeability surface area-product (PS) in the units of mL/100 g/min. Results: PS was significantly higher in COVID-19 ICU survivors (p=0.038) when compared to the controls, with values of 153.1 ± 20.9 mL/100 g/min and 132.5 ± 20.7 mL/100 g/min, respectively. In contrast, there were no significant differences in whole-brain cerebral blood flow (p=0.649) or brain volume (p=0.471) between the groups. Conclusions: There is preliminary evidence of a chronic BBB breakdown in COVID-19 survivors who had a severe acute infection, suggesting a plausible contributor to neurological long-COVID symptoms.

Downfield Proton MRSI at 3 Tesla: A Pilot Study in Human Brain Tumors.

PURPOSE: To investigate the use of 3D downfield proton magnetic resonance spectroscopic imaging (DF-MRSI) for evaluation of tumor recurrence in patients with glioblastoma (GBM). METHODS: Seven patients (4F, age range 44-65 and mean ± standard deviation 59.3 ± 7.5 years) with previously treated GBM were scanned using a recently developed 3D DF-MRSI sequence at 3T. Short TE 3D DF-MRSI and water reference 3D-MRSI scans were collected with a nominal spatial resolution of 0.7 cm3. DF volume data in eight slices covered 12 cm of brain in the cranio-caudal axis. Data were analyzed using the 'LCModel' program and a basis set containing nine peaks ranging in frequency between 6.83 to 8.49 ppm. The DF8.18 (assigned to amides) and DF7.90 peaks were selected for the creation of metabolic images and statistical analysis. Longitudinal MR images and clinical history were used to classify brain lesions as either recurrent tumor or treatment effect, which may include necrosis. DF-MRSI data were compared between lesion groups (recurrent tumor, treatment effect) and normal-appearing brain. RESULTS: Of the seven brain tumor patients, two were classified as having recurrent tumor and the rest were classified as treatment effect. Amide metabolite levels from recurrent tumor regions were significantly (p < 0.05) higher compared to both normal-appearing brain and treatment effect regions. Amide levels in lesion voxels classified as treatment effect were significantly lower than normal brain. CONCLUSIONS: 3D DF-MRSI in human brain tumors at 3T is feasible and was well tolerated by all patients enrolled in this preliminary study. Amide levels measured by 3D DF-MRSI were significantly different between treatment effect and tumor regrowth.

Clinical and radiologic characteristics associated with multiple sclerosis misdiagnosis at a tertiary referral center in the United States.

BACKGROUND: Misdiagnosis of multiple sclerosis (MS) is common and can have harmful effects on patients and healthcare systems. Identification of factors associated with misdiagnosis may aid development of prevention strategies. OBJECTIVE: To identify clinical and radiological predictors of MS misdiagnosis. METHODS: We retrospectively reviewed medical records of all patients who were referred to Johns Hopkins MS Center from January 2018 to June 2019. Patients who carried a diagnosis of MS were classified as correctly diagnosed or misdiagnosed with MS by the Johns Hopkins clinician. Demographics, clinical, laboratory, and radiologic data were collected. Differences between the two groups were evaluated, and a regression model was constructed to identify predictors of misdiagnosis. RESULTS: Out of 338 patients who were previously diagnosed with MS, 41 (12%) had been misdiagnosed. An alternative diagnosis was confirmed in 28 (68%) of the misdiagnosed patients; cerebrovascular disease was the most common alternate diagnosis. Characteristics associated with misdiagnosis were female sex (odds ratio (OR): 5.81 (95% confidence interval (CI): 1.60, 21.05)) and non-specific brain magnetic resonance imaging (MRI) lesions (OR: 7.66 (3.42, 17.16)). CONCLUSION: Misdiagnosis is a frequent problem in MS care. Non-specific brain lesions were the most significant predictor of misdiagnosis. Interventions aimed to reduce over-reliance on imaging findings and misapplication of the McDonald criteria may prevent MS misdiagnosis.

Climate Change as a Social Determinant of Health: An Interactive Case-Based Learning Activity.

Introduction: Despite consensus on climate change's impact on humans, medical schools have not widely adopted inclusion of environmental topics into their mandatory curriculum. This educational activity explicitly addresses climate change as one of the environmental determinants of health (EDH). Methods: We developed a required, 1-hour module for all first-year medical students. This interactive, case-based, small-group activity was incorporated into a curriculum within an advising program but could be run independently. Before and after the session, participants completed evaluations assessing knowledge gains and attitude shifts. Results: Of 183 first-year students, 155 completed both pre- and postmodule surveys. Participants' rating increased on the postmodule survey item "priority should be given to the discussion of EDH in medical education." The Wilcoxon signed rank test determined this difference in priority was statistically significant (p < .001). Reported strengths of this activity included the cases, informative content on EDH, the video, the discussion, and highlighted EDH resources. Suggested areas for improvement included more information on how to apply concepts to clinical contexts, guidance on how to engage in EDH concepts, and more discussion time. As a result of the module, students planned to engage in recycling, reduced consumption, advocacy, and changes to mode of transportation. Discussion: Climate change remains the greatest global threat to human health, and future physicians must be equipped to educate patients and policymakers on the harms of environmental hazards. This brief yet effective module offers one approach to incorporating this topic into medical school curricula.

Risk factors and clinical features associated with basal ganglia manganese deposition in patients with hereditary hemorrhagic telangiectasia.

BACKGROUND: T1-hyperintensity of the basal ganglia (BG) due to manganese deposition is a known radiologic finding in patients with hereditary hemorrhagic telangiectasia (HHT), but risk factors and associated clinical manifestations are unclear. This study conducted a quantitative analysis of the association of T1-hyperintensity in HHT patients with specific risk factors, signs, and symptoms. METHODS: Patients seen at our center between 2005 and 2020 with a definitive diagnosis of HHT who had an available non-contrast T1-weighted brain MRI were included. Hyperintensity was evaluated using oval regions of interest measurements. The BG: thalamus intensity ratio was used to quantitatively evaluate T1-hyperintensity. Patient laboratory values and clinical findings were collected from electronic medical records. Hyperintensity was analyzed for its association with laboratory values, and clinical findings. Variables were analyzed through regression analysis. RESULTS: A total of 239 patients were included in this study. On 1.5 T scanners, values that were significant on multivariable regression analysis were age (p < .001), hepatic AVMs (p < .001), iron deficiency anemia (p = .0021), and cirrhosis (p = .016). On 3 T scanners, values that were significant on multivariable analysis were hepatic AVMs (p = .0024) and cirrhosis (p = .0056). On 3 T scanners, hyperintensity was significantly associated with tremor (OR = 1.17, p = .033), restless leg syndrome (OR = 1.22, p = .0086), and memory problems (OR = 1.17, p = .046). CONCLUSIONS: BG hyperintensity due to manganese deposition is significantly associated with hepatic risk factors on 1.5 T and 3 T scanners and iron deficiency anemia on 1.5 T scanners. On 3 T scanners, T1-hyperintensity is associated with neuropsychiatric signs and symptoms, such as tremor, restless leg syndrome, and memory problems.

Deep-learning-enabled brain hemodynamic mapping using resting-state fMRI.

Cerebrovascular disease is a leading cause of death globally. Prevention and early intervention are known to be the most effective forms of its management. Non-invasive imaging methods hold great promises for early stratification, but at present lack the sensitivity for personalized prognosis. Resting-state functional magnetic resonance imaging (rs-fMRI), a powerful tool previously used for mapping neural activity, is available in most hospitals. Here we show that rs-fMRI can be used to map cerebral hemodynamic function and delineate impairment. By exploiting time variations in breathing pattern during rs-fMRI, deep learning enables reproducible mapping of cerebrovascular reactivity (CVR) and bolus arrival time (BAT) of the human brain using resting-state CO2 fluctuations as a natural "contrast media". The deep-learning network is trained with CVR and BAT maps obtained with a reference method of CO2-inhalation MRI, which includes data from young and older healthy subjects and patients with Moyamoya disease and brain tumors. We demonstrate the performance of deep-learning cerebrovascular mapping in the detection of vascular abnormalities, evaluation of revascularization effects, and vascular alterations in normal aging. In addition, cerebrovascular maps obtained with the proposed method exhibit excellent reproducibility in both healthy volunteers and stroke patients. Deep-learning resting-state vascular imaging has the potential to become a useful tool in clinical cerebrovascular imaging.

Evaluation of 3D stack-of-spiral turbo FLASH acquisitions for pseudo-continuous and velocity-selective ASL-derived brain perfusion mapping.

PURPOSE: The most-used 3D acquisitions for ASL are gradient and spin echo (GRASE)- and stack-of-spiral (SOS)-based fast spin echo, which require multiple shots. Alternatively, turbo FLASH (TFL) allows longer echo trains, and SOS-TFL has the potential to reduce the number of shots to even single-shot, thus improving the temporal resolution. Here we compare the performance of 3D SOS-TFL and 3D GRASE for ASL at 3T. METHODS: The 3D SOS-TFL readout was optimized with respect to fat suppression and excitation flip angles for pseudo-continuous ASL- and velocity-selective (VS)ASL-derived cerebral blood flow (CBF) mapping as well as for VSASL-derived cerebral blood volume (CBV) mapping. Results were compared with 3D GRASE readout on healthy volunteers in terms of perfusion quantification and temporal SNR (tSNR) efficiency. CBF and CBV mapping derived from 3D SOS-TFL-based ASL was demonstrated on one stroke patient, and the potential for single-shot acquisitions was exemplified. RESULTS: SOS-TFL with a 15° flip angle resulted in adequate tSNR efficiency with negligible image blurring. Selective water excitation was necessary to eliminate fat-induced artifacts. For pseudo-continuous ASL- and VSASL-based CBF and CBV mapping, compared to the employed four-shot 3D GRASE with an acceleration factor of 2, the fully sampled 3D SOS-TFL delivered comparable performance (with a similar scan time) using three shots, which could be further undersampled to achieve single-shot acquisition with higher tSNR efficiency. SOS-TFL had reduced CSF contamination for VSASL-CBF. CONCLUSION: 3D SOS-TFL acquisition was found to be a viable substitute for 3D GRASE for ASL with sufficient tSNR efficiency, minimal relaxation-induced blurring, reduced CSF contamination, and the potential of single-shot, especially for VSASL.

Silent cerebral infarction during immune TTP remission: prevalence, predictors, and impact on cognition.

Immune thrombotic thrombocytopenic purpura (iTTP) survivors have increased risk of cardiovascular disease, including strokes, and report persistent cognitive difficulties during remission. We conducted this prospective study involving iTTP survivors during clinical remission to determine the prevalence of silent cerebral infarction (SCI), defined as magnetic resonance imaging (MRI) evidence of brain infarction without corresponding overt neurodeficits. We also tested the hypothesis that SCI is associated with cognitive impairment, assessed using the National Institutes of Health ToolBox Cognition Battery. For cognitive assessments, we used fully corrected T scores adjusted for age, sex, race, and education. Based on the diagnostic and statistical manual 5 criteria, we defined mild and major cognitive impairment as T scores with a 1 or 2 standard deviation (SD) and >2 SD below the mean on at least 1 test, respectively. Forty-two patients were enrolled, with 36 completing MRIs. SCI was present in 50% of the patients (18), of which 8 (44.4%) had prior overt stroke including during acute iTTP. Patients with SCI had higher rates of cognitive impairment (66.7% vs 27.7%; P = .026), including major cognitive impairment (50% vs 5.6%; P = .010). In separate logistic regression models, SCI was associated with any (mild or major) cognitive impairment (odds ratio [OR] 10.5 [95% confidence interval (95% CI), 1.45-76.63]; P = .020) and major cognitive impairment (OR 7.98 [95% CI, 1.11-57.27]; P = .039) after adjusting for history of stroke and Beck depression inventory scores. MRI evidence of brain infarction is common in iTTP survivors; the strong association of SCI with impaired cognition suggests that these silent infarcts are neither silent nor innocuous.