Diffusion-weighted Imaging Hyperintensity Research Articles

DWI scrolling artery sign for the diagnosis of giant cell arteritis: a pattern recognition approach

ObjectivesTo investigate the diagnostic accuracy of a pattern recognition approach for the evaluation of MRI scans of the head with diffusion-weighted imaging (DWI) in suspected giant cell arteritis (GCA).MethodsRetrospectively, 156...

Abstract WP158: Cortical Superficial Siderosis is Associated With Ischemia After Intracerebral Hemorrhage

Background: Ischemia on diffusion weighted imaging (DWI) after intracerebral hemorrhage (ICH) increases the risk of future ischemic stroke. Radiographic markers of small vessel disease, including cerebral microbleeds (CMB), are associated with DWI lesions. Though cortical superficial siderosis (cSS) is also a hemorrhagic small vessel disease subtype, it is unclear if cSS similarly relates to DWI lesions. We hypothesized that cSS would represent a more severe phenotype of small vessel disease and would associate with DWI lesions after ICH independent to other small vessel disease markers. Methods: Using the Intracerebral Hemorrhage Outcomes Project (ICHOP), we included all cases of spontaneous ICH who underwent DWI and susceptibility imaging/gradient echo. DWI hyperintensities were identified if >10mm from the hematoma with decreased ADC signal. cSS were identified as subarachnoid hemosiderin deposition without acute subarachnoid hemorrhage. The relationship of cSS with DWI lesion presence as the outcome was assessed with logistic regression adjusted for ICH score, blood pressure change within 24 hours, and small vessel disease markers (CMB and white matter hyperintensity). Sensitivity analyses were performed to adjust for demographics and ICH location. A secondary analysis using linear regression assessed the association with the number of DWI lesions adjusted for similar covariates. Results: Of 198 patients analyzed, DWI lesions were observed in 31.3% and cSS in 10.6%. The presence of cSS was associated with DWI lesions (adjusted OR 3.72, CI: 1.29-10.72), independent of other small vessel disease markers. Separate sensitivity analyses adjusting for sex, race, and ICH location did not change the association of cSS with DWI lesions. In secondary analyses, cSS was not associated with greater number of DWI lesions counts (b 0.213, CI -0.53-0.63). Discussion: cSS is associated with the presence of DWI lesions, independent to other small vessel disease markers. cSS may represent a severe phenotype of small vessel disease with a risk of ICH recurrence and ischemia. Further work is required to investigate underlying mechanisms and optimal strategies to mitigate competing risks of future hemorrhage and ischemic events in these patients.

Abstract 89: Portable, Low-Field Magnetic Resonance Imaging: Determining Mismatch Following Acute Ischemic Stroke

Background and Aims: Treatment options for acute ischemic stroke (AIS) are uniquely dependent on the time of stroke onset. Intravenous thrombolysis must be administered within 4.5 hours of symptoms commencing, yet a subset of patients wake-up with symptoms and time of onset is unknown. Mismatch between fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted imaging (DWI) MRI can be used to qualify wake-up strokes for thrombolysis. This has been shown to lead to improved functional outcomes in multicenter trials (WAKE-UP, MR-WITNESS). However, access to MRI is a barrier to differential diagnosis and subsequent treatment. Recent advances in portable, low-field MRI (LF-MRI) offer a solution to increase access to MRI technologies and circumvent the limitations of conventional systems. As such, in this pilot study, we sought to establish the utility of portable LF-MRI to identify DWI-FLAIR mismatch following AIS. Methods: Patients with a diagnosis of AIS presenting to Emergency Department or Intensive Care Unit of the Yale New Haven Hospital or Massachusetts General Hospital from January 2020 to June 2023 underwent DWI and FLAIR acquisition on a 0.064T MRI (Hyperfine Research Inc.) at <4.5 hours ( n =7), 4.5-6 hours ( n =7), and 6-48 hours ( n =110) since last known well (LKW). Conventional high-field (HF) MR images were acquired within 72 hours of LF-MRI. HF-DWI images were co-registered to LF-FLAIR and the hyperintense DWI stroke lesion segmented and superimposed on the FLAIR. The segmentation was mirrored to the contralateral hemisphere of the LF-FLAIR to establish a FLAIR signal intensity ratio (SIR). Results: The FLAIR SIR on images <4.5 hours since LKW was 0.98±0.08. The SIR for cases 4.5-6 hours was 1.34±0.33. Cases 6-48 hours produced a SIR of 1.56±0.36. The SIR at <4.5 hours was significantly less than that observed >6 hours since LKW ( p =0.03). Conclusion: This pilot study demonstrates that a 0.064T portable MRI is capable of distinguishing hyperacute stroke from later stroke onset using FLAIR SIR. Future research is needed in a larger cohort to determine if this imaging technology can be used to guide thrombolysis in the setting of wake-up stroke.

Diagnostic MR imaging features of hypomyelination of early myelinating structures: A case report.

Hypomyelination of early myelinating structures (HEMS) has recently been defined as a new genetic disorder accompanied by clinical and MR imaging characteristics. However, no studies have focused on diffusion-weighted imaging (DWI) findings of HEMS. We would like to propose a "sheep sign," which is formed by DWI hyperintensity in the medial medullary lamina along with alternating high-low-high (HLH) intensity stripes in the posterior limb of the internal capsule. We believe the presence of the "sheep sign" on DWI in combination with alternating HLH intensity stripes may be a valuable tool for diagnosing HEMS.

Magnetic resonance imaging arterial spin labeling hypoperfusion with diffusion-weighted image hyperintensity is useful for diagnostic imaging of Creutzfeldt-Jakob disease.

Magnetic resonance imaging with arterial spin labeling (ASL) perfusion imaging is a noninvasive method for quantifying cerebral blood flow (CBF). We aimed to evaluate the clinical utility of ASL perfusion imaging to aid in the diagnosis of Creutzfeldt-Jakob disease (CJD). This retrospective study enrolled 10 clinically diagnosed with probable sporadic CJD (sCJD) based on the National CJD Research & Surveillance Unit and EuroCJD criteria and 18 healthy controls (HCs). Diffusion-weighted images (DWIs), CBF images obtained from ASL, N-isopropyl-(123I)-p-iodoamphetamine (123IMP)-single-photon emission computed tomography (SPECT) images, and 18F-fluorodeoxyglucose (18FDG)-positron emission tomography (PET) images were analyzed. First, the cortical values obtained using volume-of-interest (VOI) analysis were normalized using the global mean in each modality. The cortical regions were classified into DWI-High (≥ +1 SD) and DWI-Normal (< +1 SD) regions according to the DWI-intensity values. The normalized cortical values were compared between the two regions for each modality. Second, each modality value was defined as ASL hypoperfusion (< -1 SD), SPECT hypoperfusion (< -1 SD), and PET low accumulation (< -1 SD). The overall agreement rate of DWIs with ASL-CBF, SPECT, and PET was calculated. Third, regression analyses between the normalized ASL-CBF values and normalized SPECT or PET values derived from the VOIs were performed using a scatter plot. The mean values of ASL-CBF (N = 10), 123IMP-SPECT (N = 8), and 18FDG-PET (N = 3) in DWI-High regions were significantly lower than those in the DWI-Normal regions (p < 0.001 for all); however, HCs (N = 18) showed no significant differences in ASL-CBF between the two regions. The overall agreement rate of DWI (high or normal) with ASL-CBF (hypoperfusion or normal) (81.8%) was similar to that of SPECT (85.2%) and PET (78.5%) in CJD. The regression analysis showed that the normalized ASL-CBF values significantly correlated with the normalized SPECT (r = 0.44, p < 0.001) and PET values (r = 0.46, p < 0.001) in CJD. Patients with CJD showed ASL hypoperfusion in lesions with DWI hyperintensity, suggesting that ASL-CBF could be beneficial for the diagnostic aid of CJD.

The dynamic contrast enhanced-magnetic resonance imaging and diffusion-weighted imaging features of alveolar soft part sarcoma.

Alveolar soft part sarcoma (ASPS) is a rare type of soft tissue sarcoma that predominantly affects adolescents and young adults. Early diagnosis of ASPS is crucial for optimal therapeutic planning and improving prognosis, but its diagnostic features are not well delineated. This study aimed to retrospectively analyze the imaging features of ASPS with an emphasis on the dynamic contrast-enhanced-magnetic resonance imaging (DCE-MRI) and diffusion-weighted imaging (DWI) findings to identify imaging findings that might suggest the diagnosis to radiologists. The imaging features of 34 patients with pathologically proven limb ASPS were retrospectively analyzed. A total of 23 underwent DCE-MRI, and 12 underwent DWI. Among the 34 cases of ASPS, 31 tumors were in the lower extremities, and 3 were in the upper extremities. The maximum tumor diameters ranged from 3.0 to 19.4 cm (mean, 8.7±3.96 cm). A total of 28 cases had well-defined borders. The masses demonstrated heterogeneous high signal intensity on T2-weighted imaging (T2WI) and the fat-suppressed (FS) T2WI sequence and slight hyperintensity on T1-weighted imaging (T1WI). A total of 25 lesions had thin hypointense bands on T1WI and T2WI. Intra- and peri-tumoral tubular areas of flow void were exhibited on both T1WI and T2WI in all cases. A total of 12 cases showed a high signal on DWI, and the mean apparent diffusion coefficient (ADC) value was (0.86±0.07)×10-3 mm2/s [range, (0.6-1.4)×10-3 mm2/s]. Persistent remarkable enhancement of the lesion was displayed on contrast-enhanced scans. The time-intensity curves (TICs) of 23 masses showed early arterial enhancement and slow washout of contrast. ASPS most commonly presents in the lower extremities of adolescents or young adults. Hyperintense T1WI, T2WI, and DWI signals, low ADC, flow voids, early arterial enhancement are frequent MRI features.

Residual diffusion-weighted imaging hyperintense signal in primary central nervous system lymphoma can predict early recurrence.

The treatment response of primary central nervous system lymphomas (PCNSLs) is mainly evaluated using postcontrast T1-weighted imaging (T1WI). Because poorly enhanced lesions may contain residual tumors, the combination of evaluation methods will potentially improve the accuracy of determining treatment effectiveness. In this study, we evaluated the usefulness of diffusion-weighted imaging (DWI) in predicting recurrence among patients with PCNSL who achieved complete response (CR)/unconfirmed CR (CRu). Fifty-four patients newly diagnosed with PCNSL who were treated at our institution and achieved CR/CRu at the end of treatment were included in this study. The patients were divided into two groups according to the presence or absence of residual DWI hyperintense signal at the tumor site at the end of treatment. Kaplan-Meier analysis was performed to analyze the median overall survival (OS) and progression-free survival (PFS). The mean age of the 54 patients was 66.4 ± 13.3 years. The induction therapies were HD-MTX in 20 patients, R-MPV in 29 patients, and other chemotherapies in five patients. Radiotherapy was performed in 35 patients, high-dose cytarabine therapy in 14 patients, and autologous hematopoietic stem cell transplantation in one patient, and of the 54 patients, 10 had no consolidation therapy. The residual DWI hyperintense signal sign was observed in 18 patients. The R-MPV regimen was statistically associated with a lower rate of residual DWI hyperintense signal (p = 0.0453). The median PFS was statistically shorter in the residual DWI hyperintense signal group than in the non-residual DWI hyperintense signal group (14.0 months vs. 85.1 months) (p < 0.0001, log-rank test). A residual DWI hyperintense signal at the end of treatment was statistically associated with shorter PFS. Among patients who achieved CR/CRu evaluated based on postcontrast T1WI, DWI could be a valuable additional sequence to predict the early recurrence of PCNSL.

The value of a nomogram for predicting the outcome of intracerebral hemorrhage based on clinical characteristics and diffusion-weighted imaging of hyperintense lesions

Objective: To investigate the value of a nomogram predicting the outcome of intracerebral hemorrhage (ICH) based on clinical characteristics and diffusion-weighted imaging (DWI) of hyperintense lesions. Methods: A case-control study. Consecutive patients, aged 30-88(59±13) years old, with ICH were recruited at the Stroke Center of Zhengzhou People's Hospital from January 2018 to August 2021. Patients were divided into a group with DWI lesions and a group without DWI lesions depending on whether there were DWI hyperintense lesions distant from the hematoma. Prognosis was evaluated at 90 days via the modified Rankin Scale (mRS). Univariate and multivariable logistic regression models were used to identify independent predictors of a poor ICH outcome (mRS score≥4), and a nomogram model was developed. The performance of the nomogram was validated via the area under the receiver operating characteristic curve (AUC) and a calibration chart. Results: Of the 303 patients included in the study, 24.8% presented with DWI lesions; 17.5% with asymptomatic DWI lesions and 7.3% with symptomatic DWI lesions. Poor outcomes were significantly more frequent in the group with DWI lesions than in the group without DWI lesions (χ2=21.32, P<0.001). In multivariable regression analysis, age [odds ratio (OR)=1.032, 95% confidence interval (CI) 1.002-1.063, P=0.035], hematoma volume (OR=1.050, 95%CI 1.011-1.090, P=0.012), hematoma location (OR=3.839, 95%CI 1.248-11.805, P=0.019), DWI lesions (OR=3.955, 95%CI 1.906-8.206, P<0.001), and baseline NIHSS scores (OR=1.102, 95%CI 1.038-1.170, P=0.001) were independent predictors of a poor outcome. In subgroup analysis patients with asymptomatic DWI lesions had a 3-fold greater risk of a poor outcome compared to those without DWI lesions (OR=3.135, 95%CI 1.382-7.112, P=0.006), and patients with symptomatic DWI lesions had a 7-fold greater risk of a poor outcome compared to those without DWI lesions (OR=7.126, 95%CI 2.279-22.277, P=0.001). A nomogram model was established based on the independent predictors for a poor outcome. The AUC of the nomogram was 0.846 (95%CI 0.795-0.898), and a calibration chart indicated good consistency between values predicted by the nomogram and actual observed values. Conclusions: DWI lesions are an independent risk factor for a poor outcome in patients with ICH-particularly symptomatic DWI lesions. A nomogram model based on clinical characteristics and DWI lesions exhibited good efficacy when predicting the outcome of ICH.

A weighted cranial diffusion-weighted imaging scale for Wilson's disease.

Cranial magnetic resonance imaging (MRI) could be a crucial tool for the assessment for neurological symptoms in patients with Wilson's disease (WD). Diffusion-weighted imaging (DWI) hyperintensity reflects the acute brain injuries, which mainly occur in specific brain regions. Therefore, this study aimed to develop a weighted cranial DWI scale for patients with WD, with special focus on specific brain regions. In total, 123 patients with WD were enrolled, 118 of whom underwent 1.5 T-MRI on admission. The imaging score was calculated as described previously and depended on the following sequences: one point was acquired when abnormal intensity occurred in the T1, T2, and fluid-attenuation inversion recovery sequences, and two points were acquired when DWI hyperintensity were found. Consensus weighting was conducted based on the symptoms and response to treatment. Intra-rater agreement were good (r = 0.855 [0.798-0.897], p < 0.0001). DWI hyperintensity in the putamen was a high-risk factor for deterioration during de-copper therapy (OR = 8.656, p < 0.05). The high-risk factors for readmission for intravenous de-copper therapies were DWI hyperintensity in the midbrain (OR = 3.818, p < 0.05) and the corpus callosum (OR = 2.654, p < 0.05). Both scoring systems had positive correlation with UWDRS scale (original semi-quantitative scoring system, r = 0.35, p < 0.001; consensus semi-quantitative scoring system, r = 0.351, p < 0.001.). Compared to the original scoring system, the consensus scoring system had higher correlations with the occurrence of deterioration (OR = 1.052, 95%CI [1.003, 1.0103], p < 0.05) and readmission for intravenous de-copper therapy (OR = 1.043, 95%CI [1.001, 1.086], p < 0.05). The predictive performance of the consensus semi-quantitative scoring system for cranial MRI was improved to guide medication, healthcare management, and prognosis prediction in patients with WD. For every point increase in the neuroimaging score, the risk of exacerbations during treatment increased by 5.2%, and the risk of readmission to the hospital within 6 months increased by 4.3%.

Magnetic resonance imaging characteristics of brain metastases in small cell lung cancer.

Lung is the most common primary site of brain metastases (BMs). For different pathological types of BMs have some similar characteristics, it is still a challenge to confirm the origin based on their characteristics directly. BMs of small cell lung cancer (SCLC) have favorable therapeutic expectations due to their high sensitivity to radiotherapy. This study sought to identify unique characteristics of BMs in SCLC, aiming to assist in clinical decision-making. Patients diagnosed with BMs of lung cancer who received radiotherapy from January 2017 to January 2022 were reviewed (N = 284). Definitive diagnosis of BMs of SCLC was reached for 36 patients. All patients underwent head examination using magnetic resonance imaging. The number, size, location, and signal characteristics of lesions were analyzed. There were 7 and 29 patients with single focus and non-single focus, respectively. Ten patients had diffuse lesions, and the remaining 26 patients had a total of 90 lesions. These lesions were divided into three groups according to size: <1, 1-3, and >3 cm (43.33%, 53.34%, and 3.33%, respectively). Sixty-six lesions were located in the supratentorial area, primarily including cortical and subcortical lesions (55.56%) and deep brain lesions (20%). Moreover, 22 lesions were located in the infratentorial area. According to diffusion-weighted imaging and T1-weighted contrast enhancement, the imaging characteristics were classified into six patterns. Hyperintensity in diffusion-weighted imaging and homogeneous enhancement was the most common pattern of BMs in SCLC (46.67%), while partial lesions showed hyperintensity in diffusion-weighted imaging without enhancement (7.78%). The manifestations of BMs in SCLC were multiple lesions (diameter: 1-3 cm), hyperintensity in diffusion-weighted imaging, and homogeneous enhancement. Interestingly, hyperintensity in diffusion-weighted imaging without enhancement was also one of the characteristics.

Clinical Reasoning: A 14-Year-Old Girl With Reversible Peripheral Neuropathy and Encephalopathy.

A 14-year-old girl presented with acute ascending, symmetric numbness and flaccid paralysis three weeks after a suspected gastrointestinal infection. She had experienced anorexia since this gastrointestinal episode. EMG showed a sensorimotor axonal polyneuropathy. Routine CSF analysis and serum-specific antibodies (anti-ganglioside and node of Ranvier-associated antibodies) were all negative. Laboratory investigations for possible etiologies only revealed mild metabolic perturbations. During her hospitalization, she developed mild cognitive deficits. Brain MRI showed bilateral symmetric basal ganglia lesions with hyperintensity on T2-FLAIR, DWI hyperintensity and corresponding ADC hypointensity, but without contrast enhancement. A more thorough and detailed history indicated exercise intolerance, and specific examinations subsequently revealed an underlying etiology. This case presentation discusses specific etiology of an acute-onset, diffuse and symmetric neuropathy after an acquired injury in a teenager, emphasizing the need of a broad differential diagnosis in this condition.

Clinical features and genetic analysis of two Chinese ATP1A2 gene variants pedigrees of familial hemiplegic migraine

ObjectiveTo analyze the clinical manifestations and genetic examination results of affected members of two Chinese ATP1A2 gene variants pedigrees, and to summarize their phenotypic and genotypic features. MethodsThe clinical features were recorded in detailed. The cranial magnetic resonance imaging for patients and gene sequencing of two Chinese ATP1A2 gene variant pedigrees were perform. The correlation between the types of variants and the clinical phenotypes of ATP1A2 gene were analyzed. ResultsThese two pedigrees are diagnosed as familial hemiplegic migraine type 2 (FHM2) with ATP1A2 heterozygous missense variants, c.1091C > T (p.T364M) found in pedigree 1 and c.899T > C (p.L300P) in pedigree 2. Multiple phenotypes coexist in both families, and the two probands have severe cranial magnetic resonance imaging manifesting hemiplegic contralateral cortical swelling and diffusion weighted imaging hyperintense signal, which can be fully recovered. ATP1A2 gene variants were seen in FHM2, sporadic hemiplegic migraine and atypical alternating hemiplegia of childhood (AHC) families or sporadic cases, etc. The clinical features of ATP1A2 variant c.1091C > T (p.T364M) are basically similar in Chinese patients and European patients. ConclusionThese two Chinese pedigrees had FHM2 due to ATP1A2 heterozygous missense variation. It would expand the understanding of ATP1A2.

Unraveling rare form of adult-onset NIID by characteristic brain MRI features: A single-center retrospective review.

Adult-onset neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disorder with high clinical heterogeneity. Previous studies indicated that the high-intensity signals in the corticomedullary junction on diffusion-weighted imaging (DWI) on brain MRI, known as the "ribbon sign," could serve as a strong diagnostic clue. Here we used the explorative approach to study the undiagnosed rate of adult-onset NIID in a single center in China via searching for the ribbon sign in picture archive and communication system (PACS) and report the clinical and radiological features of initially undiagnosed NIID patients. Consecutive brain MRI of 21,563 adult individuals (≥18 years) in the PACS database in 2019 from a tertiary hospital were reviewed. Of them, 4,130 were screened out using the keywords "leukoencephalopathy" and "white matter demyelination." Next, all 4,130 images were read by four neurologists. The images with the suspected ribbon sign were reanalyzed by two neuroradiologists. Those with the ribbon sign but without previously diagnosed NIID were invited for skin biopsy and/or genetic testing for diagnostic confirmation. The clinical features of all NIID patients were retrospectively reviewed. Five patients with high-intensity in the corticomedullary junction on DWI were enrolled. Three patients were previously diagnosed with NIID confirmed by genetic or pathological findings and presented with episodic encephalopathy or cognitive impairment. The other two patients were initially diagnosed with limb-girdle muscular dystrophy (LGMD) with rimmed vacuoles (RVs) and normal pressure hydrocephalus (NPH) in one each. Genetic analysis demonstrated GGC repeat expansion in the NOTCH2NLC gene of both, and skin biopsy of the first patient showed the presence of intranuclear hyaline inclusion bodies. Thus, five of the 21,563 adult patients (≥18 years) were diagnosed with NIID. The distinctive subcortical high-intensity signal on DWI was distributed extensively throughout the lobes, corpus callosum, basal ganglia, and brainstem. In addition, T2-weighted imaging revealed white matter hyperintensity of Fazekas grade 2 or 3, atrophy, and ventricular dilation. Distinctive DWI hyperintensity in the junction between the gray and white matter can help identify atypical NIID cases. Our findings highly suggest that neurologists and radiologists should recognize the characteristic neuroimaging pattern of NIID.

Cytoskeletal protein breakdown and serum albumin extravasation in MRI DWI-T2WI mismatch area in acute murine cerebral ischemia

MRI diffusion-weighted imaging (DWI)-FLAIR mismatch is known as predictive of symptom onset within 4.5 h. This study assessed the breakdown of cytoskeletal protein and blood-brain barrier (BBB) in DWI-T2 mismatch. We employed occlusion of middle cerebral artery (MCAO) in C57BL/6 mice. We serially measured MRI including DWI and T2WI. After MRI, we prepared brain sections or samples and examined microtubule-associated protein 2 (MAP2) expression, alpha-fodrin degradation, extravasation of albumin and claudin-5 expression. In permanent or transient MCAO for 45 min, DWI hyperintensities was already found at 60 min without change of T2, showing DWI-T2 mismatch. In permanent MCAO, MAP2 expressions were preserved, and no extravasation of albumin was observed. In transient MCAO, MAP2 immunoreaction was already lost in the lateral part of the striatum. In both models, alpha-fodrin degradation was already detected. At 180 min, T2 hyperintensities appeared, where MAP2 signal was lost and albumin extravasation was found. At 24 h, hyperintensities of DWI and T2WI was found in the whole MCA territory, where MAP2 signal was completely lost with marked albumin extravasation and alpha-fodrin degradation. Immunoreaction for claudin-5 was preserved up to 180 min. DWI-T2 mismatch area may not always indicate intactness of cytoskeletal protein but shows preservation of BBB.

The utility of diffusion-weighted imaging in patients with spinal cord infarction: difference from the findings of neuromyelitis optica spectrum disorder

BackgroundMagnetic resonance imaging (MRI) plays a crucial role in diagnosing spinal cord infarction (SCI). However, the findings are often indistinguishable from those of other intramedullary diseases, such as neuromyelitis optica spectrum disorder (NMOSD). Although diffusion-weighted imaging (DWI) is a promising technique, the utility for discriminating SCI from NMOSD remains unclear because the DWI findings of acute NMOSD lesions have not been investigated in detail.MethodsClinical and MRI findings were retrospectively evaluated in 15 and 12 patients with acute SCI and NMOSD, respectively. First, clinical characteristics were compared between the SCI and NMOSD groups. Second, MRI abnormalities were examined to find differences between these groups. Third, in the SCI group, factors influencing T2 and DWI abnormalities were analyzed using the mixed-effects logistic regression analysis.ResultsThe proportion of female patients was higher in the NMOSD group (92%) than in the SCI (40%). The time from symptom onset to nadir was smaller in the SCI group (median [interquartile range]; 4 [0.1–8.3] hours) than in the NMOSD (252 [162–576]). On T2-weighted images, SCI lesions had smaller length than NMOSD (2 [1–2] and 5 [2–7] vertebral segments, respectively). Focal lesions within the T9–L2 level were found only in patients with SCI. DWI hyperintensity was observed both in the SCI (frequency, 100%) and NMOSD (60%) groups. On apparent diffusion coefficient (ADC) maps, the hyperintensities of SCI had corresponding hypointensities, whereas those of NMOSD were isointense and a large portion of NMOSD lesions had hyperintense signals. Owl’s eyes sign and pencil-like hyperintensity, typically reported as T2 findings suggestive of SCI, were also found on DWI. Posterior linear hyperintensity was frequently detected on DWI in patients with posterior spinal artery infarction. The presence of MRI abnormality revealing SCI was modeled with the time from symptom onset, imaging sequence and plane, and affected vascular territory.ConclusionsDWI and ADC maps help distinguish SCI from NMOSD. The time from symptom onset, imaging sequence, and imaging plane should be considered when MRI findings are interpreted in patients with suspected SCI.

Granulomatous Prostatitis, the Great Mimicker of Prostate Cancer: Can Multiparametric MRI Features Help in This Challenging Differential Diagnosis?

Clinico-radiological presentation of granulomatous prostatitis (GP) is quite similar to cancer, and differential diagnosis can be very challenging. The study aims to highlight GP features based on clinical findings and multiparametric magnetic resonance imaging (mpMRI) characteristics. We retrospectively reviewed eleven patients from a cohort undergoing targeted biopsy between August 2019 and August 2021. Retrospective data including serum prostate-specific antigen (PSA) levels, PSA density and mpMRI findings were collected. Histopathology revealed seven cases of non-specific GP and four cases of specific GP as a result of intravesical Bacillus Calmette–Guérin (BCG) instillation. All lesions showed low signal intensity in T2w images, restricted diffusivity with hyperintensity in Diffusion-Weighted Imaging (DWI) and low Apparent Diffusion Coefficient (ADC) values. In Dynamic Contrast-Enhanced (DCE) imaging, the enhancement was high-peak and persistent in the majority of cases, especially in BCG-GPs. Moreover, almost all those latter lesions showed avascular core and peripheral rim enhancement. All areas identified on mpMRI were assessed with high to very high suspicion to hold prostate cancer (PIRADS v2.1 scores 4–5). Despite recent advances in imaging modalities and serological investigations, it is currently still a challenge to identify granulomatous prostatitis. Histopathology remains the gold standard in disease diagnosis. However, a differential diagnosis should be considered in patients with prior treatment with BCG.

Diffusion-weighted imaging hyperintensities during the chronic stage of intracerebral hemorrhage with surgery: A new clinical situation or post-surgery artifact?

Background and objectiveDiffusion-weighted imaging (DWI) hyperintensities were occasionally seen at previous hematoma in patients several months after intracerebral hemorrhage with surgery. Whether they are newly occurred clinical situations or post-surgery changes is unknown. This study aims to investigate the prevalence and possible mechanisms for this phenomenon.MethodsWe retrospectively reviewed the MRI database for intracerebral hemorrhage with surgery after 3 months of disease onset in our hospital. We also prospectively performed repeated multimodal MRI scans for two patients at the chronic stage after surgery for intracerebral hemorrhage.ResultsWe found that 14 out of 23 patients (60.9%) had DWI hyperintensities at the site of previous hematoma 3 months after intracerebral hemorrhage with surgery. All the DWI lesions were hyperintense on T1- and T2-weighted imaging, most of which appeared long and narrow in shape. The DWI lesions were usually located adjacent to the thin wall of the previous hematoma cavity close to the lateral ventricle. They were more associated with the basal ganglia hemorrhage than with the lobar hemorrhage (P = 0.02) and were more frequently seen for those with intraventricular hemorrhage than without (P = 0.02). Prospectively repeated MRI exams of two patients revealed unchanged DWI hyperintensity during the 18- and 2-month follow-up, respectively.ConclusionThe DWI lesions at previous hematoma were commonly seen in patients after surgery for intracerebral hemorrhage at the chronic stage which would persist for years. We hypothesized a possible mechanism by which extracellular methemoglobin “islands” are formed with delayed or no absorption by macrophages from adjacent thin residual brain tissue. Unnecessary further examinations and treatment would be avoided by realizing this imaging phenomenon.

A Case of Rheumatoid Meningitis

Rheumatoid meningitis, a very rare complication, is not well-recognised, and there are few reports describing its treatment. We report the case of a 74-year-old Japanese woman who was diagnosed with rheumatoid meningitis by characteristic brain magnetic resonance imaging (MRI) and was successfully treated with glucocorticoids. We observed fluid-attenuated inversion recovery and diffusion-weighted imaging hyperintensity, which had a meningeal gadolinium-enhancing characteristic of rheumatoid meningitis. We suggest that it is possible to diagnose this disease based on characteristic MRI findings and treat patients early using glucocorticoids.

Quantitative Analysis of Diffusion-Restricted Lesions in a Differential Diagnosis of Status Epilepticus and Acute Ischemic Stroke.

Background and PurposeDistinction between acute ischemic stroke (AIS) and status epilepticus (SE) on MRI can be challenging as restricted diffusion may occur in both conditions. In this study, we aimed to test a tool, which could help in differentiating AIS from SE when restricted diffusion was present on MRI.Materials and MethodsIn diffusion weighted imaging (DWI) with a b-value of 1,000 and apparent diffusion coefficient (ADC) maps, we compared the ratios of intensities of gray values of diffusion-restricted lesions to the healthy mirror side in patients with AIS and SE. Patients were recruited prospectively between February 2019 and October 2021. All patients underwent MRI and EEG within the first 48 h of symptom onset.ResultsWe identified 26 patients with SE and 164 patients with AIS. All patients had diffusion-restricted lesions with a hyperintensity in DWI and ADC signal decrease. Diffusion restriction was significantly more intense in patients with AIS as compared to patients with SE. The median ratios of intensities of gray values of diffusion-restricted lesions to the healthy mirror side for DWI were 1.42 (interquartile range [IQR] 1.32–1.47) in SE and 1.67 (IQR 1.49–1.90) in AIS (p < 0.001). ADC decrease was more significant in AIS as compared to SE with median ratios of 0.80 (IQR 0.72–0.89) vs. 0.61 (IQR 0.50–0.71), respectively (p < 0.001). A cutoff value for ratios of DWI signal was 1.495 with a sensitivity of 75% and a specificity of 85%. Values lower than 1.495 were more likely to be associated with SE and higher values were with AIS. A cutoff value for ADC ratios was 0.735 with a sensitivity of 73% and a specificity of 84%. Values lower than 0.735 were more likely to be associated with AIS and higher values were with SE.ConclusionDiffusion restriction and ADC decrease were significantly more intense in patients with AIS as compared to SE. Therefore, quantitative analysis of diffusion restriction may be a helpful tool for differentiating between AIS and SE when restricted diffusion is present on MRI.

Diffusion-Weighted Imaging Hyperintensities in Acute and Subacute-Phase Intracerebral Hemorrhage

ObjectiveDiffusion-weighted imaging hyperintensities are observed in intracerebral hemorrhage patients at times and might be associated with unfavorable functional outcomes. However, the suitable time to evaluate diffusion-weighted imaging hyperintensities to influence stroke outcome remains unclear. This study investigated the associations between acute and sub-acute diffusion-weighted imaging hyperintensities and functional outcomes among patients with acute intracerebral hemorrhage. MethodsDiffusion-weighted imaging hyperintensities were evaluated within 24 h (acute phase) and at 14 ± 5 days (sub-acute phase). An unfavorable functional outcome was a score of 5–6 on the modified Rankin Scale at 3 months. ResultsAmong 268 intracerebral hemorrhage patients, diffusion-weighted imaging hyperintensities in the acute phase were observed in 32 (11.9%). Among 227 patients who underwent a second magnetic resonance imaging in the sub-acute phase, diffusion-weighted imaging hyperintensities were observed in 57 (25.1%). Multivariable analysis revealed that the baseline intracerebral hemorrhage volume, history of stroke, and severe white matter lesions were associated with sub-acute diffusion-weighted imaging hyperintensities. The patients with unfavorable outcomes (n = 37) had a higher frequency of sub-acute diffusion-weighted imaging hyperintensities than those without (n = 190) (51.4% vs. 20.0%, P < 0.001); the frequencies of acute diffusion-weighted imaging hyperintensities were not significantly different between the groups (13.5% vs. 10.0%, P = 0.559). Sub-acute diffusion-weighted imaging hyperintensities were independently associated with unfavorable outcomes after adjusting for confounding factors (Odds Ratio, 3.35, 95% CI 1.20–9.35, P = 0.021). ConclusionThe rate of sub-acute diffusion-weighted imaging hyperintensities was higher than acute diffusion-weighted imaging hyperintensities among acute intracerebral hemorrhage patients and likely to be associated with unfavorable outcomes.