A Multicenter Study of Needle Size and Safety for Splenic Biopsy.

Background Splenic biopsy is rarely performed because of the perceived risk of hemorrhagic complications. Purpose To evaluate the safety of large bore (≥18 gauge) image-guided splenic biopsy. Materials and Methods This retrospective study included consecutive adult patients who underwent US- or CT-guided splenic biopsy between March 2001 and March 2022 at eight academic institutions in the United States. Biopsies were performed with needles that were 18 gauge or larger, with a comparison group of biopsies with needles smaller than 18 gauge. The primary outcome was significant bleeding after the procedure, defined by the presence of bleeding at CT performed within 30 days or angiography and/or surgery performed to manage the bleeding. Categorical variables were compared using the χ2 test and medians were compared using the Mann-Whitney test. Results A total of 239 patients (median age, 63 years; IQR, 50-71 years; 116 of 239 [48.5%] female patients) underwent splenic biopsy with an 18-gauge or smaller needle and 139 patients (median age, 58 years [IQR, 49-69 years]; 66 of 139 [47.5%] female patients) underwent biopsy with a needle larger than 18 gauge. Bleeding was detected in 20 of 239 (8.4%) patients in the 18-gauge or smaller group and 11 of 139 (7.9%) in the larger than 18-gauge group. Bleeding was treated in five of 239 (2.1%) patients in the 18-gauge or smaller group and one of 139 (1%) in the larger than 18-gauge group. No deaths related to the biopsy procedure were recorded during the study period. Patients with bleeding after biopsy had smaller lesions compared with patients without bleeding (median, 2.1 cm [IQR, 1.6-5.4 cm] vs 3.5 cm [IQR, 2-6.8 cm], respectively; P = .03). Patients with a history of lymphoma or leukemia showed a lower incidence of bleeding than patients without this history (three of 90 [3%] vs 28 of 288 [9.7%], respectively; P = .05). Conclusion Bleeding after splenic biopsy with a needle 18 gauge or larger was similar to biopsy with a needle smaller than 18 gauge and seen in 8% of procedures overall, with 2% overall requiring treatment. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Grant in this issue.

Comparing the benefit of ASPECTS on maximum intensity projection images of computed tomography angiography to source images and noncontract computed tomography in predicting infarct volume and collaterals extent.

INTRODUCTION: In acute ischemic strokes (AIS), the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) and CT perfusion (CTP) are commonly used to determine mechanical thrombectomy eligibility. Prior work suggests that CTA source image (CTA-SI) ASPECTS (CTAasp) and a newly described CTA maximum intensity projection (CTA-MIP) ASPECTS (MIPasp) better predict the final infarct core. Our goal was to compare MIPasp to CTAasp and non-contrast CT ASPECTS (NCCTasp) for predicting ischemic core and collaterals established by CTP. METHODS AND MATERIALS: A single institution, retrospective database for AIS due to internal carotid artery (ICA) or proximal middle cerebral artery (MCA) occlusions between January 2016 and February 2021 was reviewed. We rated ASPECTS on NCCT, CTA-SI, and CTA-MIP at baseline, then used the automated RAPID software to measure CTP ischemic core volume. The accuracy of each ASPECTS in predicting ischemic core volume (ICV) >70 cc and Hypoperfusion intensity ratio (HIR) >0.4 was compared using the receiver operating characteristic (ROC) curve. RESULTS: 122/319 patients fulfilled the inclusion criteria. Area under the curve (AUC) for MIPasp was significantly higher than NCCTasp and CTAasp for predicting ICV >70 cc (0.95 vs. 0.89 and 0.95 vs. 0.92, P =0.03 and P = 0.04). For predicting HIR >0.4, AUC for MIPasp was significantly higher than NCCTasp and CTAasp (0.85 vs. 0.72 and 0.85 vs. 0.81, P < 0.001 and P < 0.01). CONCLUSION: The predictive accuracy of detecting ischemic stroke with ICV >70cc and HIR >0.4 can be significantly improved using the MIPasp instead of CTAasp or NCCTasp.

SARS-CoV-2 infection might be a predictor of mortality in intracerebral hemorrhage.

BACKGROUND: SARS-CoV-2 infection may be associated with uncommon complications such as intracerebral hemorrhage (ICH), with a high mortality rate. We compared a series of hospitalized ICH cases infected with SARS-CoV-2 with a non-SARS-CoV-2 infected control group and evaluated if the SARS-CoV-2 infection is a predictor of mortality in ICH patients. METHODS: In a multinational retrospective study, 63 cases of ICH in SARS-CoV-2 infected patients admitted to 13 tertiary centers from the beginning of the pandemic were collected. We compared the clinical and radiological characteristics and in-hospital mortality of these patients with a control group of non-SARS-CoV-2 infected ICH patients of a previous cohort from the country where the majority of cases were recruited. RESULTS: Among 63 ICH patients with SARS-CoV-2 infection, 23 (36.5%) were women. Compared to the non-SARS-CoV-2 infected control group, in SARS-CoV-2 infected patients, ICH occurred at a younger age (61.4 ± 18.1 years versus 66.8 ± 16.2 years, P = 0.044). These patients had higher median ICH scores ([3 (IQR 2-4)] versus [2 (IQR 1-3)], P = 0.025), a more frequent history of diabetes (34% versus 16%, P = 0.007), and lower platelet counts (177.8 ± 77.8 × 109/L versus 240.5 ± 79.3 × 109/L, P < 0.001). The in-hospital mortality was not significantly different between cases and controls (65% versus 62%, P = 0.658) in univariate analysis; however, SARS-CoV-2 infection was significantly associated with in-hospital mortality (aOR = 4.3, 95% CI: 1.28-14.52) in multivariable analysis adjusting for potential confounders. CONCLUSION: Infection with SARS-CoV-2 may be associated with increased odds of in-hospital mortality in ICH patients.

The importance of precise plane selection for female adult Chiari Type I malformation midsagittal morphometrics.

INTRODUCTION: Morphometric assessment of Chiari malformation type I (CMI) is typically performed on a midsagittal MRI. However, errors arising from an imprecise selection of the midsagittal plane are unknown. We define absolute parasagittal error as the absolute difference between morphometric measurements at the midsagittal and parasagittal planes. Our objective was to determine the absolute parasagittal error at various lateral distances for morphometric parameters commonly used in CMI research. METHODS: Sagittal T1-weighted MRI scans of 30 CMI adult female subjects were included. Image sets were evaluated to assess 14 CMI morphometric parameters in the midsagittal plane and four parasagittal planes located 1 and 2 mm lateral (left and right). Comparisons between measurements at the midsagittal and parasagittal planes were conducted to determine the mean individual absolute and mean group parasagittal errors for all 14 parameters. RESULTS: The mean individual absolute parasagittal error was > 1 unit (1 mm for lengths and 1 degree for angles) for 9/14 parameters within a lateral distance of 2 mm. No significant group parasagittal errors were seen in 14/14 parameters, including tonsillar position within a lateral distance of 2 mm. CONCLUSION: Our results show that the absolute errors for imprecise midsagittal plane selection may impact the clinical assessment of an individual patient. However, the impact on group measurements, such as in a research setting, will be minimal.

MRI findings differentiating tonsillar herniation caused by idiopathic intracranial hypertension from Chiari I malformation.

PURPOSE: Some patients with idiopathic intracranial hypertension (IIH) have cerebellar tonsillar herniation ≥ 5 mm mimicking Chiari malformation I (CMI), which can result in misdiagnosis and unjustified treatment. Our purpose was to identify IIH patients with tonsillar herniation ≥ 5 mm (IIHTH) and compare with CMI patients to assess imaging findings that could distinguish the two conditions. METHODS: Ninety-eight patients with IIH, 81 patients with CMI, and 99 controls were retrospectively assessed. Two neuroradiologists blindly reviewed MR images. IIHTH patients were compared with CMI patients and controls regarding the extent of tonsillar herniation (ETH), bilateral transverse sinus stenosis (BTSS), hypophysis-sella ratio (HSR), and bilateral tortuosity of optic nerve (BTON). RESULTS: 13/98 (13.2%) IIH patients had tonsillar herniation ≥ 5 mm (IIHTH) and were significantly younger and had higher BMI compared with CMI patients and controls. ETH was significantly less in the IIHTH than CMI (6.5 ± 2.4 mm vs. 10.9 ± 4.4 mm; p < 0.001). BTSS and HSR < 0.5 were more common in IIHTH than CMI (p < 0.001 and p = 0.003, respectively). No differences were seen between CMI and controls. BTON was significantly more common in IIHTH compared to control (p = 0.01) but not to the CMI (p = 0.36). Sensitivity and specificity to differentiate IIHTH from CMI were 69.2% and 96.1% for BTSS and 69.2% and 75.3% for HSR < 0.5. CONCLUSION: The presence of BTSS and/or HSR < 0.5 in patients with ETH ≥ 5 mm should suggest further evaluation to exclude IIH before considering CMI surgery.

Diagnostic yield of CT angiography performed for suspected cervical artery dissection in the emergency department.

BACKGROUND AND PURPOSE: Computed tomography angiographies are frequently performed in the emergency department (ED) for the assessment of cervical artery dissection (CeAD) due to the high risk of associated morbidity, but their diagnostic utility is not fully evaluated. We assessed the radiological outcomes and clinical correlates of CTAs performed for suspected CeAD. MATERIALS AND METHODS: CTAs for all indications (IndicationALL) over a 10-year period were evaluated to identify those with CeAD. A subgroup of CTAs performed for suspected CeAD (IndicationDISSECTION) was identified and further assessed for clinical findings predictive of CeAD. Magnetic resonance angiography/fat-saturated images (MRA/FSI) performed after CTA were also assessed. RESULTS: Nine-thousand-two-hundred-four CTAs were performed by our ED for IndicationALL of which 850 (9.2%) were for IndicationDISSECTION. CeAD was noted in 1.5% (142/9204) among IndicationALL and in 6.1% (53/850) of IndicationDISSECTION CTAs. The most common radiological findings were mural thrombus and eccentric lumen. In the IndicationDISSECTION group, new headache (OR: 2.5, 95%CI: 1.2-5.7) and partial Horner syndrome (OR: 14.4, 95%CI: 4.2-49.9) predicted carotid dissection and cervical fracture (OR: 5.5, 95%CI: 2.1-14.6) predicted vertebral artery dissections. MRA/FSI confirmed CeAD in all positive cases, but in 2 CTAs read as negative, MRA/FSI was positive for vertebral artery dissection. CONCLUSION: Although the yield of CTAs for clinically suspected CeAD is low, the paucity of reliable clinical predictors, high risk of morbidity, availability in ED, and comparable performance to MRA/FSI justifies its widespread utilization for initial diagnosis of CeAD.

Association of Diabetes and Hypertension With Brain Structural Integrity and Cognition in the Boston Puerto Rican Health Study Cohort.

BACKGROUND AND OBJECTIVES: The Boston Puerto Rican Health Study (BPRHS) is a longitudinal study following self-identified Puerto Rican older adults living in the Greater Boston area. Studies have shown higher prevalence of hypertension (HTN) and type 2 diabetes (T2D) within this ethnic group compared to age-matched non-Hispanic White adults. In this study, we investigated the associations of HTN and T2D comorbidity on brain structural integrity and cognitive capacity in community-dwelling Puerto Rican adults and compared these measures with older adult participants (non-Hispanic White and Hispanic) from the Alzheimer's Disease Neuroimaging Initiative (ADNI) and National Alzheimer's Coordinating Center (NACC) databases. METHODS: BPRHS participants who underwent brain MRI and cognitive testing were divided into 4 groups based on their HTN and T2D status: HTN-/T2D-, HTN+/T2D-, HTN-/T2D+, and HTN+/T2D+. We assessed microstructural integrity of white matter (WM) pathways using diffusion MRI, brain macrostructural integrity using hippocampal volumes, and brain age using T1-weighted MRI and cognitive test scores. BPRHS results were then compared with results from non-Hispanic White and Hispanic participants from the ADNI and NACC databases. RESULTS: The prevalence of HTN was almost 2 times (66.7% vs 38.7%) and of T2D was 5 times (31.8% vs 6.6.%) higher in BPRHS than in ADNI non-Hispanic White participants. Diffusion MRI showed clear deterioration patterns in major WM tracts in the HTN+/T2D+ group and, to a lesser extent, in the HTN+/T2D- group compared to the HTN-/T2D- group. HTN+/T2D+ participants also had the smallest hippocampal volume and larger brain aging deviations. Trends toward lower executive function and global cognitive scores were observed in HTN+/T2D+ relative to HTN-/T2D- individuals. MRI measures and the Mini-Mental State Examination (MMSE) scores from the HTN+/T2D+ BPRHS group resembled those of ADNI White participants with progressive mild cognitive impairment (MCI), while the BPRHS HTN-/T2D- participants resembled participants with stable MCI. The BPRHS was not significantly different from the ADNI + NACC Hispanic cohort on imaging or MMSE measures. DISCUSSION: The effects of T2D and HTN comorbidity led to greater brain structural disruptions than HTN alone. The high prevalence of HTN and T2D in the Puerto Rican population may be a key factor contributing to health disparities in cognitive impairment in this group compared to non-Hispanic White adults in the same age range. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov identifier: NCT01231958.

Diagnostic utility of parasagittal measurements of tonsillar herniation in Chiari I malformation.

BACKGROUND AND PURPOSE: Although the cerebellar tonsils are parasagittal structures, the extent of tonsillar herniation (ETH) in Chiari I malformation (CMI) is currently measured in the midsagittal plane. We measured the ETH of each cerebellar tonsil in the parasagittal plane and assessed their diagnostic utility by comparing them to the midsagittal ETH measurements in predicting cough-associated headache (CAH), an indicator of clinically significant disease in CMI. METHODS: Eighty-five CMI patients with 3D-MPRAGE images were included. Neurosurgeons determined the presence of CAH. Sagittal images were used to measure ETH in the midsagittal (MS_ETH) and parasagittal planes (by locating tonsillar tips on each side on reformatted coronal images). Given the parasagittal ETH (PS_ETH) asymmetry in the majority of cases, they were considered Smaller_PS_ETH or Larger_PS_ETH. The accuracy of ETH measurements was assessed by the receiver operating characteristic (ROC) curve. RESULTS: Of 85 patients, 46 reported CAH. ROC analysis showed an area under the curve (AUC) of 0.78 for Smaller_PS_ETH significantly better than 0.65 for MS-ETH in predicting CAH (p = 0.001). An AUC of 0.68 for Larger_PS_ETH was not significantly different from MS_ETH. The sensitivity and specificity of predicting CAH were 87% and 28% for MS_ETH >6 mm versus 90% and 46% for Smaller_PS_ETH >6 mm, and 52% and 67% for MS_ETH >9 mm versus 48% and 87% for Smaller_PS_ETH >9 mm. At ETH >15 mm, no differences were seen between the measurements. CONCLUSIONS: Diagnostic utility of ETH measurements in detecting clinically significant CMI can be improved by parasagittal measurements of the cerebellar tonsillar herniation.

Shortened total spine MRI protocol in the detection of spinal cord compression and pathology for emergent settings: a noninferiority study.

BACKGROUND AND PURPOSE: Spinal cord compression (SCC) requires rapid diagnosis in the emergent setting; however, current MRI protocols may be cumbersome for patients and clinicians. We sought to validate an abbreviated total spine MRI (TS-MRI) protocol using standard non-contrast sequences in the detection of SCC and other clinically significant findings (OCSF). METHODS: Two hundred six TS-MRI scans obtained over a 30-month period for SCC were included. Sagittal T2 (T2sag), sagittal T1 (T1sag), and sagittal STIR (IRsag), as well as axial T2 (T2ax) images, were individually assessed independently by 2 reviewers for SCC, cauda equina compression (CEC), and OCSF. A protocol consisting of all the sequences was considered the gold standard. Sensitivity and specificity of single and combined MRI sequences for SCC/CEC and OCSF were determined and were tested for noninferiority relative to standard non-contrast sequences using a 5% noninferiority margin. RESULTS: An abbreviated protocol of IRsag + T2ax provided the best performance with sensitivity and specificity of 100% (95%CI, 96.0-100.0) and 98.6% (95%CI, 95.6-99.7) for SCC/CEC and 100.0% (95%CI, 96.7-100.0), and 99.3% (95%CI, 96.6-99.9) for OCSF. The mean difference of sensitivity and specificity between IRsag + T2ax and standard protocol was 0.0% (95%CI, 0.0-4.0) and - 2.1% (95%CI, - 5.4 to - 0.6) for SCC/CEC and 0.0% (95%CI, 0.0-3.3) and - 1.5% (95%CI, - 4.8 to - 0.3) for OCSF, all within the noninferiority margin of 5%. CONCLUSIONS: An abbreviated TS-MRI protocol of IRsag + T2ax is noninferior to the standard non-contrast protocol, potentially allowing for faster emergent imaging diagnosis and triage.

SARS-CoV-2 and Stroke Characteristics: A Report From the Multinational COVID-19 Stroke Study Group.

[Figure: see text].

COVID-19: Neuroimaging Features of a Pandemic.

BACKGROUND AND PURPOSE: The ongoing Coronavirus Disease 2019 (COVID-19) pandemic is caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 is occasionally associated with manifold diseases of the central nervous system (CNS). We sought to present the neuroimaging features of such CNS involvement. In addition, we sought to identify typical neuroimaging patterns that could indicate possible COVID-19-associated neurological manifestations. METHODS: In this systematic literature review, typical neuroimaging features of cerebrovascular diseases and inflammatory processes associated with COVID-19 were analyzed. Reports presenting individual patient data were included in further quantitative analysis with descriptive statistics. RESULTS: We identified 115 studies reporting a total of 954 COVID-19 patients with associated neurological manifestations and neuroimaging alterations. A total of 95 (82.6%) of the identified studies were single case reports or case series, whereas 660 (69.2%) of the reported cases included individual information and were thus included in descriptive statistical analysis. Ischemia with neuroimaging patterns of large vessel occlusion event was revealed in 59.9% of ischemic stroke patients, whereas 69.2% of patients with intracerebral hemorrhage exhibited bleeding in a location that was not associated with hypertension. Callosal and/or juxtacortical location was identified in 58.7% of cerebral microbleed positive images. Features of hemorrhagic necrotizing encephalitis were detected in 28.8% of patients with meningo-/encephalitis. CONCLUSIONS: Manifold CNS involvement is increasingly reported in COVID-19 patients. Typical and atypical neuroimaging features have been observed in some disease entities, so that familiarity with these imaging patterns appears reasonable and may assist clinicians in the differential diagnosis of COVID-19 CNS manifestations.

COVID-19 Respiratory Illness and Subsequent Cerebrovascular Events, the Initial Iranian Experience.

OBJECTIVES: COVID-19 disproportionately affects older adults and individuals with cardiovascular co-morbidities. This report presents fifteen patients who had COVID-19 respiratory illness followed by cerebrovascular events. MATERIALS AND METHODS: A call by the Iranian Neurological Association gathered cases across the country who developed neurological symptoms attributed to hemorrhagic or ischemic stroke after a definite or probable Covid-19 respiratory illness. Definite cases were those with a typical respiratory illness, positive nasopharyngeal Covid-19 PCR test, and chest CT consistent with Covid-19 infection. Probable cases were defined by a typical respiratory illness, history of contacts with a Covid-19 case, and chest CT characteristic for Covid-19 infection. RESULTS: Fifteen patients (12 men and 3 women) with an age range of 38 to 93 years old (median: 65 years old) were included. Fourteen patients had a first-ever acute ischemic stroke and one patient had a subarachnoid hemorrhage. Eleven patients (73%) had previous cardiovascular comorbidities. The median time between respiratory symptoms and neurological symptoms was seven days (range 1-16 days). Stroke severity in two patients was mild (NIHSS ≤ 6), in six patients moderate (NIHSS: 7-12), and in seven patients severe (NIHSS ≥13). One patient received intravenous tissue plasminogen activator ( IV-tPA) with improved neurological symptoms. Six out of 15 patients (40%) died. All but one of those who survived had significant disability assessed by a modified ranking scale >2. The majority of patients in this case series had vascular risk factors and their stroke was associated with severe disability and death. CONCLUSION: This report highlights the need for further investigation of the links between Covid-19 and cerebrovascular events.

Cerebral venous sinus thrombosis associated with SARS-CoV-2; a multinational case series.

BACKGROUND: SARS-CoV-2 induced coagulopathy can lead to thrombotic complications such as stroke. Cerebral venous sinus thrombosis (CVST) is a less common type of stroke which might be triggered by COVID-19. We present a series of CVST cases with SARS-CoV-2 infection. METHODS: In a multinational retrospective study, we collected all cases of CVST in SARS-CoV-2 infected patients admitted to nine tertiary stroke centers from the beginning of the pandemic to June 30th, 2020. We compared the demographics, clinical and radiological characteristics, risk factors, and outcome of these patients with a control group of non-SARS-CoV-2 infected CVST patients in the same seasonal period of the years 2012-2016 from the country where the majority of cases were recruited. RESULTS: A total of 13 patients fulfilled the inclusion criteria (62% women, mean age 50.9 ± 11.2 years). Six patients were discharged with good outcomes (mRS ≤ 2) and three patients died in hospital. Compared to the control group, the SARS-CoV-2 infected patients were significantly older (50.9 versus 36.7 years, p < 0.001), had a lower rate of identified CVST risk factors (23.1% versus 84.2%, p < 0.001), had more frequent cortical vein involvement (38.5% versus 10.5%, p: 0.025), and a non-significant higher rate of in-hospital mortality (23.1% versus 5.3%, p: 0.073). CONCLUSION: CVST should be considered as potential comorbidity in SARS-CoV-2 infected patients presenting with neurological symptoms. Our data suggest that compared to non-SARS-CoV-2 infected patients, CVST occurs in older patients, with lower rates of known CVST risk factors and might lead to a poorer outcome in the SARS-CoV-2 infected group.

Risk of stroke in hospitalized SARS-CoV-2 infected patients: A multinational study.

BACKGROUND: There is an increased attention to stroke following SARS-CoV-2. The goal of this study was to better depict the short-term risk of stroke and its associated factors among SARS-CoV-2 hospitalized patients. METHODS: This multicentre, multinational observational study includes hospitalized SARS-CoV-2 patients from North and South America (United States, Canada, and Brazil), Europe (Greece, Italy, Finland, and Turkey), Asia (Lebanon, Iran, and India), and Oceania (New Zealand). The outcome was the risk of subsequent stroke. Centres were included by non-probability sampling. The counts and clinical characteristics including laboratory findings and imaging of the patients with and without a subsequent stroke were recorded according to a predefined protocol. Quality, risk of bias, and heterogeneity assessments were conducted according to ROBINS-E and Cochrane Q-test. The risk of subsequent stroke was estimated through meta-analyses with random effect models. Bivariate logistic regression was used to determine the parameters with predictive outcome value. The study was reported according to the STROBE, MOOSE, and EQUATOR guidelines. FINDINGS: We received data from 26,175 hospitalized SARS-CoV-2 patients from 99 tertiary centres in 65 regions of 11 countries until May 1st, 2020. A total of 17,799 patients were included in meta-analyses. Among them, 156(0.9%) patients had a stroke-123(79%) ischaemic stroke, 27(17%) intracerebral/subarachnoid hemorrhage, and 6(4%) cerebral sinus thrombosis. Subsequent stroke risks calculated with meta-analyses, under low to moderate heterogeneity, were 0.5% among all centres in all countries, and 0.7% among countries with higher health expenditures. The need for mechanical ventilation (OR: 1.9, 95% CI:1.1-3.5, p = 0.03) and the presence of ischaemic heart disease (OR: 2.5, 95% CI:1.4-4.7, p = 0.006) were predictive of stroke. INTERPRETATION: The results of this multi-national study on hospitalized patients with SARS-CoV-2 infection indicated an overall stroke risk of 0.5%(pooled risk: 0.9%). The need for mechanical ventilation and the history of ischaemic heart disease are the independent predictors of stroke among SARS-CoV-2 patients. FUNDING: None.

Magnetic resonance spectroscopic findings of chronic lesions in two subtypes of multiple sclerosis: primary progressive versus relapsing remitting.

BACKGROUND: Multiple sclerosis (MS) is a highly prevalent cause of neurological disability and has different clinical subtypes with potentially different underlying pathologies. Differentiation of primary progressive multiple sclerosis (PPMS) from relapsing remitting multiple sclerosis (RRMS) could be difficult especially in its early phases. OBJECTIVES: We compared brain metabolite concentrations and ratios in patients with PPMS and RRMS by magnetic resonance spectroscopic imaging (MRSI). PATIENTS AND METHODS: Thirty patients with definite MS (15 with RRMS and 15 with PPMS) underwent MRSI and their non-enhancing lesion metabolites were measured. N-acetyl aspartate (NAA), Creatine (Cr), Choline (Cho), NAA/Cr and NAA/Cho were measured and compared between the two MS subtypes. RESULTS: When the two MS groups were compared together, we found that Cr was significantly increased (P value=0.008) and NAA/Cr was significantly decreased (P value=0.03) in non-enhancing lesions in PPMS compared with RRMS. There was no significant difference in NAA, Cho or NAA/Cho between the two MS subtypes. CONCLUSION: MRS is a potential way to differentiate PPMS and RRMS.

Differentiation between sarcoidosis and Hodgkin's lymphoma based on mediastinal lymph node involvement pattern: Evaluation using spiral CT scan.

BACKGROUND: The purpose of this study was to determine the specific and detailed anatomic sites and morphologic characteristics of mediastinal lymph nodes on spiral computed tomography for the purpose of differentiation between sarcoidosis and Hodgkin's lymphoma. MATERIAL/METHODS: Anatomical distribution of mediastinal lymph nodes on spiral CT was reviewed in 39 patients with sarcoidosis and 37 patients with Hodgkin's lymphoma using the International Association for the Study of Lung Cancer (IASLC) lymph node map. Other morphologic features such as lymph node calcification or coalescence of adjacent lymph nodes were also compared. RESULTS: Zone 10 was involved more often in sarcoidosis than in Hodgkin's lymphoma. On the other hand, there was a higher tendency for presence of zone 1 and 3 as well as retrocrural and internal mammary lymphadenopathy in Hodgkin's lymphoma than in sarcoidosis. Sarcoidosis presented with intranodal calcifications more often than Hodgkin's lymphoma. Coalescence, pressure effect on adjacent structures and central cavitations were significantly more common in Hodgkin's lymphoma. CONCLUSIONS: Findings of the present study indicate that specific anatomical distribution and morphological patterns of mediastinal lymph nodes, as demonstrated on spiral CT, can be useful in differentiating sarcoidosis from Hodgkin's lymphoma.