Small subdural hemorrhages: Does size of intracranial hemorrhage impact symptoms after discharge?

INTRO: Patients with small intracranial hemorrhage at initial presentation (ICHi) have a relatively uneventful hospital course, as compared with larger ICHi. In this study, we tested the null hypothesis that ICHi does not impact the symptom profile of patients with traumatic brain injury (TBI) after discharge. METHODS: In this retrospective study, TBI patients over 18 years of age with a head CT at initial presentation and at least one follow-up visit between 2015 and 2018 were included. Those with vascular risk factors, major psychiatric comorbidities, neurologic disorders, and TBI / CT evidence of ICH within five years were excluded. Patients were stratified based on the presence or absence of ICHi. Symptom profiles were characterized during early (0-3 months post-TBI) and late follow up (4-12 months post-TBI). An adapted 15-question Post-Concussion Symptom Scale and a vestibulo-oculomotor (VOM) exam were assessed by a TBI specialist. We compared the age adjusted clinical symptom profiles between those with and without ICHi. RESULTS: 69 patients met inclusion/exclusion criteria. 26 (37.8%) had ICHi and 43 (62.32%) did not have ICH. The severity of measured symptoms or VOM findings were not more severe in those with ICHi. Age-adjusted analyses did not show any effect on these outcomes. CONCLUSION: ICHi does not impact the symptom profile of patients with TBI in either short or long term.

Skeletal involvement in Erdheim-Chester disease: Multimodality imaging features and association with the BRAFV600E mutation.

OBJECTIVE: The aim of this study was to characterize the distribution of skeletal involvement in Erdheim-Chester disease (ECD) by using radiography, computed tomography (CT), 18F-FDG positron emission tomography/computed tomography (PET/CT), and bone scans, as well as looking for associations with the BRAFV600E mutation. MATERIAL AND METHODS: Prospective study of 50 consecutive patients with biopsy-confirmed ECD who had radiographs, CT, 18F-FDG PET/CT, and Tc-99m MDP bone scans. At least two experienced radiologists with expertise in the relevant imaging studies analyzed the images. Summary statistics were expressed as the frequency with percentages for categorical data. Fisher's exact test, as well as odds ratios (OR) with 95 % confidence intervals (CI), were used to link imaging findings to BRAFV600E mutation. The probability for co-occurrence of bone involvement at different locations was calculated and graphed as a heat map. RESULTS: All 50 cases revealed skeletal involvement at different regions of the skeleton. The BRAFV600E mutation, which was found in 24 patients, was correlated with femoral and tibial involvement on 18F-FDG PET/CT and bone scan. The appearance of changes on the femoral, tibial, fibular, and humeral involvement showed correlation with each other based on heat maps of skeletal involvement on CT. CONCLUSION: This study reports the distribution of skeletal involvement in a cohort of patients with ECD. CT is able to detect the majority of ECD skeletal involvement. Considering the complementary nature of information from different modalities, imaging of ECD skeletal involvement is optimized by using a multi-modality strategy.

The role of arachnoid granulations in idiopathic intracranial hypertension.

OBJECTIVES: Idiopathic intracranial hypertension (IIH) is a disease defined by elevated intracranial pressure (ICP) without an established etiology. Arachnoid granulations (AG) are conduits for CSF resorption from the subarachnoid space to the venous system. AG have been implicated to play a central role in maintaining CSF homeostasis. We tested the hypothesis that patients with fewer visible AG on MRI are more likely to present with IIH. METHODS: In this institutional review board (Institutional Review Board)-approved retrospective chart review study, 65 patients with a clinical diagnosis of idiopathic intracranial hypertension were compared to 144 control patients who met inclusion/exclusion criteria. Patients' signs and symptoms pertaining to IIH were obtained through the electronic medical record Brain MR images were reviewed for the number and distribution of AGs indenting the dural venous sinuses. The presence of imaging and clinical findings associated with long standing increased ICP was noted. Propensity score method (with inverse probability weighting technique) was used to compare case and control groups. RESULTS: In the control group, the number of AG indenting the dural venous sinuses on MRI (NAG) was lower in women compared to men when matched for age (20-45 yo) and BMI (>30 kg/m2). The NAG was lower in 20-45 yo females in the IIH group as compared to the 20-45 yo females in the control group. This statistically significant difference persists when controlled for BMI. In contrast, the NAG in >45 yo females in the IIH group trended higher compared to the >45 yo females in the control group. CONCLUSION: Our results suggest that alterations in arachnoid granulations could play a role in the development of IIH.

Comparison of CT and Dixon MR Abdominal Adipose Tissue Quantification Using a Unified Computer-Assisted Software Framework.

PURPOSE: Reliable and objective measures of abdominal fat distribution across imaging modalities are essential for various clinical and research scenarios, such as assessing cardiometabolic disease risk due to obesity. We aimed to compare quantitative measures of subcutaneous (SAT) and visceral (VAT) adipose tissues in the abdomen between computed tomography (CT) and Dixon-based magnetic resonance (MR) images using a unified computer-assisted software framework. MATERIALS AND METHODS: This study included 21 subjects who underwent abdominal CT and Dixon MR imaging on the same day. For each subject, two matched axial CT and fat-only MR images at the L2-L3 and the L4-L5 intervertebral levels were selected for fat quantification. For each image, an outer and an inner abdominal wall regions as well as SAT and VAT pixel masks were automatically generated by our software. The computer-generated results were then inspected and corrected by an expert reader. RESULTS: There were excellent agreements for both abdominal wall segmentation and adipose tissue quantification between matched CT and MR images. Pearson coefficients were 0.97 for both outer and inner region segmentation, 0.99 for SAT, and 0.97 for VAT quantification. Bland-Altman analyses indicated minimum biases in all comparisons. CONCLUSION: We showed that abdominal adipose tissue can be reliably quantified from both CT and Dixon MR images using a unified computer-assisted software framework. This flexible framework has a simple-to-use workflow to measure SAT and VAT from both modalities to support various clinical research applications.

Role of ultra-high b-value DWI in the imaging of hereditary leiomyomatosis and renal cell carcinoma (HLRCC).

PURPOSE: Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome is associated with an aggressive form of renal cell carcinoma with high risk of metastasis, even in small primary tumors with unequivocal imaging findings. In this study, we compare the performance of ultra-high b-value diffusion-weighted imaging (DWI) sequence (b = 2000 s/mm2) to standard DWI (b = 800 s/mm2) sequence in identifying malignant lesions in patients with HLRCC. METHODS: Twenty-eight patients (n = 18 HLRCC patients with 22 lesions, n = 10 controls) were independently evaluated by three abdominal radiologists with different levels of experience using four combinations of MRI sequences in two separate sessions (session 1: DWI with b-800, session 2: DWI with b-2000). T1 precontrast, T2-weighted (T2WI), and apparent diffusion coefficient (ADC) sequences were similar in both sessions. Each identified lesion was subjectively assessed using a six-point cancer likelihood score based on individual sequences and overall impression. RESULTS: The ability to distinguish benign versus malignant renal lesions improved with the use of b-2000 for more experienced radiologists (Reader 1 AUC: Session 1-0.649 and Session 2-0.938, p = 0.017; Reader 2 AUC: Session 1-0.781 and Session 2-0.921, p = 0.157); whereas no improvement was observed for the less experienced reader (AUC: Session 1-0.541 and Session 2-0.607, p = 0.699). CONCLUSION: The inclusion of ultra-high b-value DWI sequence improved the ability of classification of renal lesions in patients with HLRCC for experienced radiologists. Consideration should be given toward incorporation of DWI with b-2000 s/mm2 into existing renal MRI protocols.

The American Board of Radiology's Alternate Pathway for Diagnostic Radiology: What the Programs and the Applicants Need to Know.

The American Board of Radiology (ABR) developed the international medical graduate alternate pathway to give foreign trained radiologists an alternate route to independent radiology practice without having to undergo radiology residency in the United States. After 4 years of fellowship/faculty experience in the same training institution, the foreign trained radiologist becomes eligible to sit for the radiology board examinations conducted by the ABR. As this pathway is not offered at every radiology training program, many training institutions are unfamiliar with the fundamentals of this pathway. At the same time, both the training institutions and the applying foreign-trained physicians face a plethora of confusing choices on the state and federal level. In this paper, we review the main factors which both the international medical graduate radiologists and training programs must consider before embarking on the diagnostic radiology ABR Alternate Pathway, namely, eligibility, visa options, state medical licensure requirements, their costs and implications for future employment opportunities.

Quantitative Ultrasound Assessment of Hepatic Steatosis.

Background/Aims: Non-alcoholic fatty liver disease (NAFLD) is widespread chronic disease of the live in humans with the prevalence of 30% of the United States population.1,2 The goal of the study is to validate the performance of quantitative ultrasound algorithms in the assessment of hepatic steatosis in patients with suspected NAFLD. Methods: This prospective study enrolled a total of 31 patients with clinical suspicion of NAFLD to receive liver fat measurements by quantitative ultrasound and reference MRI measurements (proton density fat-fraction, PDFF). The following ultrasound (US) parameters based on both raw ultrasound RF (Radio Frequency) data and 2D B-mode images of the liver were analyzed with subsequent correlation with MRI-PDFF: hepatorenal index, acoustic attenuation coefficient, Nakagami coefficient parameter, shear wave viscosity, shear wave dispersion and shear wave elasticity. Ultrasound parameters were also correlated with the presence of hypertension and diabetes. Results: The mean (± SD) age and body mass index of the patients were 49.03 (± 12.49) and 30.12 (± 6.15), respectively. Of the aforementioned ultrasound parameters, the hepatorenal index and acoustic attenuation coefficient showed a strong correlation with MRI-PDFF derivations of hepatic steatosis, with r-values of 0.829 and 0.765, respectively. None of the remaining US parameters showed strong correlations with PDFF. Significant differences in Nakagami parameters and acoustic attenuation coefficients were found in those patients with and without hypertension. Conclusions: Hepatorenal index and acoustic attenuation coefficient correlate well with MRI-PDFF-derived measurements of hepatic steatosis. Quantitative ultrasound is a promising tool for the diagnosis and assessment of patients with NAFLD.

Acute cholecystitis: diagnostic value of dual-energy CT-derived iodine map and low-keV virtual monoenergetic images.

PURPOSE: To compare conventional and dual-energy CT (DECT) for the diagnosis of acute cholecystitis and gangrene. METHODS: Fifty-seven consecutive adult patients with abdominal pain who underwent IV contrast-enhanced abdominal DECT on a dual-layer (dlDECT) or rapid-switching (rsDECT) scanner from September, 2018 to April, 2021 with cholecystectomy and pathology-confirmed cholecystitis were retrospectively reviewed, and compared with 57 consecutive adult patients without cholecystitis from the same interval scanned with DECT. Images were reviewed independently by two abdominal radiologists with 12 and 16 years of experience in two sessions 4 weeks apart, blinded to clinical data. Initially, only blended reconstructions (simulating conventional single-energy CT images) were reviewed (CT). Subsequently, CT and DECT reconstructions including low-keV virtual monoenergetic images and iodine maps were reviewed. Gallbladder fossa hyperemia, pericholecystic fluid, subjective presence of gangrene, heterogeneous wall enhancement, sloughed membranes, intramural air, abscess, overall impression of the presence of acute cholecystitis, and intramural iodine density were assessed. RESULTS: Gallbladder fossa hyperemia was detected with increased sensitivity on DECT (R1, 61.4%; R2, 75.4%) vs. CT (R1, 22.8%; R2, 15.8%). DECT showed increased sensitivity for gangrene (R1, 24.6%; R2, 38.6%) vs. CT (R1, 5.3%; R2, 14%), heterogeneous wall enhancement (DECT: R1, 33.3%; R2, 63.2% vs. CT: R1, 7%; R2, 31.6%), and cholecystitis (DECT: R1, 86%; R2, 89.5% vs. CT: R1, 77.2%; R2, 70.2%). In addition, DECT was more sensitive for the detection of acute cholecystitis (R1, 86%; R2, 89.5%) vs. CT (R1, 77.2%; R2, 70.2%). Iodine density threshold of 1.2 mg/ml, 0.8 mg/mL, and 0.5 mg/mL showed specificity for gangrenous cholecystitis of 78.26%, 86.96%, and 95.65%, respectively, using the rsDECT platform. CONCLUSION: DECT showed improved sensitivity compared to conventional CT for detection of acute cholecystitis. Iodine density measurements may be helpful to diagnose gangrene.

Lumbar arachnoiditis: Does imaging associate with clinical features?

OBJECTIVES: Lumbar arachnoiditis is a rare and debilitating neurologic disorder with multiple etiologies and a spectrum of imaging and clinical characteristics. Prior reports have anecdotally claimed that no association exists between findings of arachnoiditis observed on magnetic resonance imaging (MRI) and those assessed clinically. The purpose of this study was to determine if MRI features of lumbar arachnoiditis associate with the clinical findings of the disorder. PATIENTS AND METHODS: Twenty eight patients with lumbar arachnoiditis reported on MRI between 2012 and 2018 were retrospectively identified. A variety of MRI and clinical features of lumbar arachnoiditis were cataloged for these patients based on common findings discovered through literature review. Imaging findings included cauda equina nerve root contour and thickening, adhesion location, level of involvement, enhancement, and Delamarter group. Clinical findings included demographics, etiology, symptom dynamics, and signs/symptoms. Fisher's exact tests were used to determine associations between the imaging and clinical features of lumbar arachnoiditis. RESULTS: In general, MRI findings did not associate with the clinical features of lumbar arachnoiditis with a few exceptions. Most notably, confounding lumbar pathology was associated with symptom dynamics (p = 0.004) and nerve root contour was associated with motor and sensory symptoms (p = 0.01). The suspected arachnoiditis etiology of the majority of patients was either post-operative or post-infectious in nature. CONCLUSION: MRI findings in lumbar arachnoiditis offer limited insight into the clinical presentation of the disorder.

A Low-Cost, Low-Skill Model for Efficient Breast Cancer Screening in Low Resource Rural Settings of a Developing Country.

Objective To suggest a low-cost, easily-operable, non-invasive imaging modality for cancer detection in rural settings. Method A total of 212 cases with palpable breast masses aged 18 - 65 years were enrolled and underwent thorough clinical, mammographic, and ultrasonographic (USG) evaluation. Imaging findings were reported using the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS®) criteria. The findings were confirmed histopathologically. Data were analyzed using the Chi-square test. Results The malignancy rate was 35.8% (n = 76). On mammography, lesions size, margins, shape, calcification, and distorted arch/skin thickening were significantly associated with malignancy. On USG, the number of nodules, shape, margins, echotexture, posterior wall echo, through transmission changes, distorted arch/skin thickening, microlobulation, duct extension, and height/width ratio were significantly associated with malignancy. Independently, mammography and USG had a sensitivity of 78.1% and 80.3%, respectively, and a specificity of 83.3% and 89.0%, respectively. Using a positive result of either study as the criteria, the sensitivity was 97.4% and the specificity was 80.1%. Conclusion The combined use of mammography and USG provides high sensitivity and specificity, thus showing that a combination of two can be used as a screening tool for use in low resource rural settings.