Therapeutic Anticoagulation Impacts MR Morphologic Recurrence Patterns in Glioblastoma—A Matched-Pair Analysis

Background: Glioblastoma (GBM) patients are at particularly high risk for thrombotic complications. In the event of a postoperative pulmonary embolism, therapeutic anticoagulation (tAC) is indispensable. The impact of therapeutic anticoagulation on recurrence pattern in GBM is currently unknown. Methods: We conducted a matched-pair cohort analysis of 57 GBM patients with or without tAC that were matched for age, sex, gross total resection and MGMT methylation status in a ratio of 1:2. Patients’ characteristics and clinical course were evaluated using medical charts. MRI characteristics were evaluated by two independent authors blinded to the AC status. Results: The morphologic MRI appearance in first GBM recurrence showed a significantly higher presence of multifocal, midline crossing and sharp demarcated GBM recurrence patterns in patients with therapeutic tAC compared to the matched control group. Although statistically non-significant, the therapeutic tAC cohort showed increased survival. Conclusion: Therapeutic anticoagulation induced significant morphologic changes in GBM recurrences. The underlying pathophysiology is discussed in this article but remains to be further elucidated.

Rare Case of Wernicke Encephalopathy with Initial Negative Diffusion-Weighted Imaging

In this report, we present a rare patient with Wernicke encephalopathy (WE) in whom the initial magnetic resonance imaging (MRI) was normal. However, cranial MRI, performed two weeks later, showed lesions compatible with WE. Via the presentation of this patient, we discuss the need for future studies of larger cases including the temporal evaluation of the MRI characteristics of Wernicke encephalopathy.

Automated Multimodal Fusion Technique for the Classification of Human Brain on Alzheimer’s Disorder

Alzheimer's Disorder (AD) may permanently impair memory cells, resulting in dementia. Researchers say that early Alzheimer's disease diagnosis is difficult. MRI is used to detect AD in clinical trials. It requires high discriminative MRI characteristics to accurately classify dementia stages. Due to the large extraction of features, improved deep CNN-based models have recently proven accurate. With fewer picture samples in the datasets, over-fitting issues arise, limiting the effectiveness of deep learning algorithms. This research article minimizes the overfitting error due to fusion techniques. This hybrid approach is used to classify Alzheimer's disease more accurately than other traditional approaches. Besides, the Convolutional Neural Network (CNN) provides more minute features of small changes in MRI scan images than any other algorithm. Therefore, the proposed algorithm provides great accuracy in the region of sagittal, coronal, and axial Mild Cognitive Impairments (MCI) in the brain segment classification. Moreover, this research article compares the proposed algorithm with previous research output that is used to help prove its superiority. The performance metrics uses Health Subject (HS), MCI, and Mini-Mental State Evaluation (MMSE) to evaluate the proposed research algorithm.

MR imaging characteristics of uveal melanoma with histopathological validation

Purpose To evaluate the magnetic resonance imaging (MRI) characteristics of uveal melanoma (UM), to compare them with fundoscopy and ultrasound (US), and to validate them with histopathology. Methods MR images from 42 UM were compared with US and fundoscopy, and on 14 enucleated cases with histopathology. Results A significant relationship between the signal intensity on T1 and pigmentation on histopathology was found (p=0.024). T1 hyperintense UM were always moderately or strongly pigmented on histopathology, while T1-hypointense UM were either pigmented or non-pigmented. Mean apparent diffusion coefficient (ADC) of the UM was 1.16 ± 0.26 × 10−3 mm2/s. Two-thirds of the UM had a wash-out and the remaining a plateau perfusion time-intensity curve (TIC). MRI was limited in evaluating the basal diameter of flat tumors. US tends to show larger tumor prominence (0.5mm larger, p=0.008) and largest basal diameter (1.4mm larger, p<0.001). MRI was good in diagnosing ciliary body involvement, extrascleral extension, and optic nerve invasion, but limited on identifying scleral invasion. An increase of tumor prominence was associated with lower ADC values (p=0.030) and favored a wash-out TIC (p=0.028). An increase of tumor ADC correlated with a plateau TIC (p=0.011). Conclusions The anatomical and functional MRI characteristics of UM were comprehensively assessed. Knowing the MRI characteristics of UM is important in order to confirm the diagnosis and to differentiate UM from other intra-ocular lesions and because it has implications for treatment planning. MRI is a good technique to evaluate UM, being only limited in case of flat tumors or on identifying scleral invasion.

MRI characteristics of brain edema in preeclampsia/eclampsia patients with posterior reversible encephalopathy syndrome

Background The neuroimaging manifestations of eclampsia and preeclampsia often overlap, mainly presenting as posterior reversible encephalopathy syndrome (PRES). The purpose of this retrospective study was to compare the extent and nature of brain edema in eclampsia and preeclampsia patients with PRES based on MRI characteristics. Methods One hundred fifty women diagnosed with preeclampsia-eclampsia and undergoing cranial MRI were enrolled; 24 of these were diagnosed as having eclampsia. According to clinicoradiologic diagnosis of PRES, eligible patients were classified as having eclampsia with PRES (group E-PRES) and preeclampsia with PRES (group P-PRES). A scale on T2W FLAIR-SPIR images was established to evaluate the extent of brain edema, and the score of brain edema (SBE) of both groups was compared. In patients of the two groups who also underwent DWI sequence, the presence or absence of hyperintensity on DWI and hypointensity on ADC maps were determined to compare the nature of brain edema. Furthermore, clinical and biochemical data of the two groups were compared. Results The incidence of PRES in eclampsia patients was significantly higher than that in preeclampsia patients (87.50% vs. 46.03%, P<0.001). The SBE of all regions and typical regions in group E-PRES patients were significantly higher than those in group P-PRES patients (15.88±8.72 vs. 10.90±10.21, P=0.021; 8.52±3.87 vs. 5.01±4.19, P=0.002; respectively). The presence of hyperintensity on DWI was determined more frequently in group E-PRES patients than group P-PRES patients (71.43% vs. 32.00%, P=0.024). Age, systolic blood pressure, white blood cell count, neutrophil count and percentage of neutrophils were significantly different between the two groups (P<0.05). Conclusions Certain MRI characteristics that reflect the extent and nature of brain edema were different between eclampsia and preeclampsia patients with PRES. Additional prospective studies are still required to explore whether these MRI characteristics of brain edema may further become a potential predictor for eclamptic seizures in preeclampsia patients with PRES.

Predicting Reparability of Meniscal Tears Pre-Operatively Using 3-Tesla MRI (111)

Objectives: The ability to predict meniscus tear reparability based on pre-operative MRI is desirable for pre-operative patient counseling. However, the accuracy of MRI-based predictive methods varies widely within the orthopedic and radiology literature. We hypothesized that modern higher resolution 3-Tesla (T) MRI improves the accuracy of predicting reparability compared to prior investigations using 1.5T MRI assessments. Methods: We identified 44 patients (age 16 to 40 years) who were known to have undergone arthroscopic meniscal repair at our institution between the dates of January 1, 2013 and June 1, 2019. The MRI characteristics of this meniscus repair group were then compared to 43 age- and sex-matched patients who underwent arthroscopic partial meniscectomy during the same time period. 3T MRI images from the repair (Figure 1A) and the partial meniscectomy (Figure 1B) groups were all obtained pre-operatively at the author’s institution. Images from all 87 patients were independently reviewed by two fellowship-trained musculoskeletal radiologists and one orthopedic surgery fellow specializing in sports medicine. Each examiner was blinded with regard to meniscus tear treatment (repair versus partial meniscectomy). Meniscal tear MRI characteristics were evaluated based on established arthroscopic criteria including tear length greater than 10 mm, tear location within 3 mm of the menisco-synovial junction, tear greater than 50% thickness, and the presence of an intact inner meniscal fragment. We then analyzed the predictive accuracy and interrater reliability of this method. Results: With regards to accurately predicting meniscal reparability using the established criteria, the three MRI examiners accurately predicted repair 58% (orthopedist), 60% (radiologist 1), and 63% (radiologist 2) of the time, with respective positive predictive values of 60%, 62%, and 70%. The three examiners agreed upon tear reparability (i.e., a score of 4 versus not 4) only 41% of the time (κ = 0.173, p = .005). For 2 of the examiners (orthopedist and radiologist), none of the individual criteria were significantly predictive of tear reparability. For the 3rd examiner (radiologist), tear location within 3mm of the meniscosynovial junction was the most predictive individual criterion and the only criteria that reached statistical significance (OR = 9.83, p = .04). Conclusions: Although 3T MRI is higher resolution than 1.5T MRI, 3T MR imaging assessments performed by experienced examiners demonstrated a poor ability to predict the reparability of meniscus tears based on the application of previously established arthroscopic criteria. In addition, inter-observer reliability in this setting was also poor. Arthroscopic inspection remains the gold standard for the determination of meniscus tear reparability.

Baseline MRI findings as predictors of hypopituitarism in patients with non-functioning pituitary adenomas

Hypopituitarism tends to occur in large pituitary adenomas. However, similar tumors could present with strikingly different hormonal deficiencies. In this study, we looked at MRI characteristics in non-functioning pituitary adenomas (NFPA), which could predict secondary adrenal insufficiency (SAI) and central hypothyroidism (CHT). We reviewed the files of patients with NFPA attending our clinic. Tumor size, invasiveness, MR-signal intensity, and gadolinium enhancement in preoperative MRI were recorded along with documented presurgical hypopituitarism profile. Logistic regression was used to predict SAI, CHT or both (SAI/CHT) based on MRI and demographic parameters. Receiver operating characteristic curves were used to determine their diagnostic utility. 121 patients were included. Older age (P=0.021), male sex (P=0.043), stalk deviation (P<0.0001), contrast enhancement (P=0.029) and optic chiasma compression (P=0.012) were associated with SAI/CHT. Adenoma vertical height, largest diameter, and estimated volume were also strongly associated with SAI/CHT (P<0.0001). These associations remained significant in a multivariate analysis. No tumor smaller than 12mm in vertical height, 17mm in largest diameter, or 0.9 cm3 in volume was associated with SAI/CHT. At cutoff >18mm for vertical height, >23 mm for largest diameter, and >3.2 cm3 the sensitivity was around 90-92% for detecting SAI/CHT. Only vertical height was significantly associated with any one or more pituitary hormonal deficit (P=0.001). In conclusion, adenoma size, independent of the measurement used, remains the best predictor of SAI/CHT in NFPA. Dynamic testing to rule out SAI is probably indicated in adenomas larger than 18 mm vertical height, 23 mm largest diameter and 3.2cm3 adenoma volume.