Differentiation of Brain Abscess From Cystic Glioma Using Conventional MRI Based on Deep Transfer Learning Features and Hand-Crafted Radiomics Features

Objectives: To develop and validate the model for distinguishing brain abscess from cystic glioma by combining deep transfer learning (DTL) features and hand-crafted radiomics (HCR) features in conventional T1-weighted imaging (T1WI) and T2-weighted imaging (T2WI).Methods: This single-center retrospective analysis involved 188 patients with pathologically proven brain abscess (102) or cystic glioma (86). One thousand DTL and 105 HCR features were extracted from the T1WI and T2WI of the patients. Three feature selection methods and four classifiers, such as k-nearest neighbors (KNN), random forest classifier (RFC), logistic regression (LR), and support vector machine (SVM), for distinguishing brain abscess from cystic glioma were compared. The best feature combination and classifier were chosen according to the quantitative metrics including area under the curve (AUC), Youden Index, and accuracy.Results: In most cases, deep learning-based radiomics (DLR) features, i.e., DTL features combined with HCR features, contributed to a higher accuracy than HCR and DTL features alone for distinguishing brain abscesses from cystic gliomas. The AUC values of the model established, based on the DLR features in T2WI, were 0.86 (95% CI: 0.81, 0.91) in the training cohort and 0.85 (95% CI: 0.75, 0.95) in the test cohort, respectively.Conclusions: The model established with the DLR features can distinguish brain abscess from cystic glioma efficiently, providing a useful, inexpensive, convenient, and non-invasive method for differential diagnosis. This is the first time that conventional MRI radiomics is applied to identify these diseases. Also, the combination of HCR and DTL features can lead to get impressive performance.

Role of Diffusion–Weight MRI in Differential Diagnosis of Cerebral Cystic Lesions: A Prospective Study

This study aimed to determine whether diffusion–weight MRI images and ADC (Apparent Diffusion Coefficient) could help accurately in distinguishing cystic cerebral lesions. The study included 65 patients with clinically suspected cerebral masses. They underwent surgery and diagnosed histologically. A conventional MRI was carried out on a 1.5T system using T1, T2 and fat-suppressed T1-weighted sequences before and after intravenous injection of gadolinium and echo-planar spin-echo sequence diffusion weight and ADC is carried for all patients. All MR imaging features were categorized cerebral cystic lesions without knowledge of clinical details, according to the imaging features which were compared with the surgical and pathological findings. The diagnosis was confirmed with surgery and histological evaluation which included 30(48%) patients with primary cystic brain tumors, 19 (35%) with metastatic tumors and 11 (17%) with abscess. All abscess cavities showed hyper intense DWI signal intensity and low signal ADC so the sensitivity for diagnosis abscess in DWI are 100%, while in primary brain tumor only 1 from 10 cystic glioma show hyper intense on DWI and hypo intense on ADC while the remain cystic glioma 9 show hypo intense on DWI and hyper intense on ADC make the sensitivity of DWI foe diagnosis primary malignant cystic tumor 90%. The study concluded that diffusion –weight MRI and ADC is sensitive for characterizing cystic cerebral lesions.

Positional oculogyric crises

✓ A young woman with a cystic glioma in the region of the posterior third ventricle is presented. Each time she turned to the supine position she developed immediate, forceful, conjugate upward gaze (oculogyric crises) and an inability to talk. If she turned to either side, she was alert and oriented, and could talk and lie comfortably. After stereotaxic removal of the cystic fluid, this phenomenon disappeared and did not return, even when the cyst refilled.

Cystic Glioma of the Brain Stem with Prolonged Survival

An unusual case of benign stem glioma with a 15-year survival is presented. In spite of 12 years of clinical quiescence, a focus of the tumor in the upper brain stem was found at necropsy. Morphologically, the tumor was a cystic pilocytic astrocytoma. The few previously reported similar cases in the same location were also associated with a favorable prognosis. It is suggested that, in analogy to the cystic cerebellar and cerebral astrocytomas, there is a group of cystic pilocytic astrocytomas of the brain stem with benign biological behavior.