MRI radiomics-based machine-learning classification of bone chondrosarcoma.

PURPOSE: To evaluate the diagnostic performance of machine learning for discrimination between low-grade and high-grade cartilaginous bone tumors based on radiomic parameters extracted from unenhanced magnetic resonance imaging (MRI). METHODS: We retrospectively enrolled 58 patients with histologically-proven low-grade/atypical cartilaginous tumor of the appendicular skeleton (n = 26) or higher-grade chondrosarcoma (n = 32, including 16 appendicular and 16 axial lesions). They were randomly divided into training (n = 42) and test (n = 16) groups for model tuning and testing, respectively. All tumors were manually segmented on T1-weighted and T2-weighted images by drawing bidimensional regions of interest, which were used for first order and texture feature extraction. A Random Forest wrapper was employed for feature selection. The resulting dataset was used to train a locally weighted ensemble classifier (AdaboostM1). Its performance was assessed via 10-fold cross-validation on the training data and then on the previously unseen test set. Thereafter, an experienced musculoskeletal radiologist blinded to histological and radiomic data qualitatively evaluated the cartilaginous tumors in the test group. RESULTS: After feature selection, the dataset was reduced to 4 features extracted from T1-weighted images. AdaboostM1 correctly classified 85.7 % and 75 % of the lesions in the training and test groups, respectively. The corresponding areas under the receiver operating characteristic curve were 0.85 and 0.78. The radiologist correctly graded 81.3 % of the lesions. There was no significant difference in performance between the radiologist and machine learning classifier (P = 0.453). CONCLUSIONS: Our machine learning approach showed good diagnostic performance for classification of low-to-high grade cartilaginous bone tumors and could prove a valuable aid in preoperative tumor characterization.

Adrenal schwannoma: a case report.

Retroperitoneum is an uncommon site for Schwannoma tumors and among adrenal incidentaloma the Schwannoma is rare. This condition lacks of a specific clinical and radiological features, but correct diagnosis before pathological examination should be very important for clinical management and surgical decision. We describe a case of voluminous retroperitoneal incidental mass, that was proved to be an adrenal Schwannoma.

Contrast agents in diagnostic imaging: Present and future.

Specific contrast agents have been developed for x ray examinations (mainly CT), sonography and Magnetic Resonance Imaging. Most of them are extracellular agents which create different enhancement on basis of different vascularization or on basis of different interstitial network in tissues, but some can be targeted to a particular cell line (e.g. hepatocyte). Microbubbles can be used as carrier for therapeutic drugs which can be released in specific targets under sonographic guidance, decreasing systemic toxicity and increasing therapeutic effect. Radiologists have to choose a particular contrast agent knowing its physical and chemical properties and the possibility of adverse reactions and balancing them with the clinical benefits of a more accurate diagnosis. As for any drug, contrast agents can cause adverse events, which are more frequent with Iodine based CA, but also with Gd based CA and even with sonographic contrast agents hypersensitivity reaction can occur.

Internal jugular Venous Compression Syndrome: hemodynamic outcomes after cervical vertebral decompression manipulations.

OBJECTIVE: The AA studied hemodynamic effects in Venous Compression Syndrome of internal Jugular veins, after noninvasive treatment by RIMA (Ricci's manipulation) cervical manipulations. METHODS: Twenty-six subjects were enrolled with at least one jugular vein with complete (white) compression in frontal neck position, assessed by echo color Doppler. RESULTS: after first RIMA procedure we had a reduction of 81.25% (6/32) in the total number of internal jugular vein white compressions. CONCLUSIONS: Our results suggest that RIMA decompression method may be useful to restore the drainage of internal jugular veins when a white compression occurs. Considering the novelty of this work and the total absence of scientific similar works able to confirm this data, it is necessary to continue these studies in order to improve the management of this venous hemodynamic condition.