Radiomics is a process that allows the extraction and analysis of quantitative data from medical images. It is an evolving field of research with many potential applications in medical imaging. The purpose of this review is to offer a deep look into radiomics, from the basis, deeply discussed from a technical point of view, through the main applications, to the challenges that have to be addressed to translate this process in clinical practice. A detailed description of the main techniques used in the various steps of radiomics workflow, which includes image acquisition, reconstruction, pre-processing, segmentation, features extraction and analysis, is here proposed, as well as an overview of the main promising results achieved in various applications, focusing on the limitations and possible solutions for clinical implementation. Only an in-depth and comprehensive description of current methods and applications can suggest the potential power of radiomics in fostering precision medicine and thus the care of patients, especially in cancer detection, diagnosis, prognosis and treatment evaluation.

Research from JAMA — Diagnostic Accuracy of Computed Tomographic Colonography for the Detection of Advanced Neoplasia in Individuals at Increased Risk of Colorectal Cancer

To evaluate computed tomographic (CT) colonography in patients with clinical suspicion of colorectal cancer and in whom colonoscopy was incomplete. After incomplete colonoscopy, 34 patients underwent CT colonography before and after intravenous injection of iodinated contrast agent, in supine and prone positions. Twenty patients with no evidence of colon cancer after complete colonoscopy were included as a control group. Sensitivity and specificity of CT colonography were determined for detection of cancers, polyps, and metastases to liver. In 29 patients, surgery revealed 30 colorectal cancers (three synchronous cancers) and two ischemic lesions of the descending colon. Colonoscopy missed 10 colorectal cancers and three synchronous cancers; all were detected with CT colonography. Sensitivity and specificity for detection of colorectal cancer were 56% and 92%, respectively, for incomplete colonoscopy and 100% and 96%, respectively, for CT colonography (P <.01). Sensitivity and specificity of CT colonography in detection of polyps were 86% and 70%, respectively, for diameters of 5 mm or less; 100% and 80%, respectively, for 5-10-mm diameters; and 100% for diameters greater than 10 mm. Spiral CT of the liver revealed four metastases (2-5 cm); sensitivity and specificity were 100% and 43% for nonenhanced scans and 100% for contrast-enhanced scans (P <.01). In this selected group of patients, CT colonography provided complete information to properly address surgery of colorectal cancer and treatment of liver metastases.

Objectives To develop a consensus and provide updated recommendations on liver MR imaging and the clinical use of liver-specific contrast agents. Methods The European Society of Gastrointestinal and Abdominal Radiology (ESGAR) formed a multinational European panel of experts, selected on the basis of a literature review and their leadership in the field of liver MR imaging. A modified Delphi process was adopted to draft a list of statements. Descriptive and Cronbach’s statistics were used to rate levels of agreement and internal reliability of the consensus. Results Three Delphi rounds were conducted and 76 statements composed on MR technique (n = 17), clinical application of liver-specific contrast agents in benign, focal liver lesions (n = 7), malignant liver lesions in non-cirrhotic (n = 9) and in cirrhotic patients (n = 18), diffuse and vascular liver diseases (n = 12), and bile ducts (n = 13). The overall mean score of agreement was 4.84 (SD ±0.17). Full consensus was reached in 22 % of all statements in all working groups, with no full consensus reached on diffuse and vascular diseases. Conclusions The consensus provided updated recommendations on the methodology, and clinical indications, of MRI with liver specific contrast agents in the study of liver diseases. Key points • Liver-specific contrast agents are recommended in MRI of the liver. • The hepatobiliary phase improves the detection and characterization of hepatocellular lesions. • Liver-specific contrast agents can improve the detection of HCC.