Thyroid nodules are a frequent finding on neck sonography. Most nodules are benign; therefore, many nodules are biopsied to identify the small number that are malignant or require surgery for a definitive diagnosis. In 2012, the ACR convened committees to (1) provide recommendations for reporting incidental thyroid nodules, (2) develop a set of standard terms (lexicon) for ultrasound reporting, and (3) propose a TI-RADS on the basis of the lexicon.
PI-RADS is designed to improve focal lesion detection, localization, characterization, and risk stratification in patients with suspected cancer and consists of technical recommendation for MRI acquisition and a scoring system for image interpretation. PI-RADS uses a scale of 1–5 to report the overall probability of clinically significant prostate cancer on multiparametric MRI (mpMRI). The use of PI-RADS is limited to treatment naive patients and it should not be used for staging, assessment of treatment outcome, recurrence, or progression during surveillance.
The Liver Imaging Reporting and Data System (LI-RADS) standardizes the interpretation, reporting, and data collection for imaging examinations in patients at risk for hepatocellular carcinoma (HCC). It assigns category codes reflecting relative probability of HCC to imaging-detected liver observations based on major and ancillary imaging features. LI-RADS also includes imaging features suggesting malignancy other than HCC.
Positron emission tomography (PET) and computed tomography (CT) complement each other’s strengths in integrated PET/CT. Most PET/CT studies in oncology are performed with 18F-fluorodeoxyglucose (FDG). FDG is a glucose analogue that is taken up and trapped within viable cells. An increased glycolytic activity is a characteristic in many types of cancers resulting in avid accumulation of FDG. These tumours excel as “hot spots” in FDG-PET/CT imaging. FDG-PET/CT proved to be of high diagnostic value in staging and restaging of different malignant diseases, such as colorectal cancer, lung cancer, breast cancer, head and neck cancer, malignant lymphomas, and many more.
Acute radiation sickness can be categorized into three phases: prodrome, latency, and illness. The Table, summarizes the constellation of hematologic, gastrointestinal, and neurologic symptoms, along with the time to onset and dose dependence, associated with each of these phases.