C-RADS (CT Colonography)
C-RADS (CT Colonography Reporting and Data System)
Category: I-RADS
LI-RADS (Liver)
LI-RADS® (Liver Reporting and Data System)
*ACR: CT/MRI LI-RADS v2018 Core*
LI-RADS Version 2018 Ancillary Features at MRI
“[Focal perfusion alterations] are areas of arterial phase hyperenhancement most frequently caused by nontumorous arterioportal shunts or focal obstruction of a parenchymal portal vein branch. These alterations are usually peripheral, wedge shaped, and isointense relative to the surrounding parenchyma on T1- and T2-weighted MR images, and can be confidently characterized as LR-1; however, perfusion alterations can occasionally be nodular in contour and difficult to distinguish from a true enhancing lesion. Areas of nodular arterial phase hyperenhancement seen exclusively during the arterial phase are more appropriately categorized as LR-2, but if corresponding abnormalities (eg, increased T2 signal) can be seen on unenhanced images or with other sequences, perfusion alterations are considered unlikely, and the observation should be categorized as either LR-3 or LR-4 depending on its size and nonvascular features.”
Lung-RADS
Lung-RADS™ (Lung CT Screening Reporting and Data System)
NI-RADS (Head & Neck)
O-RADS (Ovarian-Adnexal)
PI-RADS (Prostate)
PI-RADS (Prostate Imaging Reporting and Data System)
TI-RADS (Thyroid)
TI-RADS (Thyroid Imaging Reporting and Data System)
- *ACR TI-RADS* Key Points
“Like other professional societies, we recommend biopsy of high-suspicion nodules only if they are 1 cm or larger.”
“However, a spongiform nodule must be composed predominantly (>50%) of small cystic spaces. Nodules should not be characterized as spongiform solely on the basis of the presence of a few, scattered cystic components in an otherwise solid nodule.”
“Echogenicity: “This feature refers to a nodule’s reflectivity relative to adjacent thyroid tissue, except for very hypoechoic nodules, in which the strap muscles are used as the basis for comparison.”
“A taller-than-wide shape is an insensitive but highly specific indicator of malignancy. This feature is evaluated in the axial [transvers] plane by comparing the height (“tallness”) and width of a nodule measured parallel and perpendicular to the ultrasound beam, respectively.”
“Notably, small echogenic foci may be seen in spongiform nodules, where they probably represent the back walls of minute cysts. They are not suspicious in this circumstance and should not add to the point total of spongiform nodules.”
“Measurements should also include the nodule’s halo, if present.”
“The committee recommends that no more than four nodules with the highest ACR TI-RADS point scores that fall below the size threshold for FNA should be followed, as detailed reporting of more than four nodules would needlessly complicate and lengthen reports. Other nodules may be reassessed on subsequent sonograms without being formally enumerated.”
“In the ACR TI-RADS, significant enlargement is defined as a 20% increase in at least two nodule dimensions and a minimal increase of 2 mm, or a 50% or greater increase in volume, as in the criteria adopted by other professional societies. Because enlargement may not be apparent if the current sonogram is compared only with the immediately preceding one, it is important to also review measurements from earlier scans, if available.”
“Biopsy of three or more nodules is poorly tolerated by patients and increases cost with little or no benefit and some added risk. Therefore, the committee recommends targeting no more than two nodules with the highest ACR TI-RADS point totals that meet criteria for FNA.”
- ACR TI-RADS Atlas