Table 1.

Code Abdomen categories, classifications, descriptors, and examples

Category	Classification	Descriptor	Example
0	Indeterminate	Incompletely evaluated. If indicated within the patient's clinical context, follow-up [MODALITY] is advised.*	Adrenal lesion with attenuation > 10 HU on enhanced CT in patient with known malignancy. Follow-up adrenal CT or MRI recommended.
1	Benign	No mass.
2	Benign	Benign. No further follow-up needed.†	Simple hepatic or renal cyst.
3	Indeterminate	Indeterminate. Future imaging follow-up may be needed. If indicated within the patient's clinical context, follow-up [MODALITY] is advised within [TIME PERIOD].*‡	Atypical hepatic hemangioma on CTor MRI. Follow-up CT or MRI recommended in 3-6 mo.
4	Suspicious	Suspicious. May represent malignancy.	Enhancing hepatic mass in cirrhotic patient without other classic imaging features of hepatocellular carcinoma (eg, delayed washout).
5	Suspicious	Highly suspicious. Clear imaging evidence of malignancy.	New hepatic soft tissue density lesions in patient with known colorectal cancer.
6	Malignant	Known cancer.	Biopsy-proven cancer or metastatic lesions
7	Benign	Completely treated cancer.	Renal cell carcinoma, status post nephrectomy without abnormality in surgical bed.
99	Cannot be classified	Technically inadequate for evaluation of masses.	Unenhanced CT in cirrhotic patient.

Note: HU = Hounsfield units.

^*If patient has known prior outside imaging, the following recommendation can be used: “If prior imaging studies can be provided for my review, direct comparison will be performed and an addendum will be issued to this report.”

^†The phrase “no further follow-up needed” may be omitted for focal masses with no malignant potential that may require follow-up (eg, abscess).

^‡If patient is known to have scheduled follow-up at our institution, the following recommendation can be used: “This may be re-evaluated at the time of routine imaging follow-up.”