Young Woman With Right Upper Quadrant Pain

A 28-year-old woman complains of intermittentright upper quadrant pain.The patient is thin, and she is not inacute distress.

Temperature is 37.2^oC (99^oF);heart rate, 68 beats per minute; respirationrate, 22 breaths per minute;and blood pressure, 110/80 mm Hg.Heart is normal, and lungs are clear.The abdomen is soft, bowel soundsare normal, and there is minimal tendernessin the right upper quadrant.

You order magnetic resonancecholangiopancreatography to evaluateher biliary tree. The bile ducts andgallbladder appear normal; however,a lesion is found on the liver.

Although the patient's age andthe shape of the lesion lead the radiologistto suspect a hemangioma, thelesion does not meet the following criteria that characterizehemangiomas on MRI:

• Intensity equal to that of the cerebrospinal fluid (CSF) onheavily T2-weighted images; this finding identifies a lesionas either a cyst or a hemangioma and makes further evaluationunnecessary.
• Peripheral nodular enhancement that fills in from the peripheryto the center over time on dynamic images.

On T2-weighted images (Figures 1 and 2), this lesiondemonstrates increased signal intensity but appears lessintense than the CSF surrounding the spinal cord. Also,the enhancement pattern of the lesion is indeterminate(not shown).

Which nuclear medicine test will you order to definitivelyevaluate this liver lesion?

WHICH TEST--AND WHY: You order a technetium-labeledred blood cell study to assess the lesion. Liver lesions canbe diagnostic challenges. In young patients, many of theselesions are discovered as incidental findings.

Often, the lesion's features on MRI indicate that it is benign. Typically,hemangiomas have the characteristics mentioned above. In addition, focalfatty infiltration on T1-weighted images and on in- and out-of-phase imaging isa reliable indication of benignity; focal nodular hyperplasia also indicates thata lesion is not malignant.

Nuclear medicine can be used to assess lesions that are probably benignbut do not have the classic appearance on MRI.

What the study shows. In this patient, the lesion demonstrates prolongedretention of technetium-labeled red blood cells on 2-hour images. This scintigraphicappearance is classic for hemangioma (Figures 3 and 4). The specificityof this test in this setting is greater than 95%.

Nuclear medicine can also help identify focal nodular hyperplasia. On asulfur colloid scan, focal nodular hyperplasia is the only lesion that demonstratesgreater activity than the remainderof the liver. The sensitivity ofthis test is approximately 80%, but itsspecificity is greater than 95%.

Outcome of this case. Biopsywas avoided, and the patient's subsequentcourse was uneventful.