Improved evaluation of technetium-99m-red blood cell SPECT in hemangioma of the liver.

This paper reports the results of a prospective study carried out to evaluate a new reading method of tomographic 99mTc red blood cell (RBC) imaging in liver hemangiomas. For this purpose, assessment of planar imaging and conventional, static 99mTc-RBC SPECT presentation (x-ray type film) (Method 1) was compared to a dynamic three-view display of SPECT slices (Method 2) in 21 patients with 56 hemangiomas and 18 patients with malignant liver lesions. Of the 56 hemangiomas, 47 were diagnosed by US, 6 by CT and 56 by MRI. Twenty-nine (52%) hemangiomas were detected by planar scintigraphy and 38 (68%) by SPECT Method 1, whereas 53 (95%) were visualized by SPECT Method 2. Comparing Methods 1 and 2 in hemangiomas < or = 1.0 cm, 1.1-2.0 cm and 2.1-3.0 cm in diameter, Method 2 improved sensitivity from 18% to 82%, 50% to 93% and 82% to 100%, respectively. The smallest hemangioma detected with Method 2 was 0.5 cm in diameter; with Method 1, 0.9 cm; and with planar imaging, 1.0 cm. As assessed by evaluation of the metastases and carcinomas, the specificity for hemangioma was 100%, independent of the method applied, resulting in a positive predictive value of 100%. This study suggests that evaluation of dynamically displayed 99mTc-RBC SPECT studies is superior to conventional reading of static display and comparable to MRI in liver hemangioma > or = 1 cm. Therefore, this approach is suggested as an alternative to MRI for confirming the diagnosis of liver hemangioma > or = 1 cm if planar imaging is negative. This option is available with most modern computer software systems and saves additional disbursement.