Abdominal diffusion mapping with use of a whole-body echo-planar system.

Abstract

To measure apparent diffusion coefficients (ADCs) of water in liver, spleen, kidney, and muscle. Ten volunteers (seven women and three men, aged 19-31 years [mean, 24 years]) and nine patients (five women and four men, aged 49-70 years [mean, 62 years]) (liver cyst, n = 3; liver hemangioma, n = 3; liver cirrhosis, n = 2; hepatocellular carcinoma, n = 1; and liver metastasis, n = 1) underwent magnetic resonance (MR) imaging. A stimulated-echo acquisition mode (STEAM)-type excitation and echo-planar imaging (EPI) readout was used in a 1.5-T echo-planar MR imaging system. ADCs measured in volunteers were liver, 1.39 x 10(-3) mm2/sec +/- 0.16; spleen, 0.95 x 10(-3) mm2/sec +/- 0.15; muscle, 1.99 x 10(-3) mm2/sec +/- 0.16; and kidney, 3.54 x 10(-3) mm2/sec +/- 0.47 (mean +/- standard deviation). Distinctive ADC values were found in organs with abnormalities. ADCs in patients with hepatic disease included liver cysts, 3.9-5.3; liver hemangiomas, 2.0-2.8; liver metastases from an islet cell tumor, 1.2; hepatocellular carcinoma, 1.7; and liver cirrhosis, 0.9-1.2 x 10(-3) mm2/sec. In vivo diffusion measurements of abdominal organs obtained with MR imaging may prove helpful in the identification and classification of abdominal disease.