OBJECTIVETo evaluate the normal appearance of large field diffusion weighted imaging (DWI) on 3.0T magnetic resonance imaging (MRI).

METHODSTwenty healthy volunteers and thirty patients with benign prostate hyperplasia were included in this study. All patients were examined with large field DWI on 3.0T MRI. Normal tissue appearance was analyzed and apparent diffusion coefficient (ADC) of normal tissue with high signal intensity was measured. The ADC values of bilateral symmetrical tissue were also compared. The ADC values of intervertebral disks of healthy people younger than 50 years and exceeding 50 years were compared.

RESULTSSalivary gland, spleen, kidney, gallbladder, bladder, prostate, seminal vesicle, testis, intervertebral disk, liquid in articular cavity and lymph node showed high signal intensity on large field DWI, while lung, liver and bone showed hypo-signal intensity. The mean ADC values of partial hyperintensity tissue were as followed: parotid gland (1.088 +/- 0.114) x 10(-3) mm2/S, submaxillary gland (1.309 +/- 0.189) x 10(-3) mm2/s, kidney (1.909 +/- 0.143) x 10(-3) mm2/s, seminal vesicle (1.669 +/- 0.168) x 10(-3) mm2/s, testis (1.028 +/- 0.075) x 10(-3) mm2/s, spleen (0.963 +/- 0.108) x 10(-3) mm2/s, bladder (2.898 +/- 0.267) x 10(-3) mm2/s, prostate (1.448 +/- 0.132) x 10(-3) mm2/s, intervertebral disks (1.360 +/- 0.140) x 10(-3) mm2/s. No statistical significance was found between the ADC values of bilateral symmetrical tissues. The difference of ADC values of intervertebral disks of healthy people younger than 50 years [(1.372 +/- 0.142) x 10(-3) mm2/s] and exceeding 50 years [(1.344 +/- 0.134) x 10(-3) mm2/s] showed statistical significance (P = 0.040).

CONCLUSIONUnderstanding the high signal intensity of normal tissue on large field DWI may help to differentiate the normal tissues and abnormal ones.