PURPOSE: To determine
the appropriate acquisition parameters for magnetic resonance cholangiopancreatography
(MRCP) with a half-Fourier rapid acquisition with relaxation enhancement
(RARE) sequence; to determine the optimal MRCP technique by comparing half-Fourier
RARE, steady-state free precession (SSFP) two-dimensional (2D) fast spin-echo
(SE), and three-dimensional (3D) fast SE sequences; and to clarify the
usefulness and limitations of MRCP in diagnosing pancreatic abnormalities.
MATERIALS AND METHODS: Half-Fourier RARE MRCP images with varying parameters
were compared by using a phantom. Duct conspicuity and contrast-to-noise
ratios (C/Ns) were compared for the four MRCP techniques in a phantom and
healthy volunteers. The optimal MRCP technique was used to study healthy
volunteers and clinical cases. Receiver operating characteristic (ROC)
curves were created for data analysis. RESULTS: A 5-mm-thick section without
intersection gap was appropriate for half-Fourier RARE MRCP. Only half-Fourier
RARE MRCP could depict a 1-mm duct. C/N was the highest with half-Fourier
RARE, followed by 3D fast SE, 2D fast SE, and SSFP sequences. ROC curve
analysis revealed no interobserver differences, and the area under the
curve for detection of strictures of the main pancreatic duct was as high
as 0.89. CONCLUSION: Half-Fourier RARE MRCP has the highest contrast and
spatial resolution among the four techniques studied and may play an important
role in diagnosing pancreatic abnormalities.
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