Comparison of Optimized 3D-SPACE and 3D-TSE Sequences at 1.5T MRCP in the Diagnosis of Choledocholithiasis.

Purpose: The aim of the study was to evaluate whether or not MRCP using a 3D-SPACE sequence allows for better image quality and a higher level of diagnostic confidence than a conventional 3D-TSE sequence at 1.5 T regarding the diagnosis of choledocholithiasis in a routine clinical setting.

Materials And Methods: 3D-SPACE and 3D-TSE sequences were performed in 42 consecutive patients with suspected choledocholithiasis undergoing MRCP. Evaluation of image quality and diagnostic confidence was done on the pancreaticobiliary tree which was subdivided into 10 segments. They were scored and statistically evaluated separately for visibility and diagnostic certainty by three radiologists with differing levels of experience on a five-point scale of 1 to 5 and -2 to 2, respectively. Student t-test was performed, and the interobserver agreement was also calculated.

Results: Image quality for each segment was significantly better for the 3D-SPACE sequence compared to the 3D-TSE sequence (4.48 ± 0.94 vs. 3.98 ± 1.20; 5-point scale p < 0.01). Diagnostic confidence for the reporting radiologist was also significantly better for 3D-SPACE than for 3D-TSE (1.68 ± 0.56 vs. 1.46 ± 0.70; 3-point scale; p < 0.01). The interobserver agreement was high in both sequences, 0.62 - 0.83 and 0.64 - 0.82, respectively.

Conclusion: The optimized 3D-SPACE sequence allows for better image quality in 1.5 T MRCP examinations and leads to a higher diagnostic confidence for choledocholithiasis compared to the conventional 3D-TSE sequence.

Key Points: • 3D-SPACE allows for better image quality in 1.5 T MRCP.• This leads to a higher diagnostic confidence particularly in the periampullary region.• 3D-SPACE should be considered to substitute conventional 3D-TSE sequences in clinical routine MRCP.