Comparison between in-phase and opposed-phase T1-weighted breath-hold FLASH sequences for hepatic imaging

Area of Science:

• Radiology
• Medical Imaging
• Hepatobiliary Imaging

Background:

• Gradient Recalled Echo (GRE) sequences are crucial for hepatic MRI.
• In-phase (IP) and opposed-phase (OP) imaging offer distinct tissue contrast.
• Assessing the diagnostic utility of IP vs. OP sequences in liver imaging is important.

Purpose of the Study:

• To compare the efficacy of in-phase (IP) and opposed-phase (OP) GRE sequences for breath-hold hepatic imaging.
• To evaluate quantitative and qualitative differences between IP and OP sequences in abdominal MRI.

Main Methods:

• 104 patients undergoing non-contrast-enhanced abdominal MRI at 1.0 T were included.
• Standardized GRE breath-hold sequences (IP and OP) were utilized.
• Quantitative (signal difference-to-noise ratio) and qualitative (lesion detection, artifacts) analyses were performed.

Main Results:

• No significant difference in quantitative or qualitative parameters was observed between IP and OP sequences in general.
• In patients with hepatic steatosis (fatty infiltration), OP sequences showed significantly lower liver/spleen and liver/lesion signal difference-to-noise ratios compared to IP sequences.
• Focal liver lesions were more frequently identified on IP images in cases with fatty infiltration.

Conclusions:

• IP and OP GRE sequences provide complementary information for liver MRI.
• Reliance solely on OP sequences can lead to obscured focal liver lesions in the presence of fatty infiltration.
• A comprehensive liver MR evaluation should incorporate both IP and OP imaging sequences.