In Vitro Intraductal MRI and T2 Mapping of Cholangiocarcinoma Using Catheter Coils

Area of Science:

• Medical Imaging
• Oncology
• Biophysics

Background:

• Diagnostic imaging of early-stage cholangiocarcinoma (bile duct cancer) presents significant challenges.
• Previous studies explored T2 mapping with duodenoscope coils on fixed tissues for quantitative MRI.
• This research extends these methods to unfixed liver specimens using novel catheter-based receivers.

Purpose of the Study:

• To apply and evaluate T2 mapping using catheter coils for enhanced quantitative MRI of unfixed cholangiocarcinoma specimens.
• To investigate the utility of catheter-based receivers in overcoming non-uniform coil sensitivity for improved signal-to-noise ratio (SNR).
• To correlate T2-derived imaging features with histopathological findings in cholangiocarcinoma.

Main Methods:

• Ex vivo intraductal MRI and T2 mapping were performed at 3T on unfixed liver resection specimens from cholangiocarcinoma patients.
• A catheter coil, utilizing a thin-film magneto-inductive waveguide, was inserted into intrahepatic ducts.
• Fast spin-echo sequences were employed, and T2 maps were generated by fitting data to mono-exponential models.

Main Results:

• High-resolution T2 maps successfully visualized polypoid intraductal cholangiocarcinoma.
• Increased T2 values were observed in unfixed specimens compared to fixed ones.
• Differences in T2 values enabled the differentiation of tumor tissue and the identification of malignant features like polypoid morphology.

Conclusions:

• Catheter coils, despite limited fields of view, yield valuable data for cholangiocarcinoma imaging.
• T2 mapping effectively leverages the local SNR advantage of catheter coils without requiring image correction.
• This approach offers a promising method for improved quantitative MRI in diagnosing early-stage cholangiocarcinoma.