MRI of the Pancreas

Abstract

MRI has played a critical role in the evaluation of patients with pancreatic pathologies, from screening of patients at high risk for pancreatic cancer to the evaluation of pancreatic cysts and indeterminate pancreatic lesions. The high mortality associated with pancreatic adenocarcinomas has spurred much interest in developing effective screening tools, with MRI using magnetic resonance cholangiopancreatography (MRCP) playing a central role in the hopes of identifying cancers at earlier stages amenable to curative resection. Ongoing efforts to improve the resolution and robustness of imaging of the pancreas using MRI may thus one day reduce the mortality of this deadly disease. However, the increasing use of cross‐sectional imaging has also generated a concomitant clinical conundrum: How to manage incidental pancreatic cystic lesions that are found in over a quarter of patients who undergo MRCP. Efforts to improve the specificity of MRCP for patients with pancreatic cysts and with indeterminate pancreatic masses may be achieved with continued technical advances in MRI, including diffusion‐weighted and T1‐weighted dynamic contrast‐enhanced MRI. However, developments in quantitative MRI of the pancreas remain challenging, due to the small size of the pancreas and its upper abdominal location, adjacent to bowel and below the diaphragm. Further research is needed to improve MRI of the pancreas as a clinical tool, to positively affect the lives of patients with pancreatic abnormalities. This review focuses on various MR techniques such as MRCP, quantitative imaging, and dynamic contrast‐enhanced imaging and their clinical applicability in the imaging of the pancreas, with an emphasis on pancreatic malignant and premalignant lesions.Level of Evidence 5Technical Efficacy Stage 3J. MAGN. RESON. IMAGING 2021;53:347–359.

Abnormal Findings on “T1WI or DWI or MRCP:” An Effective Boolean Interpretation Model in Discriminating Small Pancreatic Ductal Adenocarcinoma from Control Group

“…Harrington et al reported that small PDAC could be detected as a mass on T1WI or an MPD abnormality on MRCP. [22] Ichikawa et al demonstrated the high sensitivity and specificity of DWI for detecting PDAC. [23] Our results were consistent with these previous reports showing the usefulness of T1WI, DWI, and MRCP.…”

“…reported that small PDAC could be detected as a mass on T1WI or an MPD abnormality on MRCP. [ 22 ] Ichikawa et al . demonstrated the high sensitivity and specificity of DWI for detecting PDAC.…”

“…[ 17 ] Especially the MIP, which is reconstructed from three-dimensional MRCP, can identify the three-dimensional anatomy of pancreatic ducts with high resolution. [ 22 ] An abrupt cutoff of the MPD strongly suggests the presence of mass. [ 30 , 31 ] However, an abrupt cutoff of the MPD is a secondary finding, and it is difficult to detect small PDAC in patients in which the MPD is unaffected or small lesions in the tail of the pancreas.…”

Cystic Neoplasms of the Pancreas: Differential Diagnosis and Radiology Correlation

“…Noninvasive medical imaging such as US, MRI, CT, and positron emission tomography (PET) can be used to assess tumor and anatomical tissue features for tumor management (55)(56)(57). Radiomics can obtain high-content information through identification, extraction, quantitation, and processing to identify imaging signatures or phenotypes.…”

Longitudinal Monitoring of Simulated Interstitial Fluid Pressure for Pancreatic Ductal Adenocarcinoma Patients Treated with Stereotactic Body Radiotherapy

“…However, response to RT varies significantly among individual patients and may be in part related to the unique characteristics of the PDAC tumor microenvironment, including hypoxia [2]. There is a need to develop and translate new imaging biomarkers that may predict early treatment efficacy to allow for better risk stratification and possible treatment intensification in appropriate candidates [13]. RT using high doses per fraction may be associated with rapid, immediate changes to the tumor microenvironment, including tumor cellularity and vascularity, which correlate with eventual clinical RT response [14,15].…”