MR Cholangiopancreatography: What Every Radiology Resident Must Know

ESGAR consensus statement on MR imaging in primary sclerosing cholangitis

OBJECTIVES

To provide a consensus statement and recommendations on MR imaging in primary sclerosing cholangitis (PSC).

METHODS

The European Society of Gastrointestinal and Abdominal Radiology (ESGAR) convened a multinational European panel of experts selected based on a literature review and their leadership in the field. A modified Delphi process was adopted to draft a list of statements. For each statement, the panelists indicated the level of agreement using a 5-point Likert scale, where 1 means "no agreement," 2 means "poor agreement," 3 means "slight agreement," 4 means "fair agreement," and 5 means "complete agreement." The median score for each statement was collected. The level of evidence was reported according to the Oxford Centre for Evidence-Based Medicine. Descriptive statistics were used to rate agreement levels and the consensus' internal reliability.

RESULTS

The 12 voting committee members were from Italy (n = 4, 33.4%), Austria (n = 2, 16.7%), Sweden (n = 1, 8.3%), France (n = 1, 8.3%), the United States (n = 1, 8.3%), Switzerland (n = 1, 8.3%), and Belgium (n = 2, 16.7%). The final questionnaire consisted of 55 statements. The agreement reached by the expert panel was complete for 23 statements (41.8%), fair for 16 (29.1%), slight for 15 (27.2%), and poor for 1 (1.9%). Statements that received complete agreement were used to structure a reporting template.

CONCLUSIONS

This statement paper recommends how and when to perform MRI in PSC patients. A structured reporting template has been created to improve quality care and communication among radiologists and clinicians.

KEY POINTS

Question A standard MR protocol and the most common imaging features to be reported are fundamental for the correct evaluation of primary sclerosing cholangitis (PSC) patients. Findings Twelve expert radiologists reported which are the most important imaging features and how and when to perform MR in PSC patients. Clinical relevance The identified statements reported in this paper and the structured reporting template are useful for radiologists and clinicians to help correctly manage PSC patients.

Beyond the Common: A Pictorial Review of Rare and Atypical Periampullary Lesions

The periampullary region, defined as the area within 2 cm of the major papilla of the duodenum, is associated with various benign and malignant conditions. Although periampullary cancers are rare, they are the third leading cause of cancer-related deaths in the Western world. Tumors in this area often mimic benign lesions due to overlapping clinical presentations. Diagnostic imaging techniques, including computed tomography, magnetic resonance imaging, ultrasonography, and MR cholangiopancreatography, are commonly used in clinical practice and typically confirmed by pathological analysis. Therefore, evaluating imaging characteristics of rare and atypical periampullary conditions and classifying them into 4 categories (anatomical variations, tumors, inflammatory conditions, and miscellaneous disorders) can aid in the differential diagnosis and improve understanding of these lesions.

Body MRI Approach: Guide for Common Indications

The slide presentation demonstrates an approach to body MRI for common indications in the abdomen and pelvis, incorporating clinical information, knowledge of imaging patterns, and various scoring paradigms.

Aetiological Spectrum of Pancreaticobiliary Diseases in Adult Nigerians on Magnetic Resonance Cholangiopancreatography

BACKGROUND

Imaging is vital for assessing pancreaticobiliary diseases.

AIM

The aim of the study was to investigate the spectrum and pattern of pancreaticobiliary diseases in adult Nigerians using magnetic resonance cholangiopancreatography (MRCP).

METHODS

This was a retrospective, descriptive cross-sectional study. The electronic radiological records of 110 adult Nigerians who had undergone MRCP were reviewed. The MRCP images were evaluated for bile duct dilatation, intraluminal filling defects, strictures, calculi, and other abnormalities.

RESULTS

There were 45 males (40.9%) and 65 females (59.1%) aged 18-83 years, with a mean age of 51.93 ± 15.22 years. Jaundice (59.1%) and right hypochondrial pain (31.8%) were the most common presenting complaints. Gallstones (32.7%), common bile duct strictures (15.5%), choledocholithiasis (11.8%), pancreatic head carcinoma (10.9%), and gallbladder carcinoma (2.7%) were the most frequent abnormalities. There was biliary obstruction in 56.4% of participants, mostly at the distal and proximal common bile duct. Other findings include hepatomegaly (23.6%), hepatic cysts (6.4%), hepatic steatosis (0.9%), duodenal wall thickening (1.8%), and ascites (5.5%). MRCP was normal in 25 (22.7%) participants.

CONCLUSION

Gallstones were the predominant pathology of the various pancreaticobiliary diseases, while Pancreatic head and gallbladder carcinoma were the most common malignant diseases.

Using deep learning models in magnetic resonance cholangiopancreatography images to diagnose common bile duct stones

BACKGROUNDS AND AIMS

Magnetic resonance cholangiopancreatography (MRCP) plays a significant role in diagnosing common bile duct stones (CBDS). Currently, there are no studies to detect CBDS by using the deep learning (DL) model in MRCP. This study aimed to use the DL model You Only Look Once version 5 (YOLOv5) to diagnose CBDS in MRCP images and verify its validity compared to the accuracy of radiologists.

METHODS

By collecting the thick-slab MRCP images of patients diagnosed with CBDS, 4 submodels of YOLOv5 were used to train and validate the performance. Precision, recall rate, and mean average precision (mAP) were used to evaluate model performance. Analyze possible reasons that may affect detection accuracy by validating MRCP images in 63 CBDS patients and comparing them with radiologist detection accuracy. Calculate the correctness of YOLOv5 for detecting one CBDS and multiple CBDS separately.

RESULTS

The precision of YOLOv5l (0.970) was higher than that of YOLOv5x (0.909), YOLOv5m (0.874), and YOLOv5s (0.939). The mAP did not differ significantly between the 4 submodels, with the following results: YOLOv5l (0.942), YOLOv5x (0.947), YOLO5s (0.927), and YOLOv5m (0.946). However, in terms of training time, YOLOv5s was the fastest (4.8 h), detecting CBDS in only 7.2 milliseconds per image. In 63 patients the YOLOv5l model detected CBDS with an accuracy of 90.5% compared to 92.1% for radiologists, analyzing the difference between the positive group successfully identified and the unidentified negative group not. The incorporated variables include common bile duct diameter > 1 cm (p = .560), combined gallbladder stones (p = .706), maximum stone diameter (p = .057), combined cholangitis (p = .846), and combined pancreatitis (p = .656), and the number of CBDS (p = .415). When only one CBDS was present, the accuracy rate reached 94%. When multiple CBDSs were present, the recognition rate dropped to 70%.

CONCLUSION

YOLOv5l is the model with the best results and is almost as accurate as the radiologist's detection of CBDS and is also capable of detecting the number of CBDS. Although the accuracy of the test gradually decreases as the number of stones increases, it can still be useful for the clinician's initial diagnosis.

Comparison between Conventional Breath-hold and Respiratory-triggered Magnetic Resonance Cholangiopancreatography with and without Compressed Sensing: Cross-sectional Study

AIM

The application of compressed sensing (CS) has enabled breath-hold 3D-MRCP with a shorter acquisition time in clinical practice.

INTRODUCTION

To compare the image quality of breath-hold (BH) and respiratory-triggered (RT) 3D-MRCP with or without CS application in the same study population.

METHODS

In this retrospective study, from February to July 2020, a total of 98 consecutive patients underwent four different acquisition types of 3D-MRCP.; 1) BH MRCP with the generalized autocalibrating partially parallel acquisition (GRAPPA) (BH-GRAPPA), 2) RT-GRAPPA-MRCP, 3) RT-CS-MRCP and 4) BH-CS-MRCP. Relative contrast of common bile duct, 5-scale visibility score of biliary pancreatic ducts, 3-scale artifact score and 5-scale overall image quality score were evaluated by two abdominal radiologists.

RESULTS

Relative contrast value was significantly higher in BH-CS or RT-CS than in RT-GRAPPA (0.90 ± 0.057 and 0.89 ± 0.079, respectively, vs. 0.82 ± 0.071, p < 0.01) or BH-GRAPPA (vs. 0.77 ± 0.080, p < 0.01). The area affected by artifact was significantly lower in BH-CS among 4 MRCPs (p < 0.08). Overall image quality score in BH-CS was significantly higher than BH-GRAPPA (3.40 vs. 2.71, p < 0.01). There were no significant differences between RT-GRAPPA and BH-CS (vs. 3.13, p = 0.67) in overall image quality.

CONCLUSION

In this study, our results revealed BH-CS had higher relative contrast and comparable or superior image quality among four MRCP sequences.