Quantitative MRCP Imaging: Accuracy, Repeatability, Reproducibility, and Cohort-Derived Normative Ranges.

BACKGROUND: Magnetic resonance cholangiopancreatography (MRCP) is an important tool for noninvasive imaging of biliary disease, however, its assessment is currently subjective, resulting in the need for objective biomarkers. PURPOSE: To investigate the accuracy, scan/rescan repeatability, and cross-scanner reproducibility of a novel quantitative MRCP tool on phantoms and in vivo. Additionally, to report normative ranges derived from the healthy cohort for duct measurements and tree-level summary metrics. STUDY TYPE: Prospective. PHANTOMS/SUBJECTS: Phantoms: two bespoke designs, one with varying tube-width, curvature, and orientation, and one exhibiting a complex structure based on a real biliary tree. Subjects Twenty healthy volunteers, 10 patients with biliary disease, and 10 with nonbiliary liver disease. SEQUENCE/FIELD STRENGTH: MRCP data were acquired using heavily T2 -weighted 3D multishot fast/turbo spin echo acquisitions at 1.5T and 3T. ASSESSMENT: Digital instances of the phantoms were synthesized with varying resolution and signal-to-noise ratio. Physical 3D-printed phantoms were scanned across six scanners (two field strengths for each of three manufacturers). Human subjects were imaged on four scanners (two fieldstrengths for each of two manufacturers). STATISTICAL TESTS: Bland-Altman analysis and repeatability coefficient (RC). RESULTS: Accuracy of the diameter measurement approximated the scanning resolution, with 95% limits of agreement (LoA) from -1.1 to 1.0 mm. Excellent phantom repeatability was observed, with LoA from -0.4 to 0.4 mm. Good reproducibility was observed across the six scanners for both phantoms, with a range of LoA from -1.1 to 0.5 mm. Inter- and intraobserver agreement was high. Quantitative MRCP detected strictures and dilatations in the phantom with 76.6% and 85.9% sensitivity and 100% specificity in both. Patients and healthy volunteers exhibited significant differences in metrics including common bile duct (CBD) maximum diameter (7.6 mm vs. 5.2 mm P = 0.002), and overall biliary tree volume 12.36 mL vs. 4.61 mL, P = 0.0026). DATA CONCLUSION: The results indicate that quantitative MRCP provides accurate, repeatable, and reproducible measurements capable of objectively assessing cholangiopathic change. Evidence Level: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;52:807-820.

Postoperative follow-up strategies for patients after potentially curative surgery for colorectal cancer at Christchurch Hospital.

AIM: To describe the follow-up patterns of patients with colorectal cancer (CRC) having had surgery with curative intent. METHODS: A retrospective study was undertaken of follow-up patterns in patients who had undergone 'curative' surgery for colorectal cancer at Christchurch Hospital from 1 January 1996 to 31 December 2000. Patients were identified from three sources: the General Surgical Audit Database (Otago system), the hospital clinical Casemix DRG Database, and the Oncology Service database. Patients were included only if they had surgery with curative intent, within the stated period, and had follow-up at Christchurch Hospital. Data extracted included: patient demographics, details of initial surgery, adjuvant therapies, recurrences, and details of follow-up arrangements (including investigations). RESULTS: Of 893 patients coded as having CRC, 284 patients met the inclusion criteria. Patients were excluded for the following reasons: no operation (64), operation before 1996 (18), palliative surgery (345), previous cancer (55), no cancer (32), died within 30 days of surgery (26), follow-up outside of Christchurch region (39), and notes unavailable (30). The median age was 72 (range 28.6-99.9 years). Median follow-up time was 732 days. Most patients (91%) were followed-up by their surgeon. Patients had an average of 2.6 visits to their specialist in the first year of follow-up. Unplanned clinic visits accounted for 8.3% of all clinic visits--resulting in a number of unplanned investigations. During the follow-up period, patients had 112 colonoscopies, 68 CT scans, 8 abdominal ultrasounds, and 7 barium enemas. Recurrence was detected in 58 patients (20.4%); 23 (39.7%) recurrences were detected in the first year of follow-up. Of the 279 patients who had some form of follow-up, 9 asymptomatic patients had recurrent disease (detected as a result of a planned clinic visit) and had a potentially curative procedure for recurrence. CONCLUSIONS: The number of visits per year correlated closely with the earlier findings of Connor et al,4 however the number of investigations carried out was variable and substantially less than had been reported. Follow-up visits have limited value for the detection of asymptomatic potentially curable recurrent disease.