Reporting ADPK Disease Phenotypes on Abdominal Scans

Introduction

Kidney and liver volumes from abdominal magnetic resonance imaging (MRI) and computed tomography (CT) scans are critical biomarkers recommended by Kidney Disease: Improving Global Outcomes (KDIGO) for autosomal dominant polycystic kidney disease (ADPKD) progression and response to therapy. The purpose of this study was to determine how often these biomarkers are included in radiology reports as well as their reproducibility.

Methods

Outside abdominal MRI (n = 102) and CT (n = 43) studies were reviewed retrospectively and independently by 2 observers for prevalence of reporting ADPKD-relevant findings with discrepancies resolved by 2 radiologists. These 2 radiologists independently reevaluated all examinations to assess interobserver reproducibility.

Results

Outside reports (n = 145; males: 46%; median age: 47 [interquartile range: 35–61] years) by 122 radiologists from 88 institutions included kidney volumes in only 30 (21%) reports. Out of 140 imaging examinations that included the entire liver, 1 (1%) outside report provided liver volume. Comparison of outside and study radiologists’ kidney volume measurements showed a median absolute difference of 15%, using the ellipsoidal method and 8% using model-assisted contouring. Additional positive findings not mentioned in 145 outside reports included umbilical hernia (n = 44), hepatic steatosis (n = 3), inguinal hernia (n = 4), pancreatic cyst (n = 6) and severe inferior vena cava (IVC) compression by cysts (n = 2).

Conclusion

Radiologists report reliably on complex cysts, calcifications, ascites, and abdominal aortic aneurysms in ADPKD. However, the clinical utility of these reports can be improved more reliably by including kidney volume and other important imaging features of ADPKD recommended by clinical guidelines.