Emergency Interventional Radiology in Rural Japan: Spatial Transfer Patterns, Temporal Workload Distribution, and the
Kento Hatakeyama1, Tomoki Tozawa1, Takashi Etchuya1
1Department of Radiology, Akita University Graduate School of Medicine, Akita, Japan.
Purpose:
To characterize emergency interventional radiology (IR) practice at a tertiary care center in a rural Japanese prefecture, focusing on spatial transfer patterns, temporal workload distribution, and the clinical and procedural spectrum.
Materials And Methods:
This retrospective single-center study included patients who underwent emergency IR between February 2023 and April 2025. Patient demographics, referral status, medical region, procedure timing, indications, procedural categories, and 7- and 30-day outcomes were analyzed. Interregional transfer patterns were evaluated using both former 8 and current 3 secondary medical service areas, with transfer rates standardized per 100,000 population.
Results:
A total of 150 emergency IR procedures were analyzed. Most procedures involved interhospital transfers (64.0%), while 36.0% were in-hospital emergencies. Among transferred patients, the median transfer distance was 40 km, the median time to procedure was 339 minutes, and no significant association was observed between transfer distance and time to procedure. Population-adjusted transfer rates differed from absolute case counts. After-hours procedures accounted for 65.3% of all cases. Nonneoplastic conditions were the most frequent indication. Embolization constituted 89% of procedures. The 7- and 30-day mortality rates were 6% and 10.7%, respectively, consistent with previously reported outcomes.
Conclusions:
Emergency IR in this rural prefecture was characterized by substantial interregional patient transfers, a high after-hours workload, and a predominance of embolization procedures for hemorrhagic conditions. Given the low case volume per region and limited workforce, a centralized hub-based model with structured regional transfer systems may represent a practical and sustainable approach for delivering emergency IR services in rural settings.
Related Concept Videos
Radiological Investigation II: MRI and Ventilation Perfusion Scan
Magnetic Resonance Imaging (MRI) and Ventilation Perfusion Scans are two radiological investigations that offer detailed diagnostic images of the body, particularly lung structures.
MRI
MRI uses magnetic fields and radiofrequency signals to distinguish between normal and abnormal tissues. This technology provides a more detailed diagnostic image than CT scans, enabling it to characterize pulmonary nodules, stage bronchogenic carcinoma, and evaluate inflammatory activity in...
Radiological Investigation III: Pulmonary Angiogram and PET Scan
Pulmonary Angiogram
A Pulmonary Angiogram is an invasive procedure involving injecting a contrast medium through a catheter threaded into the pulmonary artery or the right side of the heart to visualize the pulmonary vasculature. Computed Tomography (CT) scans have mainly replaced this...
Imaging Studies for Cardiovascular System III: X-Ray
Definition and Purpose
An X-ray, or radiograph, is a non-invasive method that uses ionizing radiation to take images of internal structures. It is mainly used in cardiac imaging to examine the heart, lungs, and major blood vessels, aiming to identify abnormalities in the heart's size, shape, and position, such as heart failure, congenital defects, and vascular...
Aneurysm III: Interprofessional Care
Acute Coronary Syndrome IV: Interprofessional Care
Coronary Artery Disease V: Interprofessional Care

