Longitudinal trends in X-ray, CT, MRI, and ultrasound utilisation among the adult population in Ireland (2018–2023): A multi-centre study

Abstract

Introduction

This multi-centre study investigates longitudinal trends in adult diagnostic imaging utilisation in Ireland, addressing a critical knowledge gap due to the lack of detailed national data and a focus on paediatric populations in prior research. It aims to characterise imaging use by modality, age group, and anatomical region.

Methods

A retrospective study was conducted using National Integrated Medical Imaging System data from 11 public hospitals. The dataset included over 5.2 million examinations across X-ray, CT, MRI, and ultrasound on adult patients (≥18 years) conducted between 2018 and 2023. Data were analysed using descriptive statistics, joinpoint regression, chi-squared tests, and Spearman's rank-order correlation to identify trends, inflection points, and associations between age, modality, and anatomical region.

Results

X-ray remained the most utilised modality (64.9 %), but CT and MRI exhibited the largest growth, increasing by 27 % and 32.9 % respectively over the study period. The COVID-19 pandemic caused a significant utilisation decline in 2020, identified as a key inflection point, followed by a recovery surpassing pre-pandemic levels. CT and X-ray were primarily used in adults over 60, while MRI and ultrasound usage was more evenly distributed among middle-aged adults. Head imaging predominated for CT and MRI, abdominal and pelvic regions for ultrasound, and thoracic and extremity imaging for X-ray.

Conclusion

This study provides the first comprehensive multi-modality analysis of adult diagnostic imaging trends in Ireland, revealing significant recent increases in CT and MRI utilisation.

Implications for practice

These findings provide essential evidence to inform healthcare policy, strategic planning, and service development to meet evolving diagnostic demands.