Computed tomography (CT) and magnetic resonance imaging (MRI)
Coronary artery disease, peripheral vascular disease (PVD), renal artery stenosis, lung cancer screening, pulmonary embolism (PE), carotid artery disease, cerebral aneurysms, headaches, head injuries, seizures, stroke, arteriovenous malformations (AVMs), and urinary tract calculi screening
There is increasing demand for the use of CT and MRI techniques for a variety of clinical disorders. Because CT and MRI are costly to buy and to operate, cost effectiveness should be established to optimize their use.
Methods and Results
Published economic evaluations (EE) were systematically identified by searching multiple databases using a defined strategy and selection criteria. Of 423 potentially relevant EE, 21 studies of eight clinical conditions were identified: PVD, renal artery stenosis, lung cancer screening, PE, carotid artery disease, cerebral aneurysms, head injuries, and stroke. No economic studies addressed coronary artery disease, headaches, seizures, AVMs, or urinary tract calculi screening.
Implications for Decision Making
- MRI angiography is of unproven advantage in terms of cost-effectiveness compared to duplex ultrasonography or digital subtraction angiography for patients with peripheral vascular disease
- CT scanning within 48 hours for stroke patients can improve QALYs, but the costeffectiveness of more rapid scanning is contingent on avoiding or shortening inpatient admissions, and capturing the associated savings.
- Limited evidence suggests that the preliminary imaging of medication-resistant renovascular hypertension with MRI is more cost-effective than with CT or conventional angiography compared to enhanced medical therapy. Additional evaluation is required.
- Limited evidence suggests that immediate CT for mild head injuries, and discharge home if the result is normal are cost-saving compared to in-patient observation. Better evidence of effectiveness is required to confirm this.
- The evidence is equivocal for a costeffectiveness advantage versus standard care for CT and MRI used in lung cancer screening, PE, carotid artery disease, and cerebral aneurysms.
This summary is based on a comprehensive health technology assessment available from CADTH’s web site (www.cadth.ca): Murtagh J, Warburton RN, Foerster V, Lentle BC, Wood RJ, Mensinkai S, Husereau D. CT and MRI for selected clinical disorders: a systematic review of economic evaluations.