Magnetic resonance imaging (MRI) is the most commonly utilized advanced imaging modality for the evaluation of intracranial disease in veterinary patients. Photon-counting computed tomography (PCCT) is an emerging technology that offers improved spatial resolution, spectral imaging capabilities, and rapid image acquisition. The objective of this study is to evaluate the agreement between PCCT and MRI for the detection and characterization of intracranial lesions in dogs and cats.

We hypothesize that PCCT will demonstrate substantial agreement with MRI for lesion detection and that agreement will be higher for mass-like lesions than for diffuse inflammatory lesions. We further hypothesize that agreement will vary among lesion types, including neoplasia, hemorrhage, infarction, inflammatory disease, edema, and neurodegenerative disease.

Client-owned dogs undergoing MRI for suspected intracranial disease will be prospectively enrolled. Patients will undergo contrast-enhanced PCCT and MRI, and imaging studies will be independently reviewed by blinded observers. Agreement between modalities will be assessed using kappa statistics. Results will provide foundational data regarding the clinical utility of PCCT and help define its role in veterinary neuroimaging