Advancing quantitative imaging of neuroblastoma

Neuroblastoma is an embryonal cancer that exhibits marked heterogeneity of presentation and prognosis, ranging in outcomes from amongst the poorest in paediatric oncology to spontaneous remission. Scintigraphy using ¹²³I-meta-Iodobenzylguanidine (MIBG) provides unique functional information and is commonly used to manage Neuroblastoma alongside MRI. This thesis advances the imaging of neuroblastoma through SPECT/MR integration and quantitative SPECT/CT optimisation. A simulation study of Dixon Magnetic Resonance Attenuation Correction (MRAC) was undertaken using ⁹⁹ᵐTc-MDP SPECT/CT studies. These simulations showed that SPECT MRAC could achieve superior perfomance to PET/MR in cases without signifciant lung coverage. Observer studies were also undertaken to evaluate a novel ¹²³I-MIBG SPECT/MR fusion dataset and the impact of this technique on semiquantitative scoring of Neuroblastoma. The observers identified multiple clinically significant findings when using SPECT/MR versus planar scintigraphy. The ¹²³I imaging performance of Siemens parallel hole collimators was assessed using a custom precision sensitivity phantom. The contributions from photopeak and septal penetration were spectrally decomposed and the medium energy collimator shown to be optimal. Existing methodologies for optimisation were found to be inadequate for quantitative SPECT. A measurement-dependent methodology was proposed and used to optimise reconstruction parameters for ¹²³I-MIBG SPECT/CT. Optimised parameters were applied to wholebody SPECT/CT scans of Neuroblastoma and patterns and ranges of uptake in the liver and brain were evaluated. Right lobe of liver was shown to provide a significantly lower and more statistically consistent physiological reference than the left lobe. Standardised Uptake Values (SUVs) scaled to lean body mass were found to be superior to body weight scaled SUVs and absolute activity concentrations. Normal ranges and limits of variation were recommended as quality contro