Computed tomography imaging of the heart
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Date
02/07/2016Item status
Restricted AccessEmbargo end date
31/12/2100Author
Williams, Michelle Claire
Metadata
Abstract
Computed tomography imaging has revolutionised modern medicine and we can
now study the body in greater detail than ever before. Cardiac computed tomography
has the potential to provide information not just on coronary anatomy, but also on
myocardial function, perfusion and viability. This thesis addresses the optimisation
and validation of computed tomography imaging of the heart using a wide volume
320-multidetector scanner.
Computed tomography coronary angiography now has diagnostic accuracy
comparable to invasive coronary angiography. However, radiation dose remains an
important concern. It is therefore important to minimise computed tomography
radiation dose while maintaining image quality. I was able to demonstrate that
iterative reconstruction and patient tailored imaging techniques led to a 39%
reduction in radiation dose in computed tomography coronary angiography, while
maintaining subjective and objective assessments of image quality. In addition, I
demonstrated that diagnostic images can be obtained in 99% of unselected patients
presenting with suspected coronary artery disease when using single heart-beat 320-
multidetector computed tomography coronary angiography.
Computed tomography myocardial perfusion imaging can provide additional and
complementary information as compared to computed tomography coronary
angiography that can aid diagnosis and management. I established both quantitative
and qualitative assessment of computed tomography myocardial perfusion imaging
and validated it against both a clinical “gold-standard”, fractional flow reserve during
invasive coronary angiography, and a physiological “gold-standard”, positron
emission tomography with oxygen-15 labelled water. Finally, I was able to show that
techniques to reduce radiation dose can also be applied to computed tomography
myocardial perfusion imaging, leading to a 60% reduction in radiation dose, while
maintaining image quality.
In my thesis, I have established that comprehensive cardiac angiographic and
perfusion imaging can be performed with wide volume computed tomography in a
broad generalizable population of patients with relatively low radiation exposure.
These techniques provide both structural and functional assessments from a single
imaging modality that are valid and readily applicable to the clinic in the assessment
and management of patients with suspected coronary artery disease.