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Microvasculature density (MVD) provides an established biomarker for the prognosis of numerous diseases associated with abnormal microvascular networks. The accurate, robust and timely assessment of MVD changes facilitates disease detection, treatment monitoring and patient stratification. Nevertheless, the current gold standard (PET) for MVD quantification is not used in clinical practice due to its high costs and potential health hazards. Contrast Enhanced Ultrasound (CEUS) imaging can provide an attractive alternative. However, the limited dissociation between larger vessels and microvasculature in the imaged tissues limits the accuracy and robustness of CEUS. This study proposed a novel, and fully automatic technique that dissociates larger vessels from microvasculature in CEUS imaged tissues. The ovine Corpus Luteum (CL) was used as an in vivo model for the development and assessment of the proposed technique.

The accurate assessment of visual field function can provide valuable information on a range of visual disorders. Saccadic Vector Optokinetic Perimetry (SVOP) is a novel instrument for measuring supra-threshold visual fields in young children who are otherwise unable to perform Automated Static Perimetry (ASP). However, limitations in Liquid Crystal Display (LCD) technology restrict the ability of SVOP to determine threshold values at various points in the visual field, often required in detailed perimetry examinations. This paper introduces a purpose-specific LCD luminance non-uniformity compensation approach to address this limitation. Thorough quantitative evaluation identifies the effectiveness of the proposed approach in (i) compensating for luminance non-uniformities across an LCD, and (ii) enabling SVOP to perform accurate and precise threshold visual field tests. The findings demonstrate that SVOP provides a promising alternative to the current threshold ASP standard (Humphrey Field Analyser).

Perimetry is essential for identifying visual field defects due to disorders of the eye and brain. However, young children are often unable to reliably perform the preferred method of visual field assessment known as automated static perimetry (ASP). This paper introduces a novel method of ASP specifically developed for children called Saccadic Vector Optokinetic Perimetry (SVOP). SVOP uses eye tracking to detect the natural saccadic eye response of gaze orientation towards visual field stimuli if they are seen. In this paper, the direction and magnitude of a sample of subject gaze responses to visual field stimuli is used to construct a software decision algorithm for use in SVOP. SVOP was clinically evaluated in a group of 24 subjects, comprising children and adults, with and without visual field defects, by comparison with an equivalent test on the Humphrey Field Analyser (HFA). SVOP provides promising visual field test results when compared with the reference HFA test, and has proven extremely useful in detecting visual field defects in children unable to perform traditional ASP.

Echocardiography provides a powerful and versatile tool for assessing cardiac morphology and function. However, cardiac ultrasound suffers from speckle as well as static and dynamic noise. Over the last three decades, a number of studies have attempted to address the challenging problem of speckle/noise suppression in cardiac ultrasound data. No single method has managed to provide a widely accepted solution. Temporal Compounding is a noise suppression method that utilises spatial averaging of temporally aligned cardiac B-Mode data. Reliable temporal alignment is vital for effective Temporal Compounding. In this study we introduce a novel, accurate and robust technique for the temporal alignment of cardiac cycles with variable temporal characteristics and examine the effect of Temporal Compounding in four clinical measurements performed on routine echocardiographic examinations. Results from 32 patients demonstrate speckle/noise suppression, shadowing reduction, anatomical structure enhancement and improvement in measurement repeatability with no significant or systematic bias introduced. Temporally compound data may be able to provide a good alternative to B-Mode data in clinical measurements as well as a first step to further post-processing of cardiac ultrasound data.