An optoacoustic imaging feature set to characterise blood vessels surrounding benign and malignant breast lesions

Combining optoacoustic (OA) imaging with ultrasound (US) enables visualisation of functional blood vasculature in breast lesions by OA to be overlaid with the morphological information of US. Here, we develop a simple OA feature set to differentiate benign and malignant breast lesions. 94 female patients with benign, indeterminate or suspicious lesions were recruited and underwent OA-US. An OA-US imaging feature set was developed using images from the first 38 patients, which contained 14 malignant and 8 benign solid lesions. Two independent radiologists blindly scored the OA-US images of a further 56 patients, which included 31 malignant and 13 benign solid lesions, with a sensitivity of 96.8% and specificity of 84.6%. Our findings indicate that OA-US can reveal vascular patterns of breast lesions that indicate malignancy using a simple feature set based on single wavelength OA data, which is therefore amenable to application in low resource settings for breast cancer management.

Imaging hypoxia in gliomas

Hypoxia plays a central role in tumour development, angiogenesis, growth and resistance to treatment. Owing to constant developments in medical imaging technology, significant advances have been made towards in vitro and in vivo imaging of hypoxia in a variety of tumours, including gliomas of the central nervous system. The aim of this article is to review the literature on imaging approaches currently available for measuring hypoxia in human gliomas and provide an insight into recent advances and future directions in this field. After a brief overview of hypoxia and its importance in gliomas, several methods of measuring hypoxia will be presented. These range from invasive monitoring by Eppendorf polarographic O(2) microelectrodes, positron electron tomography (PET) tracers based on 2-nitroimidazole compounds [(18)F-labelled fluoro-misonidazole ((18)F-MISO) or 1-(2-[((18))F]fluoro-1-[hydroxymethyl]ethoxy)methyl-2-nitroimidazole (FRP-170)], (64)Cu-ATSM Cu-diacetyl-bis(N4-methylthiosemicarbazone) (Cu-ATSM) or (99m)Tc- and (68)Ga-labelled metronidazole (MN) agents to advanced MRI methods, such as blood oxygenation level dependent (BOLD) MRI, oxygen-enhanced MRI, diffusion-weighted MRI (DWI-MRI), dynamic contrast-enhanced MRI (DCE-MRI) and (1)H-magnetic resonance spectroscopy.

Tc-99m DTPA renography in children following renal transplantation: its value in the evaluation of rejection

A retrospective analysis of the value of Tc-99m DTPA DRS in children requiring renal biopsy following transplantation. Thirty-one children following renal transplantation with possible rejection underwent thirty-nine DRS and biopsy within a 72-h period and clinical followed up for 12 months. The biopsy was classified according to the Banff 97. The DRS assessed semi-quantitatively images of renal perfusion and filtration, and the balance between these two images. The clinical notes were reviewed. Based on the biopsy results 15 children had acute rejection, three children chronic rejection, nine children a mixed appearance of both acute and chronic rejection while 12 children had no rejection. Based on the long-term clinical outcome, the DRS had an overall sensitivity of 76% and specificity of 86%. While renal biopsy remains the gold standard for the diagnosis of rejection, if the perfusion and filtration phases of the DRS are analysed separately and the results integrated, there is a possibility of suggesting that acute rejection is not the cause of the increase in creatinine. The DRS provides useful information to the nephrologist when taken in conjunction with the biopsy result and other investigations.