The British journal of radiology
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A case of radiation nephritis was diagnosed by the effect of delayed excretion of 99Tcm MDP on the superomedial aspects of both kidneys, which had been included in a radiation port to the thoracolumbar spine 6 months previously. Knowledge of the past history of radiotherapy and the radiation port, together with the classic scintigraphic features enable the diagnosis of this rarely demonstrated condition to be made.
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Comparative Study
Technetium-99m-HMPAO labelled leucocytes in the detection and monitoring of inflammatory bowel disease in children.
This study was a retrospective evaluation of the use of technetium-99m hexamethylpropyleneamineoxime (HMPAO) labelled leucocytes in the investigation of suspected inflammatory bowel disease in children. The images were analysed in 35 children and the findings were compared with the results of endoscopy/biopsy, barium studies and antinuclear cytoplasm antibody (ANCA) serology. ⋯ This compares well with other studies in adults and is superior to barium investigations. The technique is recommended as a first line investigation to detect inflammatory bowel disease with a resultant reduction in the use of endoscopy and barium imaging.
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Comparative Study
The influence of the number of fractions and bi-exponential repair kinetics on biological equivalence in pulsed brachytherapy.
A linear-quadratic radiobiological model incorporating single or bi-exponential repair kinetics has been used to show the following and other features when a continuous low dose rate (CLDR) 70 Gy/140 h brachytherapy protocol is replaced by a radiobiologically equivalent pulsed dose rate (PDR) system using 140 fractions for reasons of dosage homogeneity. (1) For equivalent effects in late-reacting tissues, the PDR dose (at 5 or 0.05 Gy min-1) x 1 h intervals needs to be reduced by up to only 3%. Progressively further reductions in dose are required when fewer larger fractions are used. (2) When equivalence using pulsed doses is achieved for one normal tissue type, and extrapolated response doses (ERD) are calculated for other tissue types in the irradiated volume, values of the ERD remain within 5% of each other using the above PDR protocol and associated parameters. (3) For tumours with alpha/beta = 10 Gy and a single repair halftime of 0.1-1.0 h, there is no significant loss of therapeutic benefit using the PDR protocol equivalenced for late normal tissue reactions. ⋯ These calculations also highlight the importance of the values assumed for the conventional alpha/beta ratio and the repair kinetics when estimating equivalent PDR protocols. The use of an inappropriate radiobiological parameterization will lead to erroneous conclusions with the potential to advocate PDR protocols which will, in practice, lead to an increase in late complications.
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We describe the use of a purpose-built portable ultrasound device to assist puncture of the internal jugular vein during percutaneous insertion of tunnelled central venous catheters such as Hickman lines. In many situations the internal jugular route is safer, faster and less costly in comparison with the subclavian approach. The use of ultrasound allows an accurate initial venous puncture with fewer complications, in the hands of both experienced operators and those less familiar with the internal jugular vein approach.
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Imaging with three-dimensional (3D) sequences is a frequently used magnetic resonance (MR) technique in the assessment of ear, nose and throat (ENT) tumours near the skull base. Few reports on the contrast behaviour of 3D magnetization prepared rapid gradient echo (MP-RAGE) sequences and their application in ENT tumours exist in the published literature. This paper discusses whether 3D MP-RAGE is an alternative to conventional 3D gradient echo (3D GE) sequences for the diagnostic evaluation of the visceral cranum. ⋯ The advantages of 3D MP-RAGE over 3D FLASH 40 degrees include decreased imaging time with decreased motion artifacts and a relatively high contrast between tumour and surrounding tissues. The tissue contrast yielded by the T1/T2* weighted 3D gradient echo sequence FISP with a flip angle of 70 degrees was not as good as that yielded by 3D MP-RAGE with and without contrast together. In conclusion a combination of contrast enhanced and unenhanced 3D MP-RAGE sequences is the technique of choice for the examination of ENT tumours near the base of the skull.