1Individual adjustment of frequency-to-electrode assignment in cochlear implants may 2 potentially improve speech perception outcomes. Twelve adult cochlear implant (CI) 3 users were recruited for an experiment, in which frequency maps were adjusted using 4 insertion angles estimated from post-operative X-rays; results were analyzed for ten 5 participants with good quality X-rays. The allocations were a mapping to the 6 Greenwood function, a compressed map limited to the area containing spiral ganglion 7 cells (SG), a reduced frequency range map (RFR) and participants' clinical maps. A 8 trial period of at least six weeks was given for the clinical, Greenwood and SG maps 9 although participants could return to their clinical map if they wished. Performance 10 with the Greenwood map was poor for both sentence and vowel perception and 11 correlated with insertion angle; performance with the SG map was poorer than for the 12 clinical map. The RFR map was significantly better than the clinical map for three 13 participants, for sentence perception, but worse for three others.

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Malignant external otitis (MEO) is a severe infection of the external auditory meatus caused by Pseudomonas aeruginosa. Classical features include unrelenting deep otalgia, otorrhoea and granulations in the floor of the ear canal. Treatment is generally protracted antibiotic therapy and monitoring of inflammatory markers; the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Traditionally computed tomography (CT) has been the imaging modality of choice. The authors present a case where magnetic resonance imaging (MRI) has been crucial in the diagnosis and follow up of a patient with MEO.

We present dosimetry for spinal metastases and red bone marrow in two patients who received 89Sr therapy for disseminated prostatic carcinoma. Absorbed dose to metastases was estimated by combining 85Sr gamma camera studies with computed tomographic measurements of bone mass, and doses of 20 cGy/MBq and 24 cGy/MBq were found for vertebral metastases that uniformly involved the bodies of L3 and D12 respectively. Absorbed dose to red bone marrow was estimated from total body strontium retention studies using the ICRP model for bone dosimetry, and a ratio of metastatic to marrow dose of around 10 was found in each patient. Although they received comparable treatment activities of around 200 MBq, the patients showed markedly different haematological response, this difference being confirmed when each received a second 89Sr treatment 6 months after the first. As a result, clinically significant thrombocytopenia occurred in one patient which prevented further radiostrontium therapy being given.

Reports of congenital anomalies of the Eustachian Tube (ET) are scarce, and often associated with chromosomal abnormalities. We report a unique case of a completely bony left Eustachian tube which communicated with the sphenoid sinus. This report details these findings and discusses the potential embryological basis and implications of such an unusual anatomy, in the context of a comprehensive literature review.

Thirteen patients undergoing selective coeliac angiography before insertion of an indwelling hepatic arterial cannula underwent injection of 3 ml radiolabelled Lipiodol (2 MBq 131I) into the hepatic artery at the end of the procedure. At subsequent laparotomy 1-9 days later, biopsies were taken from normal liver and metastases. The radioactivity of this material was measured to establish the tumour:liver ratios. Two patients with large metastases (> 10 cm in diameter) had low ratios. In the remainder, the median ratio at 24 h was 1.5:1 (range 1.1-2.5:1; n = 5) and 2.6:1 (range 1.5-64.0:1; n = 6) at 3-9 days. Four patients underwent single photon emission computed tomography, which confirmed selective retention of Lipiodol in small metastases, although no activity was detected in a large deposit (> 15 cm) 10 days after injection. The tumour:liver ratio in the other three patients increased from 3.0-5.6:1 on day 1 to 4.5-7.2:1 on day 6. This study suggests that Lipiodol may be a useful therapeutic delivery agent to small colorectal liver metastases.

Measurements of the functioning volume of thyroid tissue have been made in 22 patients undergoing radioiodine therapy for thyrotoxicosis, using a prototype multiwire proportional counter positron camera. Tomographic images were produced of the distribution of 124I in the thyroid. Functioning volumes were found to be in the range 21-79 cm3 with volume errors of the order of +/- 4% to +/- 14%. Radioiodine uptake varied from 28% to 98%. Using a value of 6 days for the effective half-life of radioiodine in hyperactive thyroids, radiation doses from a standard therapy administration of 75 MBq of 131I varied from 11 to 48 Gy (compared with a recommended 50-70 Gy). In five cases PET imaging showed a non-uniform distribution of radioiodine in thyroids thought to have uniform uptake from conventional pinhole scintigraphy.

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