High resolution computed tomography (HRCT) of the temporal bone is performed routinely in the preoperative evaluation for cochlear implantation. The largest multicentre retrospective analysis of data was undertaken to compare the findings on HRCT with the surgical findings in an attempt to determine the accuracy of HRCT. Of the 1009 patients referred, 525 were scanned of whom 335 were implanted. As part of this study we were also able to identify both radiological and non-radiological reasons for rejection of patients for cochlear implantation. the commonest cause being adequate residual hearing. The accuracy of HRCT in predicting cochlear ossification was 94.6%, with a 100% specificity and a 71%, sensitivity. Meningitis was the leading cause of cochlear ossification (44%). We conclude from this extensive multicentre study of both adult and paediatric patients that HRCT is accurate in predicting cochlear abnormality. In post-meningitic patients magnetic resonance imaging (MRI) may be a useful additional investigation.

No abstract

No abstract

No abstract

The paper describes a case study on spring development in a typical midland region of the Thiruvananthapuram District in Kerala, India. Field investigations show that there are eleven perennial springs, which can be developed as drinking water supply schemes. These springs are 'contact ' springs formed at laterite-sandstone, laterite- khondalite, and laterite-coastal alluvium. One of the springs developed between the contact of laterite and khondalite in the midland area is presented in this paper. The summer discharge of the spring is 28.800 l/day and benefits 100 local people. The paper also brings out a comparison between bored well and spring water supply scheme in this midland area.