PubMed Health⌕ Search

Biomedical subjects

J R Nettle

Publications and source records attributed to J R Nettle.

5 recordsLinked to original sources
PubMed1980

An evaluation of four rare-earth film-screen combinations.

Objective and subjective assessments are made on four film-screen combinations at 140 kV for use on an EMI body scanner. The combinations used were: 3M XD film + Trimax Alpha 8 screens; Agfa Gevaert RP film + MR600 screens; Kodak Ortho G film + Lanex regular screens and Ilford type S film + rare earth rapid R screens. The objective assessment is based on the optical density of the image of a test object on a radiograph. Receiver operating characteristic techniques are used in the subjective assessment. The best results in each assessment were obtained using the Kodak Ortho G film + Lanex regular screens.

Beryllium↗
PubMed1979

The Nicholas Research Award for Radiographers 1977: anatomical and radiological registration in whole body computed tomography.

Accurate registration of a section 13 mm in depth in different patients or reregistration in the same patient during whole body computed tomography is a significant problem. The method described here attempts to overcome some of these difficulties. The feasibility of using the EMI Scanner X-ray tube and a pair of Kodak Lanex intensifying screens in a vacuum pack cassette has been examined. A registration system which as an accuracy to within 1 pixel has been described. This technique has its major application in the registration and recognition of the axial skeleton, on fixed bony structures. The registration of soft tissue structures, subject to greater physiological variation poses problems which are the subject of further investigation.

Bone and Bones↗
PubMed1977

Computer tomography of the spinal canal using metrizamide.

Eleven patients have been examined by whole body CT employing the EMI CT 5000 following lumbar injection of 10 ml of metrizamide (Amipaque) 170 mg I/ml. The distribution, flow and dilution of the contrast medium have been investigated. The results suggest that whilst metrizamide is necessary in the spinal canal to demonstrate the neural axis and pathologic processes affecting it, it appears to enter the extracellular space of the spinal cord during the first hour and achieves an equilibrium in the subarachnoid space and spinal cord from 3 to 6 hours. The medium may concentrate in a second compartment, possibly intracellular, from 3 to 6 hours. The effect of spectral filtering by metrizamide on the attenuation values of the spinal cord has been modelled and shown not to be significant at the anticipated dilution of the medium in the cerebrospinal fluid space and the spinal canal.

Humans↗