Nuclear magnetic resonance is a noninvasive technique of imaging the brain using signals produced by magnetic fields and radiowaves. Sixteen patients with refractory temporal lobe epilepsy (TLE) had magnetic resonance imaging (MRI) during investigation for possible surgical management. These images plus those of 10 normal controls, were interpreted blind and the results from the TLE patients compared to the EEG and computerized tomographic (CT) scan findings. Fourteen patients compared with one normal control had one or more of the following: small temporal lobe, small mesial temporal structures, small hemisphere, and focal mesial temporal prolonged spin-spin relaxation time. These findings correlated with the electrographically determined seizure focus in 11 patients. Enlarged or asymmetrical temporal horns were seen with equal frequency in patients and controls and did not correlate with the seizure focus. CT scans were less likely to show these changes than MRI. Correlation of the MRI changes with histopathology of resected temporal lobes was poor. MRI reveals structural and possibly functional alterations which may aid in the localization of the seizure focus in the temporal lobes of patients with refractory complex partial seizures.

Contrary to common perception, the advent of third- and fourth-generation scanners has lead to a significant increase in radiation dose to the patient per computed tomography (CT) head scan. With that in mind, a pilot study was designed with the objective of assessing the effectiveness of a dental-style protective bib in reducing the dose to the radiosensitive organs of the neck and thorax. Radiation doses over the thyroid gland and breast were measured with thermoluminenscent dosemeters and an ionization chamber respectively in 110 patients undergoing routine head scans. Half the patients wore the protective bib and collar. With lead protection, the thyroid measurements were reduced by an average of 45 % and the breast measurements by an average of 76 %. Similar results were seen in phantom measurements.

Commercial phantoms designed for radiologists to practise the skills needed to biopsy lesions under ultrasound guidance can be prohibitively costly, and do not have an indefinite shelf-life. A gelatin-based in-house model has been developed to recreate the conditions found in human tissues, using materials which are cheap and in everyday use. This phantom remains useful for several weeks, although tears produced by the biopsy needle take progressively longer to bond when the reconstructed gelatin is older than a month. However, new phantoms can be built quickly and easily using fresh gelatin while recycling other components.

A computer-assisted mapping program was developed to determine changes of cerebral perfusion in normal and pathological aging using single photon emission computer tomography (SPECT) and 99mTc-hexamethylpropyleneamine oxime (HMPAO). The software program outlined the cortex on 14 adjacent brain slices, and superimposed a ring of 12 regions of interest on each slice. Regional/global and regional/cerebellar relative flow values were calculated in 27 patients with clinically diagnosed Alzheimer's disease (AD) (mean age 71 years, SD 7.6) and in 10 normal controls (mean age 73.7 years, SD 7.3). The Dementia Rating Scale (DRS) was used to assess mental status in all subjects. Multiple regression analysis demonstrated a significant correlation between relative flow values and the DRS score. Regional/cerebellar (R = 0.88, p < 0.0001) relative flow values were a better indicator of cortical impairment than regional/global relative flow values (R = 0.68, p = 0.003). Of the brain regions of interest, the left parietal flow values correlated best with the DRS score (r = 0.83, p < 0.0001), a cutoff value of 77 accurately classifying 80% of the normals and 100% of the patients diagnosed as having Alzheimer's disease. The data show that computer-assisted mapping of SPECT can provide semiquantitative flow values with high diagnostic accuracy.