BACKGROUND AND PURPOSE: to compare diagnostic performances for cholesteatoma diagnosis of incremental MRI protocols including non-echo planar diffusion-weighted imaging (DWI) performed on 3T and 1.5T scanners. MATERIALS AND METHODS: Thirty-nine patients with suspected cholesteatoma underwent 3T and 1.5T non-echo planar DWI and additional unenhanced T1-, delayed gadolinium-enhanced T1- and high-resolution T2-weighted standard acquisitions. Patients either underwent surgical tympanoplasty (n=21) or close clinicoradiological follow-up (n=18). Four radiologists independently and prospectively interpreted two incremental MRI protocols, differing in the magnetic field strength of the diffusion-weighted acquisition and comprising the three standard sequences. At each step, diagnostic performances were expressed as sensitivity, specificity, positive predictive value, negative predictive value and accuracy. RESULTS: Forty middle ear lesions including 21 cholesteatomas were identified. Univariate and multivariate analysis did not demonstrate significant reader, sequence addition or DWI magnetic field effect on diagnostic performances. Concerning non-echo planar DWI alone, sensitivity, specificity, positive predictive value, negative predictive value and accuracy ranged between 90.5-100%, 68.4-100%, 76.9-100%, 90.0-100% and 82.5-95.0, respectively. CONCLUSION: Non-echo planar DWI for cholesteatoma diagnosis can be performed on 1.5T or 3T scanners indifferently. High sensitivity and negative predictive value and relatively lower specificity and positive predictive value are achieved by a single non-echo planar DWI protocol.

Osteoporotic fractures of the spine are associated with significant morbidity, are highly predictive of hip fractures, but frequently do not present clinically. When there is a low to moderate clinical suspicion of vertebral fracture, which would not justify acquisition of a radiograph, vertebral fracture assessment (VFA) using Dual-energy X-ray Absorptiometry (DXA) offers a low-dose opportunity for diagnosis. Different approaches to the classification of vertebral fractures have been documented. The aim of this study was to measure the precision and accuracy of SpineAnalyzer™, a quantitative morphometry software program. Lateral vertebral assessment images of 64 men were analysed using SpineAnalyzer™ and standard GE Lunar software. The images were also analysed by two expert readers using a semi-quantitative approach. Agreement between groups ranged from 95.99% to 98.60%. The intra-rater precision for the application of SpineAnalyzer™ to vertebrae was poor in the upper thoracic regions, but good elsewhere. SpineAnalyzer™ is a reproducible and accurate method for measuring vertebral height and quantifying vertebral fractures from VFA scans.

OBJECTIVE: Failure to identify fractures is the most common error in accident and emergency departments. Therefore, the current research aimed to understand more about the processes underlying perceptual expertise when interpreting skeletal radiographs. MATERIALS AND METHODS: Thirty participants, consisting of ten novices, ten intermediates, and ten experts were presented with ten clinical cases of normal and abnormal skeletal radiographs of varying difficulty (obvious or subtle) while wearing eye tracking equipment. RESULTS: Experts were significantly more accurate, more confident, and faster in their diagnoses than intermediates or novices and this performance advantage was more pronounced for the subtle cases. Experts were also faster to fixate the site of the fracture and spent more relative time fixating the fracture than intermediates or novices and this was again most pronounced for subtle cases. Finally, a multiple linear regression analysis found that time to fixate the fracture was inversely related to diagnostic accuracy and explained 34 % of the variance in this variable. CONCLUSIONS: the results suggest that the performance advantage of expert radiologists is underpinned by superior pattern recognition skills, as evidenced by a quicker time to first fixate the pathology, and less time spent searching the image.

Increasing trainee numbers and changes to working patterns have resulted in a scarcity of training opportunities for training-grade doctors wishing to learn nephrostomy tube insertion techniques. A method of introducing trainees to the skills required to perform percutaneous nephrostomy in a safe, non-threatening environment, without risk to patients, is desirable. Commercial and biological nephrostomy phantoms are available, but they are expensive and not widely available, and a cheap, safe, valid alternative is desirable. We describe a simple technique for producing a gelatin-based phantom, which we suggest has face and content simulator validity. The use of this nephrostomy phantom could optimise existing clinical training opportunities through familiarisation with nephrostomy technique and equipment, and development of the psychomotor skills required for successful nephrostomy insertion prior to undertaking supervised procedures on patients. © 2010 the British Institute of Radiology.

Illicit drug abuse is a continuing menace of epidemic proportions associated with serious medical and social problems. Drug abuse can have a wide variety of presentations some of which can be life-threatening. The clinical diagnosis can be challenging as the history is usually limited or absent. Radiologists need to be familiar with varied imaging presentations and the related complications of illicit drug abuse to ensure correct diagnosis and appropriate timely treatment. This review will illustrate the imaging spectrum of illicit drug abuse involving several organ systems and also discuss the pathophysiological consequences of drug abuse.