Cadaveric study of movement of an unstable atlanto-axial (C1/C2) cervical segment during laryngoscopy and intubation using the Airtraq(®) , Macintosh and McCoy laryngoscopes.

Concern that laryngoscopy and intubation might create or exacerbate a spinal cord injury has generated extensive research into cervical spinal movement during laryngoscopy. We performed a randomised trial on six cadavers, using three different laryngoscopes, before and after creating a type-2 odontoid peg fracture. Our primary outcome measure was the change in the space available for the spinal cord at the C1/2 segment measured by cinefluoroscopy. Tracheal intubation was performed using a minimal view of the glottis, a bougie, and manual in-line stabilisation. In a cadaveric model of type-2 odontoid fracture, the space available for the cord was preserved in maximum flexion and extension, and changed little on laryngoscopy and intubation.

FIESTA: an MR arthrography celebration of shoulder joint anatomy, variants, and their mimics.

Magnetic resonance (MR) arthrography is currently the gold standard radiological investigation for shoulder joint instability. Not only does this investigation allow for identification of important disease processes, but the reduced slice thickness and increased in-plane resolution allowed by the latest imaging sequences also gives excellent demonstration of shoulder joint internal anatomy. This article describes the technique of MR arthrography of the shoulder practiced at our institution, briefly outlining features of the FIESTA (fast imaging employing steady state acquisition) MR sequence employed, including its advantages and limitations. A pictorial review of shoulder MR arthrography performed with this technique is presented, concentrating on normal shoulder joint internal anatomy and anatomical variants that may mimic pathology.

Injuries to the lower back in elite fast bowlers: acute stress changes on MRI predict stress fracture.

In our study, the aims were to describe the changes in the appearance of the lumbar spine on MRI in elite fast bowlers during a follow-up period of one year, and to determine whether these could be used to predict the presence of a stress fracture of the posterior elements. We recruited 28 elite fast bowlers with a mean age of 19 years (16 to 24) who were training and playing competitively at the start of the study. They underwent baseline MRI (season 1) and further scanning (season 2) after one year to assess the appearance of the lumbar intervertebral discs and posterior bony elements. The incidence of low back pain and the amount of playing and training time lost were also recorded. In total, 15 of the 28 participants (53.6%) showed signs of acute bone stress on either the season 1 or season 2 MR scans and there was a strong correlation between these findings and the later development of a stress fracture (p < 0.001). The prevalence of intervertebral disc degeneration was relatively low. There was no relationship between disc degeneration on the season 1 MR scans and subsequent stress fracture. Regular lumbar MR scans of asymptomatic elite fast bowlers may be of value in detecting early changes of bone stress and may allow prompt intervention aimed at preventing a stress fracture and avoiding prolonged absence from cricket.

Undisplaced scaphoid waist fractures: is 4 weeks' immobilisation in a below-elbow cast sufficient if a week 4 CT scan suggests fracture union?

This prospective study investigated a cohort of 59 scaphoid waist fractures which were treated nonoperatively in a below-elbow plaster cast for 4 weeks and then underwent a Week 4 CT scan to assess displacement and progress to union. Forty-three were classed as undisplaced and 37 of these 43 were also classed as 'united'. All the 37 undisplaced and 'united' fractures united with up to 8 weeks' cast immobilisation, including 26 which were taken out of plaster at 4 weeks and mobilised. We conclude that scaphoid waist fractures which appear to be undisplaced and united on a week 4 CT scan will unite, and may not need to be immobilised in a plaster cast for more than 4 weeks. Such a treatment policy may reduce the period of disability and time off work associated with nonoperative treatment.

Magnetic resonance imaging of the lumbar spine in asymptomatic professional fast bowlers in cricket.

Low back injuries account for the greatest loss of playing time for professional fast bowlers in cricket. Previous radiological studies have shown a high prevalence of degeneration of the lumbar discs and stress injuries of the pars interarticularis in elite junior fast bowlers. We have examined MRI appearance of the lumbar spines of 36 asymptomatic professional fast bowlers and 17 active control subjects. The fast bowlers had a relatively high prevalence of multi-level degeneration of the lumbar discs and a unique pattern of stress lesions of the pars interarticularis on the non-dominant side. The systems which have been used to classify the MR appearance of the lumbar discs and pars were found to be reliable. However, the relationship between the radiological findings, pain and dysfunction remains unclear.

Comparing spondylolysis in cricketers and soccer players.

OBJECTIVE: To determine whether the location of spondylolysis in the lumbar spine of athletes differs with biomechanical factors. METHODS: Single photon emission computerised tomography and reverse gantry computerised tomography were used to investigate 42 cricketers and 28 soccer players with activity related low back pain. Sites of increased scintigraphic uptake in the posterior elements of the lumbar spine and complete or incomplete fracture in the pars interarticularis were compared for these two sports. RESULTS: Thirty seven (90.4%) cricketers and 23 (82.1%) soccer players studied had sites of increased uptake. In cricketers, these sites were on the left of the neural arch of 49 lumbar vertebrae and on the right of 33 vertebrae. In soccer players there was a significantly different proportion, with 17 sites on the left and 28 on the right (difference of 22.0%; 95% confidence interval (CI) 0.04 to 0.38). Lower lumbar levels showed increased scintigraphic uptake more frequently than did higher levels, although the trend was reversed at L3 and L4 in soccer. Forty spondylolyses were identified in the lumbar vertebrae of the cricketers and 35 spondylolyses in the soccer players. These comprised 26 complete and 14 incomplete fractures in the cricketers, and 25 complete and 10 incomplete fractures in the soccer players. Similar numbers of incomplete fractures were found either side of the neural arch in soccer players, but there were more incomplete fractures in the left pars (14) than in the right (2) in cricketers. The proportion of incomplete fractures either side of the neural arch was significantly different between cricket players and soccer players (difference of 37.5%; 95% CI 0.02 to 0.65). Most complete fractures were at L5 (66.7%) and more were found at L3 (15.7%) than L4 (6.9%). However, incomplete fractures were more evenly spread though the lower three lumbar levels with 41.7% at L5, 37.5% at L4, and 20.8% at L3. CONCLUSIONS: Fast bowling in cricket is associated with pars interarticularis bone stress response and with development of incomplete stress fractures that occur more frequently on the left than the right. Playing soccer is associated with a more symmetrical distribution of bone stress response, including stress fracturing. Within cricketers, unilateral spondylolyses tend to arise on the contralateral side to the bowling arm.

The value of combining single photon emission computerised tomography and computerised tomography in the investigation of spondylolysis.

The aim of this study was to assess the diagnostic value of combining single photon emission computerised tomography (SPECT) with reverse gantry computerised tomography (rg-CT) in the investigation of spondylolysis. Patient characteristics and imaging results in 118 patients, aged 8-44 years, with low back pain (LBP) were analysed. SPECT showed increased scintigraphic uptake in 80 patients, and spondylolysis was identified on rg-CT in 53. The Cohen Kappa ratio of 0.362 (95% CI: 0.198-0.526) suggests only fair agreement for the result of increased scintigraphic activity with the finding of spondylolysis on rg-CT. We conclude that these investigations give mutually exclusive information, which leads to four diagnostic categories. When there was increased scintigraphic activity on SPECT, 58.8% (95% CI: 48.0-69.5%) of patients had spondylolysis on rg-CT. With rest from provoking activities, these lesions may heal. We interpret the findings of increased scintigraphic activity, but no spondylolysis demonstrated on rg-CT as indicating a bone stress response. These also require rest from provoking activity to prevent a stress fracture developing. In this study, 84.2% (95% CI: 72.67-95.8%) of those patients without increased activity on SPECT had no spondylolysis identified on rg-CT. These patients may need further investigations such as magnetic resonance imaging (MRI) to diagnose pathology, which typically does not involve the posterior elements--but rest from sport may not be so important. There were five patients in our study, without increased scintigraphic activity, but in whom bilateral chronic-appearing (wide separation, smooth sclerotic bone margins) spondylolyses were identified at L5. These all were anticipated from previous plain radiographs or MRI. This group will almost certainly not heal, and if the spondylolyses are the cause of pain these vertebrae will need stabilisation by surgery if physiotherapy fails.

Primary obturator pyomyositis: a diagnostic challenge.

Pyomyositis of the obturator muscles is a rare condition, characterised by pain in the hip and features of systemic infection. It may follow minor trauma to the hip, sometimes in the presence of an apparently innocuous infective source. All previously reported cases have been diagnosed conclusively on the initial CT or MR scan. We present a case of obturator pyomyositis in a 21-year-old football player in which the first MR scan was misleading. A radiolabelled, white blood cell scan was also negative and the resultant delay in diagnosis proved dangerous. The crucial importance of careful and repeated clinical examination is emphasised.

Clinical outcome and return to sport after the surgical treatment of spondylolysis in young athletes.

We studied prospectively 22 young athletes who had undergone surgical treatment for lumbar spondylolysis. There were 15 men and seven women with a mean age of 20.2 years (15 to 34). Of these, 13 were professional footballers, four professional cricketers, three hockey players, one a tennis player and one a golfer. Preoperative assessment included plain radiography, single positron-emission CT, planar bone scanning and reverse-gantry CT. In all patients the Oswestry disability index (ODI) and in 19 the Short-Form 36 (SF-36) scores were determined preoperatively, and both were measured again after two years in all patients. Three patients had a Scott's fusion and 19 a Buck's fusion. The mean duration of back pain before surgery was 9.4 months (6 to 36). The mean size of the defect as determined by CT was 3.5 mm (1 to 8) and the mean preoperative and postoperative ODIs were 39.5 (SD 8.7) and 10.7 (SD 12.9), respectively. The mean scores for the physical component of the SF-36 improved from 27.1 (SD 5.1) to 47.8 (SD 7.7). The mean scores for the mental health component of the SF-36 improved from 39.0 (SD 3.9) to 55.4 (SD 6.3) with p < 0.001. After rehabilitation for a mean of seven months (4 to 10) 18 patients (82%) returned to their previous sporting activity.

CT imaging and three-dimensional reconstructions of shoulders with anterior glenohumeral instability.

Glenohumeral instability is a common occurrence following anterior dislocation of the shoulder joint, particularly in young men. The bony abnormalities encountered in patients with glenohumeral instability can be difficult to detect with conventional radiography, even with special views. The aim of our study was to evaluate the bony abnormalities associated with glenohumeral instability using CT imaging with 3-D reconstruction images. We scanned 11 patients with glenohumeral instability, one with bilateral symptoms; 10 were male, one female, and their ages ranged from 18-66 years. Contiguous 3 mm axial slices of the glenohumeral joint were taken at 2 mm intervals using a Siemens Somatom CT scanner. In the 12 shoulders imaged, we identified four main abnormalities. A humeral-head defect or Hill-Sachs deformity was seen in 83% cases, fractures of the anterior glenoid rim in 50%, periosteal new bone formation secondary to capsular stripping in 42%, and loose bone fragments in 25%. Manipulation of the 3-D images enabled the abnormalities to be well seen in all cases, giving a graphic visualization of the joint, and only two 3-D images were needed to demonstrate all the necessary information. We feel that CT is the imaging modality most likely to show all the bone abnormalities associated with glenohumeral instability. These bony changes may lead to the correct inference of soft tissue abnormalities making more invasive examinations such as arthrography unnecessary.

Vertebral osteomyelitis as a complication of Crohn's disease.

Vertebral osteomyelitis arising from an enteric fistula in patients with inflammatory bowel disease is rare. We report on a patient with Crohn's disease who developed an enteric fistula, resulting in a presacral abscess and vertebral osteomyelitis involving the L4 and L5 vertebral bodies and related disc spaces. This was managed by a defunctioning colostomy with drainage of the pre-sacral abscess. The vertebral lesion was successfully managed non-operatively.

Atlanto-axial dislocation without fracture: case report of an ejection injury.

We describe an unusual injury to the upper cervical spine sustained during ejection from an aircraft. MRI provided an accurate and direct diagnosis of the severe ligamentous injuries.

False aneurysm of a lumbar artery following vertebral biopsy.

Vertebral body biopsy is regarded as a simple and relatively safe technique, with a low complication rate. We report the case of an 80-year-old man who developed a false aneurysm of a lumbar artery following biopsy of the fourth lumbar vertebra.

Dynamic gradient-echo and fat-suppressed spin-echo contrast-enhanced MRI of the breast.

PURPOSE: To evaluate heavily T2-weighted, dynamic contrast-enhanced and fat-suppressed magnetic resonance imaging (MRI) of the breast in comparison with conventional imaging and fine needle aspiration cytology (FNAC). PATIENTS AND METHODS: Fifty patients with surgically/pathologically proven breast disease were examined pre-operatively by MRI. The majority, 45 patients, had invasive carcinoma. T1-weighted spin-echo, T2-weighted fast spin-echo (with chemical-shift-selective fat-suppression in 20 cases), rapid dynamic contrast-enhanced gradient-echo and post-contrast fat-suppressed T1-weighted images were obtained. Signal intensity changes during dynamic scanning were assessed qualitatively and quantitatively. Comparison was made with the results of X-ray mammography, ultrasound and fine needle aspiration cytology. RESULTS: Unenhanced MRI was inadequate for determining the location, extent or nature of most lesions even when fat-suppressed T2-weighted images were obtained. Following contrast injection, there was significantly greater enhancement of invasive carcinomas than normal parenchyma. Invasive carcinomas of ductal and lobular subtypes did not differ significantly in their enhancement profiles. Prominent enhancement of the lesion periphery, which was a feature in 33 out of 50 cases (the majority of which were invasive carcinomas) was not due to central tumour necrosis. In four cases, invasive carcinomas which were clearly visible on early dynamic scans could not be identified on post-contrast fat-suppressed images. Lesions that were more numerous or extensive than had been recognised clinically or mammographically were revealed by MRI in 14 patients, though MRI was no more specific than conventional assessment. Invasion of the chest wall was accurately predicted by MRI in three cases. There was excellent correlation between tumour size shown by MRI and histopathology. FNAC was accurate in predicting the final histological diagnosis except in those cases where samples were unsatisfactory. CONCLUSIONS: Contrast-enhanced MRI appears useful in the assessment of suspected malignant breast masses, especially in younger women with predominantly glandular breast tissue. Specificity is no better than FNAC but tumour extent and multifocality are more accurately disclosed than by conventional imaging techniques. Contrast-enhanced chemical-shift-selective fat-suppressed images are sub-optimal in a small proportion of cases (particularly where lesions are located posteriorly) and some benign breast disease may appear misleadingly conspicuous on such images. Morphological features and quantification of lesion enhancement during dynamic scanning presently offer only limited prospects for discrimination between various pathologies. Heavily T2-weighted sequences appear of marginal value.

Dynamic contrast-enhanced and fat suppressed magnetic resonance imaging in suspected recurrent carcinoma of the breast: preliminary experience.

20 women with suspected recurrent breast cancer who had undergone previous breast-conserving operations were investigated using dynamic contrast-enhanced gradient echo (GRE) and fat suppressed spin echo (SE) magnetic resonance (MR) imaging. Histologically confirmed recurrent tumour was readily recognized on dynamic GRE scans by virtue of rapid, early and avid enhancement. Benign scars enhanced more slowly and reached lower magnitudes of enhancement. Fat suppressed SE images, which were typically acquired 10 min after contrast administration, were sensitive for the detection of tumour recurrence but lacked specificity. Early scanning after contrast administration offers the best prospects for distinguishing tumour recurrence from benign scarring. The criteria used to distinguish these two entities are highly dependent on the scan technique and the time at which images are obtained post-contrast.

Quantitative analysis of multi-slice Gd-DTPA enhanced dynamic MR images using an automated simplex minimization procedure.

Quantitative analysis of Gd-DTPA enhanced dynamic MR images has potential for discriminating lesions, especially because the introduction of clinical fast imaging techniques has enabled good sampling of the relatively rapid Gd-DTPA wash-in curves. Analysis of such data requires curve fitting to a nonlinear model, which to date has been performed using a nonlinear least squares (NLLS) fitting procedure. However, this method often fails to converge to the appropriate minima without good initial parameter estimates when multi-exponential models are involved, making automated analysis of complete multislice or volume data sets problematic. In this report we demonstrate the robust performance of a simplex minimization procedure compared with NLLS, by the method of Marquardt, using a Monte Carlo simulation. Further, we illustrate the applicability of such a technique to the analysis of dynamic contrast enhanced images on a pixel-by-pixel basis. As a preliminary example, the technique is applied to a breast lesion but is expected to be suitable for examination of many lesion types.

Review article: computed tomography and magnetic resonance in the diagnosis of intraventricular cerebral masses.

We describe a series of 60 cases of patients with masses arising within the cerebral ventricles. The site and relative frequency is noted for each histological type. The differential diagnosis depends on patient age and sex, site, morphology and number of masses, presence and type of hydrocephalus and the characteristics of the mass on computed tomography (CT) and magnetic resonance (MR) images. A review of the literature has been performed and this information collated with our own experience to give detailed descriptions of the typical features of each intraventricular mass. Attention is drawn to intraventricular neurocytoma, a recently described tumour that may be mistaken histologically for intraventricular oligodendroglioma or ependymoma. A comparison is made of the value of CT and MR in the diagnosis of intraventricular masses.