MRI ankle and subtalar characteristics in haemochromatosis arthropathy: a case-control study.

AIM: To examine the magnetic resonance imaging (MRI) features of the ankle and subtalar joints that might distinguish genetic haemochromatosis (GH). MATERIALS AND METHODS: The present study was a retrospective case-control study comparing 30 MRI studies of GH patients with ankle or subtalar arthropathy with 30 matched controls with ankle pain. Anonymised images were scored using a semi-quantative tool adapted from the MRI osteoarthritis knee score. Scores were generated for bone marrow lesions size, number, and distinguishing the proportion of each lesion consisting of subchondral cyst versus oedema. Articular cartilage loss and osteophytes were documented. The primary comparator was bone marrow lesion size. Paired Student's t-test and the chi-squared test were utilised to compare outcomes. RESULTS: Bone marrow lesion/cyst size and number, presence and extent of full-thickness cartilage loss, and osteophyte scores were significantly higher in ankle joints of GH cases (p<0.01). In the middle subtalar articulation, there were significantly higher scores for full-thickness cartilage loss and extent and osteophytes in GH cases (p<0.05). There were no significant differences in the posterior subtalar articulation. CONCLUSION: The finding of both numerous and large cysts on ankle MRI should raise suspicion of GH. Other MRI features of potential diagnostic value include large osteophytes and the presence of extensive full-thickness cartilage loss in the ankle joint and middle subtalar articulation.

Catel-Manzke syndrome: a case report of a female with severely malformed hands and feet. An extension of the phenotype or a new syndrome?

An unusual case of a female infant with Catel-Manzke syndrome is presented. Additional features not previously reported include three accessory ossicles at the bases or associated with the proximal phalanx of the index, middle, ring and little fingers bilaterally. There are also numerous bony abnormalities in both feet. Previous cases have shown no more than 2 accessory ossicles in the hand and these usually involve the index alone. The foot abnormalities are more extensive than any previously seen in this syndrome. This is only the 8th female case out of a total of 27 reported cases.

Effect of MRI noise on cochlear function.

A disadvantage of magnetic resonance imaging (MRI) is the high level of noise produced (peaking between 122 dB and 131 dB). We used otoacoustic emissions (OAEs) as a method to quantify the effect of MRI-generated noise on the cochlea. OAEs were measured in 16 patients before and after MRI and in 16 controls. OAEs decreased in patients after MRI, but the controls, who were not exposed to MRI noise, showed no decrease over the same period. The change in OAEs shows a clear effect of MRI noise on cochlear function, despite use of earplugs. The importance of correctly fitted earplugs cannot be underestimated.

Contrast-enhanced magnetic resonance angiography of the iliac arteries: optimization by injection simulation.

Protocols for contrast-enhanced magnetic resonance angiography (CE-MRA) of the iliac arteries were optimized by computer simulations based on an impulse response function (IRF) of contrast agent (CA) concentration as a function of time obtained for 20 patients. Protocols with sequential, centric, and elliptical k-space coverage, different repetition rates (5 and 10 ms), and CA doses (0.1, 0.2, and 0.3 mmol/kg b.w.) were compared in terms of signal-to-noise ratio (SNR), distortion of vessel profiles, and sensitivity to timing errors. IRF-based simulations successfully characterized CA recirculation. Slow-rate CA infusions were found to achieve relatively high enhancement. In terms of SNR, there is no advantage in increasing the repetition rate. Distortion of vessel profiles is more likely in elliptic and centric k-space coverage. Protocols based on sequential k-space coverage and relatively long CA infusions proved to be particularly suited to large-FOV iliac examinations as they are relatively insensitive to timing errors.

A painful shoulder.

A case is outlined of a patient presenting with a painful shoulder. Metastatic malignant melanoma was diagnosed. The sites of origin of melanotic lesions as well as metastatic sites are described. Both gross and radiological appearances of such lesion are not uniform, varying from osteolytic to osteoblastic forms. Treatment is for the most part ineffective. The outcome is rapid and invariably fatal.

MRI appearances of the asymptomatic patellar tendon on gradient echo imaging.

Thickening of the patellar tendon and foci of increased signal intensity have been described as characteristic features of "jumper's knee" (chronic patellar tendinitis) on magnetic resonance imaging (MRI). It was our impression that such appearances may be seen in the patellar tendons of patients without symptoms referable to the anterior part of the knee when using gradient echo images. The appearances of the asymptomatic patellar tendon on three-dimensional gradient echo sequences were studied by retrospectively reviewing the images of 60 patients, none of whom had symptoms related to the anterior part of the knee. The anteroposterior width of the patellar tendon was measured at three levels (superior, middle and inferior) on the central sagittal image of a gradient echo sequence. The relative signal intensities at the same levels were recorded. In 97% of subjects the superior part of the tendon was wider than the midpoint, and in 97% the inferior part was wider than the midpoint. The range of widths was wide, and there was no significant difference between sexes. Focal increased signal intensity in the superior part was shown in 75%, and in the inferior part in 43%. The asymptomatic patellar tendon shows uniform thickness throughout most of its length, but there are focal expansions at the proximal and distal ends. It usually demonstrates low signal on MRI, but may contain foci of increased signal intensity at either or both ends when imaged on gradient-echo sequences.

Review article: MRI of the knee.

The inherent vulnerability of the knee to injury and degenerative change means that there is a major requirement for an imaging technique capable of assessing such damage accurately, rapidly and non-invasively. Over a relatively short time magnetic resonance imaging (MRI) has emerged as the technique of choice in the assessment of internal derangement of the knee. The present review describes the wide application of MRI to the knee and considers the position of MRI in relation to other diagnostic methods.

Bowel preparation before intravenous urography: is it necessary?

Whether or not bowel preparation should be used before intravenous urography (IVU) remains a controversial issue. Despite strongly held views on both sides there is little scientific evidence to support either viewpoint. We have conducted a prospective randomized study designed to test the hypothesis that adequate bowel preparation before IVU facilitates better quality studies requiring fewer films and consequently less time and a lower radiation exposure. Data on 188 patients were analysed; 90 patients received bowel preparation and 98 received no bowel preparation. There was no difference between the groups in terms of the number of films taken, the duration of the procedure, the visibility of the renal tracts or the overall quality of the studies. The prepared group did have significantly less faecal residue than the unprepared group. However, the renal tract visibility was no greater, as the combination of gas and haustral folds seen after bowel preparation obscured fine detail of the urinary tract as effectively as faecal residue. The hypothesis that adequate bowel preparation before IVU facilitates better quality studies must therefore be rejected.

Three-dimensional gradient-echo MR imaging of the knee: comparison with arthroscopy in 100 patients.

To compare the findings on magnetic resonance (MR) images of the knee obtained with a three-dimensional gradient-echo (GRE) sequence with findings at arthroscopy, the menisci, cruciate ligaments, and hyaline cartilage were assessed in 100 patients. At MR imaging (performed by means of fast imaging with steady-state precession) and arthroscopy, the menisci (n = 200) and areas of hyaline cartilage (n = 500) were assigned grades of zero (normal) to three (greatest abnormality). The cruciate ligaments were considered intact, partially torn, or completely torn. The sensitivity of MR imaging in diagnosis of meniscal tears seen at arthroscopy was 97% and the specificity, 94%. For complete tears of the anterior cruciate ligament, the sensitivity was 92% and specificity, 96%. In the posterior cruciate ligament, both the sensitivity and specificity were 100%. Good correlation existed between findings at MR imaging and those at arthroscopy in assessment of focal thinning and full-thickness loss of hyaline cartilage, but arthroscopy enabled superior visualization of minor fissuring. Three-dimensional GRE MR imaging enables accurate assessment of the articular cartilage of the knee. The evaluation of meniscal tears and the cruciate ligaments has a high negative predictive value.

Spiking of the tubercles of the intercondylar eminence of the tibial plateau in osteoarthritis.

"Spiking", "sharpening" or "peaking" of the tubercles of the intercondylar eminence of the tibial plateau has been described as an early sign of osteoarthritis of the knee joint, but there are no reports confirming this association. The radiographs of 55 patients with established osteoarthritis of the knee joint and 36 controls were reviewed. Measurements were made of the angulation of the tips of the medial and lateral tubercles, and the ratio of the tubercle height to the width of the tibial plateau was calculated. There was a significant difference in both these parameters between the two groups, confirming that lengthening and sharpening of the angles of the tubercles are features of osteoarthritis of the knee joint.

CT scanning as an adjunct to screening for medullary carcinoma of the thyroid.

CT scanning of the thyroid following oral administration of potassium iodate was performed on two sisters in whom raised calcitonin levels had been found at a pentagastrin stimulation test undertaken to screen for medullary carcinoma of the thyroid. Three histologically proven, clinically occult C-cell carcinomas measuring 2 mm or less were detected by CT scanning. This technique may be useful prior to surgery in patients in whom medullary carcinoma of the thyroid is suspected but not proven.

Bladder cancer: staging with CT and MR imaging.

Magnetic resonance (MR) imaging and computed tomography (CT) were compared in 30 patients with histologically proved bladder cancer. MR imaging was accurate in depicting the presence or absence of extravesical spread in 22 patients (accuracy, 73%; sensitivity, 82%; specificity, 62%), and CT was accurate in 24 patients (accuracy, 80%; sensitivity, 94%; specificity, 62%). The MR examinations of two patients were of undiagnostic quality and therefore considered to be technical failures. Each technique resulted in five false-positive and one false-negative examination for the diagnosis of extravesical tumor spread. In 28 patients the integrity of the bladder wall was assessed with MR imaging. In 22 patients the bladder wall was disrupted, and 18 of these patients had deep muscle invasion. In six patients the bladder wall was intact, and none of these patients had evidence of deep muscle invasion at pathologic examination. In this study MR imaging was slightly inferior to CT in the delineation of invasive tumors beyond the bladder wall. However, if one excludes from analysis the two patients with undiagnostic studies, there is no significant difference in accuracy between the two techniques.

Magnetic resonance imaging in recurrent carcinoma of the cervix.

Twenty patients with suspected recurrent cervical carcinoma were evaluated with computed tomography (CT) and high-field magnetic resonance imaging (MRI). Histological verification of the imaging findings were available in all cases. Computed tomography and MRI were equally effective in making the diagnosis of disease recurrence. The extent of vaginal recurrence and involvement of pelvic floor muscles was better shown on MRI than on CT.

Fast magnetic resonance imaging of intracerebral metastatic disease.

The appearance of intracerebral metastases imaged with a multi-slice fast imaging sequence (FLASH) is described. Images were obtained using a Siemens 2.0 T Magnetom operating at 1.5 T. Results of the FLASH imaging sequence at different values of repetition time, different values of "flip angle" and different numbers of acquisitions are described both qualitatively and quantitatively. At low flip angles, both tumour and oedema appear brighter than surrounding white matter. Increasing the flip angle tends to make oedema brighter than both tumour and white matter and increasing the flip angle still further makes tumour and oedema darker than white matter. A major limitation of this technique is that the low flip angle images, in particular, suffer from low signal-to-noise ratios. High flip angle FLASH images have higher signal-to-noise ratios but show similar contrast behaviour to T1-weighted spin-echo images and are likely to be no better as a screening sequence for intracerebral metastases. All the FLASH sequences showed a sensitivity to changes in magnetic susceptibility. This made small intratumoral haemorrhages and basal ganglia "calcification" easier to detect than on spin-echo images but also caused susceptibility artefacts in images around the base of the skull.