The role of imaging in the evaluation of parotid disease.

In this review the imaging features of a range of parotid lesions are presented and the roles of ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) in the assessment of parotid disease are discussed.

Scintimammography: a pictorial review of the variable normal, post surgical and pathological appearances.

Scintimammography has a high specificity and sensitivity for the detection of primary and metastatic breast carcinoma and in the evaluation of the postoperative breast. This review highlights the spectrum of pathological features as well as the normal postoperative and postreconstruction changes and the variable normal appearances that may be encountered with this technique.

Pictorial review. Ultrasound of the testis.

Ultrasound examination is the primary imaging investigation used in initial evaluation of the symptomatic testis. In this review the ultrasound appearances of a range of testicular lesions are demonstrated. Particular attention is given to the subject of testicular microlithiasis and its link with germ-cell neoplasia, and also to the sonographic features of epidermoid cysts that may allow testis-sparing surgery.

Talocalcaneal coalition. Diagnosis with the C-sign on lateral radiographs of the ankle.

We analysed 42 weight-bearing lateral radiographs of the ankle, 20 of which were from patients with a clinical and plain radiological diagnosis of talocalcaneal coalition (TCC) who subsequently had CT. The remainder were from 22 healthy volunteers with no clinical findings suggestive of hindfoot pathology. Four observers, blinded to the CT findings, independently evaluated the radiographs on two separate occasions. With the 95% confidence interval and using the CT findings as the comparison we calculated the sensitivity, specificity, accuracy, and positive and negative predictive values for the C-sign, and for other signs known to be associated with TCC. Similarly, we also calculated the interobserver and intraobserver reliability for these signs using the kappa statistic. Our results suggest that the C-sign is highly sensitive and specific for TCC. It is an accurate indicator and significantly more reliable than other previously recognised radiological signs of TCC. Features of the C-sign, however, cannot be relied upon to indicate whether the TCC is fibrous or bony.

Monoarticular synovial lesions: radiologic pictorial essay with pathologic illustration.

A wide variety of common focal monoarticular synovial lesions may be encountered on imaging studies. A multi-modality approach to these lesions, with appreciation of the differing appearances, can often yield the correct diagnosis. This pictorial essay demonstrates and describes the imaging with illustration of pathologic findings in a spectrum of conditions.

Chemo-embolization of hepatic tumours.

Over the past decade, increasing use of chemo-embolization with chemotherapeutic agents emulsified in oil has been made in the treatment of both primary and metastatic liver tumours. These lesions are often not amenable to surgical resection and are not responsive to systemic chemotherapy. Chemo-embolization provides an additional therapeutic option which, in some instances, can provide significant benefit. This pictorial review discusses the technique of chemo-embolization, as well as aspects of patient selection, complications, and tumour response.

Transfemoral venous liver biopsy: common problems and complications.

Liver biopsy is still most commonly done via the percutaneous route; however, increasingly, transvascular venous liver biopsy has been used in patients with bleeding disorders. Although the jugular route is now generally favoured, a transfemoral route can be a useful alternative technique when the jugular route is not available. We describe the transfemoral technique and outline a number of commonly encountered problems and complications and suggested methods of addressing them.

Malignant fibrous histiocytoma of soft tissue imaging with emphasis on MRI.

Malignant fibrous histiocytoma (MFH) is the most common soft tissue sarcoma in adults. This pictorial essay describes and illustrates the clinical, pathologic, and radiologic features of MFH. The cross-sectional imaging features on CT and MRI are emphasized in relation to the diagnosis and staging of MFH.

Three-dimensional CT measurement of adult acetabular dysplasia: technique, preliminary results in normal subjects, and potential applications.

OBJECTIVE: To assess a three-dimensional computed tomography (3DCT) technique for measurement of acetabular coverage in adults. DESIGN: We used 3DCT to define the geometric centre of the femoral head and to measure centre-edge angles (CEAs) at 10 degrees rotational increments around the acetabular rim. The means, ranges, standard deviations and 95% confidence intervals for the CEAs at the various rotational increments were determined. Inter- and intra-observer variability was measured. The normal values are compared with two example cases of acetabular dysplasia. PATIENTS: The normal hips of 15 subjects aged 1949 years (mean 34.2 years) were measured. RESULTS: The 3DCT measurements are reproducible (mean difference interobserver, 1.7 degrees - 7.9 degrees; mean difference intra-observer, 0.6 degrees-6.9 degrees). Mean normal CEA at the lateral rim was 33 degrees with a 95% confidence interval of 23 degrees - 43 degrees. Mean normal CEAs at 10 rotational increments from anterior to posterior rim were determined, and graphed as a 'normal curve'. CONCLUSION: This new 3DCT method of assessing acetabular dysplasia is simple, reproducible, and applicable to diagnosis, quantification and surgical planning for adult acetabular dysplasia patients.

The MRI appearance of the optic nerve sheath following fenestration for benign intracranial hypertension.

Optic nerve fenestration is carried out in cases of severe benign intracranial hypertension. This study aimed to monitor the optic nerve sheath appearances and orbital changes that occur following this procedure. The eight patients were all female with an average age of 37.3 years and a range of 20-58 years. The duration of symptoms was 2-6 years. Symptoms included headaches, diplopia and visual obscurations. Examination revealed severe papilledema. All investigations, including MRI, biochemical and immunological tests, were negative. Patients had fenestration of a 2 mm x 3 mm segment of the medial aspect of the optic nerve sheath. Imaging was obtained with a 1 T MRI machine using a head coil. Coronal, axial and sagittal 3 mm contiguous sections using STIR sequences with TR 4900 ms, IT 150 ms and TE 60 ms were obtained. Five patients showed clinical improvement. The post-operative MRI findings in four of these included a decreased volume of cerebrospinal fluid (CSF) around the optic nerve sheaths and a localized collection of fluid within the orbit. There were no MRI changes in the three patients with no clinical improvement. Decreased CSF volume around the optic nerve and a fluid collection within the orbit may indicate a favorable outcome in optic nerve fenestration.

Pictorial review: giant cell tumours of bone.

Giant cell tumour of bone is a relatively common neoplasm with limited potential for metastatic spread. These tumours usually occur at the ends of bones with their epicentre in the epiphysis. This essay will review the various common and some of the less frequently encountered manifestations of giant cell tumours at multiple different sites, as well as postoperative recurrence. Different imaging modalities including plain film, tomography, computed tomography and magnetic resonance imaging are shown.

Case report: the diagnostic value of contrast-enhanced computed tomography in acute bilateral renal cortical necrosis.

Acute bilateral renal cortical necrosis is a relatively rare cause of acute renal failure accounting for only 2% of cases in the Western World. The pathophysiology of this condition is complex, but ultimately leads to the destruction of the renal cortex with sparing of the renal medulla. A definitive diagnosis is based on renal histology. In this report we describe a patient in whom this diagnosis was made using contrast-enhanced computed tomography as renal biopsy was contraindicated.