SPECT bone scintigraphy in the diagnosis and management of mandibular condylar hyperplasia.

Isotope bone scans have been used for a number of years to assess growth activity in the mandibular condyle in patients who present with facial asymmetry. The aim is to distinguish normal bone growth within the condyle from increased activity that may be the cause of the asymmetry. Previous studies have, however, relied only on planar images. SPECT (single photon emission computed tomography) has been used with quantitative assessments of one mandibular condyle to clivus or lumbar spine, but we have compared one condyle with the other, which is more sensitive and accurate in detecting abnormal activity. A relative percentage uptake of 55% or more in the affected mandibular condyle is considered to be abnormal, and this has been validated by comparison with an age-matched control group. We have used SPECT as an aid to diagnosis and treatment in 18 patients with asymmetrical growth and have constructed a therapeutic algorithm to aid the treatment of these patients.

Magnetic resonance imaging of acute intraosseous disc herniation.

Schmorl's nodes, the result of previous intraosseous disc herniation (IODH), are a common incidental finding on plain radiographs, computed tomography (CT) and magnetic resonance imaging (MRI). Acute IODH can, however, cause severe back pain, and the radiological features may also lead to inappropriate suspicion of malignancy or infection. We present eight cases of acute IODH in order to illustrate how the correct diagnosis can be made by MRI. In six cases isotope bone scintigraphy had been performed, demonstrating focal increased activity at the site of IODH. MRI can reinforce the concern about serious underlying pathology by the demonstration of marrow oedema, which may be localized around the disc herniation or extensive, extending throughout the vertebral body and into the pedicles. The key to the correct diagnosis is the recognition of the endplate defect and disc herniation. In three cases the diagnosis may have been possible from plain radiographs in which disc calcification visible on previous radiographs had migrated into an intraosseous location.

The technetium white cell scan as an initial imaging investigation for evaluating suspected childhood inflammatory bowel disease.

BACKGROUND: The technetium white cell scan (WCS) may be a useful investigation for patients with inflammatory bowel disease (IBD). In a retrospective study we assessed the use of the WCS as an initial imaging investigation in evaluating children with suspected IBD. METHODS: Over a 3-year period, 60 WCS were performed on 55 patients (25 boys, median age 12.1 years, age range 1.5-18 years) with known or suspected IBD. There were two clinical groups: those with previously diagnosed IBD (histologically and radiologically) and in clinical relapse (13 patients), and newly presenting patients with suspected IBD (42 patients). RESULTS: Eighteen scans were performed on the 13 patients presenting with relapse. Seventeen were positive and one patient, subsequently shown to have an inactive stricture, had a negative scan. Seven of the 42 newly presenting patients had abnormal scans, confirmed to be due to IBD by a combination of histology and barium examinations. Of the remaining 35 scans, three were abnormal and 32 were normal. None of these patients were subsequently proven to have IBD. These results show that in detecting active IBD, a positive WCS has a 100% sensitivity (24/24) and a 91% specificity (32/35) in the diagnosis of IBD. CONCLUSIONS: Our results show that the WCS is very useful as an initial imaging investigation in evaluating patients with suspected IBD to select patients for further investigation.

Iliopsoas bursitis-an unusual presentation of metastatic bone disease.

Diagnostic uncertainty concerning the nature of an enlarging inguinal mass in an elderly male with a short history of hip pain was resolved by a combination of ultrasound and magnetic resonance imaging (MRI). Subsequent investigations showed that the enlarged iliopsoas bursa, which contained a number of atypical cells, was an unusual presenting feature of a destructive metastatic lesion in the right hip.

Pitfalls of bone scintigraphy in suspected hip fractures.

In a review of 2617 patients who were admitted with a suspected fractured neck of femur over a period of five years, 213 had normal or equivocal plain radiographs, and were subsequently investigated by bone scintigraphy. Normal scans were obtained in 127 (60%) cases. Of the remaining 86 cases, 82 (38%) were reported to show fractures of the proximal femur, three showed pubic ramus fractures, and one acetabular fracture was demonstrated. Review and follow-up has revealed eight false positive and two false negative scans. The various factors accounting for these errors are considered, and the clinical implications discussed. Careful analysis of accompanying plain radiographs is stressed when interpreting scintigrams.

Portal hypertension with a large spontaneous spleno-renal shunt in the absence of splenomegaly.

Splenomegaly is a cardinal manifestation of portal hypertension. We describe a case of portal hypertension with a large spontaneous spleno-renal shunt in the absence of splenic enlargement. The vascular anatomy is evaluated by the combined use of duplex Doppler ultrasonography and computed tomography (CT).