Benign versus malignant osseous lesions in the lumbar vertebrae: differentiation by means of bone SPET

Bone scanning is a well-accepted and frequently performed diagnostic procedure with a high sensitivity, especially when single-photon emission tomography (SPET) acquisitions are added. However, the differentiation of benign from malignant osseous lesions often poses difficulty. The purpose of this study was to find out whether the particular localisation of an intraosseous lesion in a lumbar vertebra is an indicator of its aetiology. Bone scintigraphy including planar whole-body scans as well as SPET imaging of the lumbar spine was performed in 109 patients. The diagnoses of osseous lesions in the lumbar vertebrae were made strictly on the basis of the findings of magnetic resonance imaging, computed tomography or plain radiography. Sixteen patients had to be excluded from the study because they did not undergo adequate radiological examination. To determine the particular localisation of vertebral lesions in the bone scan, two experienced nuclear medicine physicians examined the studies independently while blinded to the radiological results. Four anatomical regions were differentiated within the vertebra: the vertebral body, the pedicle, the facet joints and the spinous process. Clopper-Pearson analysis, which takes into account the number of examinations, yielded the following probability intervals for the malignancy of intraosseous lesions in the lumbar spine: vertebral body 36.8%-57.3%, pedicle 87.7%-100%, facet joints 0.8%-21.4% and spinous process 18.7%-81.3%. It was concluded that lesions affecting the pedicle are a strong indicator for malignancy, whereas involvement of the facet joints is usually related to benign disease. Lesions affecting the vertebral body or the spinous process do not show a clear tendency towards either malignancy or benignity. In contrast to other studies, a significant probability of malignancy (35.6%) was observed in lesions affecting exclusively the vertebral body.

[Increase of kidney enzymes in urine after administration of contrast media: comparison of the nephrotoxicity of ionic and nonionic substances]

In a double blind clinical study, 50 patients with healthy kidneys were tested for the discharge of renal marker proteins before and after receiving a high or low osmoloar contrast medium (Meglium-Ioglicinat, Imeprol) using i.v. urography. The renal excretion of the tubular indicator enzymes alanine aminopeptidase, beta-Glutamyltranspeptidase and alkaline phosphatase increased in all patients after administration of the contrast media. The enzymuria was significantly lower with the non-ionic contrast medium with the ionic one, thus demonstrating that the non-ionic contrast medium has a lower nephrotoxic potential than the conventional ionic contrast medium. Three independent investigators evaluated the radiograms with regard to the contrast quality using prearranged criteria in a 5 point system. The diversity of the evaluations clearly favoured the non-ionic contrast medium.

[Osteonecrosis of the ossa sesamoidea hallucis--its pathology, diagnosis and differential diagnosis]

Basing on case reports, the embryology and anatomy of the great toe sesamoid bones are described. Pathogenesis of the osteonecrosis of these bones is explained, and the role of radiology in diagnosis and as an important aid in differential diagnosis is pointed out.

[Asymptomatic calcified aneurysm of the inferior pancreaticoduodenal artery--differential diagnostic considerations]

A calcified aneurysm of the inferior pancreaticoduodenal artery with simultaneous occlusion of the celiac axis but without any local symptoms is presented. In the description of the diagnostic procedure, the considerations relating to differential diagnosis against solitary circumferentially calcified masses in the right upper quadrant of the abdomen are discussed. As a result of increasingly sophisticated examination techniques, especially digital subtraction angiography, computed tomography and ultrasonography, these aneurysms, which were formerly thought to be rare, are now discovered surprisingly often. Knowledge of this vascular malformation and its differential diagnoses helps to avoid risky methods of examination.