Occult posttraumatic avascular necrosis of hip revealed by MRI.

Three hips with avascular necrosis in two patients had associated traumatic lesions noted on magnetic resonance imaging. Location of stress fracture in two femoral necks and acetabular contusion development prior to avascular necrosis favors these processes as being etiologic. These cases are particularly noteworthy in that nondisplaced fractures or other musculoskeletal trauma not visible on plain films has rarely been associated with subsequent development of avascular necrosis.

Imaging of plantaris muscle rupture.

Rupture of plantaris muscle is demonstrated in two patients, one with magnetic resonance imaging (MRI) and one with ultrasound. This entity, thought to be clinically common, has never before been demonstrated at surgery or with imaging. Anatomic and physiologic aspects of the diagnosis that enable radiologists to make the diagnosis, once familiar with the entity, are discussed.

Fatal destructive cervical spondyloarthropathy in two patients on long-term dialysis.

Two patients with fatal cervical cord compressive myelopathy are described, both of whom had been on dialysis for more than 15 years. Destructive changes were noted in mid and upper cervical regions, with soft tissue mass in the atlanto-occipital region in one patient. Clinical and radiographic findings suggest both amyloid and hyperparathyroidism as possible etiologies for these destructive spinal changes. Clinicians should be aware that the full picture of quadriparesis may be associated with destructive spondyloarthropathy (DSA) in long-term dialysis patients.

CT of primary adrenal lymphoma.

We present a case of primary adrenal lymphoma with CT appearance of a cystic mass containing mural calcification. Sonographic findings are correlated. Comparison of imaging features is made with the few previously reported cases of this rare entity.

Irreducible posterior dislocation of the shoulder: MR and CT findings.

Failure to reduce an acute posterior dislocation of the shoulder is rare and is usually due to the interposition of a structure into the joint. In this paper we report the MR and CT findings of a failed reduction due to interposition of a dislocated biceps tendon between the humeral head and anterior glenoid fossa. This was associated with an avulsed subscapularis tendon with its attachment to the lesser tuberosity and a nondisplaced fracture of the humeral neck, findings which were only evident on MR.

Magnetic resonance imaging in a family with hereditary cerebral arteriovenous malformations.

Because of a family history of neurologic problems and the documentation of three vascular lesions in one patient, we evaluated 18 members representing three family generations with magnetic resonance imaging. Of these, eight were normal, two had abnormalities probably not related to arteriovenous malformation, one scan was suboptimal, and the remaining eight had evidence of hemorrhagic lesions characteristic of arteriovenous malformation. Four of these patients had multiple lesions, and three patients with lesions had no neurologic symptoms. The findings suggest an autosomal dominant mode of inheritance in this unique case of familial cerebral arteriovenous malformation.

Unilateral absence of the external carotid artery.

We report a patient with absence of the external carotid artery. The major external branches originate from the internal carotid artery which is really a common arterial trunk. The embryology and clinical significance of this rare vascular anomaly are discussed.

Thyroid uptake of gallium in Graves' disease.

A patient with hyperthyroid Graves' disease presented with ptosis, leading to a workup for myasthenia gravis. An enlarged thymus gland was noted on computed tomography. A scan with gallium-67 citrate showed prominent and diffuse thyroid gland activity as well as prominent lacrimal activity. This finding of thyroid uptake of gallium led to the correct diagnosis of Graves' disease. Such a finding has not been reported previously. The associated thymic, thyroid, and orbital findings in Graves' disease are discussed.

Hepatocellular carcinoma imaging.

Radionuclide scintigraphy can give a specific diagnosis when a hypervascular "cold" defect on colloid scans "fills in" with gallium scanning. The majority of hepatocellular carcinomas will also accumulate hepatobiliary agents especially in delayed images. Magnetic resonance imaging is superior to other modalities in providing anatomic detail, such as location and relation to vessels, needed by the surgeon in operative planning.

Right ventricular tardokinesis in cardiac contusion: a new observation on phase images.

The usefulness of gated blood pool (GBP) scintigraphy in evaluating cardiac contusion among trauma patients was examined. In ten of 62 patients who sustained blunt chest trauma, phase images of GBP studies demonstrated delayed onset of right ventricular (RV) contractions (RV tardokinesis). Clinical charts of these ten patients were reviewed to determine the significance of this finding. Only one had no supportive evidence of cardiac injury. Four patients were determined to have clinically significant cardiac contusion on the basis of the occurrence of arrhythmias of cardiac failure during their hospital course. These patients had ventricular histogram widths greater than 30 degrees of the entire cardiac cycle at half maximum height and had a bifid peak in their ventricular contraction histograms. Of the 52 patients who did not have RV tardokinesis, only one had a clinically significant cardiac contusion, resulting in a false-negative rate of 2% for the test. This new observation of RV tardokinesis may be clinically useful in establishing the difficult diagnosis of cardiac contusion.

Discordant uptake of technetium-99m DISIDA and technetium-99m sulfur colloid in an amebic abscess.

Hepatobiliary imaging in a patient with an amebic abscess showed an early cold defect that later showed rim enhancement. A Tc-99m SC scan did not show prominent flow (making hepatoma unlikely) and showed the previously noted defect to appear larger and without rim enhancement. The differential damage to Kupffer cells and hepatocytes or edema may account for these findings. Amebic abscess should be included in the differential diagnosis of lesions that give increased Tc-99m IDA but cold Tc-99m SC images.

Percutaneous treatment of an intrahepatic abscess caused by a penetrating duodenal ulcer.

We present a well-documented case of duodenal ulcer that penetrated into the quadrate lobe of the liver with subsequent abscess and fistula formation. An accurate diagnosis depended on the use of ultrasound to identify the presence of an abnormal gas pattern in the liver which had been mistaken for bowel on computed tomography. Successful percutaneous drainage under ultrasound guidance was then accomplished. This is the first recorded case we can find in which percutaneous drainage combined with antibiotic and H2 blocker therapy was able to supplant the surgical treatment of liver abscess with an enteric fistula. The diagnosis and management of this condition are discussed. Special reference is made to the use of ultrasound to overcome a major pitfall in the use of computed tomography for diagnosing liver abscesses with fistula formation.

[Acquired renal cystic disease in patient on long-term hemodialysis (author's transl)]. / Les reins polykystiques acquis de l'hémodialysé.

We report two cases of acquired cystic disease of the kidneys in patients on long-term hemodialysis. The gross appearance of these polycystic kidneys can be distinguished from the congenital adult type by their normal size and weight and by the small range of their cysts. We found some similarity between these numerous cysts and the simple retention cysts. This polycystic disease could concern about 30 % of the whole patients on long-term hemodialysis ; the mechanisms of its development are unknown. Clinically, this lesion is mostly asymptomatic but could sometimes be discovered by intra or perirenal haemorrhage.