Magnetic resonance imaging of an osteoid osteoma of the proximal femur: a potentially confusing appearance.

Osteoid osteomas are common benign pediatric bone tumors. However, radiographic diagnosis and location of the tumor nidus can be difficult. We recently diagnosed and treated an osteoid osteoma of the right proximal femur in a 9-year-old girl in whom the preoperative magnetic resonance images demonstrated a well-marginated lesion in the medullary canal but no tumor nidus. This was confusing and misleading. Correct diagnosis was made with a computed tomography (CT) scan. Care must be taken in interpretation of magnetic resonance imaging (MRI) in disorders in which secondary bone marrow changes occur to avoid erroneous diagnoses and possible incorrect operative procedures.

CT demonstration of a caseating granuloma forming a cyst in mediastinal lymph node.

The computed tomography (CT) appearance of a large cystic caseating granuloma in the middle mediastinum is reported. CT is helpful in evaluating the extent and density of the lesion and its relationship to neighboring structures.

The bare area of the spleen: a constant CT feature of the ascitic abdomen.

On computed tomographic (CT) scans of the abdomen in patients with ascites, there is one consistently recognizable area of the spleen that is not surrounded by fluid. This area, designated the bare area of the spleen, is related anatomically to the upper anterior part of the left kidney, specifically the Gerota fascia. Awareness of this relation enables differentiation of intraperitoneal fluid from pleural fluid on cross-sectional CT images.

Liver abscess: complication of a ventriculoperitoneal shunt.

Liver abscess is a previously unreported complication of ventriculoperitoneal shunting. We present such a case, which was diagnosed by computed tomography (CT) and managed by CT-guided percutaneous catheter drainage of the liver abscess, appropriate antibiotics, and shunt externalization.

Discrepant opacification of the internal jugular veins: indicator of innominate vein occlusion on computed tomography of the neck.

Discrepant enhancement of an internal jugular vein on computed tomography during intravenous infusion of contrast material via an upper extremity vein constitutes an abnormal finding. We demonstrate that the greater degree of opacification of the internal jugular vein on the affected side is due to reversal of flow on that side and is indicative of occlusion of a major venous pathway proximally.

CT-guided percutaneous catheter drainage of lymphocele complicating splenorenal anastomosis.

We report the successful management by CT-guided percutaneous catheter drainage of a lymphocele complicating a Warren-Zeppa distal splenorenal venous anastomosis. The early postoperative course of this 31-year-old male with homozygous alpha 1-antitrypsin deficiency was complicated by chylous ascites and a large lymphocele demonstrable on CT scanning. The persistent 10.5 cm diameter lymphocele was drained percutaneously 5 weeks later by a CT-guided catheter. Drainage of lymph continued at decreasing rates for 13 days when the catheter was removed. Complete resolution of the lymphocele was confirmed at 2 1/2 months. The successful treatment of a lymphocele by percutaneous catheter drainage may obviate major surgery and has not been previously documented.

Cerebrospinal fluid trace element content in dementia: clinical, radiologic, and pathologic correlations.

Using inductively coupled argon plasma emission spectroscopy, we measured 19 trace elements in cerebrospinal fluid of 265 patients who were undergoing diagnostic lumbar puncture. Thirty-three patients had Alzheimer-type dementia (ATD); 16 patients had other dementing illnesses; and 20 had no neurologic disease. There were seven cases of autopsy-proven Alzheimer's disease (AD) and eight autopsy controls. We found elevated CSF silicon in 24% of ATD and 71% of AD patients. We found no relationship between CSF aluminum, arsenic, lead, or manganese and ATD, AD, or other dementing illnesses.

Computed tomography of the nasopharynx and neck.

Computed tomography (CT) is unparalleled for evaluation of the nasopharynx and the neck in comparison with other radiologic modalities. Its ability to demonstrate soft tissue and bone abnormalities has established its role as a primary method of radiologic diagnosis, frequently obviating the need for further radiologic elaboration. Furthermore, in many cases, CT provides distinction among inflammatory, neoplastic, and traumatic conditions.

Gastrointestinal perforation: early diagnosis by computed tomography.

Five cases of gastrointestinal perforation are presented in which computed tomography (CT) successfully demonstrated the abnormalities directly related to the perforation. In all cases, CT played a significant role in establishing a correct diagnosis, and in four cases permitted precise localization which facilitated the surgical approach. We believe that in cases where conventional radiographic examinations are not diagnostic, CT is particularly valuable because of its superior ability to depict anatomic abnormalities in the mesentery and surrounding tissue planes to suggest bowel perforation.

Modification of Klein's wet ashing procedure for determination of mercury.

An investigation of the use of HCl in Klein's method (25.108-25.115) to prevent loss of mercury during wet digestion resulted in consistently good recoveries from jowar and fish samples. Recoveries for the modified method ranged from 90.9 to 97.0% compared with 14.4 to 35.5% for the original method.

Case report. Aortic aneurysm presenting as psoas enlargement.

We present a case of abdominal aortic aneurysm in which erosion and bleeding into the psoas muscle caused enlargement of that structure but remained confined within it until needle biopsy produced communication with the extraperitoneal space. This confirms the observation that separate compartmentalization of retrofascial and extraperitoneal spaces normally maintains.