Antropyloric muscle thickness at US in infants: what is normal?

The authors reviewed the ultrasonographic (US) images and medical records of 145 consecutive infants who were seen for evaluation of the upper gastrointestinal tract because of chronic vomiting and/or regurgitation. At US, the antropyloric muscle of each patient was measured in the midlongitudinal plane. On the basis of this measurement, the patients were divided into the following categories: group 1 (1-2 mm; 99 patients), group 2 (greater than or equal to 3 mm; 40 patients), and group 3 (2- less than 3 mm; six patients). Patients in group 1 were considered to have normal antropyloric muscle thickness, those in group 2 had abnormal thickness, and those in group 3 had muscle thickness that was not definitely normal or abnormal. The final clinical diagnoses for all of the infants in the three groups confirmed the authors' initial impressions that antropyloric muscle thickness of less than 2 mm was anatomically normal, muscle measuring 3 mm or greater was abnormal and diagnostic for pyloric stenosis, and muscle from 2 to less than 3 mm was abnormal but not specifically diagnostic for pyloric stenosis. Two of the six patients in group 3 eventually were diagnosed as having pyloric stenosis; thus, the authors believe that only those patients with antropyloric muscle less than 2 mm thick should be considered unequivocably normal.

Mediastinal pseudomass caused by compression of the thymus in neonates with anterior pneumothorax.

We studied the radiographs of 115 neonates with anterior pneumothoraces to determine how often the pneumothorax created the impression of a mediastinal pseudomass. The pseudomass results from compression of the thymus gland by air under pressure. To the unwary, the resulting configuration can lead to an erroneous diagnosis of a mediastinal mass. In experienced hands, however, it can serve as a strong clue to the presence of an underlying anterior pneumothorax. A pseudomass was present in 27 (33%) of 82 neonates with unilateral pneumothoraces and in 29 (88%) of the 33 patients with bilateral anterior pneumothoraces. A free lung edge was visualized in 26% of the patients with a unilateral pseudomass and in 55% of the neonates with a bilateral pseudomass. The pseudomass was large enough to potentially lead to a misdiagnosis in one third of the cases. In the other neonates the mass was smaller and not particularly problematic. The majority of the neonates with pseudomasses were large, not intubated, and not on positive-pressure assisted ventilation. Over half had no underlying pulmonary disease. The appearance of a mediastinal pseudomass on radiographs of neonates can obscure a pneumothorax, and lead to an erroneous diagnosis. Recognition of the pseudomass as a manifestation of pneumothoraces is important.

The radiologic manifestations of alveolar soft-part sarcoma.

Alveolar soft-part sarcoma is a rare soft-tissue tumor of unknown cellular origin that is characterized histologically by its organized "pseudoalveolar" pattern. The radiologic findings in 11 patients with this neoplasm were reviewed. The six men and five women were 16-48 years old (mean, 27 years). Nine patients had untreated primary tumors (thigh, four; forearm, two; and buttock, rectus abdominis muscle, and infratemporal fossa, one each) and two had locally recurrent masses (one each in the retroperitoneum and retrocrural space). All patients were evaluated by conventional radiography, two by sonography, eight by CT, five by angiography, and three by MR. Conventional radiographs showed the soft-tissue mass in only four patients; four lesions caused destruction of adjacent bone and two had soft-tissue calcification. Unenhanced CT showed low-attenuation lesions in four of five patients. The lesions were hypervascular on contrast-enhanced CT or angiography in each of nine patients studied. Prominent draining veins were shown by CT or angiography in five patients. Three lesions had a prolonged capillary stain on angiography. Alveolar soft-part sarcoma should be considered in the differential diagnosis of a hypervascular soft-tissue mass, particularly in the thigh of a young adult.

Current status of myelography in the evaluation of the thoracic spinal cord.

The myelographic features in 35 patients with clinical thoracic spinal cord disease and normal plain radiographs were reviewed to re-evaluate the role of pre-operative myelography since the advent of computed tomography and magnetic resonance. The most frequent lesions were meningioma (9 cases), prolapsed intervertebral disc (9 cases), and metastases (8 cases). The extent and anatomical location of the lesion was demonstrated in all 19 patients without myelographic block. In 16 cases with complete block, the anatomical location was demonstrated in 14, and the extent of the lesion in four, using cervical puncture in two and CT myelography in one. Myelography remains a valuable method of assessment of the thoracic spinal cord and canal and is sufficient to allow the preoperative planning of surgical management in the absence of complete block. Additional investigation by computed tomography or magnetic resonance imaging is advised in the presence of complete block or an intramedullary lesion.

Arterial embolization of adrenal tumors: results in nine cases.

Adrenal arterial embolization was performed in nine patients, four with inoperable adrenal cortical carcinoma and five with metastatic adrenal tumors. Embolic agents used were polyvinyl alcohol foam (Ivalon) in seven patients, stainless steel coils in four, ethanol in three, and surgical gelatin (Gelfoam) in two. In eight patients, embolization was performed for palliation, either to decrease tumor bulk (all patients), suppress tumor hormonal function (three patients), or relieve pain (four patients). One patient had an embolization to facilitate subsequent adrenalectomy. In four patients in whom it was possible to assess the effect of embolization on tumor bulk by follow-up CT, a striking reduction in size has occurred in one, the lesions remained stable in size for 12 months in two, and the tumor continued to increase in size in the fourth. A striking reduction in the production of the cortisol for 12 months was seen in two of three patients with Cushing syndrome. This reduction was considered due at least in part to embolization. Adrenal embolization resulted in effective palliation of pain in three of four patients and may have contributed to palliation in the fourth. Apart from a hypertensive episode in one patient, the cause of which was unclear, no serious side effects occurred. Adrenal arterial embolization may play an effective role without serious side effects in palliation of pain and reduction of hormone production in inoperable adrenal lesions.