Spontaneous regression of juvenile nasopharyngeal angiofibroma.

This report describes the spontaneous regression of a biopsy-proved juvenile nasopharyngeal angiofibroma that was first diagnosed when the child was age 11 years. The patient was followed up over a 12-year period during which he did not receive any therapy. Total involution of this lesion can be demonstrated by serial computed tomographic studies. Our report supports the theory of hormonal influence on this group of tumors and the possibility of spontaneous involution.

Multiple spin echo magnetic resonance imaging of the brain.

Advantages of 3D multiecho: 1. High signal to noise ratio which is useful for: a) Long TE b) Short TR c) Thin slices 2. Reduced paradoxical enhancement of blood vessels 3. Contiguous slices 4. Number of slices per scan is not reduced by short TR or long TE 5. Thin slices easily generated 6. A short TR multiecho sequence can produce a spectrum of images reflecting a range of both T1 and T2 weighting in the same scan. This information can often improve specificity. Disadvantages of 3D multiecho: 1. Increased motion sensitivity of 3D acquisitions 2. Scan times increase with TR.

Role of iodinated contrast material in the evaluation of myocardial infarction by computerized transmission tomography.

In vivo and in vitro studies have shown that areas of myocardial infarctions can be delineated on CT scans after intravenous administration of iodinated contrast material to dogs with experimental myocardial infarctions. Within the first minute after intravenous administration of contrast material (initial myocardial perfusion phase), the infarct appears an as area of decreased x-ray attenuation (cold spot image). Studies using radiolabeled microspheres indicate that the relative attenuation numbers throughout the myocardium in this phase reflect myocardial perfusion (Hessel et al, 1978). Delayed scans obtained at 5 minutes and later showed a reversal in the attenuation values of normal and infarcted myocardium with the infarct appearing as an area of homogeneous or mottled increase in x-ray density compared to normal myocardium. (Siemers et al, 1978; Carlsson et al, 1977; Higgins et al, 1979). This phenomenon of delayed contrast enhancement of myocardial infarctions ensues as early as 8 hours after coronary occlusion (Higgins et al, 1979) and is present in evolved infarcts as old as 51 days (Newell et al, 1979). Direct measurements of iodine concentration in infarcts, normal myocardium, and organs surrounding the heart were performed in dogs with 48-hour-old myocardial infarctions using fluorescent excitation analysis (Higgins et al, 1978, 1979). These measurements of iodine concentration in tissue samples obtained at 10-180 minutes after intravenous administration of contrast material indicated that the highest iodine concentration in the infarct was at 10 minutes, but the highest ratio of iodine concentration of the infarct to normal myocardium was at 180 minutes. At all time intervals, the concentration of iodine within the infarct was fivefold greater than in the normal myocardium.

Needle biopsy under computerized tomographic control: a method for tissue diagnosis in intracranial lesions.

Thirteen patients with intracranial lesions were submitted to a twist drill needle biopsy under computerized tomographic (CT) control, with sedation and local anesthesia. (The patients' ages ranged from 12 to 81 years.) The final diagnoses were glioblastoma in 7 patients and 1 case each of anaplastic astrocytoma, low grade astrocytoma, thrombosed arteriovenous malformation, cerebral infarct, 3rd ventricular epidermoid, and degenerative disease of the brain. Definitive diagnosis was obtained in all but 2 patients with this technique. Appropriate therapy was subsequently instituted in 11 patients without further operation. Transiently increased weakness of the previously affected limbs was the only untoward effect (4 patients). Intracranial hematoma after this procedure was seen in 1 patient in this series, as detected by the postprocedure CT scan, but there was no change in the clinical course. All patients were treated with dexamethasone for 24 to 48 hours before and for several days after the procedure to avoid decompensation of intracranial dynamics because of edema. The procedure, including appropriate level CT scans of the lesion area, was performed in approximately 1 hour in all patients. (Neurosurgery, 5: 671--674, 1979).

Evaluation of myocardial ischemic damage of various ages by computerized transmission tomography. Time-dependent effects of contrast material.

The potential role of computerized transmission tomography (CTT) in the detection and quantitation of acute myocardial ischemic damage was assessed in 42 excised canine hearts at 2 hours, 8 hours, and 48 hours after coronary occlusion. The CTT scan detected by myocardial damage that was 2-48 hours old each time the presence of regional ischemia was confirmed by histochemical straining or epicardial electrocardiographic mapping. Intravenous administration of contrast material enhanced the x-ray attenuation of areas of ischemic damage of 8 and 48 hours duration compared with normal myocardium, but enhanced only normal myocardium in those of 2 hours duration. Volumetric estimation of the extent of damage from the CTT scans in dogs with ischemia of 48 hours duration showed a close linear relationship with the morphometric volume in the absence of contrast material. Quantitation of the area of ischemic damage from the CTT scan after contrast administration resulted in substantial underestimation of the volume of damaged tissue.

Control of hemorrhage from a common carotid arterial-cutaneous fistula by temporary implantation of a balloon catheter.

Hemorrhage from an infected carotid arterial-cutaneous fistula was treated by occlusion of the common carotid artery with a 6-French (Swan-Ganz) balloon catheter. After nine months, there was no recurrence of bleeding or neurological sequelae. Temporary balloon occlusion to induce thrombosis of a major artery is an alternative to transcatheter embolization of small particulate material and larger foreign bodies.

Differential accumulation of radiopaque contrast material in acute myocardial infarction.

The differential accumulation of radiographic contrast materials in ischemically damaged and normal myocardium was assessed with direct measurement (fluorescent excitation analysis) of the iodine content of tissue samples from dogs with 48 hour old myocardial infarctions. Tissue samples were obtained 10, 30, 60 and 180 minutes after the intravenous administration of 2 ml/kg body weight of diatrizoate meglumine and sodium (Renografin-76). At all time intervals, the iodine concentration of infarcted tissue was at least threefold greater than that of normal myocardium. At 180 minutes the ratio between iodine concentration in infarcted myocardium and that in normal myocardium was 8.5 and between that in infarcted myocardium and that in blood was 2.6. The iodine concentration in the liver was similar to or greater than that in the infarcted area at time intervals after 10 minutes. These results suggest that the intravenous administration of contrast material may facilitate the identification of acutely infarcted myocardium with computerized X-ray transmission tomography.

Uptake of contrast materials by experimental acute myocardial infarctions: a preliminary report.

The concentration of iodine within infarcted and normal myocardium after intravenous administration of contrast material was determined by fluorescence excitation analysis in seven dogs at 48 hours after coronary arterial ligation. The iodine concentration of infarcted myocardial tissue was several times greater than normal myocardium after administration of meglumine/sodium diatrizoate, iodipamide, and an experimental polymer of iothalamic acid.

Detection, quantitation and contrast enhancement of myocardial infarction utilizing computerized axial tomography: comparison with histochemical staining and 99mTc-pyrophosphate imaging.

The potential role of the CAT scan in detecting and quantitating acute myocardial infarctions was assessed in the excised hearts of 25 dogs with 48-hour-old myocardial infarctions. The CAT scan detected the infarct in every instance and distinguished subendocardial from transmural infarctions. While the CAT scan slightly underestimated the volume of infarcted tissue, this volume had a close linear relationship to the true volume determined by histochemical staining. On the other hand, the 99mTc-pyrophosphate scintiscans grossly overestimated the volume of infarcted tissue. Intravenous administration of contrast material prior to sacrifice produced contrast enhancement either of the rim or diffusely throughout the infarct. Thus CAT should have an important role not only in detecting but also in estimating the volume of acute myocardial infarctions.

Solitary renal plasmacytoma with palisading tumor vascularity.

A solitary extramedullary plasmacytoma of the kidney associated with contralateral myeloma kidney is reported. The tumor demonstrated extensive palisading tumor vessels, heretofore thought to be characteristic of renal lymphoma. Plasmacytoma as the etiology of a renal mass should be considered when there is nonfunction of a normal-appearing contralateral kidney.

Percutaneous aspiration of adrenal cysts.

Percutaneous needle aspiration was performed in three cases of cystic lesions of the adrenal gland which had been evaluated with nephrotomography, ultrasound, and angiography. The characteristics of the fluid aspirate were used as a guideline to further management. Two lesions were clearly benign cysts and were treated conservatively. The third lesion had a bloody aspirate and was surgically removed. The diagnostic evaluation of adrenal masses should follow a directed approach currently advocated for renal mass lesions.

Pneumoperitoneum: importance of right upper quadrant features.

Supine abdominal radiographs of 59 patients with documented pneumoperitoneum were evaluated for findings of pneumoperitoneum. The commonly described signs were seen in only 17%. Localized intraperitoneal air in the right upper quadrant was the most frequent finding, seen in 49% of patients. Identification of these collections of air is dependent upon knowledge of the anatomy of the perihepatic spaces.

Perforation of the nasopharynx by nasogastric intubation: a rare cause of left pleural effusion and pneumomediastinum.

A case of nasogastric tube perforation of the posterior nasopharynx producing a left pleural effusion and pneumomediastinum is reported. Findings which led to the correct diagnosis were the rapid appearance of a left pleural effusion simultaneous with the initiation of tube feedings, the intrathoracic location of the nasogastric tube, and demonstration of perforation of the posterior nasopharynx. Potentially hazardous intubation techniques are discussed.