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Biomedical subjects

J L Doppman

Publications and source records attributed to J L Doppman.

At least 253 records · Page 14Linked to original sources
PubMed1984

Segmental hyperlucent defects in the liver.

When lucent defects in the liver have a segmental configuration, they may be on an ischemic basis and related to decreased vascular perfusion. Portal venous inflow, by virtue of its low pressure, is particularly susceptible to diversion by focal intrahepatic masses, intravenous thrombi, or external compression. Innovative operative techniques for tumor enucleation may also result in lucent defects that can be confused with, or conceal, pathology. A hypothesis relating such defects to diminished portal inflow and reduced glycogen content is proposed.

Female↗
PubMed1984

Computed tomography with metrizamide myelography to define the extent of spinal canal block due to tumor.

In five patients with complete spinal block due to tumor, CT was used to show the upper level of the block. In each case metrizamide myelography demonstrated the lower level of the block, but not enough metrizamide leaked past the block to allow myelographic identification of the upper level. However, the subarachnoid space both below and above the level of the block was clearly outlined by metrizamide on CT in each case.

Adolescent↗
PubMed1984

Petrosal sinus sampling for Cushing syndrome: anatomical and technical considerations. Work in progress.

ACTH-producing microadenomas of the pituitary gland drain unilaterally into the adjacent cavernous sinus; therefore, petrosal sinus sampling to distinguish pituitary from ectopic-ACTH syndromes must always be performed bilaterally. A negative finding from a unilateral petrosal sinus sample does not exclude the presence of a contralateral ACTH-producing microadenoma. Hemiresection of the pituitary gland based on results of bilateral sampling can be performed if the adenoma is too small to be recognized at surgery. Large pituitary adenomas produce elevated ACTH levels in the petrosal sinuses bilaterally. However, if plain radiographs or CT scans provide unequivocally positive findings in Cushing syndrome (less than 20%), inferior petrosal sinus sampling is not indicated.

Adenoma↗
PubMed1984

Adrenal ablation by retrograde venous ethanol injection: an ineffective and dangerous procedure.

Venous injection of ethanol was used to ablate the left adrenal gland in nine monkeys. Severe hypertension and tachycardia occurred in all animals not pretreated with alpha- or beta-adrenergic blockers. On postmortem examination the left adrenal glands were reduced in size but still retained some normal tissue. This procedure, while technically simple, is neither effective nor safe.

Adrenal Glands↗
PubMed1984

Parathyroid aspiration directed by angiography: an alternative to venous sampling.

Not all parathyroid glands can be visualized by CT or ultrasound and, therefore, cannot be aspirated using these techniques. We report the localization of a parathyroid gland by arteriography and needle aspiration under fluoroscopic guidance. This technique can be used to confirm a diagnosis of hypervascular parathyroid tissue that cannot otherwise be confirmed.

Adult↗
PubMed1984

Bile duct scarring following ethanol embolization of the hepatic artery: an experimental study in monkeys.

Alcohol is a popular embolizing agent, especially in renal tumors and esophageal varices, and results of its use are encouraging. Alcohol embolization of hepatic tumors offers theoretic protection of hepatocytes by portal venous dilution. To verify this, we performed hepatic artery embolization in six adult Rhesus monkeys by alcohol infusion. Although injury to liver cells was minimal, we observed severe damage to intrahepatic bile ducts. Our experience showed that alcohol in the hepatic artery perfused the peribiliary plexus and produced scarring of the bile ducts, resulting in a cholangiographic picture that resembled that of sclerosing cholangitis. Further studies are necessary before alcohol is recommended for hepatic embolization.

Animals↗
PubMed1984

Hyperfunctioning cystic parathyroid glands: CT and sonographic findings.

Four functioning cystic parathyroid glands were evaluated with computed tomography (CT) and sonography in four patients, only one of whom had prior surgery. Sonography demonstrated solid lesions of decreased echogenicity with fluid-filled cavities near the lower thyroid poles or in the posterosuperior mediastinum. On CT the cystic parts of the lesions were of low attenuation (1-44 H), often with a well defined wall that was better demonstrated after intravenous contrast administration. Fine-needle aspiration biopsy of two of the cystic parathyroids revealed elevated parathyroid hormone levels. These lesions probably represent degenerating adenomas rather than true parathyroid cysts. While the CT and sonographic findings are nonspecific, the diagnosis of a cystic parathyroid should be entertained when a fluid-filled lesion is encountered in the neck of a patient with or without hypercalcemia. The diagnosis may be confirmed by assay of parathyroid hormone from the fluid aspirate.

Adenoma↗
PubMed1984

Detection of mediastinal parathyroid glands by nonselective digital arteriography.

Six patients with failed previous operations and anterior mediastinal parathyroid glands were evaluated with selective angiography and nonselective arterial digital arteriography. Selective angiography depicted two of nine mediastinal glands; nonselective arterial digital arteriography depicted only one of nine mediastinal glands and missed a sizable (4.5 cm) gland demonstrated by routine arteriography. Nonselective arterial digital arteriography did not demonstrate any additional mediastinal glands. From this preliminary experience, it was concluded that nonselective arterial digital arteriography is not a sensitive method for detecting mediastinal glands.

Adult↗
PubMed1984

CT of the liver and spleen with EOE-13: review of 225 examinations.

EOE-13 is an experimental liver-spleen-specific computed tomographic (CT) contrast agent developed at the National Institutes of Health. Experience with this agent in 225 clinical examinations is described. On average, use of EOE-13 increases the attenuation of normal liver by 32.5 H and that of normal spleen by 52.3 H. Tumors in these organs increase only 2.6 H, making them more easily detectable. Most of the iodine in EOE-13 appears to clear from the liver and spleen by 24 hr after injection. No deaths or permanent morbidity have been observed. The complication rate is 3.6%. EOE-13 is valuable for the detection of hepatic and splenic tumors.

Adult↗
PubMed1984

Localization of islet cell tumors by dynamic CT: comparison with plain CT, arteriography, sonography, and venous sampling.

Ten patients with suspected islet cell tumors (seven with possible gastrinomas, three with insulinomas) underwent diagnostic evaluation with dynamic CT scanning, routine CT scanning, angiography, and sonography. Venous sampling was also performed in selected instances. Nine sites of gastrinoma and three insulinomas were confirmed surgically in eight patients. Two patients had negative surgical explorations. Routine CT demonstrated five of the nine gastrinomas and one of two insulinomas. Angiography was positive in six of nine gastrinomas and all three insulinomas. Sonography showed only two of the nine gastrinomas and two of the three insulinomas. Dynamic CT scanning demonstrated three additional lesions (two gastrinomas, one insulinoma) not visible on routine CT scanning. Although most of these lesions were visible arteriographically, dynamic CT scans at the appropriate level localized the pathology in the transverse plane and greatly aided in surgical resection of these lesions. Dynamic CT scanning is a useful adjunct to routine angiographic and CT workup of patients with islet cell tumors.

Adenoma, Islet Cell↗
PubMed1984

Assessment of perfusion patterns during hepatic artery infusion chemotherapy: EOE-13 CT and 99mTc-MAA scintigraphy.

Hepatic perfusion patterns were evaluated in five patients receiving hepatic artery infusion chemotherapy. All patients underwent 99mTc macroaggregated albumin (99mTc-MAA) scintigraphy and CT with EOE-13. In each case, the diagnostic agent was administered through the infusion catheter at 0.66 ml/min. Hepatic perfusion patterns were identified with both imaging methods, but CT with EOE-13 yielded more precise anatomic detail and was unique in demonstrating the perfusion status of each hepatic metastasis. Further evaluation of EOE-13 for this purpose is warranted.

Adult↗
PubMed1984

Intraarterial administration of EOE-13 for the CT evaluation of hepatic artery infusion chemotherapy.

EOE-13 was infused directly into the hepatic artery through a surgically implanted hepatic artery infusion pump in a patient with liver metastases. A computed tomographic scan obtained after EOE-13 infusion accurately showed the perfusion pattern of the implanted catheter. It also demonstrated the hepatic metastases more clearly than scintigraphy with 99mTc-macroaggregated albumin. EOE-13 may prove useful for the evaluation of hepatic perfusion patterns in patients receiving hepatic artery infusion chemotherapy.

Adult↗
PubMed1983

Influence of glycogen on liver density: computed tomography from a metabolic perspective.

The liver is a metabolically active organ with a radiographic density that can be modified by its glycogen and fat content. In rhesus monkeys an increase in liver glycogen induced by glucose loading was accompanied by an increase in attenuation values on computed tomography and a decrease in total liver fat. Conversely, fasting depleted glycogen, increased fat, and decreased liver attenuation. Acute glycogen depletion without significant change in fat was induced by administration of glucagon and accompanied by a decrease in attenuation. These results along with in vitro measurements of glycogen solutions suggest that an increase of approximately 3 Hounsfield units can be expected for each percent increase in liver glycogen content.

Absorptiometry, Photon↗
PubMed1983

CT findings in acid lipase deficiency: wolman disease and cholesteryl ester storage disease.

Acid lipase deficiency leads to the abnormal accumulation of cholesteryl esters and triglycerides in many tissues. It is manifested clinically in two forms: Wolman disease, which is usually fatal in infancy, and cholesteryl ester storage disease (CESD), which is clinically milder. One case of each is presented. In the patient with Wolman disease, computed tomography (CT) showed an enlarged liver of diminished density and enlarged adrenals with cortical calcification. Computed tomography of the patient with CESD showed an enlarged liver of normal density and normal adrenals. In vitro CT density is inversely related to cholesterol content. However, CT is unreliable in assessing liver cholesterol in these patients due to their poor nutrition and concomitant changes in liver glycogen and fat.

Adrenal Gland Diseases↗