Tumors and arteriovenous malformations of the spinal cord: assessment using MR.

Thirty-three patients with either primary spinal cord tumors (n = 18), intradural tumors excavating into the cord (n = 9), or spinal arteriovenous malformations (AVM) (n = 6) were studied with magnetic resonance (MR) imaging. In 25 of 38 examinations (66%) (five patients were studied twice), MR provided more information than that provided by other neuroradiologic procedures. In several cases, MR affected patient management decisions.

Distinction between adrenal adenomas and metastases using MR imaging.

Magnetic resonance imaging was performed on 12 patients with known neoplastic disease and adrenal masses shown by CT. Three patients with metastases had high signal intensity in the adrenals on T2 weighted spin echo scans (SE 2,500/80) and nine patients with nonfunctioning adenomas had low signal intensity on T2 weighted images. The ability to distinguish metastases from nonhyperfunctioning adrenal adenomas may be of use in the pre-operative evaluation in patients with known carcinoma and incidental adrenal masses.

Constrictive pericardial disease: prognostic significance of a nonvisualized left ventricular wall.

Twenty-six patients with pericardial constriction confirmed by catheterization were studied by dynamic computed tomography (CT). The posterolateral wall of the left ventricular myocardium was not detected in five patients (19.2%).

MR imaging of pheochromocytomas.

Magnetic resonance imaging (MRI) of seven patients with pheochromocytomas demonstrable by CT was performed. Magnetic resonance imaging showed all primary pheochromocytomas, as well as metastatic lesions to the thorax, retroperitoneum, and liver. The ability to distinguish pheochromocytomas from surrounding structures without the need of an intravenous contrast agent and to provide direct coronal and sagittal images suggests that MRI may be useful in detecting and localizing these tumors.

Basilar venous plexus of the posterior fossa: a potential source of error in petrosal sinus sampling.

Sampling of serum from the inferior petrosal sinus can provide important information about the source of elevated adrenocorticotropic hormone (ACTH) levels. This often leads to improved results of pituitary surgery for Cushing disease. The authors describe a successful catheterization technique and illustrate the venous anatomy of the inferior petrosal sinuses and basilar plexus.

Aspiration of blood from the jugular vein during intracarotid drug infusion in monkeys. Implications for extracorporeal drug removal.

Circulation of blood in the ipsilateral jugular vein through an extracorporeal circuit for drug removal during intracarotid chemotherapy has recently been reported to decrease the systemic drug exposure. The reduced systemic exposure achieved by the use of this technique should permit a several-fold increase of the intracarotid dose of chemotherapy without increasing systemic toxicity. To determine the influence of the rate of blood removal from the jugular vein on the fraction of the blood flowing through the ipsilateral internal carotid artery (ICA) collected for extracorporeal drug removal, the authors aspirated blood from the jugular bulb into an extracorporeal circuit at varying rates during a constant infusion of the indicator dye, indocyanine green (ICG), into the ICA of rhesus monkeys.

Origin of spinal arteriovenous malformation and normal cord vasculature from a common segmental artery: angiographic and therapeutic considerations.

The dural type of spinal arteriovenous malformation (AVM) can be cured by excision or by embolization of the nidus. The common origin of the blood supply to the malformation and to the cord from the same segmental artery would profoundly affect therapeutic choices. This anatomic situation was encountered in two of nine such lesions.

Arterial drug infusion with extracorporeal removal. II. Internal carotid carmustine in the rhesus monkey.

During cancer chemotherapy by intra-arterial drug administration, systemic toxicity often limits the tolerable dose. We evaluated the pharmacokinetic advantage obtained by infusing carmustine (BCNU) into the internal carotid artery during BCNU removal from the blood from the perfused region by hemoperfusion. A hemoperfusion column (XR-010, Extracorporeal Medical Specialties) was shown to remove BCNU quantitatively from sheep blood flowing at 300 ml/minute when the drug was infused at 13 mg/minute for 30 minutes.

Localization of an occult insulinoma by intraoperative ultrasonography.

Intraoperative ultrasonography has not been used previously to locate an insulinoma that was not surgically palpable or that could not be seen by selective arteriography. In this report we described a patient with an insulinoma localized to the pancreatic head identified by transhepatic portal venous sampling but not by selective arteriography or palpation. At operation intraoperative ultrasonography demonstrated an 8 mm tumor in the pancreatic head and guided the successful enucleation.

NIH conference. Clinical applications of corticotropin-releasing factor.

Ovine and human corticotropin-releasing factors (CRF) have similar potencies in causing adrenocorticotropic hormone (ACTH) and cortisol secretion in normal humans. Using long-acting ovine CRF (1 microgram/kg body weight as an intravenous bolus), we tested patients with Cushing's syndrome, adrenal insufficiency, and psychiatric conditions with mild hypercortisolism. Over 95% of hypercortisolemic patients with a pituitary adenoma responded with increases in plasma ACTH and cortisol concentrations; patients with the ectopic ACTH syndrome had no ACTH or cortisol responses; patients with ACTH-independent hypercortisolism of adrenal origin had low or undetectable plasma ACTH concentrations before and after CRF without any cortisol response.

Absolute ethanol injection of the adrenal artery: hypertensive reaction.

Transcatheter injection of 0.4 ml of absolute ethanol into the adrenal artery was performed in three Rhesus monkeys. The injection produced a mean increase of 60 mmHg in systolic blood pressure and 50 mmHg in diastolic blood pressure within two minutes.

CT evaluation of hepatic and splenic trauma with EOE-13. An experimental study in monkeys.

EOE-13 is a liver-spleen specific CT contrast agent currently undergoing clinical trials. It is an aqueous emulsion of iodinated fatty acids. We studied eight rhesus monkeys with surgically created blunt trauma to the liver and spleen.

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.

Giant rectus sheath hematomas of the pelvis complicating anticoagulant therapy: CT findings.

We present three cases of giant rectus sheath hematomas in patients on anticoagulant therapy studied by ultrasound and CT. The anatomy of the posterior rectus sheath is described to explain why blood tracks into the pelvis when the hematomas enlarge.

Improved detection of focal lesions with computerized tomographic examination of the liver using ethiodized oil emulsion (EOE-13) liver contrast.

A prospective study of computerized tomography (CT) of the liver using a liver contrast agent compared to conventional CT was undertaken. CT scanning without contrast agents (NC-CT), CT with water-soluble contrast (WSC-CT), and CT with ethiodized oil emulsion (EOE-CT) were performed on patients with possible or probable hepatic metastases. The findings on these three examinations were compared to the objective findings at surgery in 53 patients.

Removal of gastrinomas for control of Zollinger-Ellison syndrome.

There are two distinct problems in patients with Zollinger-Ellison Syndrome (ZES): peptic ulcer diathesis and malignant tumors. Antisecretory drugs have allowed us to control the ulcer symptoms and acid output in 45 patients with ZES. We report here the initial seven patients selected for surgical exploration with the goal of removing their gastrinomas.

Intraoperative urinary cyclic adenosine monophosphate as a guide to successful reoperative parathyroidectomy.

Sixty patients with persistent or recurrent primary hyperparathyroidism underwent reexploration during which urinary cyclic adenosine monophosphate (UcAMP) levels were determined at half-hour intervals by radioimmunoassay. Retrospective analysis of the data allowed us to develop UcAMP criteria for surgical success. Following removal of parathyroid tissue, if an individual UcAMP level dropped 50% from the median baseline level, or if elevated levels dropped to less than 4.

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.

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.

Measurement of blood-brain barrier permeability with positron emission tomography and [68Ga]EDTA.

Positron emission tomography (PET) was employed to examine time-dependent changes in blood-brain barrier (BBB) permeability to [68Ga]ethylenediaminetetraacetate (EDTA) in the rhesus monkey, following reversible barrier opening by intracarotid infusion of a hypertonic mannitol solution. The PET technique, when combined with measurements of plasma radioactivity, provided a quantitative measure of the cerebrovascular permeability-area product (PA) at different times following mannitol infusion. Hypertonic mannitol treatment reversibly increased PA to [68Ga]EDTA more than 10-fold; much of the barrier effect was over by 10 min after mannitol treatment.

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.