Bronchobiliary fistula detected by cholescintigraphy.

We present a case of a bronchobiliary fistula initially detected by hepatobiliary scintigraphy. The patient developed bilioptysis 18 mo after undergoing a right hepatic lobectomy and resection of the common bile duct for cholangiocarcinoma. The procedure was complicated by the development of a subphrenic abscess that required percutaneous biliary drainage.

The effects of iodixanol and iopamidol on hemodynamic and cardiac electrophysiologic parameters in vitro and in vivo.

Iodixanol is a new, nonionic, dimeric contrast medium which, in concentrations appropriate for radiographic use, is hypotonic with respect to plasma. The purpose of these in vivo and in vitro studies was to compare the effects of iopamidol, iodixanol formulated to isotonicity with sodium salts (sodium formulation), and iodixanol formulated to isotonicity with sodium, calcium, and magnesium salts (cationic formulation) on hemodynamic and electrophysiologic parameters. In vitro, the spontaneous rate of contraction by guinea pig right atrial and force development by right ventricular papillary muscles were evaluated in the presence of 1% to 100% (v/v) of the three contrast media. Iopamidol significantly (P less than .05) decreased the rate of atrial contraction to a greater extent than either formulation of iodixanol. Iopamidol decreased papillary muscle force development more than the sodium formulation of iodixanol (P less than .05). The cationic formulation of iodixanol had little effect (less than 30% change) on papillary muscle force development at concentrations up to 100%. The contrast media were also injected into the left coronary arteries of open-chest, anesthetized dogs at 0.8 mL/second for 5 to 30 seconds. All contrast media increased (P less than .05) systolic blood pressure (SBP), mean arterial pressure (MAP), and peak left ventricular pressure (LVP). Iopamidol increased LVP and LV end diastolic pressure to a greater extent (P less than .05) than the cationic formulation of iodixanol. We conclude that iopamidol affected cardiovascular parameters more than iodixanol.

Premature aging in persons with Down syndrome: MR findings.

PURPOSE: To determine whether persons with Down syndrome have features of premature aging on routine MR imaging sequences. METHODS: Sixty MR studies (in 30 persons with Down syndrome and 30 age- and sex-matched control subjects) were reviewed retrospectively by two blinded examiners. Sagittal T1-weighted and axial T2-weighted spin-echo images were evaluated for the presence and severity of three markers of brain aging: atrophy, white matter lesions, and T2 hypointensity of the basal ganglia, referenced to the examiner's internal standard of normal for that age and sex. RESULTS: Persons with Down syndrome had higher prevalence and severity of the three markers studied than the control subjects. Atrophy and white matter lesions increased in prevalence with age; abnormal T2 hypointensity of the basal ganglia was more equally distributed with age. CONCLUSION: Persons with Down syndrome have features of premature aging detectable at routine MR imaging.

The Proteus syndrome: CNS manifestations.

Proteus syndrome is a complex hamartomatous disorder characterized by multiple, diverse, somatic manifestations. We present a case in which severe, evolving CNS abnormalities were also exhibited. Imaging findings at presentation included hemimegalencephaly, subependymal calcified nodules, and periventricular cysts. Subsequently, dural sinus thrombosis developed. Eight previously reported patients may also have had hemimegalencephaly. When neuroimaging studies show hemimegalencephaly in a child with pigmented skin lesions, Proteus syndrome should be considered in the differential diagnosis.

Pharmacokinetic changes induced by vasomodulators in kidneys, livers, muscles, and implanted tumors in rats as measured by dynamic Gd-DTPA-enhanced MRI.

The effects of three physiologically different vasomodulators, angiotensin II (a vasoconstrictor), hydralazine (a vasodilator), and histamine (a permeability modulator), on the pharmaco-kinetics of entry of small molecules (measured by Gd-DTPA concentration) into normal and abnormal tissue were studied in rats implanted with R3230 AC tumors. Sequential dynamic Gd-DTPA-enhanced MRI studies, one before and one after vasomodulator administration, were performed, and the signal intensities of various tissues analyzed. Angiotensin II (6 micrograms/kg) reduced blood flow in tumors, but increased it in muscles. Hydralazine (5 mg/kg) reduced blood flow in tumors, kidneys, and livers, and slowed Gd-DTPA clearance from tumors, livers, and muscles. Histamine (25 micrograms/kg) increased renal blood flow, hastening Gd-DTPA clearance causing reduced measurable blood flow in tumors and muscles. By simultaneously monitoring the effects in various tissues, the pharmacokinetic effect of each drug in the entire body could be obtained.