Case report: ectopic pancreas with pseudocyst and pseudoaneurysm formation.

Ectopic pancreas is a rare congenital anomaly. It is usually asymptomatic, or presents with non specific gastrointestinal symptoms. We describe here a case of ectopic pancreas in the gastric antrum, with pseudocyst and pseudoaneurysm formation. This entity has not been reported previously in the literature.

A delayed diagnosis of an unstable os odontoideum.

We report the case of a 2-year old child from Kuwait with known history of tetraparesis from birth. Radiological evaluation including computed tomographic scan and magnetic resonance imaging confirmed an unstable orthotopic os odontoideum which was complicated by cervical myelopathy.

Clinical use of ultrashort-lived radionuclide krypton-81m for noninvasive analysis of right ventricular performance in normal subjects and patients with right ventricular dysfunction.

The ultrashort-lived radionuclide krypton-81m, eluted in 5% dextrose from a bedside rubidium-81m generator, was intravenously infused for rapid imaging of the right-sided heart chambers in the right anterior oblique projection adjusted for optimal right atrioventricular separation. Left-sided heart and lung background was minimized by rapid decay and efficient exhalation of krypton-81m, requiring no algorithm for background correction. A double region of interest method decreased the variability in the assessment of ejection fraction to 5%. In 10 normal subjects, 11 patients with pulmonary hypertension, 4 patients with right ventricular outflow tract obstruction and 4 patients with right ventricular infarction, right ventricular ejection fraction determined by krypton-81m equilibrium blood pool imaging ranged from 14 to 76%. The correlation between these values and those determined by cineangiography according to Simpson's rule was close: r = 0.93 for all data points (p less than 0.001), r = 0.92 for studies at rest (p less than 0.001) and r = 0.93 for exercise studies (p less than 0.001). Exercise-related changes in right ventricular function revealed a disturbed functional reserve with pulmonary hypertension and right ventricular infarction, whereas in compensated right ventricular outflow tract obstruction there was a physiologic increase in ejection fraction with exercise (p less than 0.001). Thus, equilibrium-gated right ventricular imaging using ultrashort-lived krypton-81m is a simple, accurate and reproducible method with potential for serial assessment of right ventricular ejection fraction in a variety of right ventricular anatomic and functional abnormalities, both at rest and during exercise. Advantages of this method include an extremely low radiation dose to patients and clear right atrioventricular separation without the need to correct for background activity.

Syncope in hypertrophic cardiomyopathy: multivariate analysis of prognostic determinants.

Twenty-nine consecutive patients with symptomatic hypertrophic cardiomyopathy and a mean age of 44.8 +/- 12.2 years (range 21 to 63) underwent complex invasive and noninvasive testing to identify a risk profile for syncope. Clinical, morphologic, electrophysiologic and hemodynamic variables at rest and at a symptom-limited pacing rate were analyzed for a significant association with syncope. Exact stepwise logistic regression analysis identified three variables as significant independent predictors of syncope in hypertrophic cardiomyopathy: 1) age less than 30 years (beta = 4.803; p = 0.0007); 2) left ventricular end-diastolic volume index less than 60 ml/m2 (beta = 3.302; p = 0.006); and 3) nonsustained ventricular tachycardia on 72 h ambulatory electrocardiographic monitoring (beta = 2.5909; p = 0.03). The combined occurrence of all three variables had a sensitivity and specificity of 100% in identifying eight patients with syncopal events. Thus, the risk for syncope in hypertrophic cardiomyopathy is high in young patients with the combination of low left ventricular filling volume and episodes of nonsustained ventricular tachycardia. This finding might also explain the mechanism of syncope in hypertrophic cardiomyopathy as low input-low output failure induced by a sudden increase in heart rate in the presence of a low filling volume.

[Evaluation of testicular volume in 0- to 18-year-old boys by sonography]. / Sonographische Bestimmung der Hodenmaße im Alter von 0 bis 18 Jahren.

BACKGROUND: Reference values are necessary in clinical practice in order to correctly evaluate testicular volume and detect disorders. OBJECTIVES: The objective of this prospective cross-sectional study was to evaluate reference values for testicular volume dependent on age, height, and weight in boys aged 0-18 years. MATERIAL AND METHODS: During their inpatient stay, the testes of 174 boys, who were free of disease or therapy that might influence testicular development, were examined by sonography. High resolution ultrasound transducers ranging from 7.5-14 MHz were used for evaluation. The testicular volume was calculated by the ellipsoid formula: length • width • height • (π/6). RESULTS: The subject age ranged from 0-18 years (average 7.1 ± 5.3 years). At the age of 0-8 years, the left testicular volume (1.2 ml) was less than the right testicular volume (1.3 ml). At the age of 13 years, the testicular volume of all subjects was over 3 ml. Left testicular volume of boys aged 16.5-18 years ranged from 7 to 22 ml and the right testicular volume ranged from 6 to 22 ml. CONCLUSION: Reference value tables of testicular volume dependent on age, and for the first time dependent on weight and height in boys aged from 0-18 years were compiled. Tables of testicular length, width, and height dependent on age are provided.

Tomographic myocardial perfusion scintigraphy in children with Kawasaki disease.

Myocardial infarction and stenotic coronary lesions are serious late complications in children with Kawasaki disease. For the noninvasive assessment of myocardial perfusion, dipyridamole-redistribution 201Tl emission computed tomography (ECT) was performed in seven children (age 2 8/12-8 7/12 yr) 3-20 mo after the acute stage of the disease. In all patients, coronary aneurysms had been demonstrated by cross-sectional echocardiography. The scintigrams of six children showed no significant regional reduction of myocardial thallium uptake. These children had remained asymptomatic since the acute stage of Kawasaki disease. Persistent and transient thallium defects were present in one child with documented myocardial infarction. For this patient, obstruction of corresponding coronary vessels was confirmed by contrast angiography. It is suggested, that 201Tl ECT after dipyridamole-induced vasodilation may be used as a safe alternative to invasive coronary angiography for follow-up investigations in patients with Kawasaki disease.

Comparison of the acute hemodynamic response to intravenous nisoldipine (Bay k 5552) and intravenous nifedipine for left ventricular dysfunction secondary to myocardial infarction.

Dihydropyridine calcium blocking drugs exert potentially dangerous negative inotropic action in selected patients with severe left ventricular dysfunction. In 10 patients peripheral and central hemodynamic effects of nisoldipine were intraindividually compared with nifedipine using a sequential crossover protocol. The drugs were titrated to a similar steady-state reduction of mean arterial pressure by 15 +/- 3% and 15 +/- 2% and systemic vascular resistance by 25 +/- 5% and 17 +/- 2%, respectively. The equi-effective dosage was 0.17 +/- 0.06 microgram/min/kg for nisoldipine and 0.58 +/- 0.1 microgram/min/kg for nifedipine. In contrast to nifedipine, administration of nisoldipine was associated with increases in cardiac index of 0.45 +/- 0.33 liters/min/m2 (p less than 0.05), stroke volume index of 3.91 +/- 3.0 ml/m2 (p less than 0.05) and left ventricular ejection fraction of 4.6 +/- 2.8% (p less than 0.05). Mean pulmonary capillary wedge pressure decreased with nisoldipine from 11.8 +/- 3.4 to 8.0 +/- 3.4 mm Hg (p less than 0.005) and mean pulmonary arterial pressure from 20.4 +/- 4.06 to 16.1 +/- 3.2 mm Hg (p less than 0.005); these variables were unaffected by nifedipine. Thus, intraindividual comparison revealed no cardiodepressive action of nisoldipine, whereas with nifedipine the conceptually beneficial effect of afterload reduction appears to be offset by intrinsic negative inotropic action. Due to higher vasospecificity and more effective unloading, nisoldipine appears to be superior to nifedipine in patients with left ventricular dysfunction secondary to ischemic heart disease.

Detection of human collateral circulation by vasodilation-thallium-201 tomography.

Coronary arteriolar vasodilation may provoke redistribution of flow to collateral-dependent jeopardized myocardium. To assess the physiologic significance of collaterals, 80 consecutive post-infarction patients (age 58 +/- 8 years) underwent vasodilation-redistribution thallium-201 tomographic imaging after administration of 0.56 mg of intravenous dipyridamole/kg body weight. Circumferential profile analysis of thallium-201 uptake and redistribution in representative left ventricular tomograms provided quantitative assessment of transient and fixed defects and separation between periinfarctional and distant inducible hypoperfusion. Tomographic perfusion data were correlated to wall motion and collateral circulation between distinct anatomic perfusion territories. Patients were grouped according to presence (59%) or absence (41%) of angiographically visible collateral channels to jeopardized myocardium. In the presence of collaterals, distant reversible defects were larger than in absence of collaterals (p less than 0.05); the extent of combined periinfarctional and distant redistribution was also larger in collateralized patients (p less than 0.025), whereas the size of the persistent perfusion defect was similar in both groups. By prospective analysis the tomographic perfusion pattern of combined periinfarctional and distant redistribution revealed a sensitivity of 85% and a specificity of 78% for the detection of significant collateral circulation in this group of patients. Thus, using the exhausted flow reserve as a diagnostic tool, vasodilation-thallium-201 tomography has the potential to identify and quantitate collateralized myocardium in post-infarction patients and may guide diagnostic and therapeutic decision-making.

Direct measurement of sound velocity in various specimens of breast tissue.

RATIONALE AND OBJECTIVES: Previous studies using ultrasound CT or clinical amplitude/velocity reconstruction imaging ultrasound may indicate that cancers differ from normal breast tissue by increased sound velocity. However, only limited experience with direct measurements of sound velocity exists. This study aimed to investigate sound velocity measured directly in a variety of breast specimens. METHODS: Sound velocity was measured directly by forceps in fresh breast specimens chosen to contain one type of tissue only. Eighty specimens (31 cancers, 18 benign changes of glandular/fibrous tissue, 22 fatty tissues, 5 fibroadenomas, 2 compound tissues, 1 phylloides tumor, and 1 inflammation) were analyzed. RESULTS: Ultrasound velocities in carcinoma, benign changes, fibroadenoma, inflammation, and the phylloides tumor were very similar, with almost complete overlap. In contrary, the ultrasound velocity of fatty tissue was significantly lower. Compound tissues containing fat had an intermediate sound velocity. CONCLUSIONS: Sound velocity may add complementary information to echogenicity (B-scan). Because fat lobules exhibit low ultrasound velocity and carcinomas do not, a locally exact combination of ultrasound velocity information and reflexivity information should allow improved breast cancer detection by ultrasound.

Flurazepam: effects on sodium and potassium currents in myelinated nerve fibres.

The effect of flurazepam-HCl on single myelinated nerve fibres of the frog Rana esculenta was investigated. Flurazepam affected both Na and K currents: 0.25 mM of the drug decreased the peak Na inward current to about 50%. The initial increase and subsequent decay of the Na current was slowed down by a factor of 1.5 independent of membrane potential. The drug induced a slow phase in the recovery from Na inactivation and frequency dependence of the Na current block. The K current rose at a normal rate and was then inactivated to a sustained outward current. The time constant of block development (tau k) and the steady state block were potential-dependent. With 1 mM flurazepam, tau k decreased from 2.9 ms at E = 10 mV to 1.5 ms at E = 90 mV, and the steady state block increased from 65% at E = -20 mV to 81% at E = 90 mV. Recovery from the block proceeded faster at E = -70 mV (tau = 27 ms) than at E = -120 mV (tau = 89 ms). The effects of the drug on the K current were interpreted in terms of the reaction scheme proposed by Armstrong (J. Gen. Physiol. 54, 553; 1969).

Oscillating repolarization in action potentials of frog sensory myelinated nerve fibres.

Current and voltage clamp experiments were performed in single myelinated sensory nerve fibres of Rana esculenta. The K current was blocked by external tetraethylammonium-chloride and internal CsCl. Negative prepotentials led to the formation of a plateau in the repolarization phase of the action potential, and further regenerative depolarizations emerged from this plateau. A three-state model for Na inactivation based on voltage clamp data was sufficient to simulate these observations.

Appearance of poststenotic jets in MRI: dependence on flow velocity and on imaging parameters.

A flow model was used to study the appearance of poststenotic jets in MRI. Jets in CuSO4-doped water and bovine blood were imaged by spin-echo (SE) and fast-field-echo (FFE) pulse sequences at different degrees of stenosis and various flow rates. On flow-compensated FFE images, the jets were characterized by signal void if the mean flow velocity within the stenosis exceeded a limit, which was independent of the degree of the stenosis and the type of the fluid. On SE images and on FFE images without flow compensation, signal void occurred at significantly lower flow velocity. The extension of the poststenotic signal void on flow-compensated FFE images was increased by either reduction of the pixel diameter or by prolongation of the echo time. However, it was independent of the orientation of the imaging plane relative to the direction of flow. The results have an impact on attempts to use signal void for the assessment of turbulent jets with MRI.

Magnetic resonance imaging and pulsed Doppler sonography of poststenotic jets: correlation between signal void and flow velocity distribution.

To correlate the appearance of poststenotic jets on gradient echo images with features of localized Doppler spectra of the jets, we studied an in vitro model of steady flow-through stenoses of 86, 96, and 99% area reduction. As fluids, water and a 40% glycerol solution in water were used. MRI was performed with a 1.5 T whole body imager and gradient echo images were obtained in planes parallel to the direction of flow. Doppler spectra were acquired separately from the MR measurements at 1 cm intervals for a distance of 10 cm downstream from the stenosis. Poststenotic signal void was observed for water and for the 40% glycerol solution only if the mean velocity within the stenosis exceeded a limit of 50-60 cm/sec. On the MR images, the jets could be divided into two segments: A proximal jet segment of uniform width equal to the diameter of the stenosis, followed by a distal jet segment which was characterized by broadening and then dissipating signal void. Except for the 99% stenosis, a high signal intensity core was present within the proximal jet segment. In the proximal jet segment, the Doppler measurements showed a low temporal fluctuation of the maximal flow velocity and only little flow opposite to the main flow direction. In the distal jet segment, the velocity fluctuation and the intensity of reverse flow increased sharply. The high signal intensity core of the jet was associated with a poststenotic zone of constant maximal flow velocity. The results demonstrate a close relationship between characteristic features of poststenotic jets in MRI and pulsed Doppler sonography.

Pancreatic contrast enhancement with Mn-bis pyridoxal ethylene diamine diacetic acid and the influence of a hormonal stimulation of the pancreas in pigs.

RATIONALE AND OBJECTIVES: Pancreatic and hepatic contrast enhancement after different modes of administration of Mn-bis pyridoxal ethylene diamine diacetic acid (Mn-DPDP) and the influence of the hormones secretin and cholecystokinin on the uptake of this new contrast agent were studied by using magnetic resonance (MR) imaging and atomic absorption spectroscopy (AAS) examinations carried out on 13 young domestic pigs. METHODS: Mn-DPDP was administered either as bolus injection or 30-min infusion. The course of contrast enhancement was noted. MR imaging was carried out with or without pancreatic stimulation. The Mn content in pancreatic and hepatic tissue was analyzed by using AAS. RESULTS: Mn-DPDP caused a significant increase (66 +/- 40.1%) in pancreatic signal intensity, an increase in hepatic signal intensity (78 +/- 23.0%), and a significantly higher Mn content on tissue samples of both organs. The results showed a wide individual range. With infusion of Mn-DPDP, pancreatic enhancement was slower, with a peak at 82 +/- 34 min compared with 54 +/- 51 min following bolus injection. The Mn content of both hepatic and pancreatic tissue determined by AAS seemed to be higher after infusion. An incomplete washout of Mn after 24 hr was demonstrated. Hormonal stimulation of the pancreas further increased pancreatic signal intensity but did not influence hepatic contrast enhancement. CONCLUSION: Infusion is the method of choice for administering Mn-DPDP because it causes an increase in hepatic signal intensity but does not change pancreatic enhancement. Although pancreatic hormonal stimulation intensifies enhancement, the increase is not statistically significant, and this practice will not contribute to day-to-day clinical practice.

Vertigo after stapes surgery: the role of high resolution CT.

CT findings in patients with vertigo after stapes surgery include a prosthesis shaft entering the vestibule and compressing the saccule, a complete dislocation of the stapes prosthesis, air bubbles and fluid collections within the vestibule and outside the oval window indicating a perilymphatic fistula, and bony fragments leading to compression of the basal saccule. Although immediate post-operative vertigo is often transient, patients with persistent or recurrent vertigo should be imaged as high resolution CT will determine the underlying cause in the majority of cases.

Value of spiral CT in patients with cricothyroid approximation.

Cricothyroid approximation raises the vocal pitch by simulating contraction of the cricothyroid muscle with sutures. The aim of this study was to determine the role of spiral CT in patients scheduled for cricothyroid approximation. 29 transsexual patients were examined with spiral CT prior to and after laryngoplastic surgery. CT findings were correlated with phonographic findings in all patients. The average reduction of the cricothyroid distance was 6 mm (range 2-10 mm). Vocal pitch elevation was greatest in patients with the largest reduction of the cricothyroid distance. CT accurately determines the cricothyroid distance prior to and after surgery and is an ideal method for follow-up, especially in post-operative reversion towards a lower pitch. In addition, CT provides important data in determining the most appropriate extent and site of intracordal intervention to achieve a desired pitch elevation.

Quantification of recalcification of irradiated vertebral body osteolyses by dual-energy computed tomography.

In 12 patients with osteolyses of the spine, the change of the vertebral mineral content after radiotherapy was quantified by Dual-Energy Computed Tomography (CT). In 11 of the patients, recalcification of radiated vertebral body metastases could already be detected at the completion of a 4 week course of radiotherapy. However, the amount of recalcification varied considerably between the patients. The methodological approach is described and the different reactions of the vertebral body osteolyses to radiotherapy are discussed.

[MR of acute aortic dissection]. / MR bei akuter Aortendissektion.

Acute aortic dissection is an emergency which requires a fast and reliable diagnosis. We performed MRI in 9 cases of acute aortic dissection. The information obtained with MRI is described and compared to the results of 2-dimensional echocardiography and contrast enhanced CT.

[Computed tomographic volumetry of the pneumatic system of the ear. Comparison of normal subjects and patients with ear diseases]. / Computertomographische Volumetrie des pneumatischen Systems des Ohres. Ein Vergleich zwischen Normalkollektiv und Patienten mit Ohrerkrankungen.

The volume of the pneumatised portion of the ear was determined by computed tomography in 235 patients. Amongst the 470 ears examined, 320 had no disease in the ear, nose or throat. Normal pneumatisation of the ear can be quantified by CT and strict correlation has been demonstrated between the air content and age from ten to 17 years. Chronic inflammatory processes of the middle ear occurring during childhood interfere with pneumatisation on one or both sides. The most severe failure of pneumatisation occurs with congenital abnormalities of the ear, most cases never showing significant pneumatisation. Chronic infection of the tonsils or adenoids causes much less interference with pneumatisation.

[Magnetic resonance tomography of a thoracic aortic aneurysm]. / Kernspintomographie des thorakalen Aortenaneurysmas.

The results of magnetic resonance imaging in 16 patients with non-dissecting aneurysm of the thoracic aorta are presented. Scans with ECG-gated spin-echo sequences in transversal, coronal, and left anterior oblique views demonstrated the size and extent of the aneurysms. Measurements of the maximum aneurysmal diameter differed by less than 5 mm from measurements obtained with computed tomography. In 6 of 7 patients with presence of wall adherent intraluminal signal, phase images were able to differentiate accurately between mural thrombus and slow blood flow.