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PubMed1995

Early prediction of stroke severity. Role of the erythrocyte sedimentation rate.

BACKGROUND AND PURPOSE: Early predictors of functional outcome after stroke are necessary for better planning of treatment and care. METHODS: We evaluated prospectively early clinical predictors of short-term functional outcome in a group of patients with ischemic cerebral infarction and explored whether the intensity of the acute-phase response provided further information concerning the short-term functional outcome. We evaluated a group of 208 ischemic stroke patients using the Mathew scale at entry. All patients had neuroimaging studies and routine blood tests, including erythrocyte sedimentation rate (ESR), within 72 hours from clinical onset. At discharge, functional outcome was graded according to a Stroke Outcome Scale. RESULTS: Larger infarcts, more embolic infarcts, and fewer lacunar infarcts were observed in the poor-outcome group. Vascular risk factors, radiological findings not related to the index stroke, time to admission, and treatment were similar in the two outcome groups. Variables with statistically significant differences between outcome groups included the following: age > 65 years, female sex, admission Mathew score < 75, worsening at clinical presentation, infarct volume > 6 cm3, complicating infections, fasting glucose > 110 mg, nonfasting glucose > 130 mg, and elevated ESR. With stepwise logistic regression analysis, Mathew score on admission, infarct volume, mode of clinical presentation, and ESR remained in the predictive model of stroke outcome, with a sensitivity and specificity of 89.91% and 85.71%, respectively. After removing the computed tomographic information from the model the same variables remained, with a sensitivity and specificity of 83.05% and 94.29%, respectively. CONCLUSIONS: Infarct size and clinical severity on admission are the stronger predictors of short-term functional outcome. Mode of clinical presentation, clinical evolution during the first day of stroke, and ESR are also independent predictors of short-term stroke outcome. These findings might be indicative of an inadequate collateral profile and/or a more pronounced prothrombotic state.

Adult↗

PubMed1988

Exercise-induced precordial ST-segment depression in prior inferior myocardial infarction with single-vessel disease; with special reference to its mechanisms and distinction from multi-vessel disease.

We investigated the mechanisms of exercise-induced precordial ST-segment depression on the electrocardiogram in prior inferior myocardial infarction with single-vessel disease and attempted to differentiate the ST-segment depression between single- and multi-vessel disease. Subjects included three groups: group Ia (n = 11), inferior myocardial infarction with single-vessel disease that showed no precordial ST-segment depression; group Ib (n = 7), inferior myocardial infarction with single-vessel disease accompanied by precordial ST-segment depression; and group II (n = 10), inferior myocardial infarction with multi-vessel disease. The subjects underwent 12-lead exercise electrocardiography, stress Tl-201 myocardial imaging and stress radionuclide ventriculography. Exercise-induced precordial ST-segment depression observed in group Ib was associated with large infarction and infarction extending into the inferoseptal wall of the left ventricle on myocardial image. On stress ventriculography, worsening of the septal wall motion was more frequently observed in group Ib than in group Ia. Coronary arteriography revealed a higher rate of rich collateral vessels to the infarcted zone in group Ib than in group Ia. When we compared the diagnostic ability for detecting multi-vessel disease in prior inferior myocardial infarction, although sensitivity was not different among three tests, both exercise electrocardiography and radionuclide ventriculography had poor specificity and predictive value compared to stress Tl-201 myocardial imaging. Thus we concluded that exercise-induced precordial ST-segment depression observed in prior inferior myocardial infarction with single-vessel disease should reflect a peri-infarctional ischemia located in the inferoseptal wall of the left ventricle, and that stress Tl-201 myocardial imaging is the most accurate method for diagnosing multi-vessel disease in prior inferior myocardial infarction.

Cardiac Output↗

PubMed1995

Angioscopic identification of coronary thrombus in patients with postinfarction angina.

OBJECTIVES: The purpose of this study was to determine the prevalence of intracoronary thrombus and associated anatomic abnormalities in patients with postinfarction angina using coronary angioscopy and angiography. BACKGROUND: Postinfarction angina, previously studied by angiographic methods only, identifies patients at high risk for sudden death, recurrent angina and refractory angina. The recent development of coronary angioscopy, which permits direct observation of a thrombus or atheroma and is especially used for the detection of intraluminal changes, encourages a reexamination of the pathogenesis of postinfarction angina. METHODS: Fifty-one consecutive patients with a diagnosis of acute myocardial infarction underwent cardiac catheterization. Coronary angiography followed immediately by coronary angioscopy was performed in 17 patients with and 34 without postinfarction angina during the same period of time (10.2 +/- 3.7 or 15.7 +/- 5.5 days [mean +/- SD]) after the onset of acute myocardial infarction. RESULTS: The frequency of thrombus, as observed by angioscopy, was significantly higher in patients with than without postinfarction angina (17 of 17 vs. 5 of 34, respectively, p < 0.01). There were no significant differences between groups with respect to degree of stenosis in the infarct-related artery, number of vessels with significant stenosis, presence of collateral flow, type of therapy and risk factors. CONCLUSIONS: Infarct-related artery thrombus is universally present in postinfarction angina and may be the primary pathogenic factor. Angioscopy is much more sensitive than coronary angiography for the detection of coronary thrombus.

Aged↗

PubMed2002

Exercise induces early and late myocardial preconditioning in dogs.

OBJECTIVE: We tested the hypothesis that exercise induces myocardial preconditioning in dogs. METHODS: We instrumented dogs with a snare on the anterior descending coronary artery and catheters in the root of the aorta, left ventricular cavity and coronary sinus. After recovering from surgery the dogs were trained to stay in the laboratory and run on a treadmill. Subsequently, they were randomly allocated to five groups: (1) non-preconditioned dogs: under anesthesia, the anterior descending coronary artery was occluded during 1 h and then reperfused during 4.5 h. (2) Early preconditioned dogs: procedure similar to group 1 but the dogs performed exercise on a treadmill for five periods of 5 min each before the coronary occlusion. (3) Late preconditioned dogs: procedure similar to group 2 but 24 h were allowed to elapse between the preconditioning exercise and the coronary occlusion. (4) Early preconditioned dogs plus 5-hydroxydecanoate: procedure similar to group 2 but 5-hydroxydecanoate was administered prior to exercise. (5) Non-preconditioned dogs with 5-hydroxydecanoate: procedure similar to group 1 but 5-hydroxydecanoate was administered at a time equivalent to that in group 4. RESULTS: Exercise did not induce myocardial ischemia and the hemodynamics during the experiments did not differ between groups. Exercise immediately before the coronary occlusion decreased the infarct size (percent of the risk region) by 78% (P<0.05), an effect that was abolished with 5-hydroxydecanoate. Exercise 24 h prior to coronary occlusion decreased infarct size by 46% (P<0.05 vs. non-preconditioned dogs, P<0.05 vs. early preconditioned dogs). 5-Hydroxydecanoate by itself did not modify infarct size. These effects could not be explained by changes in collateral flow to the ischemic region. CONCLUSIONS: Exercise prior to a coronary occlusion induces early and late preconditioning of the infarct size. The early effect is mediated through mitochondrial ATP-sensitive potassium channels.

Analysis of Variance↗

PubMed2003

LTP in cultured hippocampal-entorhinal cortex slices from young adult (P25-30) rats.

Cultured hippocampal neurons and immature organotypic slice cultures overcome temporal limitations of acute hippocampal slices and have been useful for investigating long-lasting plasticity. Difficulties with culturing adult neurons have restricted such studies to preparations from embryonic, perinatal, and juvenile tissue. By improving the methods for culturing and maintaining hippocampal-entorhinal cortex slices obtained from mature rats (P25-30), we show that their use in long-term electrophysiological investigations is feasible. Our cultured slices maintained an intact and functional trisynaptic cascade, normal synaptic function, and reliable long-term recording stability for at least 14 days in vitro. The electrophysiological properties and, in particular, the induction of long-term potentiation (LTP) in our mature organotypic slices were highly sensitive to dissection and tissue culture techniques. We present data describing the extracellular stimulation requirements for LTP-induction and its long-lasting maintenance (>4 h) at the Schaffer-collateral-CA1 synapse, and show that such changes in synaptic efficiency are NMDA receptor dependent. Our hippocampal-entorhinal cortex cultures from mature tissue can retain the electrophysiological properties required for long-term plasticity for several weeks in vitro.

2-Amino-5-phosphonovalerate↗

PubMed2003

Transection of intrinsic polysynaptic pathways reduces N-methyl-D-aspartate neurotoxicity in hippocampal slice cultures.

Hippocampal CA1 neurons have been shown to be highly susceptible to excitotoxicity produced by various forms of insult. CA1 neurotoxicity is partly dependent on over activity of N-methyl-D-aspartate (NMDA) receptors. It is unclear, however, if sensitivity of this region to excitotoxicity is related to inherent properties of CA1 neurons and/or network activation of polysynaptic pathways. The present studies examined the role of mossy fiber and Schaffer collateral function in promoting NMDA-induced neurodegeneration. Organotypic hippocampal cultures were subjected to transection of mossy fibers, Schaffer collaterals, or CA1 efferent fibers and then exposed to NMDA (20 microM) for 1 h. Hippocampal damage was assessed 24 h later via fluorescent microscopy. NMDA exposure produced significant excitotoxicity in all regions (160-500% of control), particularly in the CA1. In each region, toxicity was reduced by co-exposure to NMDA with MK-801 (20 microM), to near-control levels. Surgical transection of mossy fibers and Schaffer collaterals significantly reduced NMDA-induced neurotoxicity in the CA1 ( approximately 20%), and to a lesser extent, the CA3 and dentate regions. Conversely, transection of CA1 efferent fibers did not reduce the neurotoxicity in these regions. These data indicate that CA1 neurotoxicity caused by excitotoxic insult depends, in part, on 'network activation' of intrinsic polysynaptic pathways.

Animals↗

PubMed2004

Pharmacological modulation of the ATP sensitive potassium channels during repeated coronary occlusions: no effect on myocardial ischaemia or function.

BACKGROUND: Repeated episodes of myocardial ischaemia may lead to ischaemic preconditioning. This is believed to be mediated by the ATP sensitive potassium channels. OBJECTIVE: To examine the effect of pharmacological modulation of the ATP sensitive potassium channels during repeated coronary occlusions. DESIGN: Double blind, double dummy study. METHODS: 38 patients with a proximal stenosis of the left anterior descending coronary artery and no visible coronary collateral vessels underwent three identical 90 second balloon occlusions, each followed by five minutes of reperfusion. The patients were randomised to pinacidil 25 mg, glibenclamide 10.5 mg, or matching placebo 90 minutes before the start of the procedure. Myocardial ischaemia was measured by continuous monitoring of ECG ST segment changes. Changes in left ventricular function were recorded with a miniature radionuclide detector, and angina was scored on the Borg scale. RESULTS: In all patients the first balloon occlusion led to significant ST segment elevation, a clear decrease in left ventricular ejection fraction, and angina pectoris. This response was not attenuated at the second or third balloon occlusion, either in the placebo group or in the patients pretreated with pinacidil or glibenclamide. CONCLUSIONS: Under the given experimental conditions, this randomised and double blind study did not support the view that the human myocardium has an intrinsic protective mechanism that is activated by short lasting episodes of ischaemia.

Adenosine Triphosphate↗

PubMed2000

[Cerebral ischemia during carotid clamping: diagnosis and prevention].

A serious complication in carotid endarterectomy (CEA) is the occurrence or aggravation of neurological deficits caused by insufficient collateral cerebral blood flow during cross-clamping. At the moment, patients with failure of collateral circulation at this point cannot be identified preoperatively. Thus, intraoperative monitoring and methods to prevent clamping-related cerebral ischemia are required. To put this strategy into clinical practice there are several methods of monitoring cerebral function (e.g. surgery performed in awake patients, electroencephalography, somatosensory evoked potentials), changes of hemodynamic (e.g. carotid stump pressure, transcranial Doppler ultrasonography) or metabolic parameters (e.g. jugular bulb oximetry or transcranial oximetry). One technique that meets nearly all requirements of an ideal monitoring under general anesthesia is the use of somatosensory evoked potentials (SEPs). Registration of SEPs is simple to perform and indicates with a high sensitivity and specificity critical cerebral hypoperfusion during cross-clamping. Thus, SEPs monitoring indicates the necessity of shunt placement. As a result, the use of an indwelling shunt as the most effective method to prevent clamping ischemia can be limited to selected cases, avoiding the risks of shunting in patients with sufficient collateral flow. In addition, correct shunt function is immediately indicated by recovering potentials. Whether a combination of SEPs with transcranial Doppler measurements will be successful to provide additional information about cerebral embolisation should be determined.

Brain Ischemia↗

PubMed1983

Failure of intact cutaneous mechanosensory axons to sprout functional collaterals in skin of adult rabbits.

The original evidence that spared cutaneous nerves will sprout following partial denervation of skin was obtained in adult rabbits, in which nociceptive function returned to the deprived areas. Recently we reported that in the adult rat intact touch-sensitive (low-threshold mechanosensory) nerves fail to establish new functional endings in adjacent denervated skin. We have now investigated low-threshold mechanosensory nerves in the skin of adult rabbits after partially denervating the ear or hind limb; the sprouting of new functional endings into neighboring skin would be revealed by an expansion of the low-threshold receptive fields of cutaneous nerves (the areas of skin from which impulses could be evoked by stroking with a bristle). The results show that intact low-threshold mechanosensory nerves do not establish functional endings in adjacent denervated skin in the adult rabbit. These findings, together with those now reported for the cat as well as the rat, support the conclusion that possibly in all adult mammals intact low- and high-threshold nerves differ in their ability to respond to the presence of adjacent denervated skin by sprouting.

Animals↗

PubMed2005

Non-invasive diagnosis of liver cirrhosis: magnetic resonance imaging presents special features.

OBJECTIVE: Liver cirrhosis and its complications constitute a daily clinical challenge. The diagnosis of cirrhosis is traditionally established with the invasive method of liver biopsy. We undertook the present study in order to investigate the sensitivity and specificity of magnetic resonance imaging (MRI) in diagnosing cirrhosis. MATERIAL AND METHODS: A total of 56 patients were included in our retrospective study. The liver cirrhosis group comprised 30 patients and the control group 26 patients. All cases were histologically verified. A 1.5T MRI unit was used. Twelve radiological features of cirrhosis (enlargement of segment one, narrowing of hepatic veins, enlargement of spleen, fibrosis, nodular liver surface, ascites, regenerative nodules, enlargement of hilar periportal space, atrophy of right lobe, portosystemic collaterals, expanded gallbladder fossa, iron depositions) and tumour-load were evaluated by consensus reading. The ratio between segment one and right lobe was measured and the livers were classified as cirrhotic or non-cirrhotic. The chi2-test and t-test were used to indicate statistical difference. RESULTS: The sensitivity of MRI in diagnosing liver cirrhosis was 87% and the specificity 92%. The most characteristic MRI features were enlargement of segment one (83%), narrowing of hepatic veins (83%), signs of portal hypertension (77%), fibrosis (77%), and nodular liver margin (67%). There were statistical differences in all MRI signs between the cirrhosis and control groups. The ratio between segment one and right lobe also showed statistical significance between the two groups. All occult hepatocellular carcinomas were detected in the cirrhosis group. CONCLUSION: MRI has high sensitivity and specificity in the diagnosis of liver cirrhosis.

Adult↗

PubMed1999

The effects of median raphé electrical stimulation on serotonin release in the dorsal hippocampal formation of prenatally protein malnourished rats.

Our previous work had shown an enhanced inhibition in the hippocampal formation of prenatally protein malnourished rats. We have also found a diminishment in 5-hydroxytryptamine (5-HT) fibers in the hippocampal formation of malnourished rats as well as increased levels of 5-HT in the brain. The purpose of the present study was to determine 5-HT release in the dorsal hippocampal formation following electrical stimulation of the median raphé nucleus (MRN) in unanesthetized prenatally malnourished rats. Stimulation of this nucleus at 20 Hz in malnourished rats resulted in a significantly diminished release of 5-HT compared to well-nourished rats. The latter group showed a lesser, though still significant, decrease in 5-HT release following raphé stimulation. Basal release of 5-HT prior to stimulation was significantly higher in malnourished rats as compared to well-nourished controls. This may be the result of a decreased density of 5-HT neurons leading to a diminished control of release. Stimulation of the MRN in behaving malnourished animals may markedly affect the recurrent negative feedback collaterals onto somatodendritic 5-HT(1A) and 5-HT(1D) autoreceptors thus enhancing the inhibitory effects of stimulation of the median raphé on 5-HT release. Studies are underway to examine the sensitivity of both the somatodendritic and terminal 5-HT autoreceptors in malnourished animals, in order to understand possible mechanisms for our findings.

Analysis of Variance↗

PubMed2002

Impaired hypoxic tolerance and altered protein binding of NADH in presymptomatic APP23 transgenic mice.

It is being discussed whether impairment of energy metabolism is a final common pathway of neurodegeneration or initiates the neurodegenerative cascade. The goal was to investigate hypoxic tolerance and oxidative energy metabolism in 4-month-old, presymptomatic B6-Tg(ThylAPP)23Sdz (APP23) mice, a transgenic mouse model of Alzheimer's disease. Posthypoxic recovery of the population spike amplitude in hippocampal region CA1 upon stimulation of Schaffer collaterals in region CA3 (15 min hypoxia, 45 min recovery) was 43+/-46% (mean+/-S.D.) vs. 19+/-35% (P<0.05) in slices from wild-type and transgenic animals, respectively. Fluorescence lifetime sensitive spectroscopy of NADH in the CA1 pyramidal cell layer (gate set for detection of protein-bound NADH) showed a wavelength maximum at 455.3+/-1.6 nm (mean+/-S.D.) in controls and 453.5+/-2.4 nm (P<0.05) in mutants. We conclude that hypoxic tolerance is impaired in presymptomatic APP23 mice and occurs prior to extracellular deposition of amyloid plaques. Impaired energy metabolism may thus partake in initiating the neurodegenerative cascade in a transgenic model of Alzheimer's disease. The blue shift of the spectrum of NADH in mutant mice indicates an altered protein microenvironment of energy metabolism under control conditions.

Action Potentials↗

PubMed1999

EUS analysis of collateral veins inside and outside the esophageal wall in portal hypertension.

BACKGROUND: The relation between esophageal varices and venous collaterals outside the esophageal wall in patients with portal hypertension remains unclear. We investigated this relationship with endoscopy and endoscopic ultrasound (US). METHODS: Twenty-two patients with untreated varices were examined. The collaterals were studied with a 20 MHz US catheter probe. Collaterals were divided into two groups: (1) periesophageal collateral veins adjacent to the muscularis externa of the esophagus and (2) paraesophageal collateral veins external to the esophageal wall but without contact with the muscularis externa. Periesophageal and paraesophageal collateral veins were scored as mild or severe according to stage of development. RESULTS: Varix form as defined endoscopically was significantly larger in the severe periesophageal collateral veins group than in the mild periesophageal collateral veins group (p < 0. 01). In contrast, varix form did not differ significantly between the mild and severe paraesophageal collateral veins groups. Perforating veins were detected in the distal esophagus in 18 of 22 patients (81.8%) by means of US. The prevalence of perforating veins increased in relation to varix form. Two types of perforating veins were found on the basis of connection with periesophageal and paraesophageal collateral veins. The frequency with which perforating veins were connected to periesophageal collateral veins was 81.8%; the frequency of connection to paraesophageal collateral veins was 27.3%. CONCLUSION: Periesophageal collateral veins play a more important role in the formation of esophageal varices than do paraesophageal collateral veins.

Adult↗

PubMedDate not supplied

Electrothermal shrinkage reduces laxity but alters creep behavior in a lapine ligament model.

Thermal denaturation of collagen in ligament tissue has the potential to enhance arthroscopic shoulder stabilization. Previous studies have shown that laser energy produces significant capsular shortening without alteration of viscoelastic properties, but little information is available on the effects of radio frequency electrothermal energy. We assessed the acute effects of radio frequency shrinkage with use of the lapine medial collateral ligament model, in which the tibial insertion was shifted proximally to produce abnormal laxity. Thermal treatment resulted in restoration of laxity from 3.33 +/- 0.25 mm to 0.66 +/- 0.31 mm, which was not significantly different from medial collateral ligaments replaced anatomically (0.50 +/- 0.34 mm). When tested at 4.1 megapascals, cyclic and static creep strains were increased twofold to threefold in thermally-treated ligaments (P <.01), and partial failure occurred in 2 of 8 cases. We conclude that radio frequency electrothermal shrinkage is effective at reducing laxity but significantly alters viscoelastic properties, posing a risk of recurrent stretching-out at "physiological" loads.

Analysis of Variance↗

PubMed2005

Species and strain differences in the expression of a novel glutamate-modulating cannabinoid receptor in the rodent hippocampus.

A novel, non-CB1 cannabinoid receptor has been defined by the persistence of inhibition of glutamatergic EPSPs by the cannabinoid receptor agonist WIN55,212-2 in mice lacking the cloned CB1 receptor (CB1-/-) (Hajos et al., 2001). This novel receptor was also distinguished from CB1 by its sensitivity to the antagonist SR141716A and its insensitivity to the antagonist AM251 (Hajos & Freund, 2002). We have chosen to refer to this putative receptor as CBsc due to its identification on Schaffer collateral axon terminals in the hippocampus. We examined properties of CBsc receptors in Sprague Dawley (SD) rats and two strains of wild-type (WT) mice (C57BL/6J and CD1) used as backgrounds for two independent lines of CB1-/- mice (Ledent et al., 1999; Zimmer et al., 1999). The inhibition of synaptic glutamate release by WIN55,212-2 was observed in hippocampal slices from WT CD1 mice and SD rats but was absent in WT C57 mice. We also found that AM251 and SR141716A antagonized the effect of WIN55,212-2 in hippocampal slices from CD1 mice and SD rats demonstrating a lack of selectivity of these ligands for CB1 and CBsc receptors in these animals. The results indicate that the glutamate-modulating CBsc cannabinoid receptor is present in the hippocampi of CD1 mice and SD rats but not in C57BL/6J mice. Thus, we have identified animal models that may permit the study of cannabinoids independently of the novel CBsc receptor (C57CB1+/+), the CBsc receptor independently of the cloned CB1 receptor (CD1CB1-/-), or in the absence of both receptors (C57CB1-/-).

Adenosine↗

PubMed1999

Otolith ocular reflex function of the tangential nucleus in teleost fish.

In teleost fish, the tangential nucleus can be identified as a compact, separate cell group lying ventral to the VIIIth nerve near the middle of the vestibular complex. Morphological analysis of larval and adult hindbrains utilizing biocytin and fluorescent tracers showed the tangential nucleus to be located entirely within rhombomeric segment 5 with all axons projecting into the contralateral MLF. Combined single-cell electrophysiology and morphology in alert goldfish found three classes of neurons whose physiological sensitivity could be readily correlated with rotational axes about either the anterior (45 degrees), posterior (135 degrees), or horizontal (vertical axis) semicircular canals. Tangential neurons could be distinguised from those in semicircular-canal specific subnuclei by an irregular, spontaneous background of 10-15 sp/s and sustained static sensitivity after +/- 4 degrees head displacements. Each axis-specific tangential subtype terminated appropriately onto oculomotor subnuclei responsible for either vertical, torsional, or horizontal eye movements and, in a few cases, axon collaterals descended in the MLF toward the spinal cord. We hypothesize, therefore, that the tangential nucleus consists of 3 axis-specific phenotypes that process gravitoinertial signals largely responsible for controlling oculomotor function, but that also in part, maintain body posture.

Animals↗

PubMed1982

[K+]o accumulation and electrophysiological alterations during early myocardial ischemia.

Double-barreled valinomycin K+-sensitive electrodes and floating microelectrodes were used to monitor extracellular K+ concentration ([K+]o) and intracellular potential, respectively, in the isolated arterially perfused rabbit interventricular septum, under conditions of global ischemia without collateral flow and hypoxia with maintained flow. During ischemia [K+]o reproducibly increased at rates of 0.5-1 mM/min, usually in a triphasic pattern, and was accompanied by shortening of the action potential duration (APD) and an increase in conduction time (CT). Hyperkalemia, equivalent to that occurring during ischemia, in combination with respiratory acidosis (pH 6.2-6.5) and catecholamines reproduced quantitatively the ischemia-induced changes in APD and CT. None of these factors alone produced quantitatively comparable electrophysiological changes. Faster heart rates increased [K+]o accumulation during ischemia and accentuated the changes in APD and CT during ischemia. These findings suggest that local hyperkalemia, intracellular acidosis, and catecholamines release during early ischemia may account for electrophysiological changes predisposing to the development of reentrant arrhythmias.

Acidosis, Respiratory↗

PubMed1993

Evaluation of cavernous transformation of the portal vein by magnetic resonance imaging.

We describe two children who underwent magnetic resonance imaging (MRI) as part of the evaluation of isolated splenomegaly after Doppler ultrasound was unable to identify the portal vein. The diagnosis of cavernous transformation of the portal vein and the normalcy of the biliary tract and hepatic architecture were confirmed by MRI. Because of the risks associated with computed tomography (CT) and angiographic evaluation of such patients, the use of MRI, a noninvasive modality, in the evaluation of pediatric patients requires further consideration.

Angiography↗