MnDPDP enhancement characteristics and differentiation between cirrhotic and noncirrhotic livers.

RATIONALE AND OBJECTIVES: The objective was to analyze if liver enhancement with mangafodipir trisodium was influenced by liver cirrhosis. METHODS: Eighty patients (49 with cirrhotic and 31 with noncirrhotic livers) were studied with spin-echo and spoiled gradient-echo T1-weighted images, before and after administration of mangafodipir trisodium. Hepatic insufficiency was assessed using the Child classification. Image analysis was performed both qualitatively and quantitatively. RESULTS: Noncirrhotic livers enhanced homogeneously but 37% of cirrhotic livers did not; the difference was significant. Areas corresponding to collapsed fibrous zones enhanced less than the rest of the parenchyma; areas of regenerating nodular zones enhanced more. Signal-to-noise ratios were significantly less for cirrhotic livers on postcontrast spoiled gradient-echo images. Cirrhotic livers had significantly lower relative enhancement ratios than noncirrhotic ones. The Child index and aspartate aminotransferase values were statistically related to the enhancement ratio. CONCLUSIONS: Mangafodipir trisodium enhancement in cirrhotic livers is related to necrosis and regeneration of the hepatocytes. Cirrhotic livers enhanced less than noncirrhotic ones.

Neurofibromatosis type 1 in children: MR imaging and follow-up studies of central nervous system findings.

PURPOSE: To determine the frequency, evolution and diagnostic impact of characteristic central nervous system MR imaging lesions in children with neurofibromatosis type 1 (NF1). SUBJECTS: We reviewed 89 children with established or clinically suspected disease. A final diagnosis of NF1 was made in 72 (age range, 10 months to 14 years). RESULTS: Hyperintense lesions on long TR images were detected in 78% of patients, principally involving the basal ganglia, cerebellum and brain stem. In 30% of the globus pallidus lesions, hyperintensity was seen on short TR images, being usually isointense on IR T1 weighted images. Globus pallidus lesions did not enhance. Eight patients presented atypical unenhanced lesions showing either edema, mass effect or hypointensity on short TR images; 2 of them were considered symptomatic brain stem gliomas. Six other children showed one or more growing enhanced cerebral lesions classified as tumors. Other child developed a growing enhanced lesion that markedly decreased in the follow-up studies. Twenty patients (28%) had optic gliomas. In two children, under 6 years old, this tumor appeared de novo. Forty-five children had several follow-up MR imaging studies (mean interval, 3 years). Regression of the basal ganglia lesions, both in size and/or intensity was noticed in 42% of cases, enlargement or new appearance of lesions in 24.5%, mixed increased/decreased in 7%, and stability in 26.5%. White matter lesions of the cerebellum and brain stem decreased in size in 40%, grew in 15.5%, showed a mixed increased/decreased pattern in 11%, and remained unchanged in 33.5% of cases. An involutional tendency of these lesions occurred in children older than 10 years, while progression was more frequent in younger children (P<0.05). CONCLUSIONS: Hyperintense lesions are highly prevalent and characteristic in patients with NF1. MR imaging contributed to a definitive diagnosis of NF1 in 53% of suspected cases. Follow-up studies are necessary in the evaluation of suspected NF1, even if the first examination is negative.

[Arterial gas embolism progressing to a massive stroke]. / Embolismo gaseoso arterial con evolución a accidente cerebrovascular masivo.

INTRODUCTION: Arterial gas embolism (AGE) is a main iatrogenic complication resulting from the use of invasive procedures. It is difficult to diagnose if it is not clinically suspected. CASE REPORT: A 67-year-old male patient, with a history of interventions involving a mitral prosthesis and a double aortocoronary bypass, who visited Emergency room with symptoms of a high temperature and general malaise. He was canalised peripherally and the electrocardiogram (ECG) showed an auricular fibrillation that had already been detected. While under observation he suffered a loss of consciousness, generalised hypotonia, conjugated gaze deviation towards the right, lower left facial paralysis and left Babinski positive. A new ECG showed ST segment elevation in V2-V5. A cranial computerised tomography (CAT) scan with no contrast revealed a number of serpiginous images caused by the presence of air in vascular structures. A second cranial CAT scan showed the disappearance of the visible air and signs of ischemic stroke in the territory of the right middle and posterior cerebral arteries and the left middle cerebral artery. Clinical-radiological findings suggested an AGE in the brain with massive stroke and acute myocardial infarct with similar causation. CONCLUSIONS: It is not clear what caused the air embolism in this patient but it can most probably be explained by air accidentally entering a peripheral vein. Carrying out an early cranial CAT scan can provide us with a diagnosis and a later CAT scan can evaluate the consequences of the embolism.

[MELAS syndrome: clinical, pathological and neuroimaging study]. / Síndrome de Melas: estudio clínico, patológico y de neuroimagen.

The form of presentation of a new case of Melas Syndrome is described, together with a pathological and neuroimage study, including clinical development over a 3 year period. The usefulness of MR should be underlined here, given clinical doubts, and also normality in the EMG early phases of and the association with obstructive hypertrophic miocardiopathy.

[Intra-arterial fibrinolysis in acute thrombosis of the basilar artery]. / Fibrinólisis intrarterial en la trombosis aguda de la arteria basilar.

INTRODUCTION: Ischemia in the territory of the basilar artery presents with a variable clinical picture of hemiparesia-tetraplegia, progressive deterioration of level of consciousness, irregular respiration and apnea leading to irreversible coma and death in between 75% and 86% of cases. The usual treatment is supportive. CLINICAL CASE: We present the case of a 49 year old woman with acute thrombosis of the basilar artery and a progressive course leading to coma. No bulbar lesions were seen on the CT scan done in the Emergency Department. Thrombosis of the basilar artery and permeable bilateral carotid systems were shown on arteriography. There were no contra-indications to fibrinolysis. Following local fibrinolytic treatment with urokinase the patient had full recovery from her neurological disorder and no sequelae. The basilar artery remained permeable six months later. CONCLUSIONS: Emergency treatment with cerebral intra-arterial fibrinolysis within the first six hours, in a case of neurological deficit progressing in the basilar artery territory, with persistence of brain-stem functions and no signs of decerebration (provided there are no contra-indications to fibrinolysis and the initial cerebral CT scan shows no bulbar lesions) may save the patient's life, with total or partial recovery of brain-stem function.

[The relation between the clinical symptoms and the findings on magnetic resonance in children with periventricular leukomalacia]. / Relación entre los síntomas clínicos y los hallazgos en resonancia magnética en niños con leucomalacia periventricular.

OBJECTIVES: To assess whether there is a relationship between the various clinical symptoms and imaging findings on MR in children with periventricular leukomalacia (PVLM). PATIENTS AND METHODS: We made a retrospective study of 41 consecutive paediatric patients, 19 boys and 22 girls, with an average age of 30.5+/-19 months (range 8 84 months) who had been diagnosed as having PVLM and studied using MR, recording imaging, clinical and epidemiological data. RESULTS: The MR images showed areas of gliosis in all the children (few foci in 68.3% and multiple foci in 31.7%), with cysts in 22%. The changes were seen mainly in the parietal and occipital regions, were bilateral and symmetrical in 80.5%, with ventricular dilatation in 75.6%, atrophy of the parenchyma in 48.8%, Wallerian degeneration in 7.3%, delay in myelination in 31.7%, lesions in the optic radiations in 9.8%, thalamus 12.2% and anomalous venous drainage in 2.4%. The overall degree of involvement on MR was severe in 43.9%, moderate in 31,7% and mild in 24.4%. There was a history of perinatal foetal distress in 56.8%, hyaline membrane disease in 40.5%, intracranial hemorrhage in 35.1%, psychomotor retardation in 58.5%, motor retardation in 29.3%, and squint in 22%. A significant relationship was found only between acute foetal distress and lateralization of the lesions (p= 0.038) and the presence of parenchymatous cysts (p= 0.024). CONCLUSION: The patients with a history of foetal distress had a greater tendency to symmetrical, bilateral involvement with cysts in the white matter of the brain. It was not possible to establish a model for classification of the overall involvement using MR and the data recorded. The imaging findings were not related overall to the patients symptoms.

Diagnosis of Sturge-Weber syndrome: comparison of the efficacy of CT and MR imaging in 14 cases.

Sturge-Weber syndrome is a neurocutaneous syndrome that includes facial and leptomeningeal angiomas. Imaging findings include cerebral lobar atrophy, brain calcifications, choroid plexus enlargement, cranial diploë prominence, and venous abnormalities. We compared the efficacy of CT and MR imaging in making the diagnosis in 14 consecutive patients. CT, with and without contrast enhancement, was performed in all patients, and 11 of the 14 had MR imaging (eight before and after administration of IV gadopentetate dimeglumine). MR imaging was better than CT in showing the extent and degree of brain parenchymal atrophy, the presumed ischemic changes affecting the gray and white matter, and the cranial diploetic prominence on the affected side. MR imaging after contrast administration permitted a better evaluation of the extent and patency of the leptomeningeal angiomatous malformation and the parenchymal venous anomalies. CT was better than MR imaging in showing the presence and extent of cortical calcifications. Enhanced CT and MR imaging were equal in evaluating the prominence of the ipsilateral choroid plexus. Our experience indicates that contrast-enhanced MR imaging is the method of choice in the diagnosis of Sturge-Weber syndrome. Unenhanced CT should be used only if MR findings are normal, to exclude the presence of intracranial calcifications.

[Disseminated encephalomyelitis. A study of 5 cases]. / Encefalomielitis diseminada. Estudio de una casuística.

Five cases of acute disseminated encephalomyelitis (ADE) with a follow-up longer than 5 years are presented. The clinical picture, CT images, MR and laboratory tests, specially LCR and evoked potentials presented in a variable form. In two cases the symptoms were preceded by viral infection. The course was acute in one case while the other four evolved in a subacute form during weeks. In two patients a pseudotumoral pattern was observed in the CT and MR images leading to difficulties in the diagnosis. Clinical improvement was accompanied by a partial resolution of the lesions. Steroid treatment improved symptomatology in all the cases. Knowledge of this process may avoid the unnecessary practice of other, more aggressive tests.

Brodie abscess: MR imaging appearance in 10 patients.

The magnetic resonance (MR) imaging features of Brodie abscess have not yet been fully evaluated. Ten patients with Brodie abscess, eight of long bone and two of vertebra, were studied with MR imaging. Long bone abscess had a characteristic "target" appearance with four layers: (a) a center with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR (short-inversion-time inversion recovery) images, (b) an inner ring isointense to muscle on T1-weighted images and with high signal intensity on T2-weighted and STIR images, (c) an outer ring hypointense on all images, and (d) a peripheral halo hypointense on T1-weighted images. In six of eight cases, a soft-tissue mass was found. The two vertebral abscesses had a less specific appearance, with low signal intensity on T1-weighted images and high signal intensity on T2-weighted and STIR images. Only the peripheral halo was clearly identified in both cases.

Neuroimaging in tuberous sclerosis: a clinicoradiological evaluation in pediatric patients.

CT, MRI and neurological features of 27 children with tuberous sclerosis were prospectively compared. Imaging studies were positive in 92.5% of cases. CT was more useful in detecting subependymal nodules, while MRI showed the number and location of cerebral cortical and subcortical lesions more accurately. Cortical lesions in the cerebellar hemispheres were present in 26% of patients. Gadolinium-DTPA used in 10 patients showed slight enhancement of the subependymal lesions in 80% of cases, probably representing active lesions with alteration of the blood-brain barrier. None of the cortical and subcortical lesions enhanced. Giant-cell astrocytomas were detected in 5 patients, the postcontrast CT and MRI studies improving their assessment. Unlike subependymal nodules, all tumors showed marked enhancement regardless of their size. Seizures were present in 96% of patients, mostly beginning before 1 year of age. There was no clear relationship between the radiological features and the neurological evolution of these patients. Therefore, it is not possible to establish a clinical prognosis based on the radiological findings. MRI is the procedure of choice in the diagnosis of tuberous sclerosis. When pre and postcontrast MRI are negative, CT is used to exclude small calcified subependymal nodules. MRI follow-up is required only when tumoral development is clinically suspected.

Administration of oral chloral hydrate to paediatric patients undergoing magnetic resonance imaging.

Sedation is frequently required in children undergoing magnetic resonance imaging (MRI). 172 Paediatric patients (82 female and 90 male, age 42 +/- 26 months, weight 14.7 +/- 5.6 kg) entered an open, non-comparative, prospective study to assess the utilization of oral chloral hydrate. Chloral hydrate syrup (70 mg/ml) was administered 20-30 min prior to the procedure. Effective sedation was reached in 80.3% with an average initial dose of 55 mg/kg and in 93.6% with an average total dose of 65 mg/kg. Significant differences in effectivity were correlated with the dose (54 +/- 11 mg/kg in failure cases versus 66 +/- 16 mg/kg in effective cases; p < 0.05) and diagnosis (effectivity falls to 62.5% and 76.0% in children with medullar tumours and encephalic white matter alterations, respectively; p < 0.01). Average sleep induction time was 30 +/- 19 min, and average duration of sleep was 62 +/- 24 min. Adverse reactions occurred in 4.7%, with nausea, vomiting and stomach pain being the most common side-effects (3.5%). Multivariate statistical analysis selects total dose and age into the discriminant function, with a 100% relative percentage of correct classification. A simple method for optimizing the chloral hydrate dose in children is proposed: the dose in mg/kg is calculated as half the age in months + 50.

Tumoural portal vein thrombosis. Enhancement with MnDPDP.

PURPOSE: Intrahepatic thrombus is usually associated with either cirrhosis or hepatocellular carcinoma (HCC). Most HCCs enhance after the administration of MnDPDP (Teslascan). Our objective was to analyze the enhancement characteristics of tumour portal vein thrombi. MATERIAL AND METHODS: Thrombi affecting the main or segmental portal veins (17 cases) and the suprahepatic inferior vena cava (1 case) were retrospectively selected from a series of 128 patients studied with MR imaging before and after the administration of MnDPDP. Enhancement was assessed qualitatively and quantitatively. RESULTS: All tumour thrombi enhanced after MnDPDP administration. The enhancement was more conspicuous in the GRE images. On the quantitative evaluation, the portal thrombus enhancement was greater for GRE images than SE images. Portal thrombi enhanced more than the liver and the HCCs. There was a significant difference between the enhancement of the HCCs and the thrombi with both MR imaging techniques. CONCLUSION: The greater enhancement of the tumour thrombus associated with the liver and HCC may suggest that other mechanisms, apart from accumulation of the contrast medium within the hepatocytes inside the thrombi, are involved in thrombus enhancement.

Prenatal diagnosis of idiopathic neonatal hemochromatosis with MRI.

Intrauterine diagnosis of perinatal hemochromatosis is difficult. Noninvasive detection of hepatic iron deposition is crucial. We report the first case diagnosed intrauterine with magnetic resonance imaging (MRI). By visual analysis, if the fetal liver is less intense than maternal or fetal fat signal for T2* gradient echo image, hemochromatosis should be suggested.

Klippel-Trenaunay syndrome: frequency of cerebral and cerebellar hemihypertrophy on MRI.

We examined 11 patients, clinically and radiographically diagnosed as having the Klippel-Trenaunay syndrome (KTS) by MRI. There were four females and seven males, aged 3-51 years (mean 21 years). Two had clear asymmetry of the cerebral and cerebellar hemispheres. The thickness of the grey matter was normal, without sulcation abnormalities, but the thickness of the white matter was increased; the size of the ipsilateral ventricle was normal. These patients had hypertrophy of the leg and a cutaneous haemangioma on the same side as the brain abnormality. No patient had an intracranial vascular malformation, unilateral megalencephaly, cerebral atrophy or hydrocephalus. The prevalence of cerebral hemihypertrophy in our series of patients with KTS was thus 18%.

Oral chloral hydrate provides effective and safe sedation in paediatric magnetic resonance imaging.

Sedation is routinely required for successful Magnetic Resonance imaging in infants and children. Five hundred and ninety-six paediatric patients (270 female and 326 male, age (mean +/- SD) 41 +/- 30 months and weight 14.8 +/- 6.5 kg) entered an open, non-comparative, prospective study to assess oral chloral hydrate sedation in a large and homogeneous paediatric population undergoing Magnetic Resonance imaging. Chloral hydrate syrup 70 mg/ml was administered 20-40 min prior to the procedure. Effective sedation was reached in 94.1% with a total dose (mean +/- SEM) of 68 +/- 1 mg/kg (range 20-170 mg/kg). Statistical analysis of sedation failures vs. successful examinations after the total dose showed significant differences for dose (62 +/- 4 vs. 69 +/- 1 mg/kg; P < 0.05), age (64 +/- 7 vs. 40 +/- 1 months; P < 0.001) and weight (19.8 +/- 1.5 vs. 14.5 +/- 0.0 kg; P < 0.001). Effectiveness fell to around 80% in children with encephalic white matter alterations, medullary tumours or syringohydromyela (P = 0.07). The mean time of onset of sedation was 26 +/- 1 min, and the mean time to spontaneous awakening after the completion of the Magnetic Resonance examination was 38 +/- 2 min. Fifty-nine children (9.9%) experienced adverse reactions, with nausea and vomiting being the most common (n = 41), followed by nervousness and unusual excitement (n = 6). Discriminant function analysis identified age and total dose as the quantitative variables helping to differentiate between sedation failures and satisfactory examinations (sensitivity = 0.73, and specificity = 0.61; r = 0.20, P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)