Francisco Menor

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. There-fore, 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 followup is required only when tumoral development is clinically suspected.

Primary Intraosseous Meningiomas

Purpose: A retrospective study was performed to evaluate the clinical, radiological and histological findings of 14 intraosseous meningiomas. Material and Methods: 14 histologically proved intraosseous meningiomas were studied with plain skull film and CT. Pathological records were reviewed. Results: We found 9 calvarial cases and 5 spheno-orbital ones. The most common symptom in the calvarial cases was a lump in the scalp, and in the spheno-orbital lesions it was exophtalmos. Hyperostosis was present in all 5 spheno-orbital cases and in 3 out of the 9 calvarial ones; in the other 6 cases it had a mixed pattern. Enhanced dura was present in 3 calvarial cases and in 2 sphenoidal ones. Dura was involved in 5 cases: 2 with inflammatory changes, 2 with a minimal intradural tumour and one with a subdural tumour. Conclusion: CT better detected both the bony reaction and the intraosseous extension of the tumour. The dural changes were not specific of tumoural involvement. The differential diagnosis comprises: fibrous dysplasia, osteoma, blastic metastasis and mainly meningioma en plaque (MEP). Comparing our findings with other series, we noticed that in some cases the term MEP was used for similar cases. As the name MEP is merely descriptive and both entities share a larger number of similarities than differences, we believe that a differentiation between hyperostotic en plaque meningioma and intraosseous meningioma can hardly be made.

Intradiploic epidermoid cysts.

We studied 37 intradiploic epidermoid cysts, reviewing typical and atypical radiological features and the differential diagnosis. The most common clinical feature was a long standing lump in the scalp, occurring in 25 patients (67.7%). Plain films were the most cost-effective radiological technique in diagnosis. The typical finding was a well-defined lytic lesion with sclerotic border, seen in 29 cases (78%). Atypical lesions were those larger than 5 cm and/or with an ill-defined edge, being observed in 8 cases (22%). CT and MRI were the best methods for assessing atypical ones. In all cases with typical radiological findings a preoperative diagnosis of intradiploic epidermoid cyst was suggested.

Safety and efficacy of Omniscan (gadodiamide injection) at 0.1 mmol/kg for MRI in infants younger than 6 months of age: phase III open multicenter study.

RATIONALE AND OBJECTIVES To demonstrate that gadodiamide injection is a safe and efficient contrast agent for MRI in infants younger than 6 months of age. METHODS The authors designed a phase III multicenter nonrandomized study using a control group. Gadodiamide injection at a dosage of 0.1 mmol/kg body weight was administered to 39 children; 20 received no contrast. The mean age was 10.6 weeks in the contrast group and 9.3 weeks in the control group. MR examinations, blood (serum creatinine, S-ASAT, S-ALAT, S-bilirubin, alkaline phosphatase) and urine (proteins, blood, others) sampling before sedation and after examination, heart rate (electrocardiography) and oxygen saturation (pulse oximetry) during examination, adverse events, and efficacy parameters were analyzed. RESULTS In the contrast group, 18 (51.4%) children had 31 abnormal changes in one or more of the safety parameters and vital signs. In the control group there were 16 (80.0%) children with 19 abnormal changes. Gadodiamide injection had no negative influence on the safety parameters. No serious adverse events occurred, and only three clinically relevant adverse events (elevation of S-ALAT and S-ASAT, elevation of bilirubin) in two patients in the contrast group and one event (vomiting) in one patient in the control group were documented. The benefit of the contrast medium was clearly shown for all evaluated parameters. CONCLUSIONS Gadodiamide injection is safe, well tolerated, and effective in infants younger than 6 months of age.

The Sturge-Weber syndrome: correlation between the clinical status and radiological CT and MRI findings

In the Sturge-Weber syndrome facial venous and leptomeningeal angiomas are associated. We studied 14 consecutive cases with clinical and radiological evaluations [computed tomography (CT) and magnetic resonance imaging (MRI)]. Radiological studies demonstrated the extent and patency of the leptomeningeal angiomatous malformation, the degree of parenchymal atrophy, the presumed ischemic changes affecting the gray and white matter, the presence and extent of cortical calcifications, cifications, the prominence of the choroid plexus, the parenchymal venous anomalies, and the diploic prominence in the affected side. The white matter alterations, being greater, the extent of lobar involvement, and the degree of parenchymal atrophy all correlated with the patients clinical status being poorer. MRI is more efficient in the detection of the radiological findings related to the clinical status: seizure control, degree of psychomotor development and hemiparesis. Therefore, MRI is the imaging modality of choice in the diagnosis of these patients.

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.

Imaging considerations of central nervous system manifestations in pediatric patients with neurofibromatosis type 1

CT and MRI were used in a prospective study of the central nervous system (CNS) manifestations in 41 consecutive children with neurofibromatosis type 1 (NF-1). Gadolinium-DTPA was used in 15 patients. MRI was more effective than CT in delimiting the extension of the optic pathway glioma and in evaluating associated cerebral malformations. MRI visualized lesions generally undetected by CT, in the form of iso- or hyperintense foci with respect to the cerebral cortex in T2-weighted sequences. Well-delimited lesions of high signal intensity were observed in the globus pallidus (22 cases), the internal capsule (6 cases), corpus callosum (2 cases), anterior commissure (1 case) and semioval center (2 cases). Poorly defined hyper- or isointense areas were also observed affecting the cerebellar white matter (21 cases) and brain stem (17 cases). None of these lesions showed Gadolinium-DTPA enhancement, and were of no clinical significance. MRI has displaced CT in the initial diagnosis of patients with NF-1. Periodic annual MRI controls are only justified in patients with MRI changes to evaluate the progression or stabilization of the lesions.

Hepatic mesenchymal sarcoma: MRI findings

Hepatic undifferentiated mesenchymal sarcoma is a rare pediatric malignant neoplasm. We present three children, aged 7, 8, and 12 years, with this tumor. Clinical presentation was abdominal pain, palpable mass, asthenia, anorexia, and weight loss. One had jaundice. All three lesions were detected on ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI). MRI localized the lesions more accurately than the other methods, with good resectability correlation. On MRI, these tumors were markedly hyperintense on long TR/TE spin-echo (SE) and short-time inversion recovery (STIR) sequences. This was due to the cystic areas with myxoid material and necrosis. The internal septations were hypointense on these sequences. On short TR/TE SE sequences the lesions presented a fibrous pseudocapsule (two cases), and internal hyperintense areas representing hemorrhage (two cases). MRI also detected vascular invasion (one case), biliary obstruction (one case), and biliar adenopathies (one case). The combination of hemorrhage (hyperintense on short TR/TE SE) and cystic or myxoid components (markedly hyperintense on long TR/TE SE and STIR sequences) is common in this tumor.

Lipoma of the liver: US, CT, and MRI appearance

A case of hepatic lipoma is reported. Since the sonographic (US), computed tomographic (CT), and magnetic resonance imaging (MRI) findings are characteristic, we believe more aggressive diagnostic procedures are not necessary.

Effectiveness of pneumatic reduction of ileocolic intussusception in children

A total of 158 consecutive therapeutic air enemas were performed upon 133 patients during a 2-year period. Perforation and/or an impairment of the general condition of the children were the only main contraindications for the reduction attempt (five patients). Successful reductions were achieved in 89% of cases with no complications. Operation was performed in all 17 cases of unsuccessful reduction: resection in four cases, easy manual reduction in nine, difficult manual reduction in two, and spontaneous reduction in two. There were 16 (12%) patients with one or more recurrent episodes. In 23 (16%) cases, following pneumatic reduction, a swollen ileocecal valve showing a multiple appearance was observed. This fact sometimes results in a differential diagnosis with incomplete reduction; in all these cases, small bowel aeration was always a sign of complete reduction. No significant difference was noted between a swollen ileocecal valve and patient age, duration of symptoms, presence of small bowel obstruction, and further recurrences. Air enema has improved our previous success obtained with hydrostatic reduction (79%), as well as being a simpler, cleaner, and faster technique for intussusception reduction in children.