Diffusion-Weighted Imaging of Brain Injury Due to Neonatal Hypoglycemia: A Case Report

Profound hypoglycemia results in significant brain injury because glucose is essential for normal brain functioning. We present here a case of transient neonatal hypoglycemia with diffuse brain injury. Magnetic resonance imaging was performed 2 days after onset, and this revealed bilateral regions of restricted diffusion in the parietal, occipital, frontal and temporal lobes. On the T1-weighted images, the regions showed indistinct gray matter-white matter differentiation. There were subtle high signal intensity lesions along the corresponding regions of the FLAIR and T2-weighted images.

Usefulness of MR Cholangiography in the Evaluation of Neonatal Cholestasis: Comparison with 99mTc DISIDA Scan

PURPOSE: To evaluate the diagnostic validity of MR cholangiography as a second-line imaging tool following sonography in the evaluation of neonatal cholestasis, we compared MR cholangiography with 99mTc DISIDA scan. MATERIALS AND METHODS: We retrospectively evaluated sonography, 99mTc DISIDA scan and MR cholangiography in twenty-two neonates and infants (age range, 23-103 days; mean age, 57 days) presenting with conjugated hyperbilirubinemia. Of the 22 patients, 15 were diagnosed as biliary atresia by operative cholangiography and liver biopsy and six as neonatal hepatitis by imaging finding and clinical data. Remaining one patient was diagnosed as neonatal hepatitis by operative cholangiography and liver biopsy. Two independent observers for each study were assigned to review the images of 99mTc DISIDA scan and MR cholangiography without giving the final diagnosis or other clinical data. Diagnostic accuracy and interobserver variability for each study were evaluated. RESULTS: On 99mTc DISIDA scan, biliary atresia was mistaken for neonatal hepatitis in eight patients and vice versa in four patients. On MR cholangiography, it was mistaken biliary atresia as neonatal hepatitis and vice versa in each two patients. Sensitivity, specificity, accuracy, positive and negative predictive values of 99mTc DISIDA scan were 48%, 47%, 48%, 66% and 30%, respectively, and those of MR cholangiography were 90%, 71%, 84%, 87% and 81%, respectively. Interobserver variabilities for 99mTc DISIDA scan and MR cholangiography were 0.62 and 0.85, respectively. CONCLUSION: In the evaluation of patients with neonatal cholestasis, it would be advisable to use MR cholangiography, having superior diagnostic accuracy to 99mTc DISIDA scan, as a second-line imaging tool following sonography.

Human Tail: A Case Report

Human tail is a rare congenital anomaly in which a lesion protrudes from the lumbosacrococcygeal region. We encountered a case of human tail involving an intradural lipoma and tethered cord, occurring in a 1-day -old female who presented with an 8 cm-sized tail shown by MRI to arise from the S3-4 level. The cauda equina and film terminale were entrapped by the lipoma, but there were no bony abnormalities.

Comparison of Surface and Saddle Endoanal Coil to Evaluate anal Sphincter in Infants and Young Children: Experimental Study Using Phantom and Cats

PURPOSE: We designed an inside-out-type endoanal surface and saddle coil to evaluate the anal sphincter of young children who have difficulty in controlling defecation after the correction of anorectal malformation, and compared two coils using an imaging phantom and cats. MATERIALS AND METHODS: Using two coils, T1- and T2-weighted axial and coronal images of the phantom and of the anorectal region of cats were obtained, and the results were compared in terms of changes in signal intensity and SNR according to the distance from the coil's surface. We also compared the capability of the coils to delineate the internal and external anal sphincter of cat anorectum, both of which are important in the control of defecation. RESULTS: The saddle coil was slightly superior to the surface coil in terms of SNR, but inferior in terms of the signal intensity of the region of interest of the cat's anorectum. Moreover, artifacts of low signal intensity appeared in an azimuthal direction on axial images acquired using the saddle coil and prohibited delineation of the whole of the anal sphincter. In terms of image quality, the surface coil was therefore superior to the saddle coil. CONCLUSION: Our findings suggest that among inside-out-type endoanal coils, the surface coil may be superior to the saddle coil in MR imaging to evaluate the anal sphincter of young children.

Congenital Bilateral Neuroblastoma (Stage IV-S): Case Report

Congenital neonatal neuroblastoma is not uncommon but bilateral adrenal neuroblastoma is rare, accounting for about ten percent of neuroblastomas in children. We report the US and MR findings of a stage IV-S congenital bilateral neuroblastoma occurring in a one-day-old neonate.

Reversible Posterior Leukoencephalopathy Syndrome in Children: MR Imaging Findings

PURPOSE: To find out the characteristic MR findings of reversible posterior leukoen-cephalopathy syndrome (RPLS) due to various causes in children. MATERIALS AND METHODS: Eight children with RPLS underwent MR imaging, and the findings were retrospectively analyzed. All eight were acutely hypertensive at the time of a neurotoxic episode. Three had intra-abdominal tumors (one adrenal pheochromo-cytoma, one para-aortic paraganglioma and one para-aortic ganglioneuroma encasing the left renal artery); three were being treated with cyclosporine; one was being treat-ed with steroid; and one had hemolytic uremic syndrome. Initial cranial MR images were analyzed with particular emphasis on the distribution of the lesions. To assess possible sequelae, follow-up MR images were obtained in seven patients at least one week after the treatment of hypertension. Four underwent proton MR spectroscopy. RESULTS: Characteristic distribution of lesions in the occipital and posterior parietal lobes was identified in all cases regardless of the causes of RPLS. The cerebellum, basal ganglia, anterior parietal, and frontal lobe were involved in four, two, one, and one case, respectively. Cortical gray matter involvement was predominant in six and subcortical white matter involvement predominated in two patients. The distribution of lesions was bilateral and asymmetric. Gyriform enhancement was identified in six cases, and small hemorrhage was noted in one. In seven patients, the clinical and MR findings improved without sequelae on follow-up study. In one, proton MR spectroscopy demonstrated a high lactate peak at the time of the neurologic event. Nearnormal spectra were noted in three children who underwent proton MR spectroscopy after recovery. CONCLUSION: The MR findings of RPLS are characteristic in that lesions are distributed in the posterior region of the brain and they are reversible on follow-up study. In children with RPLS due to unknown causes, the possibility of intra-abdominal tumors should also be considered.

CT and MR Findings of Neonatal Dermoid ("Hairy Polyp")Developed at Eustachian Tube: A Case Report

Nasopharyngeal dermoid is a rare disease which in neonates leads to respiratory failure. We report the CT and MR imaging findings of a case of neonatal dermoid which developed in the Eustachian tube. The neonate involved was referred to our hospital because of respiratory difficulties and cyanosis.

Relative Signal Intensity Changes of Frontal and Occipital White Matters on T2 Weighted Axial MR Image: Correlation with Age

PURPOSE: To assess relative signal intensity changes in frontal and occipital white matter with age, as seenon T2 weighted axial MR images. MATERIALS AND METHODS: Thirty eight normal adults (20-29 years old) and 114children (0-11 years old) were investigated. All had nonspecific neurologic symptoms and their MR images, obtainedusing a 1.5T system (Signa, GE Medical Systems, Milwaukee, U.S.A), appeared to be normal. The signal intensitiesof frontal and occipital white matter were evaluated on T2 weighted axial images at the level of the foramen ofMonro. When the signal intensity of white matter was higher than that of gray matter, grade 0 was assigned ; whenthe opposite situation pertained, this was graded I_III. Grade I indicated that the signal intensity of occipitalwhite matter was lower than that of frontal white matter ; grade II, that the signal intensity of white matter ofboth lobes was similar. When the signal intensity of frontal white matter was lower than that of occipital whitematter, grade III was assigned. We divided the children's age by six months before 2 years of age, and by one yearafter 2 years of age, and then determined grade according to age, age distribution according to grade, and theages at which signal intensities were similar to those of adults. RESULTS: All 38 adults showed a grade IIIpattern ; this grade was apparent as early as 1.5 years of age and by 3 years of age, it was seen in over 50% ofchildren. After 8 years of age, all children were grade III. The age distribution of grade 0 was 0-0.5 years ofage, for grade I this was 0.5-2 years of age, for grade II it was 1-7, and for grade III, it was 1.5-11. CONCLUSION: On T2-weighted MR images, the signal intensity of frontal white matter ultimately shows a lowersignal intensity than that of occipital white matter.

Early Periventricular Leukomalacia: MRI and Ultrasonographic Correlation on First one Month of Life

PURPOSE: To compare the findings of early periventricular leukomalacia on MR imaging and on US. MATERIALS AND METHODS: MR imaging was performed in 17 neonates in whom well-demarcated increased periventricular echogenicity was seen on sonography. One more patient was included during the same period because MR imaging of this patient showed a periventricular lesion not suspected on previous US. Initial sonography was performed within 6 days of birth and was followed up between one week and one month later. MR images were obtained within the first month of life. RESULTS: Twelve of 17 neonates showed abnormal periventricular signal intensities on MR imaging. Follow up sonography revealed cystic changes in two cases and heterogeneous hyperechogenicities in three. All patients except the two with cystic changes showed normal periventricular echogenicity on final sonography, On MR imaging,11 cases showed multifocal periventricular increased signals on T1-weighted images, and two cases showed mainly decreased signals representing cysts. Positive findings were more evident on T1-weighted than on T2-weighted image. CONCLUSION: on T1-weighted imaging, the characteristic finding of early periventricular leukomalacia was multifocal periventricular hyper or hypointensities, and hyperintense lesions were more common than hypointense. In the diagnosis of early noncystic periventricular leukomalacia, MR imaging was more objective than US.

The Role of MR Imaging in Determination of Atrial Situs in Congenital Heart Disease with Situs Ambiguus

PURPOSE: to assess the role of MR imaging in determining of the atrial situs in complicated congenital heart disease with situs ambiguus. MATERIALS AND METHODS: In order to classify the situs, the morphology of atrial appendages, on bronchial length ratio, the superior-inferior relation of the pulmonary artery (PA) and main bronchi on each side, and splenic abnormality were evaluated by MR imaging in 22 patients (12 boys and 10 girls), and the results were compared. RESULTS: In all patients, the superior-inferior relation of the PA and main bronchi tended to lateralize, and in one, bronchial length ratio was not consistent with the relation between the PA and bronchus. Bronchial and atrial situs, as determined by appendage morphology, were consistent in ten of 13 right isomerism patients, and in only three of nine of these with left isomerism. All 13 right isomerism patients, classified by the relation of the PA and main bronchi, showed asplenia, whereas eight of nine of these with left isomerism had polysplenia. CONCLUSION: In the assessment of atrial situs by MR imaging, the positional relation of a bronchus and the PA, bronchial length ratio, and splenic abnormality are constant and reliable. The accuracy of classification of situs on the basis of atrial appendage morphology is, however, limited.

MR Imaging of the Currarino Triad

PURPOSE: The purpose of this study was to describe the MR findings of the spectrum of the Currarino triad and to discuss the potential role of MR imaging in evaluating these anomalies. MATERIALS AND METHODS: Seven children (age range: 2-12 months) with Currarino triad were evaluated using MR imaging, plain radiography, and barium study. In addition, CT scans (n=3) and sonography (n=2) were performed. We retrospectively analyzed MR imaging findings and correlated these with the findings of other imaging modalities. RESULTS: Anorectal anomalies included anorectal stenosis in five patients and an imperforate anus in two. MR imaging findings of anorectal stenosis included an elongated thick-walled anorectal canal and dilatation of the proximal segment of the rectum. In the patients with an imperforate anus, the location of the blind rectal pouch and sphincteric musculature was delineated. In one case, a transcolostomy enema revealed a fistula not evident on MR images. Presacral masses included four teratomas and three lipomas associated with various spinal anomalies. On MR imaging, which gave better results than CT or sonography, a detailed evaluation of presacral masses and associated anomalies was possible. Sacral anomalies included a typical scimitar-shaped sacral defect in five patients, abnormal curvature in one, and malsegmentation in one. In all cases, MR imaging showed the abnormal sacrum, but plain radiography more clearly demonstrated its anomalous shape. CONCLUSION: Various anorectal anomalies, presacral masses, and other associated anomalies were demonstrated by MR imaging. When the Currarino triad is suspected, MR imaging should therefore follow plain radiographs.