Diffusion-weighted Magnetic Resonance Imaging in the Early Diagnosis of Neonatal Adrenoleukodystrophy.

A newborn baby girl developed seizures right after birth. On the fourth day, the baby was examined using diffusion sequence magnetic resonance imaging (MRI) and diagnosed to have neonatal adrenoleukodystrophy. Laboratory findings confirmed the diagnosis. This is the first case of neonatal adrenoleukodystrophy (NALD) where diffusion MRI sequence helped in the diagnosis. We find association of NALD with seizures at birth is an extremely rare occurrence, and so far, only one case has been mentioned in the literature.

Rhombencephalosynapsis associated with Dandy-Walker malformation.

Coexistence of rhombencephalosynapsis and Dandy-Walker malformation has previously been documented in a fetus by autopsy. In addition, there are three cases in the imaging literature suggesting this combination. This paper reports an 8-month-old girl with clear MR imaging evidence of association of these two anomalies. The vermis was absent, and there was fusion of the cerebellar hemispheres, characteristic for rhombencephalosynapsis. The fourth ventricle showed cystic dilatation associated with an enlarged posterior fossa, characteristic for Dandy-Walker malformation. These findings suggest that rhombencephalosynapsis and Dandy-Walker malformation can coexist.

Colloid cyst: diffusion MR imaging findings.

Colloid cysts usually have viscid gelatinous material or denser content. In an adult patient with a colloid cyst, diffusion magnetic resonance (MR) imaging was applied to detect its features with this sequence that if its viscous content may lead to a hyperintense appearance (decreased diffusion pattern) on b= 1000 sec/mm(2) images similar to epidermoids. The colloid cyst had hypointense signal on the b= 1000 sec/mm(2) image. The ADC map had more information that the ADC value of the cyst was 1.58 x 10(-3) mm(2)/sec. This value was apparently higher than that of normal cerebral parenchyma, and was apparently lower than that of CSF. These diffusion MR imaging features of the colloid cyst are consistent with an elevated diffusion pattern in contrast to epidermoids.

Nonspecific perichondritis of the lumbar spine.

A teenage girl with soft tissue inflammation involving the L2-S1 region of the lumbar region is reported. Magnetic resonance (MR) imaging revealed high-signal lesions on T2-weighted images in association with contrast enhancement. Histology revealed nonspecific perichondritis with mononuclear inflammatory infiltration of the perichondrium and connective tissue. Six months after treatment, MR imaging was normal. No similar case of perichondritis with involvement of the lumbar region could be found in the current literature.

Maple syrup urine disease: diffusion MRI, and proton MR spectroscopy findings.

A 7-month-old boy is reported with acute metabolic crisis of maple syrup urine disease. A reversible intramyelinic type of edema was noted by diffusion MRI which completely resolved in 3 months in accordance with good clinical outcome. Proton MR spectroscopy revealed decreased NAA, and presence of methyl resonances of branched chain amino acids at 0.9 ppm, and lactic acid in the initial examination. After 3 months, NAA returned to normal, and lactic acid disappeared. The methyl resonance of branched chain amino acids, however, remained.

Malignant peripheral nerve sheath tumor of the oculomotor nerve.

We present the short-term follow-up magnetic resonance (MR) studies and 1H-MR spectroscopy in a child with malignant peripheral nerve sheath tumor of the oculomotor nerve associated with other less aggressive cranial nerve schwannomas. The tumor revealed perineural extension and diffuse nerve involvement besides rapid growth. 1H-MR spectroscopy was helpful in excluding an intra-axial neoplasm with exophytic growth, mainly due to the absence of creatine and N-acetyl aspartate peaks, and markedly elevated choline peak.

Magnetic resonance imaging morphometry of the midbrain in patients with Wilson disease.

In this study, the focus is on midbrain magnetic resonance imaging morphometric measures (transverse diameter of the midbrain peduncle [Tp], transverse diameter of the tegmentum, anteroposterior diameter of the midbrain, interpeduncular distance [IPD], and interpeduncular angle [IPA]) in a group of 47 consecutive patients with neurologic (37 patients) and hepatic (10 patients) forms of Wilson disease (WD). Morphometric measures were significantly different between the group of patients with WD and healthy controls (51 subjects) as well as patients with Parkinson disease (15 patients) and multiple sclerosis (15 patients). Among the studied variables, IPA, Tp, and IPD were particularly useful in differentiating patients from healthy subjects (probability reaching 93%).

Leptomeningeal metastasis from malignant pleural mesothelioma.

Leptomeningeal metastasis from malignant mesothelioma is very rare; to our knowledge, only one imaging report exists in the literature. We present the case of widespread leptomeningeal lesions secondary to a malignant mesothelioma in a 61-year-old woman.

Diffusion-weighted and conventional MR imaging findings of neuroaxonal dystrophy.

BACKGROUND AND PURPOSE: Neuroaxonal dystrophy is a rare progressive disorder of childhood characterized by mental deterioration and seizures. The diffusion-weighted and conventional MR imaging findings are reported for six cases. METHODS: Six patients aged 19 months to 9 years with proved neuroaxonal dystrophy (one with the infantile form, five juvenile forms) underwent imaging at 1.5 T. Echo-planar diffusion-weighted images were acquired with a trace imaging sequence in five patients and with a three-gradient protocol (4000/110) in one. Images obtained with a b value of 1000 s/mm2 and corresponding apparent diffusion coefficient (ADC) maps were studied. ADCs from lesion sites and normal regions (pons and temporal and occipital lobes) were evaluated. RESULTS: A hyperintense cerebellum (a characteristic of the disease) was evident on fluid-attenuated inversion recovery images in all cases. Four patients had associated cerebral changes. Diffusion-weighted images, especially ADC maps, showed an elevated diffusion pattern in the cerebellum in the five juvenile cases (normal images at b = 1000 s/mm2, ADCs of 1.30-2.60 x 10(-3) mm2/s). A restricted diffusion pattern was evident in the infantile case (hyperintensity at b = 1000 s/mm2, low ADCs of 0.44-0.55 x 10(-3) mm2/s). ADCs were normal in the pons and temporal and occipital lobes (0.64-1.00 x 10(-3) mm2/s). CONCLUSION: An elevated cerebellar diffusion pattern is a predominant feature of juvenile neuroaxonal dystrophy. Coexistent elevated and restricted diffusion patterns were evident in different brain regions in different forms of the disease. Dystrophic axons likely account the restricted diffusion, whereas spheroid formation (swelling) and abnormal myelination result in elevated diffusion.

Subacute sclerosing panencephalitis findings at MR imaging, diffusion MR imaging, and proton MR spectroscopy.

A case of subacute sclerosing panencephalitis in a 2-year-old boy is reported. In addition to asymmetric lesions in the parietotemporal lobes, right thalamus, and globus pallidus, symmetric patterns were notable in the brain stem, middle cerebellar pedincles, and dentate nuclei. Proton MR spectroscopy revealed markedly decreased N-acetylaspartate peaks and normal choline and myo-inositol levels in the lesions. Diffusion MR imaging revealed an elevated diffusion pattern manifested with high apparent diffusion coefficient values (1.14-1.60 x 10(-3) mm(2)/s) compared with those in normal-appearing brain tissue (0.65-1.00 x 10(-3) mm(2)/s) and subtle high signal intensity characteristics on diffusion-weighted images obtained at b = 1000 s/mm(2).

Neuro-Behcet's disease: diffusion MR imaging and proton MR spectroscopy.

We herein report the case of a 53-year-old woman with Behcet's disease and an acute T2-hyperintense lesion in left side of the pons. Echo-planar "trace" diffusion MR imaging revealed high signal intensity changes at the lesion site on b = 1000 s/mm(2) images, initially suggesting restricted diffusion. On corresponding apparent diffusion coefficient maps, however, the lesion had high signal intensity and high apparent diffusion coefficient values (1.22 x 10(-3) mm(2)/s), compared with the contralateral normal side of the pons (0.86 x 10(-3) mm(2)/s) and compared with the normal temporal white matter (0.80 x 10(-3) mm(2)/s). This was consistent with the presence of increased diffusion, hence vasogenic edema. Proton MR spectroscopy excluded acute infarction. This particular pattern (high signal intensity on b = 1000 s/mm(2) images in association with high apparent diffusion coefficient values) likely represented the acute inflammatory process associated with disrupted brain-blood barrier in the fulminant form of neuro-Behcet's disease. Follow-up examinations

Pantothenate kinase-associated neurodegeneration: MR imaging, proton MR spectroscopy, and diffusion MR imaging findings.

We herein report the case of a 15-year-old male patient with pantothenate kinase-associated neurodegeneration. The classic "eye-of-the-tiger" appearance was initially present on the globus pallidi on T2-weighted MR images and had disappeared by the time of the 10-month follow-up examination. Fluid-attenuated inversion recovery images revealed marked hypointensity in the globus pallidi and dentate nuclei and high signal intensity changes in the deep cerebral white matter. Proton MR spectroscopy revealed markedly decreased N-acetylaspartate in the globus pallidi, associated with decreased N-acetylaspartate and increased myoinositol in the deep cerebral white matter. Diffusion MR images (b=1000 s/mm(2)) were negative (normal appearing) for deep cerebral white matter lesions, whereas apparent diffusion coefficient values were slightly increased (1.08-1.12 x 10(-3) mm(2)/s), compared with the apparent diffusion coefficient values from the normal white matter regions. Apparent diffusion coefficient values in the globus pallidi were lower than those in the unaffected thalamus.

Acute carbon monoxide poisoning: diffusion MR imaging findings.

During the acute stage of carbon monoxide poisoning, diffusion MR images obtained at b=1000 s/mm2 revealed high signal intensity lesions in the white matter, consistent with restricted diffusion. Low apparent diffusion coefficient values (0.18-0.34 x 10(-3) mm2/s) were noted in the affected white matter regions. Follow-up MR imaging performed 16 days later revealed disappearance of white matter lesions, suggesting that during the acute stage of carbon monoxide poisoning, white matter can be more sensitive than gray matter to ischemia.

Nonketotic hyperglycinemia: diffusion magnetic resonance imaging findings.

We report about a boy with nonketotic hyperglycinemia who was studied at 15 days of life with a follow-up examination at age 6 months. Magnetic resonance (MR) imaging revealed progressive atrophy, callosal thinning, and delayed myelination. Glycine peaks were shown by proton MR spectroscopy at 3.56 ppm with a long echo time (TE, 135 milliseconds; TR, 1500 milliseconds). Echo-planar diffusion MR imaging (TR, 5700 milliseconds; TE, 139 milliseconds) at 15 days of life revealed high-signal lesions in the pyramidal tracts, middle cerebellar pedicles, and dentate nuclei on b = 1000 s/mm2 images associated with low apparent diffusion coefficient (ADC) values. By age 6 months, the lesions became more prominent on b = 1000 s/mm2 images with lower ADC values. Diffusion MR imaging findings likely reflected the histopathologic changes of the disease which consisted of spongiosis of the myelinated brain tissue due to myelin vacuolation.

Phenylketonuria: diffusion magnetic resonance imaging and proton magnetic resonance spectroscopy.

Two patients with phenylketonuria are reported with white matter lesions. Diffusion magnetic resonance (MR) imaging revealed restricted diffusion patterns (high signal) on b = 1000 s/mm2 images associated with low apparent diffusion coefficient values ranging between 0.44 x 10-3 mm2/s and 0.56 x 10-3 mm2/s. On proton MR spectroscopy obtained in 1 of the patients, a prominent peak resonating at approximately 3.80 ppm was consistently present attributable to the peak rising from the alpha-proton of the phenylalanine molecule.

Congenital cleft in the pontomedullary junction.

A 4-month-old boy is reported with complete absence of horizontal gaze. Magnetic resonance imaging revealed a congenital cleft at the pontomedullary junction directed from the right anterior paramedian region toward the posterior midline, sparing the posterior region of the pontine tegmentum and the medulla oblongata. Such clefts are extremely rare, and there is only 1 previous report in the literature.

Epidural, paraspinal, and subcutaneous lipomatosis.

A unique case of idiopathic diffuse lipomatosis is reported. The patient was an 11-year-old boy with diffuse lipomatosis in the epidural space, paraspinal muscles, and thoracolumbar subcutaneous regions. Epidural lipomatosis involved the entire thoracolumbar spine and was associated with filar thickening and lipoma. In addition, paraspinal muscles, especially the erector spinae group, had diffuse fatty infiltration. The ultimate clinical effect of this fatty tissue was urinary dysfunction, radicular pain and hypoesthesia in both legs and difficulty walking.