Proton MR spectroscopy in a possible enhancing hamartoma in a patient with neurofibromatosis type 1 (original) (raw)
1995
To use proton MR spectroscopy in patients with neurofibromatosis type 1 to determine: (a) the spectroscopic characteristics of hamartomas and compare them with that of gliomas; (b) whether differences exist between patients with and without learning disabilities; and (c) spectroscopic patterns in normal-appearing brain (by MR imaging) in patients with and without focal lesions. METHODS: Seventeen proton MR spectroscopy volumes were obtained in 10 patients with neurofibromatosis type 1 (including hamartomas, N ϭ 7; normal-appearing brain, N ϭ 10). Seven patients had learning disorders, and 3 were mentally normal. Ten healthy volunteers and 10 patients with pathologically proved gliomas (all grades) were also examined. N-Acetyl aspartate/ creatine, creatine/choline, and N-acetyl aspartate/choline ratios were calculated for all samples. RESULTS: (a) Hamartomas showed higher N-acetyl aspartate/creatine, creatine/choline, and N-acetyl aspartate/choline ratios than gliomas. Hamartomas showed N-acetyl aspartate/creatine, creatine/choline, and N-acetyl aspartate/choline ratios similar to those of healthy volunteers. (b) No significant differences in N-acetyl aspartate/creatine, creatine/choline, and N-acetyl aspartate/ choline ratios were found in patients who had neurofibromatosis type 1 with and without learning disabilities. (c) N-acetyl aspartate/creatine, creatine/choline, and N-acetyl aspartate/choline ratios were similar for patients who had neurofibromatosis type 1 with and without focal hamartomas and in healthy volunteers. CONCLUSIONS: (a) Hamartomas have a proton MR spectroscopy pattern different from that of glioma and similar to that of normal brain. (b) As performed in this study, proton MR spectroscopy did not show significant differences in patients who had neurofibromatosis type 1 with and without learning disabilities. (c) Patients who have neurofibromatosis type 1 with and without hamartomas seem to have normal intervening brain by proton MR spectroscopy when compared with healthy volunteers.
Proton MR spectroscopy features of normal appearing white matter in neurofibromatosis type 1
Magnetic Resonance Imaging, 2003
To determine whether differences exist between neurofibromatosis type 1 (NF1) patients with or without focal lesions and healthy normal volunteers in the metabolite ratios of normal appearing white matter, 27 patients with NF1 (with parenchymal lesion, MR positive, n: 17; without parenchymal lesions, MR negative, n: 10) and 20 healthy volunteers underwent MRI and short TE (31 ms) proton MR spectroscopy (MRS). In 17 patients with parenchymal lesions, 61 focal lesions were detected by MRI. MRS was performed from normal appearing frontal and posterior parietal white matter (FWM and PWM) in NF1 and from control groups. NAA/Cr, Cho/Cr and MI/Cr ratios were calculated. Significant increase in Cho/Cr and MI/Cr ratios were found in FWM and PWM in MR negative and positive groups when compared to control group. NAA/Cr ratio in MR positive group was significantly decreased in FWM compared to control group. There were no significant differences between FWM and PWM in all metabolite ratios of MR negative group. MI/Cr ratio in MR positive group was significantly elevated in PWM compared to FWM. Metabolite changes detected by MRS could indicate demyelination and gliosis in normal appearing white matter in all NF1 patients, and additionally neuroaxonal damage in the FWM of NF1 patients with focal lesions. For that reason, in the clinical evaluation and follow-up of these patients MRS features of normal appearing white matter should be considered in addition to focal lesions.
Proton MR spectroscopy of pediatric cerebellar tumors
AJNR. American journal of neuroradiology, 1995
PURPOSE To investigate the role of proton MR spectroscopy in pediatric cerebellar tumor diagnosis. METHODS Single voxel pulse sequences with long echo time (135 or 270 milliseconds, voxel size 8 to 19 cm3), were used to obtain proton spectra of primary pediatric cerebellar tumors. Eleven primitive neuroectodermal tumors (patient age, 2 to 12 years; mean, 7 years), 11 low-grade astrocytomas (age, 2 to 16 years; mean, 9 years), 4 ependymomas (age, 1 to 6 years; mean, 4 years), 1 mixed glioma ependymo-astrocytoma (age, 11 years), 1 anaplastic ependymoma (age, 7 years), 1 ganglioglioma (age, 14 years), and 1 malignant teratoma (age, 6 days) were studied. Control cerebellum spectra were acquired from five patients without abnormality in cerebellum (age, 2 to 15 years; mean, 8 years). The signal intensities from choline-containing compounds (Cho), creatine/phosphocreatine (Cr), N-acetyl-aspartate (NAA), and lactate (Lac) were quantified. The mean and standard deviation of metabolite ratio...
Imaging Review of Neurofibromatosis: Helpful Aspects for Early Detection
Iranian Journal of Radiology
Neurofibromatosis (NF) is divided into two types, NF type 1 and NF type 2. Optic nerve gliomas have a high degree of association with NF type 1. NF 2, less commonly seen, is a complex of cutaneous and deep neural tumors. It is an autosomal dominant familial disorder in which CNS is affected in about 15% of the cases. Bilateral acoustic neuromas are pathognomonic of NF type 2 which may be associated with meningiomas or ependymomas. Typical clinical manifestations of neurofibromatosis are cafe-au-lait spots and multiple cutaneous tumors. There is bone involvement as scoliosis, pseudoarthrosis of long bones, scalloping of vertebral bodies, abnormal rib tubulation and defective ossification of the skull. Extraskeletal manifestations of neurofibromatosis include optic nerve gliomas, pheochromocytoma, aneurysms of cerebral and renal arteries, acoustic neurilemmoma and superficial skin nodular neurofibromas.
Surgical Neurology International, 2019
Background: Neurofibromatosis is an autosomal dominant disorder of the nerves, resulting in café-au-lait spots, axillary freckling, macules, and neurofibromas throughout the nervous system. Diagnosis of this condition has in the past been mainly clinical, but the usage of magnetic resonance imaging neurography (MRN) is a new diagnostic modality. Here, we report on a case of neurofibromatosis type I (NF-1) that was diagnosed using MRN after a protracted clinical course. Case Description: A 23-year-old female presented with several months of worsening right upper and lower quadrant abdominal pain. The patient underwent computed tomography (CT) of the abdomen and pelvis demonstrating multiple neurofibromas involving the psoas muscle and mesentery of the lower abdomen. Subsequent total neuronal axis magnetic resonance imaging (MRI) using the neurography protocol (MRN) showed multiple neurofibromas in both the right brachial plexus and lumbar plexus. Conclusion: We present a case of NF-1 that was diagnosed using MRN following a protracted clinical course. MRN is a diagnostic modality for NF-1 and other peripheral nerve disorders.
Proton MR spectroscopy of cerebellitis
Magnetic resonance imaging, 2002
Single voxel proton MR spectroscopy ((1)H-MRS) of the vermis was obtained in two patients with cerebellitis. In the acute phase (1)H-MRS revealed low N-acetyl-aspartate (NAA)/creatine (Cr) and NAA/choline (Cho) and normal Cho/Cr ratios. Decrease of the concentration of NAA was confirmed by quantitative analysis in one patient. The NAA/Cr and NAA/Cho ratios and NAA concentration were increased in (1)H-MRS examinations obtained 10 and 24 months after the acute episode. (1)H-MRS demonstrates reversible metabolite changes in cerebellitis.
Clinical applications of proton MR spectroscopy in the diagnosis of brain tumours
Spectroscopy, 2004
There are few but important problems in magnetic resonance (MR) diagnosis of the brain tumours such as predicting the grade, exact definition of the tumour borders, differentiation of the cystic tumours from abscess, the tumoral core from peritumoral oedema, and the tumour recurrence from radiation necrosis. MR spectroscopy (MRS) can add more information to MR imaging (MRI) in solving many of these problems. Widespread usage of faster MRS applications with higher signalto-noise ratio (SNR) and spatial resolution, allows us to detect functional metabolic changes, which provides more data to understand the exact nature of the tumour and the morphological and physiological changes occurring in the surrounding brain parenchyma.
Neurofibromatosis type 1: the evolution of deep gray and white matter MR abnormalities
AJNR. American journal of neuroradiology, 1994
To investigate the evolution of deeply located high-signal-intensity abnormalities of the brain on T2-weighted MR images of patients with neurofibromatosis type 1 (NF-1). The study consists of two patient groups: 1) retrospective evaluation of MR scans of 24 symptomatic NF-1 patients, 10 of whom were sequentially studied, and 2) prospective MR evaluations of 20 asymptomatic NF-1 subjects from 14 families; 2 of these families were sequentially studied. Deeply located, high-signal-intensity abnormalities on T2-weighted images were noted in 34 of 44 NF-1 subjects (77%). If NF-1 patients are grouped according to age, 28 of 30 subjects (93%) younger than 15 years had the lesions, whereas 4 of 7 subjects (57%) between 16 and 30 years, and 2 of 7 subjects (29%) older than 31 years had lesions. High-signal lesions in basal ganglia and brain stem were demonstrated in all decades with relatively high frequency. Lesions in the cerebellar white matter and dentate nuclei were mainly found in the...
Proton magnetic resonance spectroscopy of brain-stem lesions
Neuroradiology, 2002
Recently, proton magnetic resonance spectroscopy (MRS) has assumed a role in imaging of brain lesions [1, 2, 3, 4]. The information it provides complements that obtained from MRI and often provides greater tissue characterization. Proton MRS can be used to distinguish between normal and abnormal tissues, aid in the grading of brain tumors, and may enable the distinction between tumors and inflammatory and infectious processes [4]. Technically, proton MRS of lesions in the cerebral and cerebellar hemispheres is relatively easy. Near the base of skull, proton MRS is technically difficult due to the smallness of some structures and magnetic susceptibility artifacts from adjacent bone, fat, and air interfaces. We undertook a review of the proton MRS studies on 34 patients who, during their initial clinical presentation, showed solitary lesions in the brain stem. We compared the results with the histological or presumed diagnoses. Materials and methods We reviewed 34 patients. All spectroscopic studies were obtained one day after contrast-enhanced MRI. Axial T2-weighted images were repeated and used to guide voxel placement, which was also influenced by the position of any areas of contrast enhancement.
Clinical Proton MR Spectroscopy in Central Nervous System Disorders
Radiology, 2014
Abbreviations: CNS = central nervous system Cr = creatine Gln = glutamine Glu = glutamate Lac = lactate mIns = myo-inositol NAA = N-acetylaspartate PRESS = point-resolved spectroscopy SNR = signal-to-noise ratio STEAM = stimulated echo acquisition mode tCho = total choline tCr = total creatine TE = echo time tNAA = NAA + N-acetylaspartylglutamate
Symptomatic hamartoma of the spinal cord associated with neurofibromatosis type 1
Journal of Neurosurgery, 1998
✓ The authors present a case in which a symptomatic hamartoma was found in the spinal cord of a patient with neurofibromatosis type 1 (NF-1). This 52-year-old woman presented with painful urinary incontinence. Magnetic resonance (MR) imaging revealed an intramedullary lesion within the lower thoracic spinal cord and conus medullaris, which was surgically removed. Pathological investigation showed a hamartomatous lesion consisting of glial cells, ganglion cells, abundant disoriented axons, and thin-walled vessels. This case provides a pathological correlate to the hamartomatous lesions demonstrated on MR imaging in patients with NF-1 and illustrates that these benign lesions may become symptomatic and require neurosurgical intervention.
Characterization of intracranial mass lesions with in vivo proton MR spectroscopy
AJNR. American journal of neuroradiology, 1995
To assess the use of in vivo proton MR spectroscopy for characterization of intracranial mass lesions and to ascertain its reliability in grading of gliomas. One hundred twenty patients with intracranial masses were subjected to volume selective spectroscopy using stimulated echo acquisition mode (echo time, 20 and 270 milliseconds) and spin echo (echo time, 135 milliseconds) sequences. The intracranial lesions were grouped into intraaxial and extraaxial, as judged with MR imaging. Assignment of resonances was confirmed in two samples each of brain abscess, epidermoid cyst, and tuberculoma using ex vivo high-resolution MR spectroscopy. The in vivo spectra appeared distinct compared with normal brain in all the cases. All high-grade gliomas (n = 37) showed high choline and low or absent N-acetyl-L-aspartate and creatine along with lipid and/or lactate, whereas low-grade gliomas (n = 23) were characterized by low N-acetyl-aspartate and creatine and high choline and presence of only la...
Synthetic MRI in Neurofibromatosis Type 1
American Journal of Neuroradiology, 2021
BACKGROUND AND PURPOSE: Synthetic MRI enables the generation of various contrast-weighted images and quantitative data in a reasonable scanning time. We aimed to use synthetic MRI to assess the detection and underlying tissue characteristics of focal areas of signal intensity and normal-appearing brain parenchyma and morphometric alterations in the brains of patients with neurofibromatosis type 1. MATERIALS AND METHODS: Conventional MR imaging and synthetic MRI were prospectively obtained from 19 patients with neurofibromatosis type 1 and 18 healthy controls. Two neuroradiologists independently evaluated focal areas of signal intensity on both conventional MR imaging and synthetic MRI. Additionally, automatically segmented volume calculations of the brain in both groups and quantitative analysis of myelin, including the focal areas of signal intensity and normal-appearing brain parenchyma, of patients with neurofibromatosis type 1 were performed using synthetic MRI. RESULTS: The comparison of conventional MR imaging and synthetic MRI showed good correlation in the supratentorial region of the brain (k ¼ 0.82-1). Automatically segmented brain parenchymal volume, intracranial volume, and GM volumes were significantly increased in the patients with neurofibromatosis type 1 (P , .05). The myelin-correlated compound, myelin fraction volume, WM fraction volume, transverse relaxation rate, and longitudinal relaxation rate values were significantly decreased in focal areas of signal intensity on myelin and WM maps (P , .001); however, GM, GM fraction volume, and proton density values were significantly increased on the GM map (P , .001). CONCLUSIONS: Synthetic MRI is a potential tool for the assessment of morphometric and tissue alterations as well as the detection of focal areas of signal intensity in patients with neurofibromatosis type 1 in a reasonable scan time. ABBREVIATIONS: BPF ¼ brain parenchymal fraction; BPV ¼ brain parenchymal volume; cMRI ¼ conventional MRI; FASI ¼ focal areas of signal intensity; GMFvol ¼ mean amount of GM within a single voxel; HC ¼ healthy control; ICV ¼ intracranial volume; MY ¼ myelin; MyCvol ¼ myelin correlated fraction volume; MyF ¼ myelin fraction; MyV ¼ myelin correlated volume; NABP ¼ normal-appearing brain parenchyma; NF-1 ¼ neurofibromatosis type 1; NoN, non-GM/ WM/CSF; PD ¼ proton density; QRAPMASTER ¼ quantification of relaxation times and proton density by multiecho acquisition of a saturation-recovery using turbo spin-echo readout; R1 ¼ longitudinal relaxation rate; R2 ¼ transverse relaxation rate; SyMRI ¼ synthetic MRI; WMFvol ¼ the mean amount of WM within a single voxel
European Radiology, 2007
Benign and malignant neoplasms as well as metastatic lymph nodes of 39 patients were examined using localized single voxel magnetic resonance spectroscopy (MRS) [repetition time (TR) 1500, echo time (TE) 135) at 1.5 T. New techniques with simultaneous correction of motion artefacts during the acquisition, three-dimensional saturation pulses, respiratory triggering and smaller volume of interest (VOI) size, were applied. Ratios of peak areas under the choline (Cho) and creatine (Cr) resonances were estimated in all cases and compared with those from samples of normal tissue. Ninety one spectra were acquired in 39 patients, 63 of which were suitable for further evaluation. The smallest VOI was 0.40 cm3. The Cho/Cr ratios in all malignant neoplasms (mean: 5.2, range: 1.7–17.8) were significantly elevated relative to those in the normal muscle structures (mean: 0.9, range: 0.2–1.4), while those in the benign neoplasms were elevated (mean: 24.4, range: 1.4–59.7) with respect to those in the malignant ones. The average Cho/Cr ratio in the metastatic lymph nodes was significantly higher (mean: 4.8, range: 3.3–5.6) than that for benign lymphoid hyperplasia (mean: 2.2, range: 1.0–3.0). MRS measurements were able to differentiate recurrent disease from post-therapeutic tissue changes in 11 out of 13 patients.