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Jonas A Castelijns

Publications and source records attributed to Jonas A Castelijns.

At least 19 recordsLinked to original sources
PubMed2006

Whole-brain T1 mapping in multiple sclerosis: global changes of normal-appearing gray and white matter.

PURPOSE: To prospectively investigate whether T1 changes in normal-appearing white matter (WM) and normal-appearing gray matter (GM) in multiple sclerosis (MS) are global or regional and their relationship to disease type. MATERIALS AND METHODS: The institutional ethics review board approved study; written informed consent was obtained. Whole-brain T1 maps were obtained in 67 patients with MS and 24 healthy control subjects with three-dimensional fast low-angle shot flip angle-array method, with correction for B(1) imperfections. Analysis of variance was performed on T1 histogram parameters of global normal-appearing WM and GM. Regional mean T1 values were analyzed with a multilevel approach. Multiple linear regression analysis was performed to investigate associations with clinical disability and overall atrophy. For patients, T2 lesion load was determined. RESULTS: T1 histograms of normal-appearing WM had significantly higher peak positions for patients with MS (792 msec +/- 36 in secondary progressive [SP] MS) than for control subjects (746 msec +/- 23) and were significantly broader and lower (all P < .001). Histograms for cortical normal-appearing GM were significantly shifted (peak positions, 1263 msec +/- 44 in control subjects and 1355 msec +/- 62 in patients with SP MS) (P < .001). Histogram peak positions were significantly higher in SP MS than in relapsing-remitting (RR) and primary progressive MS (P < .05). In SP disease, at least 31% of normal-appearing WM and 20% of cortical normal-appearing GM were affected. In MS, T1 was significantly elevated in all normal-appearing WM and cortical normal-appearing GM regions (all P < .01) but was elevated only in the thalamus in deep GM (P < .05). Cortical T1 histogram peak position was associated with clinical disability; T2 lesion load was not. CONCLUSION: Results suggest that a global disease process affects large parts of both normal-appearing WM and GM in MS and effects are worse for SP MS than for RR MS.

Adult↗
PubMed2006

Distant metastases in head and neck carcinoma: identification of prognostic groups with MR imaging.

PURPOSE: To evaluate retrospectively the prognostic significance of lymph node parameters assessed on pretreatment magnetic resonance (MR) images for development of distant metastases in patients with head and neck squamous cell carcinomas. MATERIALS AND METHODS: Pretreatment MR images of 311 patients were retrospectively reviewed for the presence of lymph nodes at specific neck node levels as well as the size and the presence of a number of lymph node characteristics including extranodal spread, central necrosis and number and volume of ipsi- and contralateral nodes. Of these patients, 174 (56%) had MRI-positive nodes (defined as nodes with minimum axial diameter >8 and >4 mm for paratracheal level and retropharyngeal nodes). RESULTS: The 2-year distant-metastasis free survival rate (DMFSR) for patients without MRI-positive nodes was 94% compared to 75% for those patients with MRI-positive nodes. In patients with MRI-positive nodes, results of multivariate analysis with the Cox regression model yielded statistical significance for presence of extranodal spread (ENS), detected on MRI, as the only independent prognostic factor associated with the 2-year DMFSR (p=0.002). Based on the analysis, three risk groups regarding the DMFSR could be identified. Low-risk group (DMFSR:94%) consisted of patients without MRI-positive nodes. Intermediate-risk group (DMFSR:81%) consisted of patients with MRI-positive nodes without ENS. High-risk group (DMFSR:59%) consisted of patients with MRI-positive nodes and ENS as shown on MRI (p<0.0001). Statistical separation for different tumor locations showed MRI-determined ENS (larynx: p=0.05; oropharynx: p=0.04; oral cavity: p<0.001), lowjugular/posterior triangle nodes (oropharynx: p=0.02), paratracheal nodes (larynx: p=0.03), and contralateral node volume >5 cm3 (larynx: p=0.03; oral cavity: p=0.02) to be significant predictors with regard to DMFSR. CONCLUSION: Especially patients with on MRI demonstrating extranodal spread and with suspicious nodes at lowjugular/posterior triangle (oropharyngeal cancer) or paratracheal level (laryngeal cancer), or with contralateral enlarged nodes (laryngeal and oral cavity cancer) are at high risk for developing distant metastases and this subset of patients might benefit from supplementary imaging screening (CT-chest, PET-scan).

Carcinoma, Squamous Cell↗
PubMed2006

Performance of immuno-positron emission tomography with zirconium-89-labeled chimeric monoclonal antibody U36 in the detection of lymph node metastases in head and neck cancer patients.

PURPOSE: Immuno-positron emission tomography (PET), the combination of PET with monoclonal antibodies (mAb), is an attractive option to improve tumor detection and to guide mAb-based therapy. The long-lived positron emitter zirconium-89 ((89)Zr) has ideal physical characteristics for immuno-PET with intact mAbs but has never been used in a clinical setting. In the present feasibility study, we aimed to evaluate the diagnostic imaging performance of immuno-PET with (89)Zr-labeled-chimeric mAb (cmAb) U36 in patients with squamous cell carcinoma of the head and neck (HNSCC), who were at high risk of having neck lymph node metastases. EXPERIMENTAL DESIGN: Twenty HNSCC patients, scheduled to undergo neck dissection with or without resection of the primary tumor, received 75 MBq (89)Zr coupled to the anti-CD44v6 cmAb U36 (10 mg). All patients were examined by computed tomography (CT) and/or magnetic resonance imaging (MRI) and immuno-PET before surgery. Six patients also underwent PET with (18)F-fluoro-2-deoxy-d-glucose. Immuno-PET scans were acquired up to 144 hours after injection. Diagnostic findings were recorded per neck side (left or right) as well as per lymph node level (six levels per side), and compared with histopathologic outcome. For this purpose, the CT/MRI scores were combined and the best of both scores was used for analysis. RESULTS: Immuno-PET detected all primary tumors (n = 17) as well as lymph node metastases in 18 of 25 positive levels (sensitivity 72%) and in 11 of 15 positive sides (sensitivity 73%). Interpretation of immuno-PET was correct in 112 of 121 operated levels (accuracy 93%) and in 19 of 25 operated sides (accuracy 76%). For CT/MRI, sensitivities of 60% and 73% and accuracies of 90% and 80% were found per level and side, respectively. In the six patients with seven tumor-involved neck levels and sides, immuno-PET and (18)F-fluoro-2-deoxy-d-glucose PET gave comparable diagnostic results. CONCLUSION: In this study, immuno-PET with (89)Zr-cmAb U36 performed at least as good as CT/MRI for detection of HNSCC lymph node metastases.

Aged↗
PubMed2006

Altered diffusion tensor in multiple sclerosis normal-appearing brain tissue: cortical diffusion changes seem related to clinical deterioration.

PURPOSE: To investigate normal-appearing white (NAWM) and cortical gray (NAGM) matter separately in multiple sclerosis (MS) in vivo using diffusion tensor imaging (DTI). MATERIALS AND METHODS: In 64 MS patients (12 primary progressive [PP], 38 relapsing remitting [RR], 14 secondary progressive [SP]) and 20 healthy controls, whole-brain apparent diffusion coefficient (ADC) and fractional anisotropy (FA) maps were acquired. A stimulated echo acquisition mode (STEAM) DTI sequence was used with minimal geometrical distortion in comparison to echo-planar imaging (EPI). NAWM and NAGM were identified using conventional magnetic resonance (MR) images, allowing a cautious assessment of FA in cortex. RESULTS: Histogram analyses showed significant global FA decreases and ADC increases in MS NAWM compared to control WM. MS cortical NAGM had no significant global ADC increase, but FA was decreased significantly. In regional analyses, nearly all NAWM regions-of-interest (ROIs) had significantly increased ADC compared to controls, but FA was not changed. In nearly all cortical NAGM ROIs, ADC was significantly increased and FA significantly reduced. In multiple linear regression analyses in RR/SPMS patients, NAGM-ADC histogram peak height was associated more strongly with clinical disability than T2 lesion load. CONCLUSION: Tissue damage occurs in both NAWM and cortical NAGM. The cortical damage appears to have more clinical impact than T2 lesions.

Adult↗
PubMed2006

MR spectroscopic evidence for thalamic and hippocampal, but not cortical, damage in multiple sclerosis.

Gray matter (GM) damage is an important pathophysiological feature in Multiple Sclerosis (MS), and may be related to clinical, including cognitive, deficits. Quantitative single-voxel (1)H-Magnetic Resonance Spectroscopy (TR/TE 6000/20 ms) was performed in 33 MS patients (11 per disease subtype; mean age 48 years, 16 females) and 10 healthy controls (mean age 43 years, 7 females). No overall spectroscopic changes were found in MS cortex. In MS thalamus, a 9% decrease of N-acetyl aspartate (NAA; P=0.005) and a 31% increase of myo-inositol (Ins; P=0.002) were found. A 21% Ins increase was observed (P=0.02) in MS hippocampus. Reduced NAA and increased Ins concentrations are thought to reflect neuro-axonal damage or loss and gliosis, respectively. Significant correlations between Ins concentrations and total-brain T(2) lesion load were found for MS thalamus (r=0.65, P<0.001) and hippocampus (r=0.57, P=0.001). MS thalamic and hippocampal Ins concentrations also correlated with each other (r=0.68; P<0.001). Cortical Gln correlated with thalamic NAA (r=-0.38; P=0.03) in MS. Thalamic and hippocampal Ins increases were most prominent in secondary-progressive (SP) patients (37% and 34%, respectively), whereas the largest thalamic NAA decrease (14%) was found in primary-progressive (PP) patients. In conclusion, thalamic and hippocampal GM pathology are important features of (progressive) MS.

Adult↗
PubMed2006

Atrophic chorioretinal scar and focal scleral bowing following thermochemotherapy with a diode laser for retinoblastoma.

One of the treatment options for intraocular retinoblastoma is thermochemotherapy with diode laser combined with chemotherapy. Very little is known about the evolution of laser scars resulting from diode laser treatment for retinoblastoma. We report a case of atrophic chorioretinal scar and focal scleral bowing after thermochemotherapy with diode laser for retinoblastoma.

Antineoplastic Agents↗
PubMed2005

Screening for distant metastases in patients with head and neck cancer: is there a role for (18)FDG-PET?

The detection of distant metastases and second primary tumours at the time of initial evaluation changes the prognosis and influences the selection of treatment modality in patients with HNSCC. Until recently chest CT was the single most effective test to screen for distant metastases in HNSCC patients. In this observational cohort study we prospectively compared the yield of whole body (18)FDG-PET and chest CT to detect distant metastases and synchronous primary tumours. The results of whole body (18)FDG-PET and chest CT were analysed in 34 consecutive HNSCC patients with previously established risk factors for the presence of distant metastases. Four patients were diagnosed with distant metastases or second primary tumours: CT as well as (18)FDG-PET identified one patient with lung metastases and another with primary lung cancer. In addition, (18)FDG-PET detected second primary tumours in two patients (hepatocellular carcinoma and abdominal adenocarcinoma). However increased uptake sites at (18)FDG-PET in lung, liver and pelvis in five patients were not confirmed by other imaging modalities. The added value of whole body (18)FDG-PET versus chest CT was to identify unknown malignancy in 6% of the patients. Confirmation of positive (18)FDG-PET findings is feasible and necessary.

Adult↗
PubMed2005

Retinoblastoma: MR imaging parameters in detection of tumor extent.

PURPOSE: To assess diagnostic accuracy of preoperatively performed magnetic resonance (MR) imaging for detection of tumor extent in a large patient population with histopathologically proved retinoblastoma. MATERIALS AND METHODS: Local ethics committee approval and informed consent were not required for retrospective review of patients' images and records. Fifty-eight eyes in 28 girls (mean age, 21 months; range, 2-59 months) and 28 boys (mean age, 24 months; range, 2-76 months) with retinoblastoma were retrospectively reviewed by one radiologist on unenhanced T1-weighted, dual-echo T2-weighted, and gadolinium-enhanced T1-weighted MR images. MR imaging parameters such as growth pattern, anterior chamber hyperintensity, and involvement of choroid, ciliary body, optic nerve, sclera, orbital fat, and pineal gland were determined. Tumor volume was measured and correlated to metastatic risk factors. Imaging and pathologic findings were compared. Statistical analysis was performed by using logistic regression with log likelihood ratio chi(2) test or Fisher exact test. RESULTS: Choroidal invasion was suspected with MR imaging in 21 eyes; findings were false-positive in 13 eyes and false-negative in three (73% sensitivity, 72% specificity, 72% accuracy). Anterior chamber hyperintensity on T1-weighted MR images obtained after contrast agent administration correlated well with clinical presence of reactive neovascular processes. MR imaging findings were true-positive in 21 of 32 eyes with proved prelaminar optic nerve invasion (66% sensitivity) and false-positive in one (96% specificity, 79% accuracy). Postlaminar optic nerve invasion was correctly detected in two eyes; in two other eyes, this metastatic risk factor was missed (50% sensitivity, 100% specificity, 97% accuracy). Scleral and extrascleral tumor invasion were correctly excluded in all eyes. Tumor volume was statistically associated with prelaminar optic nerve invasion (P = .001) and choroidal invasion (P = .031). CONCLUSION: MR imaging is accurate for tumor staging and detection of metastatic risk factors; detection of intraocular tumor infiltration remains difficult. Tumor volume, measured with MR imaging, was associated with prelaminar optic nerve and choroidal involvement.

Child↗
PubMed2005

Histopathologic validation of the sentinel node concept in oral and oropharyngeal squamous cell carcinoma.

BACKGROUND: In patients with head and neck squamous cell carcinoma (HNSCC), the presence of lymph node metastases is the most important prognosticator. Sentinel node (SN) biopsy has been shown to be an accurate staging technique for patients with breast cancer and melanoma and might also be suited for patients with HNSCC. This study was undertaken to determine whether the SN concept holds true for HNSCC and could be exploited for SN biopsy. METHODS: In 22 patients with T2 to T4 N0 oral or oropharyngeal squamous cell carcinoma (SCC) who were scheduled to undergo combined primary tumor excision and elective unilateral (n = 17) or bilateral (n = 5) neck dissection, SN identification was performed the day before surgery by use of lymphoscintigraphy after peritumoral injections of 99mTc-labeled colloidal albumin. After the neck dissection specimens were removed, all SNs, all other radioactive lymph nodes, and all nonradioactive lymph nodes were retrieved for histopathologic analysis, including serial sectioning at 250-microm intervals and immunohistochemical analysis (IHC). RESULTS: Overall, in 21 (78%) of 27 neck sides, an SN was identified by scintigraphy. Of the six neck sides in which SNs were not identified by scintigraphy, four were from three patients who underwent bilateral neck dissection. In another patient treated by bilateral neck dissection, the SN identified by scintigraphy could not be found in the specimen. In the remaining 20 neck dissection specimens, 23 SNs and 30 additional radioactive lymph nodes could be found. At histologic examination of the 20 neck specimens in which the SN was found, at least one SN was tumor positive in eight cases. In one neck specimen, a metastasis was detected in a nonradioactive lymph node, whereas the SN was tumor free, also at serial sectioning and IHC. In the remaining 11 neck sides in which the SN was tumor negative, none of the other radioactive (n = 13) and none of the nonradioactive (n = 279) lymph nodes contained tumor at histopathologic analysis, including serial sectioning and IHC. The sensitivity of the SN procedure for predicting lymph node metastases, therefore, was 89% (eight of nine neck specimens) when an SN was identified by scintigraphy and found in the specimen. The overall accuracy of the SN procedure for predicting the presence or absence of lymph node metastases in the neck was 95% (19 of 20 neck specimens). CONCLUSIONS: Our study seems to validate the SN hypothesis for oral and oropharyngeal cancer. The role of SN biopsy in the management of the N0 neck in such patients has yet to be established through prospective trials. SN identification (and thus biopsy) does not seem to be reliable in patients with tumors located in or close to the midline.

Adult↗
PubMed2005

In vivo detection of myelin proteins in cervical lymph nodes of MS patients using ultrasound-guided fine-needle aspiration cytology.

Cervical lymph nodes (CLN) have been described to be the first lymphoid draining site of the brain. In this study we used ultrasound guided fine needle aspiration cytology (USgFNAC) to obtain cells, in vivo, from non-enlarged CLN of multiple sclerosis (MS) patients and HCs (HC), and investigated whether myelin proteins could be detected. Macrophages containing myelin basic protein (MBP) and proteolipid protein (PLP) were found in CLN of all MS patients, whereas these could only be detected in a minority of HC. This novel approach allows investigation of the first draining site of the brain for in vivo analysis of the immune regulation of MS.

Adult↗
PubMed2005

Screening for distant metastases in patients with head and neck cancer: is chest computed tomography sufficient?

OBJECTIVES/HYPOTHESIS: The detection of distant metastases during screening influences the choice of treatment in patients with head and neck squamous cell carcinoma. A previous study in the authors' institution showed that chest computed tomography (CT) scan was the most important screening technique. Different clinical risk factors in patients with head and neck squamous cell carcinoma for the development of distant metastases were identified. STUDY DESIGN: Retrospective cohort study. METHODS: To evaluate the authors' diagnostic strategy, the accuracy of screening for distant metastases with chest CT in 109 consecutive patients with head and neck squamous cell carcinoma with risk factors between 1997 and 2000 was retrospectively analyzed. RESULTS: Preoperative screening with CT revealed 20 patients (18%) with lung metastases and 1 liver metastasis. Despite negative screening with chest CT, 9 (11%) patients developed distant metastases within 12 months during follow-up. Sensitivity of the chest CT was 73%; the specificity was 80%. CONCLUSION: Although chest CT frequently detects distant metastases, there seems to be a need for a more sensitive and whole-body screening technique.

Algorithms↗
PubMed2005

Intracortical lesions in multiple sclerosis: improved detection with 3D double inversion-recovery MR imaging.

PURPOSE: To prospectively compare the depiction of intracortical lesions by using multislab three-dimensional (3D) double inversion-recovery (DIR), multislab 3D fluid-attenuated inversion-recovery (FLAIR), and T2-weighted spin-echo (SE) magnetic resonance (MR) imaging in patients with multiple sclerosis. MATERIALS AND METHODS: Local ethics review board approval and informed consent were obtained. Conventional T2-weighted SE and multislab 3D FLAIR and DIR images were acquired in 10 patients with multiple sclerosis (five women, five men) and 11 age-matched healthy control subjects (seven women, four men). Mean age was 40 years (range, 25-54 years) in patients and 34 years (range, 24-55 years) in control subjects. Lesions were classified according to seven anatomic regions: intracortical, mixed white matter-gray matter, juxtacortical, deep gray matter, periventricular white matter, deep white matter, and infratentorial lesions. The numbers of lesions per category were compared between techniques (Dunnett-corrected analysis of variance). Gain or loss (with 95% confidence intervals [CIs]) of numbers of lesions detected at 3D DIR imaging was calculated in comparison with those detected at T2-weighted SE and 3D FLAIR imaging. RESULTS: Total number of lesions did not differ between 3D DIR and 3D FLAIR sequences, but the 3D DIR sequence showed a gain of 21% (95% CI: 4%, 41%) in comparison with the T2-weighted SE sequence. Because of high gray matter-white matter contrast, DIR images depicted more intracortical lesions (80 lesions in 10 patients) than both SE (10 lesions) and FLAIR (31 lesions) images; gains with DIR were 538% (95% CI: 191%, 1297%) and 152% (95% CI: 15%, 453%) compared with SE and FLAIR, respectively. Only four intracortical lesions were detected in control subjects. Also, DIR imaging enabled a better definition of mixed white matter-gray matter lesions because of greater contrast between the lesion and its surroundings. CONCLUSION: MR imaging with 3D DIR enables increased intracortical lesion detection in the multiple sclerosis brain, as well as improved distinction between juxtacortical and white matter-gray matter lesions.

Adult↗
PubMed2005

Cortical lesions in multiple sclerosis: combined postmortem MR imaging and histopathology.

BACKGROUND AND PURPOSE: Cortical lesions constitute a substantial part of the total lesion load in multiple sclerosis (MS) brain. They have been related to neuropsychological deficits, epilepsy, and depression. However, the proportion of purely cortical lesions visible on MR images is unknown. The aim of this study was to determine the proportion of intracortical and mixed gray matter (GM)-white matter (WM) lesions that can be visualized with postmortem MR imaging. METHODS: We studied 49 brain samples from nine cases of chronic MS. Tissue sections were matched to dual-echo T2-weighted spin-echo (T2SE) MR images. MS lesions were identified by means of myelin basic protein immunostaining, and lesions were classified as intracortical, mixed GM-WM, deep GM, or WM. Investigators blinded to the histopathologic results scored postmortem T2SE and 3D fluid-attenuated inversion recovery (FLAIR) images. RESULTS: Immunohistochemistry confirmed 70 WM, eight deep GM, 27 mixed GM-WM, and 63 purely cortical lesions. T2SE images depicted only 3% of the intracortical lesions, and 3D FLAIR imaging showed 5%. Mixed GM-WM lesions were most frequently detectable on T2SE and 3D FLAIR images (22% and 41%, respectively). T2SE imaging showed 13% of deep GM lesions versus 38% on 3D FLAIR. T2SE images depicted 63% of the WM lesions, whereas 3D FLAIR images depicted 71%. Even after side-by-side review of the MR imaging and histopathologic results, many of the intracortical lesions could not be identified retrospectively. CONCLUSION: In contrast to WM lesions and mixed GM-WM lesions, intracortical lesions remain largely undetected with current MR imaging resolution.

Adult↗
PubMed2004

The spinal cord in multiple sclerosis: relationship of high-spatial-resolution quantitative MR imaging findings to histopathologic results.

PURPOSE: To correlate quantitative magnetic resonance (MR) imaging data (ie, relaxation times and magnetization transfer ratios [MTRs]) with histopathologic findings of demyelination and axonal disease in cervical spinal cord specimens from patients with multiple sclerosis (MS) and control subjects. MATERIALS AND METHODS: Formaldehyde-fixed cervical spinal cord specimens from 11 patients with MS-three men and eight women (mean age at death, 66 years +/- 11.3 [standard deviation])-and two female control subjects without neurologic disease (83 and 41 years of age at death) were examined at 4.7 T. Relaxation time measurements and MTR mapping were performed. Analyses included the whole cord area and region-of-interest measurements. Histopathologic analyses included semiquantitative myelin and quantitative axonal analysis. RESULTS: Compared with control specimens (P < .001, analysis of variance), specimens from patients with MS had smaller cord areas (mean area, 59.0 mm(2) +/- 12.5 vs 72.7 mm(2) +/- 10.0), significant prolongation of T1 (mean prolongation, 30%) and T2 (mean prolongation, 13%), and decreased MTRs (mean, 10.5%). Within MS specimens, 58% of the white matter area displayed signal intensity abnormalities on intermediate-weighted MR images. The number of axons in normal-appearing white matter in MS specimens was, on average, 46% lower than the number of axons in white matter in control specimens. All quantitative MR parameters correlated well with demyelination; the correlation with T2 relaxation time was the strongest (r = 0.77, Spearman and Kendall nonparametric correlations). By contrast, quantitative MR parameters correlated less well with axonal density; the correlation with T2 relaxation time was the strongest (r = -0.44, Spearman and Kendall nonparametric correlations). Multilevel analysis, corrected for age and MS phenotype, could not result in a model explaining axonal density on the basis of quantitative MR parameters when myelin density was included as a predictor. CONCLUSION: Changes in quantitative MR imaging parameters in the cervical spinal cord in MS are mainly determined by demyelination and do not reflect axonal disease well.

Adult↗
PubMed2004

Infratentorial lesions predict long-term disability in patients with initial findings suggestive of multiple sclerosis.

BACKGROUND: The number and volume of abnormalities on baseline brain magnetic resonance images in patients with initial findings suggestive of multiple sclerosis are known to predict outcome in terms of disability. However, no long-term data exist on specific locations or types of lesions. OBJECTIVE: To assess the long-term predictive value of baseline magnetic resonance imaging parameters, including location of lesions and gadolinium-enhancing and hypointense lesions in patients with initial findings suggestive of multiple sclerosis for the occurrence of clinically relevant disability as defined by an Expanded Disability Status Scale score of 3. PATIENTS: After a median follow-up period of 8.7 years, the medical records of 42 patients were reviewed and assessed for time until patients received an Expanded Disability Status Scale score of 3. Magnetic resonance imaging parameters were dichotomized according to maximum accuracy and then used to calculate hazard ratios using the Cox model for proportional hazard ratios. RESULTS: Conversion to clinically definite multiple sclerosis was observed in 26 patients (62%), of whom 14 (54%) progressed to an Expanded Disability Status Scale score of 3. Two or more infratentorial lesions best predicted long-term disability (hazard ratio, 6.3). Gadolinium-enhancing and hypointense T1-weighted lesions did not show prognostic value. CONCLUSION: Infratentorial lesions are related to long-term prognosis for patients with initial findings suggestive of multiple sclerosis and thus may help to identify patients at high risk for earlier occurrence of clinically relevant disability.

Adolescent↗
PubMed2004

Quantitative 1H-MRS of healthy human cortex, hippocampus, and thalamus: metabolite concentrations, quantification precision, and reproducibility.

PURPOSE: To evaluate metabolite concentrations in cortical gray matter, hippocampus, and thalamus of healthy adults, and to investigate precision and reproducibility of quantitative proton magnetic resonance spectroscopy (1H-MRS) in these gray matter regions. MATERIALS AND METHODS: Quantitative single-voxel short echo-time spectra were obtained from healthy human cortex, hippocampus, and thalamus. Subjects were examined twice. Metabolite concentrations, quantification precision, and reproducibility were determined. RESULTS: There were no significant differences between test and retest measurements. Regional differences were observed with respect to metabolite concentrations, quantification precision, and reproducibility. Quantification precision and reproducibility of N-acetylaspartate and N-acetyl aspartylglutamate (tNAA), creatine and phosphocreatine (tCr), choline-containing compounds (Cho), and myo-inositol (myo-Ins), were better than those of glutamate (Glu) and glutamine (Gln). Generally, precision and reproducibility were better in cortex than in hippocampus or thalamus. The quantification precision was shown to correlate both with reproducibility and spectral linewidth. CONCLUSION: The reliability of quantitative MRS depends on the metabolite concerned, its concentration, and on the brain area studied. Moreover, the quantification precision of a metabolite in a single spectrum appears to be a reliable measure for its reproducibility in a longitudinal study.

Adult↗