PATH53 Magnetic susceptibility of substantia nigra in Parkinson's disease: a 7-T in vivo MRI study

Bajaj, Nin; Schäfer, Andreas; Wharton, Samuel; Gontu, Vamsi; Bowtell, Richard; Auer, D. P.; Gowland, Penny A.; Schwartz, Shira; Lotfipour, Ashley K.

doi:10.1136/jnnp.2010.226340.21

Cited by 6 publications

(2 citation statements)

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“…Treatment of PD by means of deep brain stimulation depends greatly on correct positioning of the stimulating electrode in the target areas. Cho et al [45] showed that 7 T MRI was superior in delineating these areas compared to 1.5 T and 3.0 T. Bajaj et al [46] showed that 7 T MRI could distinguish subregions of the substantia nigra, and found an increased iron content in a part of this basal ganglion in PD patients compared to healthy volunteers. Recently, Oh et al [47] visualized differences in anatomical patterns of the substantia nigra between healthy controls and PD patients with 7 T MRI, possibly enabling earlier diagnosis of PD.…”

Section: Degenerative Brain Diseasesmentioning

confidence: 99%

Clinical applications of 7T MRI in the brain

Kolk

Hendrikse

Zwanenburg

et al. 2013

European Journal of Radiology

228

155

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This review illustrates current applications and possible future directions of 7 Tesla (7 T) Magnetic Resonance Imaging (MRI) in the field of brain MRI, in clinical studies as well as clinical practice. With its higher signal-to-noise (SNR) and contrast-to-noise ratio (CNR) compared to lower field strengths, high resolution, contrast-rich images can be obtained of diverse pathologies, like multiple sclerosis (MS), brain tumours, aging-related changes and cerebrovascular diseases. In some of these diseases, additional pathophysiological information can be gained compared to lower field strengths. Because of clear depiction of small anatomical details, and higher lesion conspicuousness, earlier diagnosis and start of treatment of brain diseases may become possible. Furthermore, additional insight into the pathogenesis of brain diseases obtained with 7 T MRI could be the basis for new treatment developments. However, imaging at high field comes with several limitations, like inhomogeneous transmit fields, a higher specific absorption rate (SAR) and, currently, extensive contraindications for patient scanning. Future studies will be aimed at assessing the advantages and disadvantages of 7 T MRI over lower field strengths in light of clinical applications, specifically the additional diagnostic and prognostic value of 7 T MRI.

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Section: Degenerative Brain Diseasesmentioning

confidence: 99%

Clinical applications of 7T MRI in the brain

Kolk

Hendrikse

Zwanenburg

et al. 2013

European Journal of Radiology

228

155

View full text Add to dashboard Cite

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“…Hence, in PD, iron accumulation may mitigate the T1 signal reduction resulting from neuromelanin loss. A recent high‐resolution iron mapping study using susceptibility mapping at 7T suggested a significant but small increase in iron content in patients with PD with significant interindividual and spatial heterogeneity 31. This may contribute to interindividual variability in T1 contrast and underscores the advantage of the proposed areametric method.…”

Section: Discussionmentioning

confidence: 98%

Combined treatment with pegylated interferon–α‐2a and dacarbazine in patients with advanced metastatic melanoma

Hauschild¹,

Dummer²,

Ugurel³

et al. 2008

Cancer

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BACKGROUND.Dacarbazine (DTIC) and pegylated interferon (IFN)–α‐2a have both demonstrated some efficacy as single agents in metastatic melanoma. To the authors' knowledge, the current study is the first to test a combination of these 2 agents in a phase 2 trial.METHODS.Twenty–eight patients with stage IV melanoma without brain metastases were treated with DTIC (at a dose of 850 mg/m2 every 3 weeks) combined with weekly pegylated IFN–α‐2a at a dose of 180 μg. The study was initiated to evaluate the efficacy and tolerability of the combination. The primary study endpoint was objective response.RESULTS.Twenty–five patients were evaluable for response. Two patients (8.0%) achieved a complete response that continued for >480 days and 746 days, respectively. Four patients (16.0%) demonstrated a partial response, and another patient experienced stable disease. Six of 7 nonprogressive patients had either not received treatment or had not developed disease progression during adjuvant IFN treatment for stage II/III disease. The median duration of response was 236 days, the median progression‐free survival was 56 days, and the overall survival time was 403 days. Few grade 3 toxicities and only 1 grade 4 toxicity were observed (according to National Cancer Institute Common Toxicity Criteria).CONCLUSIONS.The combination of DTIC and pegylated IFN–α‐2a was found to be well tolerated in patients with metastatic melanoma. The response rate of 24%, including 2 long‐lasting complete responses, is encouraging, but must be confirmed in larger trials. Cancer 2008. © 2008 American Cancer Society.

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T1-Weighted MRI shows stage-dependent substantia nigra signal loss in Parkinson's disease

et al. 2011

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Depigmentation of the substantia nigra is a conspicuous pathological feature of Parkinson's disease and related to a loss of neuromelanin. Similar to melanin, neuromelanin has paramagnetic properties resulting in signal increase on specific T1-weighted magnetic resonance imaging. The aim of this study was to assess signal changes in the substantia nigra in patients with Parkinson's disease using an optimized neuromelanin-sensitive T1 scan. Ten patients with Parkinson's disease and 12 matched controls underwent high-resolution T1-weighted magnetic resonance imaging with magnetization transfer effect at 3T. The size and signal intensity of the substantia nigra pars compacta were determined as the number of pixels with signal intensity higher than background signal intensity+3 standard deviations and regional contrast ratio. Patients were subclassified as early stage (n=6) and late stage (n=4) using the Unified Parkinson's Disease Rating Scale and the Hoehn and Yahr Parkinson's disease staging scale. The T1 hyperintense area in the substantia nigra was substantially smaller in patients compared with controls (-60%, P<.01), and contrast was reduced (-3%, P<.05). Size reduction was even more pronounced in more advanced disease (-78%) than in early-stage disease (-47%). We present preliminary findings using a modified T1-weighted magnetic resonance imaging technique showing stage-dependent substantia nigra signal reduction in Parkinson's disease as a putative marker of neuromelanin loss. Our data suggest that reduction in the size of neuromelanin-rich substantia nigra correlates well with postmortem observations of dopaminergic neuron loss. Further validation of our results could potentially lead to development of a new biomarker of disease progression in Parkinson's disease.

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PATH53 Magnetic susceptibility of substantia nigra in Parkinson's disease: a 7-T in vivo MRI study

Cited by 6 publications

References 0 publications

Clinical applications of 7T MRI in the brain

Clinical applications of 7T MRI in the brain

Combined treatment with pegylated interferon–α‐2a and dacarbazine in patients with advanced metastatic melanoma

T1-Weighted MRI shows stage-dependent substantia nigra signal loss in Parkinson's disease

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