Performance Of Magnetic Resonance Spectroscopy Research Articles

The diagnostic performance of magnetic resonance spectroscopy in differentiating high-from low-grade gliomas: A systematic review and meta-analysis.

Magnetic resonance spectroscopy (MRS) is a powerful tool for preoperative grading of gliomas. We performed a meta-analysis to evaluate the diagnostic performance of MRS in differentiating high-grade gliomas (HGGs) from low-grade gliomas (LGGs). PubMed and Embase databases were systematically searched for relevant studies of glioma grading assessed by MRS through 27 March 2015. Based on the data from eligible studies, pooled sensitivity, specificity, diagnostic odds ratio and areas under summary receiver operating characteristic curve (SROC) of different metabolite ratios were obtained. Thirty articles comprising a total sample size of 1228 patients were included in our meta-analysis. Quantitative synthesis of studies showed that the pooled sensitivity/specificity of Cho/Cr, Cho/NAA and NAA/Cr ratios was 0.75/0.60, 0.80/0.76 and 0.71/0.70, respectively. The area under the curve (AUC) of the SROC was 0.83, 0.87 and 0.78, respectively. MRS demonstrated moderate diagnostic performance in distinguishing HGGs from LGGs using tumoural metabolite ratios including Cho/Cr, Cho/NAA and NAA/Cr. Although there was no significant difference in AUC between Cho/Cr and Cho/NAA groups, Cho/NAA ratio showed higher sensitivity and specificity than Cho/Cr ratio and NAA/Cr ratio. We suggest that MRS should combine other advanced imaging techniques to improve diagnostic accuracy in differentiating HGGs from LGGs. • MRS has moderate diagnostic performance in distinguishing HGGs from LGGs. • There is no significant difference in AUC between Cho/Cr and Cho/NAA ratios. • Cho/NAA ratio is superior to NAA/Cr ratio. • Cho/NAA ratio shows higher sensitivity and specificity than Cho/Cr and NAA/Cr ratios. • MRS should combine other advanced imaging techniques to improve diagnostic accuracy.

Evaluation of the diagnostic performance of magnetic resonance spectroscopy in brain tumors: a systematic review and meta-analysis.

ObjectThe aim of this study was to determine the suitability of magnetic resonance spectroscopy (MRS) for screening brain tumors, based on a systematic review and meta-analysis of published data on the diagnostic performance of MRS.MethodsThe PubMed and PHMC databases were systematically searched for relevant studies up to December 2013. The sensitivities and specificities of MRS in individual studies were calculated and the pooled diagnostic accuracies, with 95% confidence intervals (CI), were assessed under a fixed-effects model.ResultsTwenty-four studies were included, comprising a total of 1013 participants. Overall, no heterogeneity of diagnostic effects was observed between studies. The pooled sensitivity and specificity of MRS were 80.05% (95% CI = 75.97%–83.59%) and 78.46% (95% CI: 73.40%–82.78%), respectively. The area under the summary receiver operating characteristic curve was 0.78. Stratified meta analysis showed higher sensitivity and specificity in child than adult. CSI had higher sensitivity and SV had higher specificity. Higher sensitivity and specificity were obtained in short TE value.ConclusionAlthough the qualities of the studies included in the meta-analysis were moderate, current evidence suggests that MRS may be a valuable adjunct to magnetic resonance imaging for diagnosing brain tumors, but requires selection of suitable technique and TE value.

Role of MR Spectroscopy in Characterization of Breast Masses

Introduction: Dynamic contrast enhanced magnetic resonance imaging “MRI” is not 100 percent accurate in distinguishing benign from malignant lesions, resulting in a large number of breast biopsy procedures recommended on the basis of imaging findings. Proton magnetic resonance spectroscopy “¹H MRS” can provide chemical information about a lesion by measuring the levels of choline compounds, which are markers of an active tumor. In most cases, the results indicate whether the lesion is cancerous without need for biopsy. In addition to being used in breast cancer diagnosis, in vivo ¹H MRS has also been used to monitor breast cancer response to chemotherapy as well as in differentiating between scar tissue and recurrent cancer after breast-conserving therapy. Aim of the work: To evaluate the diagnostic performance of magnetic resonance spectroscopy “MRS” in characterization of breast masses with histopathologic findings or follow up used as the reference standard. Methods: The studied group included 50 female patients referred for MRI breast for workup of a suspicious clinical, mammographic, or sonographic abnormality. ¹H MRS was added to the routine study. Results of the contrast enhanced bilateral breast MRI and ¹H MRS of the 50 patients were all reported and compared with the histo-pathological results of surgery or biopsy and with the results of follow up of lesions that were not surgically removed or biopsied. Results: there was a highly significant relation between ¹H MRS and histopathological. Follow Up results with p value = 0.005. The sensitivity, specificity, positive and negative predictive values of ¹H MRS for characterization of suspicious breast lesions in patients included in the study, were 90%, 93.3%, 90%, and 93.3% respectively. Conclusion: ¹H MRS is a short non-invasive scan that can be inserted easily into standard clinical breast MRI protocols as a potential adjunct that can be added routinely to conventional breast MRI. Detection of choline peak with estimation of the choline signal to noise ratio “SNR” can accurately differentiate benign from malignant breast lesions with high sensitivity and specificity especially when its results are combined with the results of the standard dynamic MRI scan.

Clinical magnetic susceptibility mapping of the brain.

A field mapping technique was used to detect changes in the local magnetic field in 14 tumors, five hematomas, one lacunar infarct, and two cases of multiple sclerosis. These changes were attributed to variations in the tissue susceptibility. A partial or complete rim of changed susceptibility was detected at the margin of five of the tumors and localized changes were seen within two of the tumors. All five hematomas displayed susceptibility effects. These were seen at the rim of the hematoma in all cases but central effects were also seen in four cases. One area of probable lacunar infarction also displayed susceptibility effects. The effects described may be due to the paramagnetic contribution of species such as deoxyhemoglobin, methemoglobin, free ferric iron, hemosiderin, and other breakdown products of blood. Local field inhomogeneities due to changes in tissue susceptibility have implications for magnetic resonance (MR) image interpretation and the performance of MR spectroscopy.