The Role of MRI Spectroscopy in Differentiation between Malignant and Benign Tumors - Essay Example

Research Proposal: The Role of M.R.I Spectroscopy in differentiation between Malignant and Benign tumors PROJECT The Role of M.R.I spectroscopy in differentiation between Malignant and benign tumors BACKGROUND MRI Spectroscopy involves the use of a special technique in characterizing the tumor biochemistry and of other pathology. MRI Spectroscopy is used in demonstrating aspects of physiology like anaerobic metabolism aggressiveness of tumors. In brain related studies, MRI Spectroscopy shows the characteristic internal biochemical makeup of glioblastoma multiforme, which is known to be a very aggressive brain tumor. Basically, MRI Spectroscopy is a quantitative method of displaying proton signals that are non-aqueous and are deemed to correspond to certain biological brain matter. In MRI Spectroscopy, water protons are utilized in creating images, and for producing images of the brain that are detailed and sophisticated. This is because various brain tissues contain varying amounts of water. Non-aqueous protons, which consist of the hydrogen nuclei protons which are not in water are scattered throughout the biologically significant brain molecules. The significant signals from these molecules are invisible when attempted to be viewed otherwise, due to the fact that they are overshadowed by the greater signals of the aqueous protons. Each non-aqueous molecule possesses a unique radio-frequency that is specific to that particular chemical, and which is different from the water proton frequency. The strength or amplitude attained by these radio-frequencies depends on the concentration of the molecules inside the volume in question, and each of them has its own discrete position of frequency. Thus, a graph can be displayed showing the relative amplitude peaks for various biological molecules, and these peaks of amplitude can be detected and displayed more easily if the signals generated by the aqueous protons are suppressed. AIMS AND SIGNIFICANCE MRI Spectroscopy uses an imaging technology that is non-invasive, and which records information as regards the chemical makeup of human tissue without any need for biopsy or surgery. The aim of this research is to ascertain the role of MRI Spectroscopy in the diagnosis of cancerous (malignant) tumors in contrast to benign and healthy growths that are non-cancerous, based on chemical information. “Although the spectral features of prostate tissue markedly change after radiotherapy, MRI Spectroscopy combined with multivariate methods of analysis can accurately identify histologically malignant biopsies. MRI Spectroscopy shows promise as a modality that could integrate three-dimensional measures of tumor response.” (Michael D. Kuo, 2006) This research on The Role of M.R.I spectroscopy in differentiation between the Malignant and the benign tumors is significant, as it addresses the problem of accurately identifying histological malignant biopsies. “Also, the accurate spatial representation of tumor clearance after conformal radiotherapy is an endpoint of clinical importance. Magnetic resonance spectroscopy (MRI Spectroscopy) can diagnose malignancy in the untreated prostate gland through measurements of cellular metabolites. In this study we sought to describe spectral metabolic changes in prostatic tissue after radiotherapy and validate a multivariate analytic strategy (based on MRI Spectroscopy) that could identify viable tumor.” (Michael D. Kuo, 2006) With MRI Spectroscopy, the result is displayed as a spectrum, in form of a graphical representation of the presence and relative quantities of the different biological chemicals that are present in any particular area in the body. In a study carried out by Scott B. Reeder in 2006, MR spectra were acquired both from the breast tissue of known breast cancer patients and from the breast tissue of healthy women. “By providing valuable chemical information regarding breast tissue, 2D MRI Spectroscopy may become a useful procedure to assist the early identification of benign breast tumors and diagnosis of breast cancer.” (Scott B. Reeder 2006) It is clear that MRI Spectroscopy can be used in the accurate identification of malignant biopsies. MRI Spectroscopy has shown a lot of promise as a way of integrating 3-dimensional tumour response measures, and can be combined with multivariate methods of analysis. On the other hand, the spectral features of prostate tissue are radically distorted when the process of radiotherapy is employed. PROPOSED METHODOLOGY Previous imaging methods like cerebral angiography and pneumoencephalography were known to be invasive and rather too risky, and so they were dropped in recent times, and focus was shifted to high-resolution modalities that were non-invasive. “In some other methods, benign brain tumors tend to show up as being darker than brain tissue (hypodense), with mass lesions on cranial CT-scans. On MRI, they appear either hypo- (darker than brain tissue) or isointense (same intensity as brain tissue) on T1-weighted scans, or hyperintense (brighter than brain tissue) on T2-weighted MRI. Perifocal edema also appears hyperintense on T2-weighted MRI.” (C.Menard, I.Smith, R.Somorjai, L.Leboldus, R.Patel, C.Littman, S.Robertson, T.Bezabeh) In a study investigating the applicability of MRI Spectroscopy as a breast cancer screening tool at the University of California, Los Angeles, MRI Spectroscopy was performed on groups of ten women with a known diagnoses of malignant vs. benign breast tumors. “Tumor diagnoses were established by means of biopsy followed by pathologic analysis of extracted tissue samples. It was then possible to identify the characteristic features of recorded spectra from benign and malignant tumors, in order to determine which features best allow the discrimination between benign and malignant tumors. Characteristic features included, among others, the ratios of the levels of water to fat, choline to creatine and methyl to methylene in both benign and malignant tumors.” (Nathaniel Wyckoff 2001) A control group of ten patients with healthy breast tissue was also be studied and compared with the relevant baseline measurements. Future Direction and Impact: It has been shown that MRI Spectroscopy helps in the detection of the vital chemicals contained in human breast tissue, and also the statistical pattern classification potential based on MRI Spectroscopy. One of the most attractive potential benefits of MRI Spectroscopy is the possibility of early diagnosis of malignant tissue. Although recent results have shown reliable differentiation of healthy tissue from malignant tissue, studies carried out in the future may need to examine a higher number of patients with benign tumors, as the 2D spectra of these growths have to be analyzed and compared to the spectra of malignant tumors. “Statistical MRI Spectroscopy-based classification techniques, when applied to large numbers of benign and malignant tumors, may then serve as important complements to mammography or ultrasound in breast cancer screening and diagnosis.” (James L. Lear, 1988) MRI Spectroscopy can also be used to detect the major metabolites contained in the breast tissue of human beings, and also in the detection of both cross peaks and diagonal peaks. EXPECTED OUTCOMES MRI Spectroscopy can be used to distinguish between malignant cancerous tissue and benign growths, including normal tissue. Using MRI Spectroscopy, characteristic "spectra" can be recorded, and show the relative amount of the present chemicals that comprise tissues of each type, and can also enable characterization of small tumors too. According to the results of research carried out by Nathaniel Wyckoff, “MRI Spectroscopy can enable the early detection of breast cancer, thereby giving the patient a chance to be cured.” (Nathaniel Wyckoff 2001). Breast density raises issues that limit the effectiveness of mammography, but with this is not the case with MRI Spectroscopy. Preliminary studies have shown that MRI Spectroscopy is very effective in the proper identification of benign tissue. Thus, MRI Spectroscopy is preferable to mammography, as there are several advantages of using MRI Spectroscopy over mammography, including the fact that mammography often classifies benign tumors as being cancer. “MRI Spectroscopy) can diagnose malignancy in the untreated prostate gland through measurements of cellular metabolites. In this study we sought to describe spectral metabolic changes in prostatic tissue after radiotherapy and validate a multivariate analytic strategy (based on MRI Spectroscopy) that could identify viable tumor.” (Nathaniel Wyckoff 2001) Thus, viable applications of MRI Spectroscopy include 1. reducing the rate of unnecessary biopsies in women with benign tumors 2. Introducing therapy earlier in the case of patients with malignant tumors 3. Progressively monitoring the effects of chemotherapy and radiation in patients undergoing treatment for cancer 4. Enabling cancer test for younger patients for whom mammography might not be an option. CONCLUSION It is clear that MRI Spectroscopy can be used in the accurate identification of malignant biopsies. MRI Spectroscopy and imaging also plays a vital role in diagnosing brain tumors. MRI Spectroscopy has shown a lot of promise as a way of integrating 3-dimensional tumour response measures, and can be combined with multivariate methods of analysis. In combination with multivariate methods of analysis there is high accuracy of identifying malignant tissue and differentiation of benign growths from cancerous growths. Thus, MRI Spectroscopy has shown much promise as a modality for integration of 3-dimensional measures of tumor response From a patient’s perspective, the MRI Spectroscopy process quite identical to an ordinary MRI exam. “The patient is only aware that another sequence of radio signals is being obtained. The time of each MRI Spectroscopy sequence is about the same for a standard brain imaging sequence (about five to six minutes), excluding the positioning and set-up time.” (Joe Chang, 2004) REFERENCES 1. Michael D. Kuo, MD, 2006, Assessing Global Gene Expression Programs of Cancer Using Non-invasive Imaging 2. Scott B. Reeder, MD, PhD, 2006, Quantification of Hepatic Steatosis with Magnetic Resonance Imaging 3. C.Menard, I.Smith, R.Somorjai, L.Leboldus, R.Patel, C.Littman, S.Robertson, T.Bezabeh International Journal of Radiation Oncology Volume 50, Issue 2, Pages 317-323 4. Nathaniel Wyckoff (2001) University of California, Los Angeles 5. Ashok Panigrahy, MD, 2006, Quantitative Proton MR Spectroscopy of Perinatal White Matter Injury: Correlation with Neurodevelopmental Outcome, Axonal Injury and Cytokine Inflammation 6. Patrick J. Bolan, PhD, 2006, Monitoring Chemotherapy Response in Metastatic Liver Lesions with Quantitative 1H MRI Spectroscopy 7. Bonnie N Joe, MD, PhD, 2005, Non-Invasive Evaluation of Fetal Lung Maturity by MR Spectroscopy: Development and Assessment of Ex Vivo and In Vivo Techniques 8. Christine B. Chung, MD, 2004, MR imaging of Patellofemoral and Femorotibial Articular Cartilage: Qualitative and Quantitative Assessment with Ultrashort TE (UTE) Imaging 9. Jingfei Ma, PhD, 2004, Differentiation between Benign and Malignant Vertebral Compression Fractures with Quantitative Diffusion and Fat MR Imaging 10. Joe Chang, MD, PhD, 2004, Radiotherapy Sensitization by Apoptotic Gene Therapy and Molecular Imaging of Apoptosis in a Human Lung Cancer Model 11. Alexander R. Gottschalk, MD, PhD, 2003, The Role of PTEN Mutations in the Pathogenesis of Prostate Cancer and Resistance to Therapy 12. Smita Patel, MBBS, MRCP, FRCR, 2003, ECG-gated 16-slice CT Coronary Angiography: Comparison with Catheter Coronary Angiography 13. Michelle S. Yao, MD, 2002, ATR and the Mammalian DNA Damage Response 14. Christopher G. Filippi, MD, 2000, Quantitative Diffusion Tensor MR Imaging In HIV: Developing Neuroimaging Markers of Functional Outcome 15. Christopher H. Crane, MD, 2000, Advancing Cancer Treatment Through the Combination of New Radiosensitizers and Biologic Agents with More Advanced Radiation Delivery: An Integrated, Prospective Clinical and Laboratory-Based Translational Research Proposal 16. David A. Roberts, MD, PhD, 2000, Combined Ventilation/Perfusion Pulmonary MRI with Focused MRA to Improve the Noninvasive Diagnosis of Pulmonary Embolism 17. David L. Levin, MD, PhD, 2000, The Evaluation of Regional Pulmonary Perfusion Using Ultrafast MR Imaging 18. Dmitriy A. Yablonskiy, PhD, 2000, Diffusion Lung Imaging with Hyperpolorized 3He Gas: A New Imaging Modality to Reveal the Structure and Functioning of Alveoli in Human Lung 19. Frandics P. Chan, MD, PhD, 2000, Characterization of Intraventricular Flow and Flow-Induced Wall Stress in Chronic Mitral Regurgitation Before and After Mitral Valve Repair 20. Jane P. Ko, MD, 2000, Automated Detection of Pulmonary Nodules on CT and Assessment of Change Over Time Read More