Neuroimaging techniques including magnetic resonance spectroscopy

James C. Johnston, MD, JD, is a board-certified neurologist and attorney whose current work focuses on global health issues in sub-Saharan Africa. He serves as an Honorary Professor in the Department of Neurology, Addis Ababa University, Ethiopia. In his quest to advance neurological care across the globe, Dr. James C. Johnston also serves as a Partner in Global Neurology Consultants and is the Founder and Director of Global NeuroCare, an NGO with UN Special Consultative Status.

Neuroimaging is an integral part of neurological practice for Dr. James C Johnston, whether in the United States or Africa. Neuroimaging entails the use of various techniques to directly or indirectly investigate the status of the brain or spine, and may include CT scans, MRI (magnetic resonance imaging), PET (positron emission tomography), ultrasonography, and functional imaging modalities. These tests are crucial for the accurate diagnosis and treatment of many patients with neurological diseases or disorders.

Magnetic resonance spectroscopy (MRS) is a non-invasive diagnostic test used to detect biochemical or metabolic changes in the brain, particularly for brain tumors as well as to detect tissue changes during strokes or epilepsy and evaluate Alzheimer’s disease and other conditions. This testing is typically performed in conjunction with more conventional studies in order to provide the most accurate diagnosis. For example, MRI may delineate the anatomical position of a brain tumor, while MRS detects the difference in chemical composition between normal brain tissue and the tumor which may, for example, allow differentiation of low grade from high grade gliomas, or distinguish recurrent brain tumor from radiation induced necrosis.

A conventional MRI machine is used to conduct MRS, which aims to analyze molecules such as protons or hydrogen ions. Proton MRS is the most common type of test. The spectroscopy consists of an additional series of tests to measure various metabolites of the metabolic processes, in order to differentiate between the various types of tissue and allow the most accurate diagnosis.

Many of these neuroimaging techniques including MRI are available globally, although scarce in the low resource nations. There are, for example, numerous CT machines and several MRI facilities in Addis Ababa, Ethiopia, but availability in the rural areas is limited to nonexistent, which precludes the accurate diagnosis and treatment of many patients. Dr. James C Johnston and one of his Ethiopian colleagues Dr. Mehila Zebenigus work through Global Neurocare to raise these concerns with various professional organizations, university medical centers, the World Health Organization and the United Nations.