MRI: essential tool of modern medicine

The Magnetic Resonance Imaging (MRI) is one of the most powerful imaging tools in modern medicine, producing high quality images of organs and soft tissues in the body and helps the physician in accurate diagnosis and surgical planning across specialities.

Neurology

MRI is the investigative method of choice for neuroimaging (visualising the brain and associated structures). It helps to diagnose and monitor demyelinating diseases that damage the protective covering known as myelin around nerve fibres in the brain and spinal cord.

Other conditions that can be diagnosed include dementia, cerebrovascular diseases, infectious disease, epilepsy and tumours. MRI advanced applications also help in management of stroke and non-invasive diagnosis of intracranial lesions. It can also help to assess the extent of spread of a tumour in the brain tissue, plan neurosurgeries as well as help in behavioural and cognitive research.

Liver, gall bladder, pancreas

MRI is widely used in Hepatobiliary imaging to characterise lesions in liver and pancreas. Magnetic Resonance Cholangiopancreatography (MRCP) allows imaging of the bile ducts non-invasively.

Liver fat and liver iron quantifications help in treatment planning, liver transplant assessment, follow-up and in avoiding unnecessary random liver biopsies.

MRI using contrast agents also indicates the type of lesion. Normal human liver tissue is very soft to palpation at surgery. It becomes firm to hard in chronic liver disease. MRI can measure mechanical properties of tissues and help in diagnosis of hepatic fibrosis.

Gastroenterology

MRI (Enterography) provides non-invasive assessment of inflammatory bowel disease and small tumours. It also helps in detecting active small-bowel inflammation and complications like bowel obstruction.

Orthopaedics

MRI has revolutionised the diagnosis and treatment of musculoskeletal disorders through display of high definition images of tendons, ligaments, muscles, joints, bone and articular cartilage. MRI and real-time imaging of certain joints help evaluate the interactions of bone and soft tissue and the relative position of each through a range of motions.

MRI allows visualization of the cartilage. New technology reduces the effects of distortion in images caused by metallic implants, helping the doctors monitor implants periodically.

Cardiology

Cardiac MRI is a comprehensive imaging technique providing information in acquired and congenital heart disease. It is the most precise technique for measuring volume, function and mass of the heart’s chambers.

It has wide range of applications in assessment of myocardial ischemia (reduced blood flow to heart muscle), cardiomyopathies (chronic disease of the heart muscle), myocarditis (inflammation of the heart muscle), and congenital heart disease.

Oncology

The development of intra-operative MRI techniques provides the neurosurgeon with live information required to perform accurate image-guided surgery.

It helps remove tumours without damaging adjacent brain structures. It also tells him whether the entire tumour has been resected without having to wait for imaging after the operation.

MRI guided ‘high intensity ultrasound’ helps in management of fibroids and some other tumours non-invasively. MRI guided biopsies with robotic work station allows sampling of very small lesions and are being used in prostate and breast biopsies.

Urology

MRI is clinically useful in the evaluation of suspected urinary tract obstruction, haematuria (blood in urine), and congenital defects, and can be particularly beneficial in paediatric or pregnant patients or when ionising radiation is to be avoided.

Obstetrics & gynaecology

MRI is useful in gynaecological patients giving detailed imaging of uterus and ovaries. Fetal MRI can detect foetal anomalies.

The MRI scan is critical as it can provide diagnostic information about injuries or ailments that other imaging techniques may not be able to detect and hence a proper opinion by MRI specialist is crucial before planning to go in for any surgeries.

(The writer is Lead Consultant Radiologist, Aster CMI Hospital, Bengaluru)