Nuclear medicine is a subspecialty of medicine that uses medically approved radioactive tracers called radiopharmaceuticals to assess bodily functions and to diagnose and treat diseases.
The Department of Nuclear Medicine at Amrita offers high quality state-of-the-art diagnostic and therapy services with state-of-the-art infrastructure, highly trained doctors and support staff. Nuclear medicine imaging provides superior diagnostic information based on physiological principles. It identifies disease very early at inception. It also provides guidance for initiating management and thereby provides better clinical outcome. All these investigations are safe and can be used in all age groups except in pregnant patients with relative contraindication in breast feeding patients.
The gamma camera services were launched in January 2000 with addition of high dose I 131 therapy for thyroid cancers in 2005. The department is equipped with latest state-of-the-art imaging instruments and special wards approved for radionuclide therapy. The department has grown in leaps and bounds in the past 21 years offering high-end services including MCI recognized post graduate (MD) Nuclear Medicine programme (started since 2012). State-of-the art PET CT service was inaugurated in 2008 by Ex President of India Shri A P J Abdul Kalam. The first state-of-the-art whole body PET MR facility in a university hospital and the third in the country was started in March 2018.
Single photon emission computed tomography involves acquisition of 3 D images using a gamma camera. When an additional CT counterpart is attached to the SPECT system, it is known as SPECT CT that provides additional anatomical information. Both these systems are available in the department. Medically approved gamma emitting radiotracers are used for imaging. Most commonly used radionuclide is 99mTechnetium labeled with various organ specific tracers like sestaMIBI, DTPA etc. Nuclear medicine imaging is popularly known as Scintigraphy (imaging the scintillations). Radioactive tracer in minute amounts is injected in the arm of the patient. After injection, the tracer gets localized in the organ of interest and starts emitting gamma rays that are perceived by a dual head gamma camera and its electronics. This scanner records the physiological alterations that take place in selected organs or body systems. The images are interpreted visually and quantitatively to look for pathological changes in any organ much earlier than anatomical imaging modalities. This imaging is fundamentally different from magnetic resonance imaging (MRI) and computed tomography (CT), for these methods only convey anatomic information. In most diseases, physiological changes precede anatomic changes, so scintigraphic evidence of a disease process can be diagnosed at an earlier stage. On the other hand, the MRI and CT are useful for clinical diagnosis after the disease process causes significant anatomic alterations.
|THYROID SCAN||To assess thyrotoxicosis, Graves disease, toxic MNG, thyroiditis, thyroid nodule evaluation, lingual thyroid etc|
|PARATHYROID SCAN||To assess parathyroid adenoma, hyperplasia, ectopic parathyroid adenomas|
|MYOCARDIAL PERFUSION/ THALLIUM SCAN||To evaluate IHD, physiological significance of known coronary stenosis, Coronary artery disease, False positive TMT, Baseline ECG changes like LBBB, Risk stratification of CAD, Presurgical cardiac evaluation, to assess myocardial viability before CABG prior to surgery for congenital heart disease, follow-up of Kawasaki disease|
|MUGA SCAN||To evaluate accurate LVEF, regional wall motion abnormalities in CAD, patients with obesity, COPD, prior to adriamycin and other cardiotoxic drug therapy|
|RENOGRAM||To assess GFR of individual kidneys esp. in donors, neonatal hydronephrosis, PUJ obstructions, obstructed megaureter. Relative function evaluation in patients with renal malignancy prior to nephrectomy, ectopic kidneys, post renal transplant evaluations|
|DMSA SCAN||To assess UTI (Renal scars), ectopic kidneys, accurate function assessment of individual kidneys|
|DIRECT / INDIRECT RADIONUCLIDE MCU SCAN||To assess Vesico ureteric reflux, Urinary tract infections, hydroureteronephrosis|
|WHOLE BODY BONE SCAN||To evaluate skeletal metastases, bone malignancy, low backache, tuberculosis of bone, condylar hyperplasia, avascular necrosis, metabolic bone disease, stress fracture, osteomyelitis, cellulitis especially in diabetics.|
|GALLIUM CITRATE SCAN||Assessment of prosthetic infections, evaluation of lymphoma (Hodgkin's & non Hodgkin's), fever of unknown origin|
|LUNG PERFUSION & VENTILATION||Pulmonary embolism, lung vascularity assessment in children with congenital heart disease, predict FEV1 in patients planned for pneumonectomy/lobectomy|
|LIVER-SPLEEN SCAN||Alcoholic hepatitis, cirrhosis, portal hypertension, hemangioma, jaundice, Budd chiari syndrome.|
|HEPATOBILIARY SCAN||Differentiate neonatal hepatitis vs biliary atresia, postop bile leak, choledochol cyst, post liver transplant cases, gall bladder dyskinesia, acute/chronic cholecystitis.|
|MECKEL'S SCAN||Evaluation of meckels diverticulum (Ectopic gastric mucosa), malena, GI bleed.|
|GASTRO INTESTINAL BLEEDING||To evaluate occult GI bleed and localize the site of bleed|
|GASTRIC EMPTYING||For dyspepsia, vomiting, Diabetic gastroparesis.|
|GASTRO ESOPHAGEAL REFLUX (Milk scan)||Recurrent respiratory infections, heart burns|
|DACRYO SCINTIGRAPHY FOR EYES||To evaluate tear duct patency|
|SALIVAGRAM||To look for antegrade aspiration in young children|
Positron emitters are used to identify changes in various organs while performing a whole body PET CT study. The study is performed from head to mid thigh region in euglycemic status. Oral and contrast enhanced CT is also performed along with the PET imaging. PET and CT images are fused for image interpretation. PET CT is used in staging of most of the cancers and certain specific non-oncological diseases.
|ONCOLOGY WORKUP 18 FDG (FLURODEOXYGLUCOSE)||
|GALLIUM DOTA PET CT||Neuroendocrine tumors|
|GALLIUM PSMA PET CT||Prostate cancer|
|MYOCARDIAL PET CT (FDG)||
|BRAIN PET CT (FDG)||
|INFECTION PET CT (FDG)||
The ultimate hybrid imaging technology is the integration of PET and MRI (Magnetic resonance Imaging) providing exquisite structural, functional and metabolic details of suspected sites of cancer thereby increasing the accuracy of cancer detection. Certain tumours benefit by PET MR imaging than mere PET CT like gynecological malignancies, head & neck tumours, musculoskeletal, brain and liver cancers etc. With highest resolution, PET MR can identify tiny lesions easily. The biggest benefit to the patient is lack of additional radiation when an MRI is done. Like in PET CT, FDG and specific tracers like gallium PSMA, gallium DOTA, F DOPA, F MISO etc can be used to perform a PET MR study.
MRI scanner uses a strong magnetic field to produce detailed images of internal structures of the body. They can also provide information about how well these structures are functioning.
PET scans use minute amounts of radioactive tracers (most of the time FDG fluorodeoxyglucose, a sugar molecule) to highlight cellular metabolic abnormalities indicating diseases like cancer.
Until now, scientists could not integrate PET and MRI for simultaneous scanning because MRI’s powerful magnets interfered with the imaging detectors on the PET scanner.
But now this hydrid imaging scanner PET MRI (first manufactured by Siemens Germany) is available worldwide & Amrita Hospital is the third hospital in India to acquire this state-of-the-art hybrid scanner.
It is possible to perform a whole body PET MRI or an organ specific PET MRI scanning depending on whether the patient is being imaged for cancer / non cancer organ specific diseases.
Once the radioactive injection is performed, the patient will wait approximately 60 minutes in a quiet area with limited body movement facilitating the distribution of radioactivity molecule. More radio tracer material is expected to accumulate in the cells with higher metabolism thereby identifying cancerous / non cancerous disease process of specific organs.
For the MRI portion, magnetic fields and radio frequency bursts will move the proton (hydrogen in cell) in the patient's body out of their normal alignment or their normal spinning pattern. As the molecules return to their natural positions, the machine records that activity and medical image computers uses these information to create detailed and precise structural images of organs and tissues.
The images acquired from both PET-MRI scanners are then processed, aligned, fused and interpreted by trained, highly experienced nuclear & radiology imaging experts to diagnose and stage the cancer spread in the body.
There is a definite role for PET MRI hybrid scan in many non-oncological (non cancerous) diseases involving brain and heart. The structural changes in brain and heart can be so small that only exquisite structural information providing scans like MRI is imperative in the early detection of brain, heart diseases. Epilepsy and neuro degenerative diseases like dementia (i.e. memory disorders like Alzheimer’s disease), Parkinsonism can be effectively diagnosed early with PET MRI scanning.
Changes in brain morphology and cognitive impairment are diagnosed early due to the combined effort of PET MRI scanning in dementia evaluation. In epilepsy PET MR is used to localize the site of epileptic focus in medically refractory cases to plan surgery. It can accurately localize of origin of abnormal electrical impulses in brain by demonstrating FDG distribution changes. This is incremental when combined with 3 T MRI. Thereby the functional and anatomical information gathered by this single imaging modality is invaluable.
Detection of viable (living) part of heart muscles is an integral part of coronary bypass surgery decision and this can be effectively & more accurately done by FDG PET MRI scanning. It can also detect inflammation of heart muscles (like cardiac sarcoidosis, viral myocarditis) very easily with utmost sensitivity. This can also be a useful investigation in assessing the treatment response.