Background

Nuclear imaging is a medical imaging technique that utilizes radioactive materials or tracer atoms, radiopharmaceuticals, to diagnose and analyze diseases. It provides unique insights into the function of organs and tissues and data that may be essential in evaluating ailments such as cancer, cardiovascular disease, and neurological illnesses. 

Indications

Cardiology: 

• For diagnosing and evaluating the degree of coronary artery disease using myocardial perfusion imaging. 
• The scan is helpful in ensuring the necessary efficiency of the heart by measuring its efficiency (e.g., ventriculography). 
• Diagnosing and Surveillance of heart disorders such as heart failure. 

Oncology: 

• Diagnosis and evaluation of the extent of cancers (for instance, using PET to identify cancer). 
• It identify the cause of a patient’s symptoms when conventional treatments are ineffective. 
• Evaluating suspected cancer recurrences. 

Endocrinology: 

• Measuring the level of thyroid hormones and detecting the pathological condition of the thyroid gland (e.g., thyroid scans). 
• Parathyroid glands and adrenal glands assessments. 

Neurology: 

• Detecting and monitoring different diseases related to the functions of CNS (PET or SPECT scan for Alzheimer’s disease or epilepsy). 

Orthopedics: 

• Diagnosis of bone infections/osteomyelitis, fractures, or tumors, for example, bone scans. 
• Diagnosing bone pain or any other alterations in bones that would need explanation. 

Urology: 

• Investigations/testing (e.g., a renal scan to determine the function of the kidneys in cases of other renal diseases). 
• Examining the state of urinary tract obstructions or diseases. 

Contraindications

• Pregnancy: Most nuclear imaging procedures use radiation, and this is dangerous, especially during pregnancy. Pregnant women are usually discouraged from undergoing nuclear imaging if it is not very necessary, and the benefits of the test to the mother and fetus are higher than the risks involved. 
• Allergies to Radiopharmaceuticals: It is rare for patients to develop some form of allergy to the radiopharmaceuticals employed in nuclear imaging. 
• Kidney or Liver Dysfunction: Some nuclear imaging procedures depend on kidney and/or liver for handling or elimination of the radiopharmaceuticals. Dysfunction in these organs might decrease the efficacy or increase the risk of the procedure. 
• Certain Medications: There are circumstances where specific medicines can affect the procedure or the reading of outcomes. It is responsibility of patients to disclose the medications that they are taking to their physicians. 

Outcomes

Equipment

Positron Emission Tomography (PET) 

Single Photon Emission Computed Tomography (SPECT) 

Gamma Cameras 

Radionuclide Scanners 

Hybrid Systems 

Patient Preparation

• Medication: Patient should report any drugs and supplements they are using to their doctor.  
• Comfortable Clothing: Do not wear any clothes that have any form of metal including buttons or buckles tight on the skin. You might be required to undress and wear a hospital gown for the procedure. 
• Fasting: This usually depends on the type of scan; sometimes, you are advised to come with an empty stomach a few hours before the scan. For instance, before PET or certain kinds of SPECT scans, it is necessary to abstain from eating. 

For Specific Scans: 

• PET Scan: There may be certain restrictions regarding the exercise that indicates that you may need to abstain from exercising one or two days before the scan. It also usually involves fasting most of the day before the scan so that your bowel is slightly empty. 
• SPECT Scan: The diet may also involve fasting and there may be some medications that patient cannot take in their condition. 
• Bone Scan: Hydration is usually advised in cases of bone imaging. 

Technique

Nuclear imaging 

Imaging Process 

• Preparation: The patient may have to abstain from eating, or his medications may have to be stopped before the procedure. 
• Administration of Radiopharmaceutical: The radiopharmaceutical is administered through the selected route of administration into the body. 
• Imaging: The patient lies on a table under the imaging device. The device detects the radiation emitted from the body, creating images based on the distribution of the radiopharmaceutical. 
• Image Processing: The captured data is then converted into image forms using the respective software enabling doctors to analyze the same. 

Kinds of Nuclear Medicine Research 

• Bone Scans: It is used in locating fractures, infections, and tumors in the bones of the body. 
• Cardiac Scans: Assess the heart’s performance and determine the areas where blood supply is low, or heart muscles are damaged. 
• Thyroid Scans: Diagnose hyperthyroidism, hypothyroidism, and thyroid nodules or cancer. 
• Renal Scans: Examine the function and the morphology of the kidney. 
• Brain Scans: Identify growths that may be a problem regarding blood flow, blood supply, neurological disease, etc. 
• Cancer Imaging: This position is responsible for diagnosing different types of cancer, evaluating the effectiveness of the treatment, and identifying the metastasis. 

Laboratory tests

• Positron Emission Tomography (PET) Scan: This test relies on using a radioactive tracer to see signs of alterations in the body. They reach maximum use in cancer diagnosis, heart and brain capability assessment. 
• Single Photon Emission Computed Tomography (SPECT) Scan: SPECT imaging employs a radioactive tracer but provides information different from PET. It is applied for the evaluation of the blood perfusion of organs, the evaluation of the cardiac health and the diagnostics of some types of cancer. 
• Bone Scan: This kind of scan employs the use of a radioisotope to highlight areas of bone that could be infected, contain tumor, or broken. 
• Thyroid Scan: Uses radioactive iodine or technetium, to assess the performance of thyroid gland and to diagnose diseases such as thyroid nodules or cancer. 
• Myocardial Perfusion Imaging: This test recognizes how much blood reaches the heart’s muscle and may reveal that a patient has coronary artery disease or some other heart ailment. 

Complications

• Radiation Exposure: While the dose of radiation is not large, there is still a possibility of experiencing disorders or developing cancer because of constant imaging. 
• Allergic Reactions: Certain patients may also develop hypersensitivity reactions to some of the radiopharmaceuticals applied in the imaging process. This is quite the exception, but in some cases, it may present manifestations like rash or itching or more severe ones. 
• Inaccurate Results: As much as the technology is highly advanced, some parameters like body weight, the type of medication the patient is on, or technical issues of the machine may sometimes influence the outcome of the images obtained from the machine. 
• Discomfort or Anxiety: The procedure may be somewhat unpleasant to the patients, particularly those with a known claustrophobia or who must keep still for a long time. 
• Interaction with Other Tests: Nuclear imaging can, in some cases, give out a wrong impression depending on other tests or procedures that may be carried out alongside the modality. 

References

Nuclear Medicine Imaging in Diagnosis and Treatment – Advancing Nuclear Medicine Through Innovation – NCBI Bookshelf (nih.gov) 

References

Nuclear Medicine Imaging in Diagnosis and Treatment – Advancing Nuclear Medicine Through Innovation – NCBI Bookshelf (nih.gov)