Nuclear Medicine

تاریخچه

Nuclear Medicine is a branch of medical physics and molecular radiology that uses the nuclear properties of materials (such as radioisotopes) to diagnose and treat diseases. Nuclear pharmacology also contributes to this branch of basic medical science.
Nuclear medicine is characterized by its ability to provide visual information about the body's metabolic processes and functions, while other medical imaging modalities such as computed tomography and MRI generally produce structural and anatomical information.

• background

  The first experiment using radioisotope injection to image a human was performed by Herman L. Blomgart and Soma Weiss of Harvard University. This experiment was performed in 1927 using a cloud chamber and radon. In 1958, Hellenger invented the Hellenger camera at the University of Berkeley. The use of the radioisotope technetium-99m in 1964 by a team of Paul Harper and Robert Beck of the University of Chicago marked a turning point in the history of medical physics and nuclear medicine.

• Nuclear Medicine in Iran

  The use of radioactive materials in medicine in Iran began with the measurement of radioactive iodine in 1953 using a Geiger counter at the Peyman Markazi Laboratory of Tehran University of Medical Sciences.
  

In this regard, a British expert named Malcolm Cuthbert Nokes played a great role in the development of nuclear medicine in Iran. With his help, Dr. Nizam Mafi conducted research for the first time in 1961 with a thyroid scanner and laid the foundations of nuclear medicine in Iran. In 1967, the Center for Nuclear Medicine and Endocrine Research at the University of Tehran was established, which is actually the first and oldest nuclear medicine center in the country. At that time, the facilities of this department were limited to a single camera, which was gradually improved.

Pet scan section

• What is PET CT imaging?

  A PET-CT imaging device is a type of diagnostic device and a subset of nuclear medicine devices. This device surprisingly provides the functions of two separate PET and CT devices in one set.
  The CT part of this device creates anatomical information about the body and the PET part creates physiological information about the body.
  In general; the combination of these two systems in a gantry allows very good images of the patient's body to be obtained with great accuracy and quality.

• What is the PET CT imaging method?

  In general, PET-CT imaging is non-invasive and painless. PET-CT imaging is used to diagnose a variety of diseases, including; types of cancer, infections, and inflammation of the body.
  Depending on the type of nuclear medicine test (PET-CT) requested, radiopharmaceuticals are administered intravenously or orally. Eventually, these radiopharmaceuticals accumulate in the body and, after a process with body tissue, their energy is released from the body in the form of gamma rays.
  This gamma energy is detected by a gamma camera, PET scanner, or PET probe. Today, most PET scans are performed on combined PET/CT machines. Combined PET/CT scans accurately assess abnormal metabolism in the body and help doctors make more accurate diagnoses than separate CT and PET scans.

• What diseases is PET CT useful for diagnosing?
  • Diagnosing cancer
  • Estimating the extent of cancer spread
  • Assessing the effectiveness of a treatment plan such as radiotherapy
  • Estimating the recurrence of cancer after a course of treatment
  • Assessing cardiac blood flow
  • Assessing the effects of a heart attack (stroke)
  • Assessing infection in a specific organ
  • Assessing inflammation in a specific organ or system of the body
  • Assessing brain abnormalities; such as: tumors, memory disorders, seizures and other diseases of the central nervous system
  • Mapping the function of the human brain
• How is a PET-CT scan performed?

  First, the doctor will review the patient's medications and ask questions about the patient's condition. The patient's weight and blood sugar level will be determined. All metal objects, including coins in the pocket, will need to be removed. Then, the machine operator will inject a small amount of radioactive material into the patient's body.
  The time it takes for the drug to circulate in the patient's body until it is absorbed by the organs or tissues of the body is approximately 60 minutes, depending on the type of drug. During this period, the patient is asked to remain completely at rest and avoid moving or talking.
  The patient is transferred onto the PET CT scanner bed to begin the imaging. The patient must remain completely still during the imaging. The CT scan is performed first, followed by the PET scan.
  The CT scan imaging time is 2 minutes and the PET imaging time is 20-30 minutes. As a result, the total imaging time for the PET-CT test is 30 minutes.

• Features of the PET-CT machine

  This device is a 2020 product of Siemens Germany and is a horizon model, and it uses the TOF (time of flight) feature, which will provide unparalleled image quality and reduce patient scanning time.
  
  This device is equipped with LSO crystals in the detector section, which is one of the newest and most efficient crystals available, and it is possible to activate TOF (time of flight) technology on them. Therefore, it has one of the highest spatial resolution capabilities among existing devices, which means that this higher resolution means the possibility of detecting smaller tumors.
  
  The radiopharmaceutical generator and complement to this system is the cyclotron device.

SPECT-CT Section

• What is SPECT-CT Imaging?

  A SPECT-CT device is a type of diagnostic device and a subset of nuclear medicine devices. This device provides the functions of two separate SPECT and CT devices in one unit. The CT component of this device provides useful supplementary information about the body's anatomy and increases the sensitivity and specificity of the scan findings.

• How is SPECT-CT Imaging Performed?

  SPECT-CT imaging is a non-invasive method and is used to diagnose a wide range of diseases.
  Depending on the type of scan requested, radiopharmaceuticals (radioactive drugs) are administered into the body intravenously. These radiopharmaceuticals accumulate in the body and after interacting with body tissues, their energy is emitted from the body as gamma rays. The gamma rays are detected by a gamma camera and after several stages, are reconstructed into an image.
  One of the differences between imaging with X-rays (like plain radiography or CT scans) and gamma rays is that in X-ray imaging, the X-rays are emitted from the device, pass through the patient's body, and information is recorded by the device. But in imaging with gamma rays, the source of the radiation is the radiopharmaceutical, so radiation is emitted from the patient's body until the half-life of the drug passes.

• What Diseases is SPECT-CT Useful for Diagnosing?

  Diagnosis of many diseases including:

  • Coronary artery blockages
  • Benign and malignant bone diseases
  • Pulmonary embolism
  • Thyroid and parathyroid gland disorders
  • Gastrointestinal bleeding
  • Kidney dysfunction, urinary tract obstruction, and renal artery obstruction
  • Infection and inflammation
  • Brain disorders
  • Tear duct obstruction
  • Malignancies such as neuroendocrine tumors, thyroid tumors, etc.
• How is SPECT-CT Performed?

  First, questions about the patient's condition will be asked.
  It is necessary to remove all metal items, including coins from pockets. Then, the device operator will inject a small amount of radiolabeled material (radioactive) into the patient's body.
  The time for the radiopharmaceutical to circulate within the patient's body until it is absorbed by the organs or tissues varies from 15 minutes to 24 hours, depending on the type of radiopharmaceutical and the requested scan.
  The patient will be moved onto the SPECT-CT scanner bed for the imaging to begin. The patient must remain completely still during the imaging.
  Related pages.

PET-CT Section

• Required Documents
• Necessary Preparations
• Necessary Preparations for Diabetic Patients
• PET-CT Request Form

Necessary Preparations for Different Types of Scans

• Bone Density Measurement

  Necessary Preparations for Bone Density Measurement

  • Fasting is not required for bone density measurement.
  • If you have had this test in the past, please bring your previous bone density test results with you.
  • Please avoid consuming calcium supplements for 24 hours before the test.

  
  Duration of your stay in the department for bone density measurement:

  • Reception: Approximately 15 minutes
  • Bone density measurement procedure: Approximately 30 minutes

  
  Important Notes After Bone Density Measurement
  No specific precautions are necessary after the bone density measurement.
  💡 For more information, please call 23922480 between 4 PM and 5 PM.

• Heart Scan Preparations

  Necessary Preparations for Heart Scan
  

  • An accompanying person is mandatory. Please strictly avoid bringing children under 12 years old.
  • Shower the night before the scan. Men should shave their chest hair.
  • It is necessary to fast for 2 hours before the test. Diabetic patients should follow their usual diet and medications, fasting only for 2 hours before the test.
  • Bring your medical documents, including ECG, echo, angiography report, previous hospitalization records, and your insurance card. Also, bring a pack of milk or cream with you when you come.
  • Please wear a loose-fitting, button-down, cotton shirt with wide sleeves (without metal buttons). Women should definitely wear or bring comfortable trousers. In cases where the scan involves an exercise test, comfortable shoes for brisk walking are essential.
  • Do not consume tea, coffee, or chocolate for 12 hours before the test.
  • If you are taking heart or blood pressure medications, as coordinated with your treating physician, these medications must be discontinued before the scan according to the following table (unless your doctor instructs otherwise).

  Medication Name	Required Time to Discontinue Before Scan
  Metoprolol – Propranolol – Metoral – Inderal – Atenolol – Metohexal – Sotohaxal – Omeprazole – Pantoprazole	48 hours
  Amlodipine – Amlopress – Adalat – Diltiazem – Verapamil - Cardiolol	24 hours
  Theophylline – Aminophylline – Dipyridamole	24 hours (only if the scan is with Dipyridamole)
  Nitroglycerin – Nitrocontin – Isosorbide	12 hours

  Duration of your stay in the department for heart scan:

  • Reception: Approximately 15 minutes
  • Scan procedure: 2 days, approximately 3 to 4 hours each day

  Important Notes After Heart Scan:

  • For a period, while consuming fluids, please empty your bladder frequently.
  • Maintain a distance of approximately 1.5 meters from those around you (especially children and pregnant individuals) for 48 hours.

  💡 For more information, please call 23922480 between 4 PM and 5 PM.

• Bone Scan Preparations

  Necessary Preparations for Bone Scan

  • Fasting is not required for the bone scan.
  • Please bring all your previous documents (lab tests, X-rays, CT scans, and MRIs) with you when you come.
  • Since you will need to drink more fluids before the imaging, please bring about one liter of water, weak tea, or fruit juice with you.

  
  Duration of your stay in the department for bone scan:

  • Reception: Approximately 15 minutes
  • Scan procedure: Approximately 3 to 4 hours

  Important Notes After Bone Scan:

  • For a period, while consuming fluids, please empty your bladder frequently.
  • Maintain a distance of about 1 meter from those around you (especially children and pregnant individuals) for 24 hours.

  💡 For more information, please call 23922480 between 4 PM and 5 PM.

• Preparation for thyroid scan

  Preparations for Thyroid Scan
  

  • Fasting is not required for a thyroid scan.
  • Please bring a list of your medications with you when you visit.
  • If you are taking levothyroxine tablets, make arrangements with your doctor to stop or continue the medication before the scan.

  
  Length of your stay in the ward for a thyroid scan
  

  • Admission: About 15 minutes
  • Scanning steps: About 30 to 45 minutes

  
  Important points after a thyroid scan
  

  • Empty your bladder continuously for a while while consuming fluids.
  • Keep a distance of about 1 meter from those around you (especially children and pregnant women) for 24 hours.

  💡 For more information, call 23922480 between 4 pm and 5 pm.

• UBT Preparation

  Preparations for the H.Pylori Breath Test
  

  • Please fast for 6 hours before the test, both solids and liquids, and if you need to take medication during this period, take it with the minimum amount of water that you can drink.
  • If you are pregnant or have a history of severe respiratory problems before the test, inform the department head.
  • The following medications should be discontinued according to the doctor's advice before the test.

  Drug name	Duration of withdrawal before testing
  Sucralfate- Omeprazole- Esomeprazole- Lansoprazole- Rabeprazole- Pantoprazole	2 weeks
  Bismuth compounds- Antibiotics	30 days

  Duration of your stay in the testing unit

  • Admission: About 15 minutes
  • Testing steps: About 30 minutes

  Important points after the test
  After the H. Pylori breath test or UBT, there is no need to follow any special points.
  
  💡 For more information, please call 23922480 between 4-5 p.m.