Nuclear Imaging

Terminology and Technological Aspects

Mechanism

• Nuclear medicine differs from the rest of radiology because it involves functional rather than structural imaging.
• Radioisotopes: unstable forms of an element that emit detectable particles as they decay into more stable forms
• Radiopharmaceuticals:
  • Artificially produced isotopes bound to pharmaceuticals (radioisotope + an organic molecule) 
  • Administered to patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship and used in nuclear medicine
  • The organic molecule allows isotopes to concentrate within a specific target organ.
  • The radioisotope emits detectable ionizing radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma (high-energy rays) when it decays, which is visualized during imaging.

Image creation

Equipment:

• The machine is equipped with a gamma camera that detects radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma and forms an image.
• Components of the gamma camera:
  • Collimator: 1st layer between the patient and the crystal. The collimator is made of lead with holes to reduce scatter.
  • Crystal: emits faint light after interacting with gamma rays
  • Photomultiplier tubes: detect and convert light from the crystal into electrical signals
  • Electronics for processing data: analyze signals and produce viewable images 

Imaging techniques:

• Single-photon emission computed tomography (SPECT):
  • Uses gamma-emitting radioisotopes
  • A 3D nuclear imaging made by multiple 2D images acquired at different angles
• PET:
  • Uses positron-emitting radioisotopes
  • Superior image quality Quality Activities and programs intended to assure or improve the quality of care in either a defined medical setting or a program. The concept includes the assessment or evaluation of the quality of care; identification of problems or shortcomings in the delivery of care; designing activities to overcome these deficiencies; and follow-up monitoring to ensure effectiveness of corrective steps. Quality Measurement and Improvement (contrast and resolution) but more expensive
• Combined imaging techniques:
  • CT (PET-CT or SPECT-CT) or MRI is integrated.
  • Improved localization of lesions

Common nuclear medicine exams

• Hepatobiliary iminodiacetic acid (HIDA) scan
• Ventilation Ventilation The total volume of gas inspired or expired per unit of time, usually measured in liters per minute. Ventilation: Mechanics of Breathing and perfusion (VQ) scan
• Bone scan Bone Scan Osteosarcoma
• Cardiac scan
• Thyroid Thyroid The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy scan

Hepatobiliary Iminodiacetic Acid Scan

• HIDA scan (cholescintigraphy):
  • Examination of the gallbladder Gallbladder The gallbladder is a pear-shaped sac, located directly beneath the liver, that sits on top of the superior part of the duodenum. The primary functions of the gallbladder include concentrating and storing up to 50 mL of bile. Gallbladder and Biliary Tract: Anatomy
  • The radiopharmaceutical is normally taken up by the liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy and excreted through the biliary system as bile Bile An emulsifying agent produced in the liver and secreted into the duodenum. Its composition includes bile acids and salts; cholesterol; and electrolytes. It aids digestion of fats in the duodenum. Gallbladder and Biliary Tract: Anatomy.
  • Radiopharmaceutical: technetium-99m iminodiacetic acid
  • Isotope: technetium-99m
• Indications: 
  • Acute cholecystitis Acute cholecystitis Acute inflammation of the gallbladder wall. It is characterized by the presence of abdominal pain; fever; and leukocytosis. Gallstone obstruction of the cystic duct is present in approximately 90% of the cases. Cholecystitis with equivocal ultrasound findings
  • Biliary atresia Atresia Hypoplastic Left Heart Syndrome (HLHS)
  • Biliary leak
  • Biliary dyskinesia Biliary dyskinesia A motility disorder characterized by biliary colic, absence of gallstones, and an abnormal gallbladder ejection fraction. It is caused by gallbladder dyskinesia and/or sphincter of oddi dysfunction. Cholecystectomy: Cholecystokinin Cholecystokinin A peptide, of about 33 amino acids, secreted by the upper intestinal mucosa and also found in the central nervous system. It causes gallbladder contraction, release of pancreatic exocrine (or digestive) enzymes, and affects other gastrointestinal functions. Cholecystokinin may be the mediator of satiety. Gastrointestinal Secretions is administered and gallbladder Gallbladder The gallbladder is a pear-shaped sac, located directly beneath the liver, that sits on top of the superior part of the duodenum. The primary functions of the gallbladder include concentrating and storing up to 50 mL of bile. Gallbladder and Biliary Tract: Anatomy ejection fraction Ejection fraction Cardiac Cycle is calculated.
• Contraindication: allergy Allergy An abnormal adaptive immune response that may or may not involve antigen-specific IgE Type I Hypersensitivity Reaction to the radiotracer ( anaphylaxis Anaphylaxis An acute hypersensitivity reaction due to exposure to a previously encountered antigen. The reaction may include rapidly progressing urticaria, respiratory distress, vascular collapse, systemic shock, and death. Type I Hypersensitivity Reaction) 

Ventilation and Perfusion Scan

• Phases:
  • Ventilation Ventilation The total volume of gas inspired or expired per unit of time, usually measured in liters per minute. Ventilation: Mechanics of Breathing phase:
    • The patient breathes in the radiopharmaceutical, typically Xenon-133, in the form of an aerosol (other option: technetium-99m diethylenetriaminepentaacetate (DTPA)).
    • Small particles then are deposited into the alveoli Alveoli Small polyhedral outpouchings along the walls of the alveolar sacs, alveolar ducts and terminal bronchioles through the walls of which gas exchange between alveolar air and pulmonary capillary blood takes place. Acute Respiratory Distress Syndrome (ARDS) and images are acquired.
  • Perfusion phase:
    • An injectable radiopharmaceutical (technetium-99m macroaggregated albumin Albumin Serum albumin from humans. It is an essential carrier of both endogenous substances, such as fatty acids and bilirubin, and of xenobiotics in the blood. Liver Function Tests (MAA)) is administered. 
    • Technetium-99m MAA enters the pulmonary vessels and images are acquired.
• Indications: 
  • For evaluation of pulmonary embolism Pulmonary Embolism Pulmonary embolism (PE) is a potentially fatal condition that occurs as a result of intraluminal obstruction of the main pulmonary artery or its branches. The causative factors include thrombi, air, amniotic fluid, and fat. In PE, gas exchange is impaired due to the decreased return of deoxygenated blood to the lungs. Pulmonary Embolism when CT pulmonary angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery is contraindicated:
    • IV contrast allergy Allergy An abnormal adaptive immune response that may or may not involve antigen-specific IgE Type I Hypersensitivity Reaction
    • Pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care 
    • Renal failure Renal failure Conditions in which the kidneys perform below the normal level in the ability to remove wastes, concentrate urine, and maintain electrolyte balance; blood pressure; and calcium metabolism. Renal insufficiency can be classified by the degree of kidney damage (as measured by the level of proteinuria) and reduction in glomerular filtration rate. Crush Syndrome
  • Preoperative estimates of lung function: preparation for surgical excision
• Contraindication: allergy Allergy An abnormal adaptive immune response that may or may not involve antigen-specific IgE Type I Hypersensitivity Reaction to radiotracers ( anaphylaxis Anaphylaxis An acute hypersensitivity reaction due to exposure to a previously encountered antigen. The reaction may include rapidly progressing urticaria, respiratory distress, vascular collapse, systemic shock, and death. Type I Hypersensitivity Reaction) 
• Normal VQ scan findings:
  • Normal perfusion: uniform uptake in the lungs Lungs Lungs are the main organs of the respiratory system. Lungs are paired viscera located in the thoracic cavity and are composed of spongy tissue. The primary function of the lungs is to oxygenate blood and eliminate CO2. Lungs: Anatomy with areas of photopenia in the region of the heart and hila 
  • Normal ventilation Ventilation The total volume of gas inspired or expired per unit of time, usually measured in liters per minute. Ventilation: Mechanics of Breathing: radiotracer homogeneously washing into the lung with quick washout and no evidence of air trapping
  • Always obtain a chest radiograph prior to a VQ scan to exclude consolidation Consolidation Pulmonary Function Tests, which gives a false-positive result.

Bone Scan

• The skeletal system can be assessed using nuclear medicine.
  • The radiopharmaceutical that is used chemoadsorbs to the hydroxyapatite crystals Hydroxyapatite crystals A group of compounds with the general formula m10(PO4)6(OH)2, where m is barium, strontium, or calcium. The compounds are the principal mineral in phosphorite deposits, biological tissue, human bones, and teeth. They are also used as an anticaking agent and polymer catalysts. Calcium Hemostasis and Bone Metabolism in the bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types matrix; thus, areas of bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types turnover can be identified.
  • Increased bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types turnover is seen in fractures, tumors, and acute infection.
  • Isotope: technetium-99m
  • Radiopharmaceutical: methylene diphosphonate
• Imaging:
  • Images are obtained 4 hours after injection, allowing the radiotracer to be taken up by the bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types.
  • Anterior and posterior images are obtained.
• Indications: 
  • Bony metastases screening Screening Preoperative Care
  • Evaluation of fractures (e.g., stress fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures) that are not visible on a radiograph
  • Infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease

Cardiac Scan

• Also known as myocardial perfusion imaging
• Detects variation in blood flow Blood flow Blood flow refers to the movement of a certain volume of blood through the vasculature over a given unit of time (e.g., mL per minute). Vascular Resistance, Flow, and Mean Arterial Pressure and myocardial extraction of radiotracers 
• Materials: 
  • Isotopes: 
    • Technetium-99m
    • Thallium-201 
  • Radiopharmaceuticals:
    • Sestamibi 
    • Teboroxime
• Procedure:
  • In normal coronary arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology, significant arterial dilatation is seen in response to exercise/stress.
  • Stenotic areas do not show dilatation; thus, ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage and ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) changes occur. 
  • In a cardiac scan, stress is either:
    • Induced by exercise by running on a treadmill
    • Pharmacologically induced by giving adenosine Adenosine A nucleoside that is composed of adenine and d-ribose. Adenosine or adenosine derivatives play many important biological roles in addition to being components of DNA and RNA. Adenosine itself is a neurotransmitter. Class 5 Antiarrhythmic Drugs or dobutamine Dobutamine A catecholamine derivative with specificity for beta-1 adrenergic receptors. Sympathomimetic Drugs to those who cannot run 
• Imaging is obtained at both stress and rest.
• Radiopharmaceuticals are injected when 85% of the maximum predicted heart rate Heart rate The number of times the heart ventricles contract per unit of time, usually per minute. Cardiac Physiology (MPHR) is reached.
• Indications:
  • Myocardial ischemia Myocardial ischemia A disorder of cardiac function caused by insufficient blood flow to the muscle tissue of the heart. The decreased blood flow may be due to narrowing of the coronary arteries (coronary artery disease), to obstruction by a thrombus (coronary thrombosis), or less commonly, to diffuse narrowing of arterioles and other small vessels within the heart. Coronary Heart Disease or infarction evaluation
  • Wall-motion abnormalities: performed using ECG-gated SPECT scan
  • Calculate left ventricular ejection fraction Ejection fraction Cardiac Cycle
• Normal cardiac scan obtained in 3 different planes:
  • The top row of each set is performed under cardiac stress.
  • Bottom row of each set is performed at rest.
  • Normal flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure to all aspects of the heart at both rest and stress
• Abnormal cardiac scans:
  • Myocardial ischemia Myocardial ischemia A disorder of cardiac function caused by insufficient blood flow to the muscle tissue of the heart. The decreased blood flow may be due to narrowing of the coronary arteries (coronary artery disease), to obstruction by a thrombus (coronary thrombosis), or less commonly, to diffuse narrowing of arterioles and other small vessels within the heart. Coronary Heart Disease: areas of photopenia (i.e., decreased uptake) under stress, which improve at rest
  • Myocardial infarction Myocardial infarction MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction: persistent photopenia (i.e., decreased uptake) despite rest state

Thyroid Scan

• The thyroid Thyroid The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy gland transports iodine Iodine A nonmetallic element of the halogen group that is represented by the atomic symbol I, atomic number 53, and atomic weight of 126. 90. It is a nutritionally essential element, especially important in thyroid hormone synthesis. In solution, it has anti-infective properties and is used topically. Thyroid Hormones; thus, radioiodine is used to detect the function of the whole gland or nodules.
• Radiopharmaceuticals:
  • Radioactive iodine Radioactive iodine Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes. Antithyroid Drugs (iodine-123)
  • Technetium-99 pertechnetate
• Indications: 
  • Thyroid Thyroid The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy nodules
  • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with thyrotoxicosis Thyrotoxicosis A hypermetabolic syndrome caused by excess thyroid hormones which may come from endogenous or exogenous sources. The endogenous source of hormone may be thyroid hyperplasia; thyroid neoplasms; or hormone-producing extrathyroidal tissue. Thyrotoxicosis is characterized by nervousness; tachycardia; fatigue; weight loss; heat intolerance; and excessive sweating. Thyrotoxicosis and Hyperthyroidism
  • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with thyroid Thyroid The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy cancer:
    • Distant metastasis Metastasis The transfer of a neoplasm from one organ or part of the body to another remote from the primary site. Grading, Staging, and Metastasis (whole body scan)
    • Local residual disease
  • Therapeutic use: radioactive thyroid Thyroid The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy ablation (in Graves’ disease Graves’ disease A common form of hyperthyroidism with a diffuse hyperplastic goiter. It is an autoimmune disorder that produces antibodies against the thyroid stimulating hormone receptor. These autoantibodies activate the TSH receptor, thereby stimulating the thyroid gland and hypersecretion of thyroid hormones. These autoantibodies can also affect the eyes (Graves ophthalmopathy) and the skin (Graves dermopathy). Thyrotoxicosis and Hyperthyroidism or thyroid Thyroid The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy carcinoma) using higher doses of radioactive iodine Radioactive iodine Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes. Antithyroid Drugs (iodine-131 destroys thyroid Thyroid The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy cells)
• Contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation:
  • Pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care 
  • Lactation Lactation The processes of milk secretion by the maternal mammary glands after parturition. The proliferation of the mammary glandular tissue, milk synthesis, and milk expulsion or let down are regulated by the interactions of several hormones including estradiol; progesterone; prolactin; and oxytocin. Breastfeeding

Other Imaging Modalities by System

• Imaging of the CNS ( brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification, spinal cord Spinal cord The spinal cord is the major conduction pathway connecting the brain to the body; it is part of the CNS. In cross section, the spinal cord is divided into an H-shaped area of gray matter (consisting of synapsing neuronal cell bodies) and a surrounding area of white matter (consisting of ascending and descending tracts of myelinated axons). Spinal Cord: Anatomy, and vertebral column Vertebral column The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy):
  • Radiography is often used to evaluate fractures of the vertebral column Vertebral column The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy. 
  • CT is a good choice to determine head trauma Head trauma Head trauma occurs when external forces are directed to the skull and brain structures, resulting in damage to the skull, brain, and intracranial structures. Head injuries can be classified as open (penetrating) or closed (blunt), and primary (from the initial trauma) or secondary (indirect brain injury), and range from mild to severe and life-threatening. Head Trauma and exclude intracranial hemorrhage Intracranial hemorrhage Subarachnoid hemorrhage (SAH) is a type of cerebrovascular accident (stroke) resulting from intracranial hemorrhage into the subarachnoid space between the arachnoid and the pia mater layers of the meninges surrounding the brain. Most sahs originate from a saccular aneurysm in the circle of willis but may also occur as a result of trauma, uncontrolled hypertension, vasculitis, anticoagulant use, or stimulant use. Subarachnoid Hemorrhage. 
  • MRI provides more detailed images of the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification and spinal cord Spinal cord The spinal cord is the major conduction pathway connecting the brain to the body; it is part of the CNS. In cross section, the spinal cord is divided into an H-shaped area of gray matter (consisting of synapsing neuronal cell bodies) and a surrounding area of white matter (consisting of ascending and descending tracts of myelinated axons). Spinal Cord: Anatomy, allowing identification Identification Defense Mechanisms of infarction, tumors, disk herniation Herniation Omphalocele, and demyelinating disease.
• Pulmonary radiology Pulmonary Radiology Pulmonary, or chest, imaging includes imaging of the lungs and surrounding structures in the thorax. Imaging of the chest represents a substantial portion of the imaging tests that are routinely performed. Common imaging methods include X-ray, CT, MRI, and ultrasonography (US). Imaging of the Lungs and Pleura and imaging of the mediastinum Mediastinum The mediastinum is the thoracic area between the 2 pleural cavities. The mediastinum contains vital structures of the circulatory, respiratory, digestive, and nervous systems including the heart and esophagus, and major thoracic vessels. Mediastinum and Great Vessels: Anatomy:
  • Radiography is the preferred initial imaging study for viewing lung pathology. 
  • CT provides more detailed views of the lung parenchyma, mediastinal structures, and vasculature. 
  • MRI is not often used, but may be employed for evaluating malignancies and cardiac disease. 
  • Ultrasound can be used for rapid bedside-trauma assessment and for guiding procedures ( thoracentesis Thoracentesis Aspiration of fluid or air from the thoracic cavity. It is coupled sometimes with the administration of drugs into the pleural cavity. Thoracic Surgery).
• Breast imaging Breast Imaging Female breasts, made of glandular, adipose, and connective tissue, are hormone-sensitive organs that undergo changes along with the menstrual cycle and during pregnancy. Breasts may be affected by various diseases, in which different imaging methods are important to arrive at the correct diagnosis and management. Mammography is used for breast cancer screening and diagnostic evaluation of various breast-related symptoms. Imaging of the Breast:
  • Mammography Mammography Radiographic examination of the breast. Breast Cancer Screening is often the initial choice for breast cancer Breast cancer Breast cancer is a disease characterized by malignant transformation of the epithelial cells of the breast. Breast cancer is the most common form of cancer and 2nd most common cause of cancer-related death among women. Breast Cancer screening Screening Preoperative Care. 
  • MRI can be used to further evaluate and stage breast cancers. 
  • Ultrasound is helpful in the evaluation of lymph nodes Lymph Nodes They are oval or bean shaped bodies (1 – 30 mm in diameter) located along the lymphatic system. Lymphatic Drainage System: Anatomy and in guiding biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma.
• Imaging of the abdomen and renal imaging Renal imaging The renal system is composed of 2 kidneys, 2 ureters, a bladder, and a urethra. Varying conditions such as infections, cysts, solid masses, ischemia, and mechanical obstruction can affect the renal system. Evaluation of diseases rely on imaging methods such as radiography, ultrasonography, CT, and MRI. Some of these are also used to guide tissue sampling (e.g., renal biopsy). Imaging of the Urinary System:
  • Radiography is often used to evaluate for kidney stones Kidney stones Nephrolithiasis is the formation of a stone, or calculus, anywhere along the urinary tract caused by precipitations of solutes in the urine. The most common type of kidney stone is the calcium oxalate stone, but other types include calcium phosphate, struvite (ammonium magnesium phosphate), uric acid, and cystine stones. Nephrolithiasis, bowel obstruction Bowel obstruction Any impairment, arrest, or reversal of the normal flow of intestinal contents toward the anal canal. Ascaris/Ascariasis, and pneumoperitoneum Pneumoperitoneum A condition with trapped gas or air in the peritoneal cavity, usually secondary to perforation of the internal organs such as the lung and the gastrointestinal tract, or to recent surgery. Pneumoperitoneum may be purposely introduced to aid radiological examination. Perforated Viscus. In addition, barium may be used to assess swallowing Swallowing The act of taking solids and liquids into the gastrointestinal tract through the mouth and throat. Gastrointestinal Motility and bowel function. 
  • CT and MRI provide more detailed assessments of the abdominal viscera and vasculature. 
  • Nuclear medicine can be used to assess gallbladder Gallbladder The gallbladder is a pear-shaped sac, located directly beneath the liver, that sits on top of the superior part of the duodenum. The primary functions of the gallbladder include concentrating and storing up to 50 mL of bile. Gallbladder and Biliary Tract: Anatomy function, gastric emptying Gastric emptying The evacuation of food from the stomach into the duodenum. Gastrointestinal Motility, and GI bleeding.
• Imaging of the uterus Uterus The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The uterus has a thick wall made of smooth muscle (the myometrium) and an inner mucosal layer (the endometrium). The most inferior portion of the uterus is the cervix, which connects the uterine cavity to the vagina. Uterus, Cervix, and Fallopian Tubes: Anatomy and ovaries Ovaries Ovaries are the paired gonads of the female reproductive system that contain haploid gametes known as oocytes. The ovaries are located intraperitoneally in the pelvis, just posterior to the broad ligament, and are connected to the pelvic sidewall and to the uterus by ligaments. These organs function to secrete hormones (estrogen and progesterone) and to produce the female germ cells (oocytes). Ovaries: Anatomy:
  • Ultrasound is the most commonly used modality to evaluate the ovary and uterus Uterus The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The uterus has a thick wall made of smooth muscle (the myometrium) and an inner mucosal layer (the endometrium). The most inferior portion of the uterus is the cervix, which connects the uterine cavity to the vagina. Uterus, Cervix, and Fallopian Tubes: Anatomy, including assessing pregnancies and determining the cause of abnormal uterine bleeding Abnormal Uterine Bleeding Abnormal uterine bleeding is the medical term for abnormalities in the frequency, volume, duration, and regularity of the menstrual cycle. Abnormal uterine bleeding is classified using the acronym PALM-COEIN, with PALM representing the structural causes and COEIN indicating the non-structural causes. Abnormal Uterine Bleeding. 
  • CT and MRI provide more detailed views and are often useful in assessing cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change, malignancies, and benign Benign Fibroadenoma masses.
• Imaging of the musculoskeletal system:
  • Radiography is often used to exclude fractures. 
  • CT is more sensitive to bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types pathology, including osteomyelitis Osteomyelitis Osteomyelitis is an infection of the bone that results from the spread of microorganisms from the blood (hematogenous), nearby infected tissue, or open wounds (non-hematogenous). Infections are most commonly caused by Staphylococcus aureus. Osteomyelitis. 
  • MRI is preferred for soft-tissue evaluation, such as assessing for malignancy Malignancy Hemothorax and myositis. 
  • Bone scan Bone Scan Osteosarcoma can be useful in determining occult fractures, osteomyelitis Osteomyelitis Osteomyelitis is an infection of the bone that results from the spread of microorganisms from the blood (hematogenous), nearby infected tissue, or open wounds (non-hematogenous). Infections are most commonly caused by Staphylococcus aureus. Osteomyelitis, and metabolic bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types disease.