Introduction to Radiology Welcome to Radiology 553 an Introduction to Radiology. Over the next several weeks we will be reviewing the various imaging modalities that are going to be available for your use as a clinician to assist in diagnosis and treatment of your patient.

Course Overview Four Live Lectures Four Required On-line modules Lab session Four quizzes Two examinations This course is going to be presented as 4 live lectures as well as 4 required on-line modules. These on-line modules will include a variety of materials which will assist you in learning the material required of this course. there will be a single lab session in the second half of the course which will be a live session at each of the locations with an opportunity to work or interact directly with a radiologist or radiology resident to assist you in reviewing various images, answering your questions about those images and some of the applications of the imaging modalities. Four quizzes will be included as part of the required on-line materials and there are 2 examinations, one at the midpoint of the course covering all material in the first half of the course and one at the end of the course covering material in the second half of the course

Course Overview Expectations Active participation and preparation Utilization of provided on-line materials Exciting Fun Course My expectations of you for this course are simple. I ask for active preparation and participation. I hope that you prepare prior to each of the subsequent lectures by completing the required online material. I also ask that you utilize the online materials in order to enhance or knowledge. This should be an exciting and fun course.

Introduction Lecture Historical overview X-rays Appropriateness Criteria Application of the various technologies to be discussed in the course In this first lecture I hope to first provide an historic overview of the various imaging modalities and some of the individuals who have been involved in their discovery and promotion. We will talk a bit more about x-rays and the generation of x-rays, discuss appropriateness criteria and how they may help you in deciding what imaging modalities appropriate, and then discuss the application of the various technologies that we are going to discuss as we go through the course and to various clinical conditions.

Ionizing Radiation Historical Overview Wilhelm Conrad Röentgen 1845 – 1923 November 8, 1895 – discovery of the x-ray Discovered effect of passing this ray through materials First radiograph of his wife’s hand 1901 – Nobel Prize Physics Antoine Henri Becquerel 1852-1908 Radioactive nature of Uranium 1903 – Nobel Prize Physics Let's first talk about ionizing radiation. Wilhelm Conrad Roentgen who lived from 1845 to 1923 discovered x-ray on November 8, 1895. He identified the effect of passing this ray through materials and recording that on the photographic plate. The first radiograph was a radiograph of his wife's hand. that image has been the memorialized in many historical presentations. In 1901 he won the Nobel Prize for physics. Another individual actively involved in the Discovery of radiation include Antoine Henry Becquerel. Becquerel living from 1852 - 1908 identified the radioactive nature of uranium and won the Nobel Prize for physics in 1903

Ionizing Radiation Historical Overview Marie and Pierre Curie 1867-1934, 1859 – 1906 Marie coined term “radioactivity” Discovery of Polonium and Radium 1903 - 1910 – Nobel Prize Physics - Chemistry Died July 4, 1934 – Pernicious Anemia William D. Coolidge Patent holder for the original x-ray tube 1913 Robert S. Ledley Patent holder for original CT scanner 1975 A well-recognized name in ionizing radiation is Curie, Marie and Pierre, 1867-1934 and 1859-1906 are known for Marie’s coining of the term radioactivity. She is credited with the discovery of polonium and radium and shared with her husband the Nobel prize in physics in 1903 by herself she was awarded the chemistry prize in 1910 unfortunately Marie died in 1934 as result of pernicious anemia likely brought on by her lifelong exposure to radiation. Other names known in ionizing radiation history include William Coolidge a patent holder for the original x-ray tube 1913 and Robert Leslie the patent holder for the original CT scanner in 1975. Note that the original cc scanner was a developed about 1975 so it’s life as applied to diagnostic imaging is relatively short

US Historical Overview George D. Ludwig Late 1940’s research for the Navy Classified work using US to evaluate tissues Report June 1949 first published work on US applications Douglass Howry, Joseph Holmes Pioneering work in B-Mode ultrasound Joseph Holmes, William Wright and Ralph Meyerdirk First articulated arm scanner 1963 James Griffith, Walter Henry NIH Mechanical oscillating real-time apparatus 1973 Martin H. Wilcox Linear array real time scanner 1973 A variety of individuals are known for their contribution to diagnostic ultrasound. George Ludwig in the late 1940’s was doing research for the navy related to sonar. His classified work was using ultrasound to evaluate tissues which was first reported in 1949 after World War II when he reported his work on ultrasound applications in humans. Douglas Howry and Joseph Holmes were known for their pioneering work in B-mode ultrasound the precursor to the ultrasound technology we use today. Joseph Holmes, William Wright and Ralph Meyerdirk developed the first articulated arm scanner in 1963. This would be the first true ultrasound device utilized for scanning of body parts for diagnostic purposes. James Griffith and Walter Henry at the National Institute of Health developed a mechanical oscillating real-time apparatus a precursor to today's real-time scanners in 1973. Martin Wilcox in 1973 also developed a linear-array real-time scanner which allowed real-time scanning without a mechanical device

NM Historical Overview Benedict Cassen, Lawrence Curtis, Clifton Reed Automated scintillation detector 1951 Hal Anger Scintillation Camera 1958 Picker Corporation 3 inch rectilinear scanner 1959 John Kuranz – Nuclear Chicago First commercial Anger (Gamma Camera) The history of Nuclear Medicine utilization and diagnostic imaging extends from that of the Curie family. Benedict Cassen, Lawrence Curtis and Clifton Reed developed an automated scintillation detector for detecting gamma rays in 1951. In 1958 Hal Anger developed the first scintillation camera or sometimes referred to as Anger camera or a gamma camera. Picker Corporation built on the work of Cassen and friends to develop a 3 inch rectilinear scanner in 1959. John Kuranz of Nuclear Chicago took Dr. Anger/s development into the first commercial Anger camera or gamma camera in the 1960s

MRI Historical Overview Felix Bloch, Edward Purcell NMR Spectroscopy Paul Laterbur, Peter Mansfield 2003 Nobel Prize Physiology / Medicine Raymond Damadian First patent in field of MRI 1970 MRI imaging also having a relatively short life, was built upon the building blocks created by Felix Bloch and Edward Purcell in their development of NMR spectroscopy. You may recall NMR spectroscopy from your time in the organic chemistry lab where the unknowns that you would work out with chemical means were then of evaluated utilizing NMR spectroscopy and matching that spectroscopy to known molecules. Paul Lauterbur and Peter Mansfield are felt to be the true originators of the clinically useful MRI scanner. They won the 2003 Nobel prize for physiology and medicine. Raymond Damadian also had a role in the development of MRI unfortunately was not quite clear early in his career onto the impact of this particular type of imaging. He held the first pass it in the field of MRI in 1970

Imaging Modalities Ionizing Radiation: No Ionizing Radiation: Diagnostic Radiology (X-rays) Interventional Radiology Computed Tomography (CT) Nuclear Medicine Positron Emission Tomography (PET) No Ionizing Radiation: Diagnostic Ultrasound (Ultrasonography) Magnetic Resonance Imaging (MRI) Let’s talk about the various imaging modalities that we are going to evaluate during this course. Modalities utilizing ionizing radiation include diagnostic radiology or x-ray, interventional radiology application of x-ray primarily, computed tomography, nuclear medicine, and positron emission tomography or PET scanning.. No ionizing radiation used for evaluations including MRI and Ultrasound evaluation.

X-Rays High energy electromagnetic radiation Behaves both like a particle (photon) and a wave Production of X-Rays Free electrons produced at filament of x-ray tube (cathode) High Speed movement of electrons Rapid deceleration of electrons at anode Emission of a x-ray photon Let's first talk about application and creation of x-ray. A high-energy electromagnetic radiation x-rays behave both like photons and waves. The production of x-ray is a result of the creation of free electrons at the filament of an x-ray tube or the cathode end of the tube. A filament much like the filament in an incandescent light bulb is heated up to the point where electrons float free of the filament. These electrons are accelerated at a high speed across the x-ray tube due to the potential developed between the cathode and the anode. As they rapidly decelerate as they strike the anode they emit an x-ray photon.

X-ray Tube Schematic Envelope Electron Anode – Tungsten Target Cathode Beam Anode – Tungsten Target Cathode Diagrammatically here is a schematic of an x-ray tube. As I discuss, note the cathode, the electrons moving from the cathode to the angled anode and the x-rays being directed through a window in the envelope of the tube, through a collimator to control the width and the shape of the beam down through the patient to a detector device. Window Collimator X-rays

Production of Image X-ray pass through tissue to expose detector Passage depends on Tissue characteristics Density Atomic Number Number of electrons per gram Thickness The production of the x-ray image is as a result of the x-rays passing through tissue to expose some type of detector. The passage of these x-ray photons is dependent upon the tissue characteristics of the intervening tissues including the density anatomic number the number of electrons per gram and the thickness of the structure

Production of Image Differential absorption of X-ray as the beam passes through the patient Unabsorbed X-rays expose the detector (i.e. film, CR Plate, solid state detector), creating the image (photographic effect) Differential absorption of X-ray by the tissues is the cardinal feature of image formation Special terms used on x-ray reports Radiopaque, Radiolucent, High attenuation, Low attenuation, Water density The production of the x-ray image is dependent upon the differential absorption of the x-ray beam as it passes through the patient. The unabsorbed x-rays expose a detector. The detector might be a film, but could also be a variety of detectors that allow the creation of a digital imaging. These could include such things as a computed radiography plate or CR plate or some type of a solid state detector. Whichever is used, the detector creates an image or photographic effect. The differential absorption of the x-ray by the tissue is the cardinal features that lead to image formation. There are special terms we use in x-ray reports these include radiopaque, radiolucent, high attenuation, low attenuation and water density. Radiopaque and high attenuation are similar, radiolucent and low-attenuation are also similar. Water density would fall between the two.

Standard X-Ray Machine X-Ray Tube X-Ray Tube Detector Here are photographs of a standard x-ray machine. Note the x-ray tube and detector in their relative relationship to the patient. The patient is lying on the x-ray table or standing in front of a wall Bucky or wall detector Detector

Fluoroscopic Imaging Unit X-Ray Tube Detector We can also use a fluoroscopic device, a device which allows for the continuous exposure of x-ray to a detector that can be viewed on a video screen which allows us to evaluate for motion under x-ray observation. This device also allows for the standard x-ray to be obtained as it has an adjoining or attached x-ray tube and detector. Detector X-Ray Tube

Natural Densities Natural densities in the body Bone Soft tissue and body fluid Fat Lung and air containing organs Appearance on the radiographic image White Black Shades of Gray A variety of densities can be detected by radiography and I’d like to talk a little bit about those now. The natural densities occurring in the body include bone, soft tissue and body fluid, fat, lung and air containing structures. The appearance on the radiographic images will vary from white for bone to various changes of gray for soft tissues and body fluids, fat and finally black for lung and air containing structures. I think it is useful to be familiar with this gradation of gray or black or white that we see as we pass from bone through soft tissues and body fluid through fat and finally air.

Image Density X-ray Radiopaque – High attenuation Appears white on film – black on fluoroscopy X-ray photons don’t reach the detector Radiolucent – Low attenuation Appears black on film – white on fluoroscopy X-ray photons unimpeded traveling to detector Water density Appears grey on film All soft tissues Let's explore a little more about image density on the x-ray. Here we see radiopaque or high attenuation structures appearing white on film as we look at the rib, the clavicles and scapula and black on fluoroscopy as we look at the area of barium in the stomach on an upper GI examination. x-ray photons don't reach detector leading to this appearance. Radiolucent or low-attenuation is as result of x-ray photons passing rapidly through, without interference to the detector. This would appear black on film, the lungs, or white on fluoroscopy. Again looking at the area of the lungs, in this case x-ray photons are unimpeded in their travel to the detector, thus more exposure takes place. Water density reflects the areas that appear gray on the film.

Natural Contrast Differential contrast between bone and soft tissues Differential contrast between soft tissues and air Little difference between various tissue types i.e. fat, muscle, solid organs, blood…. Natural contrast does occur in the body. This includes the differential contrast that we see between bone and soft tissues and the contrast we see between soft tissues and air. There however is little difference between various tissue types for example fat, muscle, solid organs, blood and so forth.

Natural Contrast Pathologic processes may cause differences in natural densities that can be visualized on the X-ray; high density tumor in air filled lung- white Low density cyst in radio-opaque bone- black Pathologic processes of almost the same density as adjoining structures are not visible on X-ray. May need to use additional artificial contrast to visualize a density difference Various pathologic processes can enhance the natural difference in density that can be visualized on the radiograph. This includes the presence of a high-density tumor or water-containing structure in the air-filled lung this will appear white. We can also see a low-density cystic area in a radiopaque structur, bone, and this would appear black on the radiograph. Most pathologic processes however are almost of the same density as the adjoining structures and therefore will not be visualized on standard radiography. We may need to use additional artificial contrast in order to visualize or accentuate the density difference that exist.

Contrast Agents Contrast material (radio-opaque or radio-lucent) administered to see structures or pathologic processes that would not be seen otherwise Some useful contrast agents Barium sulfate in the GI tract Iodine compounds in the vessels Carbon dioxide in the vessels or GI tract Naturally occurring air in the GI tract A variety of contrast agents can be utilized. These contrast materials which are radiopaque or radiolucent are administered in order to allow us to see structures or pathologic processes that may not be seen otherwise. Some useful contrast agents that we use for diagnostic imaging with x-ray include; barium sulfite in the gastrointestinal tract. Iodine compounds in vascular structures. Carbon dioxide can be used both in vessels or in the gastrointestinal tract. We also can utilized the presence of naturally occurring air in the gastrointestinal tract to assist in our diagnosis

Fluoroscopic Room Video Camera Radiosensitive Screen Here we see an example of a famous radiologist utilizing the video features of a fluoroscopic room to evaluate a barium study in a patient. The radio-sensitive screen exposed by the x-ray from the tube which is beneath the table allows this evaluation.

Appropriateness Criteria Guidelines to assure proper imaging choices Based on attributes developed by the Agency for Healthcare Research and Quality (AHRQ) I would like to speak the next few minutes about appropriateness criteria. Appropriateness criteria are guidelines that help assure proper imaging choices. These are based on attributes that have been developed by the agency for Health Care Research and Quality. This information I am providing comes from the ACR appropriateness review criteria. ACR Appropriateness Review Criteria Overview

Appropriateness Criteria Validity – lead to better outcomes based on scientific evidence Reliable and reproducible – other experts should develop same recommendations based on the same scientific evidence Clinical applicability – guideline indicates target population These criteria have to be valid. They need to lead to better outcomes based on scientific evidence. They must be reliable and reproducible which means that other experts should develop the same recommendations or similar recommendations when they look at the same scientific evidence. There must be a clinical applicability of these appropriateness criteria and the guideline has to indicate who the target population is. ACR Appropriateness Review Criteria Overview

Appropriateness Criteria Clinical flexibility – specify expectations Clarity – unambiguous, clear definitions Multidisciplinary – all affected groups should be represented Scheduled review – fixed time to review and revise Documentation – evidence used and approach taken is documented The criteria should be clinically flexible and they should specify our expectations. There must be clarity it should be unambiguous and it should be clearly defined, or there should be clear definitions that assist clinicians in making determination of what the appropriateness is. It should be a multidisciplinary process in which all affected groups should be represented in. Representatives on the committee creating appropriateness criteria should not just include radiologist but should include other affected physicians. for instance gastroenterologist for GI related processes. There should be a scheduled review when the criteria will be reviewed and revised based on new information and there must be documentation that evidence was used and that an evidence based approach was taken. ACR Appropriateness Review Criteria Overview

Appropriateness Criteria ACR Appropriateness Criteria search engine: http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria.aspx Allows searching by 10 diagnostic imaging expert panels Useful resource when evaluating what clinical exam may be useful The American College of Radiology has an Appropriateness Criteria search engine that you can utilize. Please feel free to use this link to take a look at their criteria. This allows searching by 10 separate diagnostic imaging expert panels of the various appropriateness criteria that have been developed. These are useful resources when evaluating what clinical exam may be useful for your patient

Appropriateness Criteria Electronic Decision Support for Medical Imaging Future opportunities to improve health care Appropriateness criteria lead to electronic decision support for medical imaging. The ability to have guidance when making decisions about what the right diagnostic test may be for your patient, so you can have some idea of what the yield will be for a particular test with the clinical condition that your patient is presenting with. This may provide us with considerable future opportunity to improve health care for our patients.

X-Ray Ionizing radiation Exposure concerns Somewhat limited discrimination between structures of similar density Tumor vs. normal organs Inexpensive Readily available First line imaging tool For the remainder of this lecture I would like to review some of the issues related to the various imaging modalities and some of their applications. This will be fleshed out and discussed in more detail as we go into the various units as well as well as we go through the on-line modules. When talking about x-ray we are talking about an ionizing radiation, so one of our primary concerns must be of exposure concern. We must be concerned that we do not overexpose our patients and we have some control of the exposure our patients receive to ionizing radiation. X-ray allows for somewhat limited discrimination between structures of similar density, for example separation of neoplasm from normal organ structures. The positives of x-ray include the fact that is relatively inexpensive, it is readily available, and it has become our first line imaging tool for a variety of abnormalities and conditions.

X-Ray Primary applications: Chest Imaging Abdominal imaging Infiltrates Masses Cardiac silhouette Abdominal imaging Gas/ bowel distribution Free air Calcifications Organomegaly/ masses Some of the primary applications of radiology include chest imaging where x-ray can be utilized in evaluation for infiltrate mass or cardiac abnormalities in shape and size. In the abdomen x-ray can be utilized for evaluation of the distribution of bowel, the presence of gas and the distribution of gas. We can evaluate for the presence of free intraperitoneal air, look for calcifications related to the biliary or the urinary tract or gastrointestinal tract. We can evaluate for the presence of organomegaly or mass

X-Ray Primary Applications Bone and Joint imaging Soft Tissues Trauma Neoplasm Soft Tissues Mass Foreign bodies Breast imaging Many of the applications of x-ray include bone and joint imaging both for the purpose of evaluation of trauma and neoplasm. Soft tissues can also be evaluated for mass or foreign bodies. Breast imaging is another important application of x-ray imaging.

X-Ray Secondary applications: Contrast enhanced examination Urinary tract IVU Cystography, urethrography Angiography Pulmonary/ Cardiac Pulmonary Coronary Great vessels General Neoplasm Vascular abnormalities Some secondary applications of x-ray include contrast-enhanced examinations. Examinations of the urinary tract have been performed for many years. Intervenous urography is less useful today than it has been in the pas,t because it is has been by and large replaced by other modalities. Cystography and urethrography however continue to be useful evaluations utilizing x-ray technology in the introduction of contrast material into the bladder through a catheter. Angiography also still plays a role at times for the evaluation of the urinary tract. In pulmonary and cardiac applications contrast-enhanced examination can evaluate for pulmonary emboli and for coronary artery disease. The great vessels can also be evaluated with angiography. In general x-ray is useful in the early evaluation of various neoplasms and vascular abnormality.

X-Ray Secondary applications: Dual energy Bone density evaluation Lung lesions Soft tissue calcifications Bone density evaluation Tomography – tomosynthesis Other more specialized applications include dual-energy x-ray evaluation. We are able to take two sequential exposures at different x-ray KV levels allow us for the discrimination of lung lesions more clearly and allow us to evaluate soft tissue calcification. Additionally, we can use various techniques with low intensity x-ray for determining the bone density of hips, back, wrist and so forth which could be useful in determining patients who may be aided by various treatment modalities or methods for possible osteoporosis. And finally tomography creating of thin sections whether by tube motion or by computer synthesis can be helpful in evaluating various structures of the body.

Interventional Radiology Minimally invasive technology Biopsy Cavity drainage Infections Neoplasm Revascularization TPA Angioplasty Stenting Interventional radiology is a minimally invasive technology that allows us to do many of the things that previously required open surgery and fairly invasive procedures. These include biopsies of lesions, drainage of cavities whether they be infectious or neoplastic, revascularization of vascular territories that have been become occluded by atherosclerotic changes, in some of these cases, the technologies utilized will include TPA, angioplasty or the placing of stents.

Interventional Radiology Lumen restoration / drainage Biliary tree Ureters Others Vertebroplasty/ kyphoplasty Interventional radiography technique can also lead to lumen restoration, improved drainage of the biliary tree and from the ureters as well as ability to drain other fluid collections . More recent technology has included the development of the process described as vertebroplasty or kyphoplasty in an attempt to re-expand collapsed vertebra by the placement of radiopaque bone cement into the vertebral bodies reducing patient pain

Computed Tomography Ionizing radiation Requires concern and careful utilization Excellent discrimination between subtle tissue density differences Moderately expensive Readily available Growing spectrum of applications across a broad spectrum of diseases and body parts Computed tomography is also a modality utilizing ionizing radiation and this requires our concern and careful utilization. Through the years it has become much easier and quicker to obtain a CT scan which has lead to dose creep and increased exposure to our patients, so we have to be careful make sure we appropriately utilize this resource. CT scanning tends to discriminate very well between subtle soft tissue density differences allowing us in many cases to detect abnormalities within solid organs without the utilization or addition of contrast agents. CT scanning is moderately expensive but is readily available in the community. There is a growing spectrum of applications across a broad spectrum of diseases and body parts where is applicable.

Computed Tomography Primary applications: First line evaluation in suspected cerebral vascular events – hemorrhagic vs. ischemic First line evaluation in soft-tissue and skeletal trauma First line evaluation in suspected pulmonary embolism First line evaluation in suspected urinary calculi CT scanning has among its primary applications a first line evaluation in suspected cerebrovascular events in attempt to discriminate between hemorrhagic and ischemic events which have totally different treatment protocols. CT also provides a first line evaluation and soft tissue and skeletal trauma in the cases. It is also one of our first line tools used in suspected pulmonary embolism and is a now a first line evaluation in suspected urinary tract calculi

Computed Tomography Primary applications: Head & Neck Thorax CVA evaluation Carotid and intra-cerebral vascular evaluation Head-neck trauma – evaluation for subdural and epidural hematoma – evaluation for cervical fracture Neoplasm staging Thorax Lung- mediastinum nodule/ mass evaluation, Cardiac, coronary, pulmonary and great vessel vascular evaluation Airway evaluation Primary applications of CT scanning include in the head and neck cerebrovascular accident evaluation, carotid and intracerebral vascular evaluation utilizing CT angiography. In head and neck trauma evaluation for subdural and epidural hematomas as well as parenchymal hemorrhage and the evaluation for cervical fractures. There is value in neoplasm staging. In the thorax CT is useful in lung and mediastinum nodule or mass evaluation. For the evaluation of cardiac, coronary, pulmonary and great vessel vascular structures utilizing CT angiography. The airway can be evaluated for its patency and its caliber and neoplastic staging can be performed with CT scanning.

Computed Tomography Primary applications: Abdomen/ Pelvis Solid organ evaluation Urinary tract evaluation for calcification CT angiography CT colonography CT urography Lumbar spine evaluation (pacemakers, stimulators) Neoplasm Staging Primary applications in the abdominal and pelvic region include evaluation for solid organ abnormalities. Looking at urinary tract for calcification. CT angiography utilized for evaluating the vascular structures of the aorta and its branches. CT colonography a minimally invasive way to evaluate the colon for polyps. CT urography replacing intravenous urography for evaluating of the kidneys, renal pelves, ureters and bladder. Evaluation of lumbar spine in patient's precluded from MRI imaging because the presence of pacemakers, neural stimulators and other implanted devices and finally neoplasm staging.

Computed Tomography Primary applications: Secondary applications: Bones & Joints 3-D joint reconstructed images Evaluation of fracture union Evaluation of neoplasm / extent Secondary applications: Evaluation of patients with a contraindication to MRI imaging Bone mineral density analysis Other primary applications for CT scanning include bone and joint evaluation, looking at 3-D joint reconstructed images can assist the orthopedic surgeon in reconstructing damaged joint. We can evaluate for the successful union of a fracture. We can evaluate the presence of neoplasm and the extent of neoplasm involving bone. Secondary applications can include evaluation of patients with contraindication to MR imaging and for bone mineral density analysis.

Nuclear Medicine / PET Ionizing radiation Radio-isotopes attached to molecules targeting specific organs or metabolic processes Spatial resolution limited Able to evaluate temporal resolution of uptake/ events Our final ionizing radiation modality is nuclear medicine / PET scanning. Radioisotopes are attached to molecules that target specific organs or metabolic processes. Nuclear medicine and PET imaging tend to have limited spatial resolution. We are not able to very accurately place in space where the abnormal activity is, but we are able to evaluate the temporal course of various events by evaluating the course of uptake of the radionuclide product and assigning that to a time scale.

Nuclear Medicine / PET Primary applications: First line evaluation of biliary function evaluation First line evaluation of cardiac perfusion First line evaluation of solid pulmonary nodules First line evaluation for many neoplasms, staging – treatment response Some a primary applications in a first line nature of nuclear medicine is in the evaluation of biliary function using the various hida, ida compounds. Also first-line evaluation of cardiac perfusion. This has been the main-stay for many years for cardiac perfusion evaluation. PET scanning provides first-line evaluation for solid solitary pulmonary nodules and also serves a role in first-line evaluation of many neoplasms for the staging and treatment response.

Nuclear Medicine / PET Primary applications: Head & Neck Thorax Brain death evaluation – cerebral blood flow CSF flow evaluation Bone abnormality evaluation Thorax V-Q Scanning – Ventilation Perfusion scanning for Pulmonary Embolism detection – secondary exam Pulmonary nodule evaluation (PET) Cancer staging (PET) The primary applications of nuclear medicine imaging of the head and neck could include evaluation for brain death by evaluation of cerebral blood flow. CSF flow can be evaluated in an attempt to evaluate for normal pressure hydrocephalus. We can evaluate for abnormalities of bone such as metastases. In the thorax ventilation/perfusion or V/Q scanning still has a role, a secondary role in evaluation of pulmonary embolus. This may be a tool that we will see more use of, as concern about radiation exposure from CT scanning is raised. PET scanning for the evaluation of pulmonary nodules and for cancer staging

Nuclear Medicine / PET Primary applications: Abdomen & Pelvis Liver – spleen scanning Hepatobiliary scanning Renal scanning Bladder & Reflux evaluation GI bleed evaluation Cancer staging (PET) Soft tissues – Bone & Joints Bone scanning Tumor scanning (Gallium, PET) Infection scanning (labeled white cells, Gallium) In the abdomen and pelvis, liver spleen scanning as well as hepatobiliary scanning allows the evaluation of the liver axis. Renal scanning can be utilized to evaluate for perfusion as well as function. Bladder and reflux evaluation can be performed with nuclear medicine techniques to reduce radiation exposure to the patient. a variety of techniques utilizing nuclear medicine allows evaluation for location of GI bleeds. Cancer staging can be performed with PET scanning. Evaluation of the soft tissues, bone and joints include bone scanning, a variety of tumors scanning technologies including gallium scanning and PET scanning and scanning of a variety of infections with labeled white blood cells or perhaps gallium

Magnetic Resonance Imaging No ionizing radiation Utilize magnetic fields and radio waves Contraindication: implanted devices, ferro-magnetic metals Relative contraindication: claustrophobia Differentiation of distribution of Hydrogen ions as impacted by adjoining molecules Ability to do spectral analysis (remember organic chemistry) Let’s talk next about MRI or magnetic resonance imaging. No ionizing radiation is necessary for this technology. It utilizes magnetic fields and radio waves which we will learn more about in the on-line modules. The contraindications to magnetic resonance imaging include the presence of implanted devices, ferromagnetic metals or wires. There are some relative contraindications which include a claustrophobic patient. MRI works on the principle of being able to differentiate the distribution of hydrogen ions as they are impacted in their neighborhood by adjoining molecules. We are also able to do spectral analysis very similar to what you may have seen in organic chemistry during your undergraduate career.

Magnetic Resonance Imaging Primary applications: First line evaluation of suspected neurologic abnormality First line evaluation of soft tissue mass/ neoplasm First line evaluation of joint disarrangements First line evaluation of bone neoplasm The primary application of MRI imaging include the first line evaluation for any suspected neurologic abnormality, first line evaluation for soft tissue mass or neoplasm, first line evaluation for joint derangements or tendon injuries, and the first line evaluation of bone neoplasm to evaluate the extent of bone involvement as well as involvement of the adjoining soft tissues.

Magnetic Resonance Imaging Primary applications: Head Neoplasm Infection CVA Developmental anomalies Trauma MR angiography Neck Effect of arthritis and degenerative changes MR Angiography More specifically the primary applications of MRI of the head include evaluation of neoplasm, infection, cerebrovascular accident, development anomalies and brain development, post trauma evaluation and utilization of MR angiography to evaluate the vascular supply to the brain. In the neck we can evaluate the impact and effect of arthritis and degenerative changes upon the spinal cord. We can evaluate for neoplasm, trauma to the neck as well as MR angiography for evaluating the carotid arteries and vertebral arteries during their cervical course

Magnetic Resonance Imaging Primary applications: Thorax Spine – cord, roots, bodies Heart – function, perfusion MR angiography Abdomen Liver – mass, iron content, biliary tree MR Cholangiography Kidneys MR Urography MR Colonography Retroperitoneum In the thorax MRI can be utilized for evaluation of the spine, looking at the cord the roots and vertebral bodies. The heart can be evaluated both for cardiac function as well as perfusion and MR angiography can also be utilized. In the abdominal region liver evaluation for the presence of mass or neoplasm or hemangioma can be easily performed with MRI imaging. Additionally MRI imaging can be utilized to determine the iron content of liver in the case of iron retaining diseases. The biliary tree can be quite easily evaluated including MRI cholangiography to look at the biliary branching structures. MR angiography has become a relatively useful tool in recent years for this evaluation. MRI is also useful in evaluating the kidneys including both MR urography as well as anatomic evaluation. MR colonography much like CT colonography provides a mechanism for evaluating the colon for polyps without use of optical colonography and is less invasive that optical colonography. Retroperitoneal structures are also well-defined with MRI imaging  

Magnetic Resonance Imaging Primary applications: Pelvis Prostate Neoplasm Hypertrophy CAD Uterus & Ovaries Masses Leiomyoma Spine Cord Roots Foramina Stenosis Arthritis In the pelvis MRI can be utilized for the evaluation of the prostate and is useful in evaluation for hypertrophy and neoplasm. Computer-aided detection technology can be applied which can assist in a better evaluation of potential areas of neoplasm within the prostate. MRI is useful for uterine evaluation, does a very good job evaluating for leiomyoma or fibroid, and can also evaluate masses and the ovaries. Also, spinal evaluation including the cord, roots, foramina and the presence of stenosis or arthritis can be evaluated using MRI technologies.

Magnetic Resonance Imaging Primary applications: Bones & Joints Tendons and ligaments injury Articular cartilage evaluation Muscle abnormality Trauma – fracture, contusion Mass/ Neoplasm – appearance and extent Soft tissues Mass/ Neoplasm MR angiography The primary MRI applications in bone and joint include evaluation of tendon and ligamentous injury, articular cartilage evaluation and muscle abnormality evaluation. The majority of these evaluations do not require contrast enhancement for diagnosis. In the case of trauma, MRI is very sensitive to subtle fractures including stress fractures as well as contusions. MRI is useful in evaluating bone neoplasm or masses, both the appearance and extent. MRI excels in soft tissue evaluation and evaluating mass or neoplasm. MR angiography can also be applied in many locations.

Ultrasound No ionizing radiation Principles of fairly uniform speed of sound transmission in human tissues Ability to differentiate fairly subtle tissue differences based on echo reflection and interactions Application of Doppler principles for fluid motion Ultrasound is our other modality that does not use ionizing radiation. The principle of ultrasound is a fairly uniform speed of sound transmission in human tissues. This allows us to differentiate fairly subtle tissue differences based on echo reflection and interactions as the ultrasound passes through various interfaces. We can as well apply Doppler principles to determine motion, velocity of motion, and direction of motion of fluid within structures.

Ultrasound Primary applications: First line evaluation of pregnancy and developing fetus First line evaluation for differentiation of cystic from solid masses/ structures First line evaluation of liver and biliary tree First line evaluation of kidneys and bladder First line evaluation of thyroid gland Primary applications of ultrasound include the first line evaluation for pregnancy and the developing fetus. Ultrasound provides a first-line evaluation for the differentiation of cystic from solid masses and structures. It is our first line tool for evaluation liver, biliary tree and gallbladder and provides in most cases a first-line easy evaluation of kidneys and bladder. The thyroid gland is typically evaluated initially by ultrasonography

Ultrasound Primary applications: Head & Neck Thorax Thyroid Adenopathy Orbits & globe Salivary glands Fetal brain Soft tissue masses Thorax Cardiac Pleural effusions Breast lesions Reviewing more detailed primary applications in the head and neck area, thyroid, evaluation for adenopathy, there are some applications for evaluating the orbits and globes with ultrasound, as well the salivary glands can be evaluated by ultrasonography. Fetal brain applications includes evaluation for possible intracranial hemorrhage or fetal brain anomalous development. Soft tissue masses in the head neck region can also be evaluated for their cystic or solid nature by ultrasound. In the thoracic region many applications of echocardiography for evaluating the heart. Pleural effusions can be evaluated and localized for drainage utilizing ultrasound technology. Ultrasound provides a support to diagnostic mammography in evaluating breast lesions for solid or cystic nature, and for the direction of biopsy. Soft tissue masses can as well be evaluated by ultrasonography.

Ultrasound Primary applications: Abdomen Liver Pancreas Spleen Kidneys Aorta Splanchnic and renal vessels In the abdominal region ultrasound primary applications is evaluation of the liver, biliary tree and gallbladder. Pancreas evaluation can be performed but may be difficult in some individuals due to the presence of bowel gas or abdominal girth. Spleen evaluation as well as kidney evaluation also is possible. Ultrasound provides an easy evaluation of the aorta for atherosclerotic disease and aneurysm formation. Ultrasound also offers evaluation of the splanchnic and renal vessels.

Ultrasound Primary applications: Pelvis Pregnant uterus and fetus Fallopian tubes Ovaries Bladder Prostate Testes and scrotum Pelvic applications of ultrasound include the pregnant uterus and fetus. Evaluation of the uterus for development of leiomyomas or fibroids and also for evaluation of the endometrium. Fallopian tubes can be evaluated using ultrasound techniques especially when they are abnormal. Ovaries can also be well evaluated by ultrasonography with ultrasound being the primary method for evaluating the female pelvis. The bladder can be evaluated for wall thickness and bladder retention with ultrasound technology and the prostate gland using a transrectal probe can be easily evaluated to identify possible areas of abnormality requiring biopsy. The testes and scrotum also structures that are well-evaluated and successfully evaluated by ultrasonography.

Ultrasound Primary applications: Soft tissues, bones & joints Tendons, Ligaments and supporting structures Fluid collections and masses Vascular malformations Artery and vein evaluation Foreign bodies There are soft tissue applications for ultrasound as well. Ultrasound can serve in the proper hands as an excellent tool for evaluation of tendons, ligaments and other supportive structures. We can evaluate for fluid collections or masses, identify vascular malformation and determine the patency of arteries and veins. Foreign body evaluation can also be performed with ultrasound. This concludes are introductory lecture in our exploration of various imaging modalities and their application to clinical diagnosis. I hope you phone this interesting and will learn more as we go forward to the next several units.