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Introduction to Radiology. Michael Solle, MD, PhD. Introduction to Radiology. I: Radiology Basics and High Yield Topics Modalities in Radiology and Cases Contrast How to look at studies Catheters: tunneled vs non-tunneled Drains and Tubes II: How to Consult Radiology
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Introduction to Radiology Michael Solle, MD, PhD
Introduction to Radiology • I: Radiology Basics and High Yield Topics • Modalities in Radiology and Cases • Contrast • How to look at studies • Catheters: tunneled vs non-tunneled • Drains and Tubes • II: How to Consult Radiology • III: Plain Film Imaging of the Abdomen • IV: Parting Thoughts • Dr. Molina and Chest Radiology
Definition of Radiology • Radiology is a medical specialty using medical imaging technologies to diagnose and treat patients.
I: Basics/Hi-Yield:Radiology Modalities • Conventional radiographs (“x-rays”) • Fluoroscopy • Mammography • Computed Tomography (CT) • Nuclear Medicine (NM) • PET-CT combines CT and NM • Ultrasound (US) • Magnetic resonance imaging (MRI)
Radiology Modalities • Conventional Radiography • Lingo: • Density • Opacity • Observable Densities: • Metal • Bone • Soft Tissue • Gas
Radiology Modalities • Fluoroscopy • “Live” imaging • Contrast agents often given
Radiology Modalities • Computed Tomography • Lingo: • Attenuation • Density • Enhancement • Hounsfield Units • -1000 air *** • -100 fat • 0 water *** • 20-80 soft tissues • 100’s bone/Ca/contrast • >1000’s metal • Large radiation dose
Radiology Modalities • Nuclear Medicine • Lingo: • Counts or Activity • Physiologic imaging • Radionuclides • Technetium • Radiopharmaceuticals • “Choletec” • Radioactivity stays with the patient until cleared or decayed
Radiology Modalities • Ultrasound • Lingo • Echogenicity • Shadowing • Doppler for flow • No radiation • Can be portable • Relatively inexpensive
Radiology Modalities • MRI • Lingo: • Signal intensity • T1 • T2 • Enhancement • No radiation • Strong magnetic field • No pacemakers • No electronic implants • Small, loud tube and patients must be able to hold still • Relatively expensive
Radiology Modalities: • Four different cases of Abdominal Pain • Can you develop a differential diagnosis based location of the abdominal pain? • Can you identify the modality used? • Diagnosis?
I: Radiology Modalities Summary: • Conventional radiographs (“x-rays”): • Great place to start (cheap, fast, low radiation). • Computed Tomography (CT): • Diagnostic dilemmas (pricier, variable speed b/c of contrast). • High radiation. • Nuclear Medicine • Physiological imaging, great for specific questions. • Ultrasound (US) • Relatively inexpensive, and no radiation. • Highly dependent on patient’s body size and US operator. • Magnetic resonance imaging (MRI) • Relatively expensive, no radiation, not fast. • Unmatched ability to contrast healthy tissue from disease.
I: Basics/Hi-Yield:A few words on contrast • CT contrast: • IV- contains Iodine; which attenuates x-rays • Contraindicated in renal failure (acute and chronic) b/c of risk of contrast induced nephropathy • Allergy issues • Power injected and causes vaso-vagal reactions (NPO) • PO- contains dilute iodine or sometimes very dilute barium (flouro studies typically use barium) • MRI contrast: • IV- contains gadolinium chelated to a carrier molecule; acts as a paramagnetic molecule which increases signal on T1 images • Contraindicated in renal failure (acute and particularly ESRD) b/c of risk of NSF
I: Basics/Hi-Yield:A few words on contrast • AVOIDING CONTRAST IN THE SETTING OF ACUTE RENAL FAILURE IS DIFFICULT for the radiologist, because the creatinine may be normal. • In hyper-acute renal failure, the creatinine hasn’t risen yet. Decreased urine output or anuria is acute renal failure – regardless of the creatinine. • Remember; first do no harm! Non-contrast studies can often be quite helpful.
I: Basics/Hi-Yield:Looking at Imaging Studies: • Adequate Study? • Correctly labeled with patient’s name, MR#, and the date of the study? • Technically adequate? • Systematic versus Focused look at a study: • Radiologist does both! • As the requesting clinician, you should also look at your patient’s study (at least plain films), as well as follow up on the final report. • PTX, PNA, pleural effusions, SBO, free air • Evaluate lines and tubes (especially the ones you placed!)
I: Basics/Hi-Yield:Looking at Imaging Studies: • PACS workstations (diagnostic versus clinical) • Picture Archiving and Communications System • Radiology, ER, ICU’s, some surgery clinics • Web based PACS (web 1000) • WebCIS based PACS (java script) • At UNC: “6-PACS” is PACS help desk
I: Basics/Hi-Yield:tunneled versus non-tunneled catheters • First, examine the patient! • Inspect • Palpate • (Don’t auscultate or percuss) • A tunnel is a short (several inches) segment of catheter that is within the superficial soft tissues (subcutaneous fat) between the venotomy site and the catheter access site. • “Perm Caths” • “PortaCaths” • “Powerlines” • A tunnel or port pocket infection usually means removal of the line. • CVAD= central venous access device
I: Basics/Hi-Yield:tubes & drains (abscesses, G-, Neph-) • Most VIR drains/tubes need to be flushed with sterile saline. • The purpose of this is simply to keep the tubes from getting clogged. All tubes should be flushed after use. • There’s usually a 3-way stopcock to accomplish this. • Nephrostomy and Gastrostomy tubes need to be changed every 3 months or so. • Abscess drains usually need a sinogram (tube injection) to evaluate the cavity size and for any fistulous connections, about 2 weeks after placement. • If cavity small and output of drain is low, then drain may be pulled. If it’s pulled too early, then the abscess will fester/return. • Surgical drains are managed by the surgical teams, and often do not need to be flushed (no 3-way stopcock).
II: Obtaining a Radiology Consult • A Radiology consult is obtained every time a study is requested! • Who handles these requests and reads these studies and/or performs these procedures?
II: Obtaining a Radiology Consult • The Department of Radiology at the University of North Carolina at Chapel Hill has eight clinical sections: • Abdominal Imaging (Body CT, US, MRI, Flouro studies such as UGI and SBFT, Biopsies) • Breast Imaging • Cardiopulmonary Imaging (Chest, Cardiac) • Musculoskeletal Imaging (Bone, ER RR, MSK MRI’s) • Neuroradiology (brain/spine CT & MRI; lumbar punctures) • Nuclear Medicine (wide variety, PET-CT, bone scans, Cards) • Pediatric Imaging (wide variety) • Vascular-Interventional (wide variety)
II: Obtaining a Radiology Consult • 6-1461- The Radiology “Front Desk” • Reading rooms (RR’s): • Body CT 3-2938 • Chest 3-2939 • GI/Adult Flouroscopy 3-2961 • Neuroradiology 3-2978 • Pediatrics 6-7554 • MSK/bone 6-8850 • US 6-0038 • MRI 6-8112 • Mammography 6-6392 • Nuclear medicine 3-2937 • VIR 6-4645
II: Obtaining a Radiology Consult (at UNC Hospitals) • Try to call the right reading room (RR). • When you call, identify yourself, and expect whoever answers to identify themselves. • Improves accountability • Good policy to know who you talked to (always) • When paging, it’s nice to put your name/pager number immediately after the call back number • After hours: • 6-8850 Lower Level/ER RR • 216-2826 Upper Level (VIR, Doppler US, MRI) • DON’T call 6-8850 during the day • unless it’s an MSK radiology issue
II: Obtaining a Radiology Consult: • VIR or any other invasive procedures: • Who gives consent? Pleae get phone number of HC POA or spouse or relative • Basics for any invasive procedure • See the patient! • Coags (PT, PTT, INR) • Platelets • NPO for sedation or GA • Don’t promise the Bx/Line/procedure, but please tell the patient before we get there….. • Don’t promise sedation (but we almost always use it) • Think about risks/benefits prior to considering invasive or expensive procedures. Ask yourself if the results will change management.
III: Plain film imaging of the abdomen • Stones • Gallstones • Renal stones • Bones • Lumbar spine, pelvis, hips • Masses • Organomegaly, ascites • Gasses • 3 cm small bowel • 6 cm large bowel • 9 cm cecum
III: Plain film imaging of the abdomen • KUB (kidneys, ureters, bladder) • 2 View---AP supine and erect abdomen • Acute abdomen series: 2 view with upright chest • Lateral decubitus (Left or Right) • Cross table lateral---prone or supine
III: Plain film imaging of the abdomen: Gallstones supine and erect
III: Plain film imaging of the abdomen: more gas & SBO easy to Dx
III: Plain film imaging of the abdomen: more gas & SBO easy to Dx
IV: A Few Random Parting thoughts • Patients want a doctor who cares about them. When admitting a patient, get their (family’s) phone numbers yourself, as part of the History and Physical. • Patients will forgive you for a host of small things if you show them that you care, will be honest with them, you will work hard for them over the long term. • Getting their phone numbers show you care about them and their family. • Learn to take ownership of your patient’s and their medical problems. • Follow up on test/imaging results. • Follow up on clinical outcomes. • Longitudinal data is often the most valuable information there is. • “Old is gold.”- in reference to getting prior imaging studies. • Serial KUB’s and serial exams is often more clinically relevant than getting a CT scan.
Hx: Please Evaluate New Line. “?!@#!%!” Thanks for listening!