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BASIC CONCEPTS IN DIAGNOSTIC IMAGING. J.J. Jimenez, M.D. A. Tamrazi PhD Carle Clinic Association University of Illinois College of Medicine. Outline. Introduction X-Rays Fluoroscopy GI GU CT MR Innovative Modalities. Modalities Available in Radiology. Plain Film / X-Ray/Mammography

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BASIC CONCEPTS IN DIAGNOSTIC IMAGING

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Basic concepts in diagnostic imaging

BASIC CONCEPTS IN DIAGNOSTIC IMAGING

J.J. Jimenez, M.D.

A. Tamrazi PhD

Carle Clinic Association

University of Illinois College of Medicine


Outline

Outline

  • Introduction

  • X-Rays

  • Fluoroscopy

    • GI

    • GU

  • CT

  • MR

  • Innovative Modalities


Modalities available in radiology

Modalities Available in Radiology

  • Plain Film / X-Ray/Mammography

  • Fluoroscopy

  • Ultrasound

  • CT

  • MRI

  • Nuclear Medicine/Molecular Imaging

  • Angiography/Interventional


Relative cost of imaging studies

Relative Cost of Imaging Studies


Relative availability of diagnostic imaging

Relative Availability of Diagnostic Imaging


X rays

X-Rays

  • Discovered in 1895 and still used today

  • Most widely performed imaging exam

  • X Rays are emitted and detected in cassette

  • Cassette can generate either a film or a digital image

  • Films are kept ‘on file’ or in a digital archive


Most useful applications for plain x rays

Most Useful Applications for Plain X-Rays

  • Chest

  • Musculoskeletal

  • Abdomen: limited usefulness


Plain x rays pros cons

Widely available

Inexpensive

Doesn’t require advanced technologist knowledge

Can be performed quickly

Portable

Ionizing Radiation

Relatively insensitive

Requires patient cooperation

Plain X-RaysProsCons


Fluoroscopy

Fluoroscopy

  • Utilizes X-Rays

  • Real-time imaging

  • Utilizes image intensifier

  • Involves use of contrast agents


Main uses of fluoroscopy

Main Uses of Fluoroscopy

  • Gastrointestinal Imaging

  • Genitourinary Imaging

  • Angiography

  • Other

    • Intraoperative

    • Foreign body removal

    • Musculoskeletal


Fluoroscopy pros cons

Widely Available

Inexpensive

Functional and Anatomic

No sedation required

Requires ingestion/injection of contrast

Patient cooperation

Time consuming

FluoroscopyProsCons


Gastrointestional fluoroscopy

Gastrointestional Fluoroscopy

  • Esophogram/Barium Swallow

  • Modified Barium Swallow/Dysphgiagram

  • Upper GI

  • Small Bowel Series

  • Enteroclysis

  • Contrast Enema

  • Defecography


Single contrast vs double contrast

Single Contrast vs Double Contrast

  • Single Contrast

    • Generally uses just thin Barium

    • Distends lumen with high density material

    • Easier for patient/less mucosal detail

  • Double Contrast/Air Contrast

    • Thick barium coats lumen

    • Effervescent tablets ingested to distend lumen with air

    • Produces ‘see-through’ images with greater mucosal detail

    • Greater sensitivity for small lesions, polyps, ulcers


Basic concepts in diagnostic imaging

Single Contrast vs Double Contrast

Single Contrast

Barium Enema

Double Contrast

Barium Enema


Contrast materials for gi exams

Contrast Materials for GI Exams

  • Barium Sulfate

    • Thick: used in double contrast studies

    • Thin: used in single and double contrast exams

    • Paste: mod Ba swallow and defogography

  • Gastrograffin

    • Full stregnth: rarely used

    • Dilute


Basic concepts in diagnostic imaging

Barium vs Gastrograffin

Gastrograffin Swallow Study

Barrium Swallow Study


Barium sulfate

Barium Sulfate

  • Most widely used

  • Better images than gastrograffin

  • ‘Chalky taste’

  • Peritonitis may develop if perforation

  • If delayed transit, may form concretions in colon


Gastrograffin

Gastrograffin

  • Water soluble

  • Foul Taste

  • Poor mucosal coating

    • Basically used for R/O obstruction

  • Won’t cause peritonitis if perforation

  • May cause severe chemical pneumonitis if aspirated

  • Osmotic pressure draws fluid into bowel lumen

    • Progressive distention in small bowel obstruction

    • ‘Therapeutic’ enema in constipation


Patient factors in gi fluoroscopy

Patient Factors in GI Fluoroscopy

  • Ability to ingest contrast

    • In order to get high quality images, a relatively large volume of contrast needs to be ingested fairly quickly

  • Mobility

    • Multiple positions required for GI exams, particularly double contrast exams.

    • Limited mobility = less diagnostic images

  • Weight

    • Tables have weight limits

    • Requires maximal radiographic technique and exposure is often suboptimal


Esophogram or barium swallow

Esophogram or Barium Swallow

  • Evaluates pharynx and esophagus

  • Limited evaluation of stomach

  • Double or Single Contrast

  • Mucosal contour and Motility


Modified barium swallow

Modified Barium Swallow

  • AKA Dysphagiagram and at Carle “cookie swallow”

  • Performed with Speech Pathologist

  • Barium administered in various bolus consistencies ranging from liquid to solid

  • Evaluates swallowing mechanism

  • Evaluates for aspiration

  • Performed on videotape


Basic concepts in diagnostic imaging

Modified Barium Swallow


Upper gi exam

Upper GI Exam

  • Evaluates esophagus, stomach and duodenum

  • Double or Single Contrast

  • Can be combined with small bowel series

  • Largely replaced by endoscopy and cross-sectional imaging

  • Fairly insensitive


Small bowel series

Small Bowel Series

  • Patient drinks 2 cups of thin Ba

  • Overhead films obtained at routine intervals

  • The Ba column is followed through until it reaches the colon

  • Transit time, mucosal contour, bowel loop distribution are evaluated.

  • Insensitive for small masses


Basic concepts in diagnostic imaging

Small Bowel Series


Small bowel enteroclysis

Small Bowel Enteroclysis

  • “Double Contrast Small Bowel Series

  • NGT placed at duodenal-jejunal junction

  • Ba injected followed by methylcellulose

  • See-through appearance to small bowel

  • Greater sensitivity for small masses and mucosal lesions

  • Patient discomfort related to NGT and diarrhea


Contrast enemas

Contrast Enemas

  • Barium or Gastrograffin

  • Double contrast or single contrast

  • Generally less sensitive than endoscopy

  • Requires bowel prep to assess for mucosal lesions

  • Requires some element of patient cooperation


Basic concepts in diagnostic imaging

Contrast Enemas

Single Contrast

Barium Enema

Double Contrast

Barium Enema


Defecogram

Defecogram

  • Barium paste is inserted into rectum

  • Patient is asked to defecate under fluoroscopy

  • Ano-rectal and pelvic floor dynamics can be assessed

  • Rectocele, intussusception, pelvic floor relaxation, stress incontinence


Genitourinary fluoroscopy

Genitourinary Fluoroscopy

  • Cystogram

  • Voiding cystourethrogram

  • Retrograde urethrogram

  • Hysterosalpingogram


Cystogram

Cystogram

  • Usually in adult patients

  • Looking for tear or intraluminal mass

  • Catheter placed and bladder filled with contrast to capacity: usually 300-500 ml.

  • Spot films obtained when full

  • Post void film: usually overhead


Basic concepts in diagnostic imaging

Cystogram

Cystogram with Intraperitoneal Rupture


Voiding cystourethrogram vcug

Voiding CystourethrogramVCUG

  • Usually in children with history of UTI

  • Searching for vesicoureteral reflux

  • In males, evaluate for urethral abnormalities: posterior urethral valves

  • Same as cystogram except when full patient voids under fluoro with spot films


Retrograde urethrogram rug

Retrograde UrethrogramRUG

  • Male patients

  • Pelvic Trauma

  • Post-infectious: STD- looking for stricture

  • Different techniques

  • Meatus occluded and contrast injected into urethra under fluoro


Basic concepts in diagnostic imaging

Retrograde UrethrogramRUG


Hysterosalpingogram

Hysterosalpingogram

  • Used to evaluate endometrial canal and fallopian tubes

  • Infertility and uterine anomalies

  • Dye injected into cervical os under fluoro

  • Injection continued with goal to opacify the fallopian tubes and spill contrast into peritoneum


Musculoskeletal fluoroscopy

Musculoskeletal Fluoroscopy

  • Fracture/Dislocation reduction

  • Hardware placement in the OR

  • Flexion/Extension views of c-spine

  • Arthrography

    • May be performed in conjunction with MRI or CT


Basic concepts in diagnostic imaging

Techniques Relevant to

MSK Radiology

  • Radiography (routine and specialized views)

  • CT

  • MRI

  • US

  • Densitometry

  • Interventional procedures (arthrography, percutaneous biopsy/vertebroplasty)


Basic concepts in diagnostic imaging

MSK Radiology

MRI—Sagittal Knee

T1 Weighted

Vertebroplasty


Basic concepts in diagnostic imaging

Computed Tomography (CT)

  • Cross Sectional imaging modality

  • Mobile X-ray tube that rotates around a pt

  • Slices of X-ray transmission data reconstructed to generate image

  • Data displayed in multiple window settings (lungs parenchyma, bone, etc.)

  • Density measurements/Hounsfield Units analyze chemical component of tissue

  • HU: -150-0 = fat, 0 = water, 0-20 = serous fluid, 45-75 = blood,

  • 100-1000 = bone/calcium


Basic concepts in diagnostic imaging

CT Contrast Agents

  • Intravenous contrast---iodinated

  • Differentiate blood vessels vs. vascular internal organs

  • Enteric contrast---barium

  • Differentiate bowel vs. intra-abdominal fluid/masses

  • Rectal contrast

  • Retrograde urinary bladder contrast


Basic concepts in diagnostic imaging

CT Applications

  • Neuro-imaging

  • -Acute head trauma, acute intracranial hemorrhage

  • -Low sensitivity for early ischemic stroke, intracranial metastatic disease, white matter degenerative disease

  • Head and Neck imaging

    • -Soft tissue of neck, paranasal sinuses, temporal bone imaging, orbital wall imaging


Basic concepts in diagnostic imaging

CT Applications

  • Body Imaging

  • -Chest, Abdomen, Pelvis (with enteric and IV contrast)

  • Pulmonary nodules, Renal Calculi (without contrast)

  • Acute appendicitis (with enteric and IV contrast)

  • Specialized protocols:

  • -Liver masses, pancreatic tissue, renal masses, adrenal masses


Basic concepts in diagnostic imaging

CT Applications

  • Acute Abdomen

    • -decrease rate of false laparotomy procedures

  • Trauma Spine Imaging (cervical, thoracic, lumbar)

  • Other osseous structures (pelvis, extremities)

  • Vascular Imaging

  • -CT angiography--- i.e. coronary arteries


Basic concepts in diagnostic imaging

CT

Axial, with oral contrast in stomach


Basic concepts in diagnostic imaging

CT

PET

PET/CT


Basic concepts in diagnostic imaging

The Power of CT

CTA

(CT Angiography)

CT Cardiac Imaging


Basic concepts in diagnostic imaging

Magnetic Resonance Imaging (MRI)

  • Multi-planar scanning

  • Without ionizing radiation

  • Images generated using powerful magnets and pulsed radio waves passing through the body

  • Data from Pt’s body used to generate image

  • Field strength of magnets 0.3-3.0 Tesla


Basic concepts in diagnostic imaging

MR Contrast Agents

  • Intravenous contrast---Gadolinium chelate-based contrast agents

  • Gadolinium is a paramagnetic lanthanide that is toxic as a free metal

  • Contrast to evaluate BBB, intracranial edema and hemorrhage

  • Novel agents being developed as tagged Monoclonal antibodies for Molecular Imaging


Basic concepts in diagnostic imaging

MR Applications

  • Neuro-imaging

  • -Excellent tool due to high soft tissue contrast resolution

  • -Abundant water content of CNS allows for imaging soft intracranial tissue

  • Head and Neck imaging

    • -Multi-planar capability allows for monitoring extent of disease

    • -Differentiating subtle soft tissue boundaries of head and neck


Basic concepts in diagnostic imaging

MRI

Axial, T2-Weighted


Basic concepts in diagnostic imaging

MR Applications

  • Body Imaging

  • -Thorax: mediastinal, hilar, chest wall abnormalities

  • Limited lung imaging due to artifacts

  • New advances in breast imaging

  • Potentials for cardiac MRI with coronary MR angiography


Basic concepts in diagnostic imaging

MRI

Breast Imaging


Basic concepts in diagnostic imaging

MR Applications

  • MSK Imaging

  • - High sensitivity for neoplastic, inflammatory, and traumatic conditions of bone and soft tissue

  • - T1-weighted---fluid collections and abnormalities in fatty marrow

  • - T2-weighted---lesions in both marrow and soft tissue


Basic concepts in diagnostic imaging

MRI

Sagittal, T1-Weighted


Basic concepts in diagnostic imaging

Innovative Modalities

  • Constantly evolving face of radiology

  • New contrast agents for CT and MR

  • Molecular Imaging

  • - Imaging molecular events---enzymatic activity, receptor binding, cellular events

  • Interventional Radiology and Interventional Neuroradiology


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