Contrast Media in Radiology Lecture Notes PDF

Contrast Media in Radiology - Lecture Module 01: Principles & Perspectives II Reynan B. Hernandez, MD, FPCR, FUSP | August 24, 2023 TABLE OF CONTENTS I. OVERVIEW: CONTRAST MATERIAL.................................................... 1 A. POSITIVE AND NEGATIVE CONTRAST MATERIALS........................

Contrast Media in Radiology - Lecture Module 01: Principles & Perspectives II Reynan B. Hernandez, MD, FPCR, FUSP | August 24, 2023 TABLE OF CONTENTS I. OVERVIEW: CONTRAST MATERIAL.................................................... 1 A. POSITIVE AND NEGATIVE CONTRAST MATERIALS........................ 1 II. TYPES OF CONTRAST MATERIAL.......................................................1 A. OVERVIEW................................................................................... 1 B. IODINE-BASED CONTRAST............................................................2 C. BARIUM SULFATE......................................................................... 4 D. WATER (STERILE SALINE)..............................................................6 E. AIR................................................................................................ 6 F. PARAMAGNETIC CONTRAST......................................................... 7 III. ADVERSE REACTIONS TO CONTRAST MATERIAL.............................. 7 A. REACTIONS TO IODINATED CONTRAST MEDIA............................ 7 ● B: Barium enema with air ○ Shows the gastrointestinal system ○ Two contrast materials used: ▸ Barium: appears white ▸ Air: appears black ● C: Kidney-urinary bladder (KUB) contrast radiography ○ Intravenous pyelography ▸ Uses contrast to emphasize the vascular system ▸ From the kidneys to the ureters and down to the bladder ○ Note the following: ▸ Renal structures (e.g., shadows, pelvic calyces) ▸ Ureters ▸ Urinary Bladder B. REACTIONS TO BARIUM SULFATE.................................................8 C. REACTIONS TO PARAMAGNETIC SUBSTANCES............................. 8 D. RISK FACTORS...............................................................................8 E. TREATMENT FOR ADVERSE REACTIONS....................................... 9 IV. REMINDERS FOR GENERAL PRINCIPLES........................................... 9 A. REPORTING ADVERSE REACTIONS............................................... 9 QUESTIONS......................................................................................... 9 ANSWER KEY..................................................................................... 10 RATIONALE........................................................................................10 LEARNING OBJECTIVES 1. To understand the role of contrast material in diagnostic imaging procedures 2. To be aware of the adverse effects of contrast material I. OVERVIEW: CONTRAST MATERIAL ● Creates a difference in optical density between anatomic structures ○ Makes anatomic details more visible Remember! ● Structures are better appreciated with contrast ● Contrasts can come in different preparations A. POSITIVE AND NEGATIVE CONTRAST MATERIALS ● Attenuation: reduction of a beam’s intensity via scattering or absorption (01.37, 2025) ● Positive contrast agent: ○ Radiopaque (i.e., will appear white/bright) ▸ X-ray, CT scan, and MRI all use bright contrast materials ○ Attenuates x-rays ○ Contains elements with high atomic weights ▸ E.g., iodine, bromine, barium ● Negative contrast agent: ○ Radiolucent (i.e., will appear black/dark) ○ Cannot attenuate x-rays ○ E.g., air, water Question ● Is bone the element that will show you the most opaque structure? ○ No, it is metal. II. TYPES OF CONTRAST MATERIAL A. OVERVIEW Figure 1. Visualizations of Contrast Radiography Figure 1 ● A: Abdominal radiograph without contrast ○ Note the following: ▸ Spine: Lumbar, Sacral, Coccyx ▸ Osseous structures (opaque/white): Pelvis, Femoral heads ▸ Gas within the stomach and bowels (black) ▸ Liver shadow (gray) YL6:01.35 ● Iodine-based contrast material ○ Most commonly used contrast ○ E.g., intravenous pyelography ● Barium sulfate (see Figure 1.B) ○ Well-established for GI tract examination ○ Can be visualized through x-ray, CT, or fluoroscopy ● Sterile saline (water) ○ Visualized through ultrasound ○ E.g., Imaging of the endometrium: saline infusion sonohysterography ▸ To check for lesions such as polyps TG06: Abangan, David, Del Corro, Layug, Mendoza, J., Mendoza, R., Ng, Santiago, Santos, Tseng, Uy, Villavicencio CG14: Acuña, Antonio, Ballelos, Carreon, Diño, Go, Lim, Liwanag, Manuel, Meneses, Plurad, Ubaldo 1 ● Air ○ Like sterile saline ○ Also visualized through ultrasound ● Paramagnetic substance ○ Visualized through MRI ○ Typically contains molecules with high molecular weights or atomic numbers ▸ E.g., barium, bromine, and iodine ▸ Better capability of attenuation B. IODINE-BASED CONTRAST ● Composed of iodinated benzene ring derivatives ● Formulated as sodium and meglumine salts ● Iodine molecules are responsible for attenuation ○ Contrast media appears radiopaque (bright) ● Prepared in terms of their osmolar content ○ ionic high osmolar contrast media ○ non-ionic low osmolar contrast media ● Used in plain radiography and CT scans (1.37, 2025) ● NOT a dye (contrast material is colorless) ○ Recall: dyes show color and may discolor organs permanently (1.37, 2025) ▸ Secondary to the absence of carboxyl groups, increased OH groups, and balanced distribution of the molecule ● Less tendency to cross cell membranes ● Decreased pseudoallergic reactions ● Does not cross the blood-brain barrier (1.37, 2025) Take Note! (1.31, 2026) ● Doc Hernandez said that iso-osmolar, nonionic contrast media may be the best among the different types of iodinated contrast material (Aspelin et al., 2003). EXAMPLES OF ADMINISTRATION ● Common routes of administration (01.37, 2025) ○ Intravenous ▸ Most common ▸ Contrast is placed in a syringe and injected via the venous system (see Figure 3) ○ Oral ○ Rectal ○ Cysta-urethral ○ Humeral ▸ Common site of intraosseous injection (when IV is not possible due to patient being critically ill) Figure 2. Transparent Appearance of Iodine-based Contrast in Vials IODINE-BASED CONTRAST CLASSIFICATIONS Ionic Contrasts ● High osmolar contrast media → ionic ○ Contains iodine ○ Increased image clarity ○ Cheaper than non-ionic contrast media but has more (albeit small) risks ● Preparations: ○ Ionic monomers: ▸ Diatrizxoate sodium (Hypaque) ▸ Iothalamate meglumine (Conray) Figure 3. Illustration of How Contrast is Administered through the Body Intravenous Pyelography Non-Ionic Contrasts ● Low osmolar contrast media → non-ionic ○ Contains iodine bound to an organic compound ● Classified as either: ○ Ionic dimers ▸ Ioxaglate meglumine (Hexabrix) ○ Non-ionic monomers ▸ Iopromide (Ultravist) ▸ Ioversol (Optiray) ▸ Iopamidol (Isovue) Advantages of Non-ionic Over Ionic Contrast Media ● Reduced tonicity (osmolality) ○ Leads to a positive diuresis effect → rapid iodine clearance ▸ Gets eliminated faster from the body ● More expensive but safer than ionic contrast (1.31, 2026) ● Less risk for neurotoxicity YL6:01.35 Contrast Media in Radiology Figure 4.Plain abdominal radiograph (A) before and (B) right after administration of contrast (during which nothing is evidently seen yet) 2 Intraoperative Cholangiogram Figure 5. Intravenous Pyelography: Contrast Material in the Urinary Tract Figure 5 ● A: 5 minutes after administration of contrast ○ Contrast is better appreciated within the pelvocalyces ● B: 10-15 minutes after administration of contrast ○ Contrast is seen: ▸ Flowing through the ureters ▸ Filling up the urinary bladder ● C: A few minutes after B ○ Almost all the contrast is in the urinary bladder Contrast Imaging of Vascular Structures Figure 7. Intraoperative Cholangiogram: Contrast Imaging of the Bile Ducts Figure 7 ● Done in the middle of surgery to rule out lesions in the biliary tract ○ E.g., Lesions may cause distensions in the biliary tract ● Contrast is administered via the cystic stump ● A: Flow of contrast through the hepatic radicles and common bile duct until it reaches the duodenum ○ CBD: common bile duct ▸ Common hepatic duct and cystic duct fuse to form the common bile duct ○ D: duodenum ○ bif: bifurcation ● B: Arrows pointing to abnormalities ○ Dilatation of ducts in the biliary tree Hysterogram Figure 6. Contrast Imaging of Vascular Structures in: (A) Chest CT Scan, (B) Magnified Fluoroscopic Image of the Heart, and (C) Reconstructed Image of the Brain Figure 6 ● A: Chest CT scan ○ Presence of ascending and descending aorta ○ Abnormal finding: aortic dissection ● B: Magnified fluoroscopic image of the heart ○ Contrast allows visualization of coronary vessels ● C: Reconstructed image of the brain ○ Tissue is removed ○ Vascular structure is left behind ▸ Clearly visualized in contrast: Circle of Willis YL6:01.35 Contrast Media in Radiology Figure 8. Hysterogram: Contrast Imaging of the Female Reproductive Tract Figure 8 ● Contrast is administered via the cervical canal ● Used to rule out anomalies, inflammatory problems, or any distortions in its anatomy ○ Allows the ff. to be seen: ▸ Endometrium and endometrial canal ▸ Right and left fallopian tubes ▸ Fallopian tube segments (from lateral to medial): ⎻ Fimbriae → infundibulum → ampulla → isthmus → intramural 3 [Fallopian Tube Segments] (from lateral to medial): Five Inches Across Is Impossible ● May be given orally (anterograde) or as an enema (retrograde, via rectum) ● Excreted via defecation BARIUM STUDIES Fimbriae Infundibulum Ampulla Isthmus Intramural Abdominal CT Scan ● Used in: ○ Upper and lower GI series ▸ E.g., fluoroscopic examinations ▸ Enable us to appreciate the upper and lower GI tract ○ Abdominal CT scans ● Preparation: ● Some appear in color ○ Some patients prefer flavored (i.e., pediatric patients) ▸ Can’t tolerate anything given to them via the mouth ○ Made to convince pediatric patients to ingest the contrast Figure 10. Barium Sulfate Prepared In Bottles (pink-colored preparation on the right to indicate strawberry flavor) Figure 9. Iodine-based Contrast Abdominal CT Scan ● Action: ○ In the esophagus, contrast outlines the lumen from superior to inferior portion ▸ EXCEPT at the esophageal constrictions (C6, T4, T10) ○ In the lower intestinal tract, contrast outlines the rectum all the way up to the cecum Figure 9 ● A: Plain slice ● B: Slice with contrast is a few seconds after ● C: Contrast is pooled in the center ○ Venous portal phase ● D: Irregular fill-in minutes after ○ Lesion becomes isodense ○ Delayed phase ● Most common tumor of the liver: hemangioma ○ Can be diagnosed with contrast imaging EXCRETION ● Iodine-based contrast is excreted via: ○ Glomerular filtration ○ Tubular reabsorption ▸ Process of moving solute and water out of the filtrate and back into the bloodstream C. BARIUM SULFATE ● White crystalline compound ● Less soluble in water ○ Makes it safer and less toxic ○ Avoids heavy metal intoxication of barium in patients (01.37, 2025) YL6:01.35 Contrast Media in Radiology Figure 11. Barium Study: Presence of a Neoplasm in the Distal Esophagus ● In this particular case, there is an abnormality that causes this type of appearance ● As imaging physicians, once we see this kind of contrast picture we can say that: 4 ○ Examination is abnormal ○ Abnormality is located in that particular area where it showed this kind of picture ○ Flow of contrast can be seen real-time ○ Check if there are (pathologic) abnormalities in terms of filling defects such as: ▸ Abnormal dilatation ▸ Abnormal constriction (narrowing) ▸ Anatomic distortions ▸ Outpouching ● C: Post-evacuation phase ○ Contrast is evacuated through defecation ○ Check for significant retention of contrast material ● D: Re-introduction of air ○ Air is introduced in a retrograde manner (via the anus) ▸ Appears black(negative contrast) ○ Check for colon’s distensibility (i.e., response to air) ▸ Nondistention of Segments may be pathologic ○ Can also be therapeutic in cases of intussusception (01.37, 2025) Nice to Know! Figure 12. Barium Enema: Barium Liquid Instilled into the Large Intestine through the Anus via Catheter This was not discussed during the lecture but was included in the previous batch’s (2026) lecture for this topic: ● Barium liquid is instilled into the large intestine through the anus via catheter ● Contrast is introduced and outlines the ff. structures: ○ Rectum ○ Sigmoid colon ○ Descending colon ○ Splenic flexure ○ Transverse colon ○ Hepatic flexure ○ Ascending colon ○ Cecum BARIUM ENEMA ADMINISTRATION Figure 14. Actual Barium Study ● Procedure for barium studies: ○ Patient is asked to take a lateral decubitus position on a surface ○ Tube is inserted into the anus via catheter (with consent) ○ Source of barium is placed in such a way that the height is above the patient ○ Fluoroscopic examination happens once contrast is introduced ● Fluoroscopic examinations ○ Flow of contrast can be seen ▸ More like a real-time examination ▸ Done intermittently to limit patient exposure to radiation ▸ Once the imaging physician achieves the picture that would enable them to assess that particular part of the colonic tract, they: ⎻ Stop the fluoroscopic examination ⎻ Start recording or taking the image Figure 13. Progression of Contrast Material in Barium Enema ● A: Preliminary film (no contrast) ○ Only gas is seen within the intestinal tract ● B: Initial Phase (introduction of contrast) ○ AKA “full barium” phase YL6:01.35 Contrast Media in Radiology 5 Active Recall Box Figure 16 1. T/F. Hysterogram uses Iodine contrast to visualize the endometrial canal. 2. Give an example of a negative contrast agent. ● Prior to examination: endometrium appears heterogeneous with a “suspicious-looking” structure inside ● Using a contrast, the water allows the sonologist to appreciate the lesion (submucosal fibroid) ○ Without the contrast, the mass will just blend with the parenchyma surrounding it (01.37, 2025) ○ Note: Doc mentioned that anything that abuts the endometrial canal is called submucosal Answers: 1F; 2 Air, water D. WATER (STERILE SALINE) ● Considered contrast material in ultrasound procedures ○ Appears anechoic (black) ● Specifically used in imaging of the endometrium ○ Saline infusion hysterography - inject water through the cervical canal until it reaches the endometrium ○ Lets you check for abnormalities and locate any lesions (e.g., polyps, blood clots, etc.) that might be inside E. AIR ● Pneumoarthrogram - examination of joints using air ○ Joints can be appreciated very well in images ○ Can be combined with water-soluble iodinated medium for double-contrast arthrography (1.37, 2025) ● Gastrointestinal studies ○ E.g., barium enema (double-contrast) (see Figure 1B) Figure 17. Pneumoarthrogram sign (black arrows) in shoulder joint Figure 15. Saline infusion sonohysterography: Sagittal view of uterus (01.31, 2026) Figure 15 (01.31, 2026) ● Structures present in this image: ○ Pink star: urinary bladder ○ Yellow star: anterior uterine wall ○ Blue star: cervix ○ White star: fundus ○ Red star: posterior uterine wall ○ Black structure in the middle: endometrium ▸ Appears black because of fluid ▸ Recall: anything that appears black on ultrasound is an anechoic element ⎻ It does not reflect echoes back to the transducer Figure 17 (01.31, 2026) ● Image shows an x-ray of the shoulder ○ Upon injection of air, the image may show a pathology involving the shoulder joint ● Assessment: (01.37, 2025) ○ Normal ▸ Crescent of air ⎻ Apparent space between humerus and glenoid fossa ▸ Density within joint F. PARAMAGNETIC CONTRAST ● Gadopentetic acid ○ Administered intravenously for MRI procedures ○ Used to assess vascular or biliary tract structures Figure 18. Gadopentetic acid contrast preparation Figure 16. Saline infusion sonohysterography: magnified sagittal view of uterus with pathology YL6:01.35 Contrast Media in Radiology 6 Figure 19. Paramagnetic contrast imaging Figures 18 and 19 ● Figure 18: Gadopentetic acid is a colorless preparation ● Figure 19A: MRI of the brain ○ Brain angiography ○ Can visualize the Circle of Willis ● Figure 19B: MRI angiography of the coronal neck ○ Can see the aorta and vascular structures coursing cephalad towards the brain (01.31, 2026) ○ The aortic arch has 3 branches: ▸ Brachiocephalic ▸ Left common carotid (goes straight up) ▸ Left subclavian ● Figure 19C: MRI cholangiopancreatography ○ Note several structures from biliary tract system: ▸ Hepatobiliary tracts ▸ Right hepatic duct ▸ Left hepatic duct ⎻ Left and right hepatic ducts fuse to form the common hepatic duct (CHD) ▸ Cystic duct ○ CHD fuses with common bile duct (CBD) ▸ Some signal voids are stones ▸ Filling defects within the midsegment of the CBD present as stones (choledocholithiasis) (01.31, 2026) III. ADVERSE REACTIONS TO CONTRAST MATERIAL ● Contrasts do have adverse effects ○ Emphasizes the importance of being mindful when requesting imaging studies that utilize contrast material/s ● Advent of contrast → improved medical imaging (01.37, 2025) ○ However, it is still not completely devoid of risks A. REACTIONS TO IODINATED CONTRAST MEDIA ● Adverse reactions to iodine-based contrast media may be classified as either: ○ Idiosyncratic ▸ Unpredictable ▸ Anaphylactic by nature (hypersensitivity reactions) ○ Non-idiosyncratic ▸ AKA “peculiar” ▸ Dose-related reactions, non-anaphylactic by nature IDIOSYNCRATIC ● Generally fast reactions to contrast media ○ Occur within 1hr of injection ● Range from mild, moderate, to severe depending on patient response to contrast agent ● Mild (most common) ○ Urticaria (hives) ○ Pruritus (itching) ○ Rhinorrhea (free discharge of thin nasal fluid) ○ Nausea and vomiting YL6:01.35 Contrast Media in Radiology ○ Diaphoresis (unusual sweating) ○ Dizziness ● Moderate ○ Persistent vomiting ○ Facial edema ○ Laryngeal edema ○ Dyspnea (secondary to laryngeal edema) ○ Bradycardia/Tachycardia (below 60/above 100) ○ Sudden onset of abdominal cramps ● Severe ○ Life threatening arrhythmias ▸ Rhythm problem of the heart where electrical impulses that coordinate heartbeats do not work properly ○ Pulmonary edema (fluid overload) ○ Seizures ▸ Sudden uncontrolled electrical disturbance in the brain ▸ Lead to changes in behavior, movements, feelings, or even levels of consciousness ○ Death Take Note! ● Be very careful in screening your patients regarding manifestations experienced in prior examinations ● Helpful to ask the patient if they had previously undergone an imaging study that made use of contrast examination ○ If yes, ask whether they experienced any reactions(e.g., the ones mentioned above) ○ If no, remind patient of the possibility of adverse reactions ▸ Also remind them that they should tell you or the people in the diagnostic center if or when they experience certain reactions NON-IDIOSYNCRATIC ● Cardiovascular reactions ○ Induced heightened parasympathetic activity ● Nephropathy ○ Elevation of creatinine level of more than 0.5 mg ▸ >50% of baseline levels 1-3 days after contrast examination ○ Hence the importance in requesting for creatine clearance before patient undergoes myelinated contrast ▸ To make sure kidney function is intact ▸ Otherwise,is contraindicated ○ Alterations of renal vasoconstriction ● Extravasation of contrast ○ Compartment syndrome ▸ Instead of flowing through the vessel, contrast goes outside vessel and accumulates ▸ May Also Restrict Blood Flow Due To Pressure ▸ Leads To Muscle And Nerve Damage ● Delayed reactions ○ Reactions 30 minutes after injection ○ Can last up to 7 days ○ E.g., urticaria, abdominal cramps, etc. 7 ● September 2010: FDA announced the risk for disease among patients with existing kidney diseases D. RISK FACTORS Figure 20. Extravasation of media in a patient’s arm during CT Scan Figure 20 ● Patient underwent CT scan and complained of arm pain ● Notes upon inspection: erythema and swelling ● Possible explanations: ○ Vessels were friable ▸ Could not withstand pressure and burst ○ Wrong placement of contrast B. REACTIONS TO BARIUM SULFATE ● Extravasation risk of contrast media in perforated intestinal tracts ○ May lead to irritation of the peritoneum (peritonitis) ○ Emphasized importance of obtaining complete history and physical examination results from patient ● Clinical history and physical exam findings that are indicative of perforation ○ Ulcer– in the form of abdominal pain ○ Pneumoperitoneum– air in the peritoneum ▸ Checked by starting with a preliminary abdominal x-ray C. REACTIONS TO PARAMAGNETIC SUBSTANCES ● Nephrogenic systemic fibrosis ○ Scleroderma-like disease ○ Common among patients with renal insufficiency (<30 mL/min of GFR) ○ Cause is unknown ○ Theory: circulating fibrocyte (CF) differentiate in dermis ○ Patients present with skin tightening after subjecting to MRI with contrast study ● Related to idiosyncratic reactions ○ Previous reactions to IV contrast media ○ History of asthma ○ Food and medication allergies ● Contrast agent-induced nephropathy ○ Advanced age ○ Pre-existing renal insufficiency ○ Diabetic nephropathy ○ Intake of medications ▸ Aminoglycoside antibiotics ▸ NSAIDs (Nonsteroidal Anti-Inflammatory Drugs) ○ Large doses of contrast media for a single study ● Related to non-idiosyncratic reactions ○ Interleukin-2 (IL-2) immunotherapy ○ Metformin intake ▸ Increase in tissue levels of this drug can induce life-threatening lactic acidosis ○ Pregnancy ▸ Contrast media can cross placenta and induce transient fetal hypothyroidism ● Patients with any of the aforementioned conditions are candidates for low-osmolar, nonionic contrast agents ● Prophylaxis for adverse reactions: corticosteroids E. TREATMENT FOR ADVERSE REACTIONS ● O2 administration (10-12 mL/min) ● Epinephrine ○ Make sure patient is not a cardiac patient taking beta-blockers ▸ Unopposed alpha effect may happen → hypertension ● Diphenhydramine ● Cold compress Table 1. Contrast-Induced Acute Kidney Injury eGFR > 60 mL/min eGFR 30-59 mL/min eGFR < 30 mL/min Treatment Oral hydration Nephrology referral IV Hydration Admission start IV Hydration Medication N-acetylcysteine 600-1200 mg PO BID for 3 days IV. REMINDERS FOR GENERAL PRINCIPLES Figure 21. Nephrogenic Systemic Fibrosis Nice to Know! ● Discovery of nephrogenic systemic fibrosis was recent ● In the past, MRI patients were not really screened for renal insufficiency ● Paramagnetic substance was considered safe for patients with renal compromise YL6:01.35 Contrast Media in Radiology ● Obtain complete clinical history ● Check for the ff: ○ Previous adverse reactions to iodine ○ Allergies ○ Asthma ○ Cardiac problems ○ Renal disease ○ Multiple myeloma ○ Sickle cell disease ○ Previous exposure within last week ● Consider pre-medications for patients with history of allergic reactions or asthma: ○ EG., antihistamines, corticosteroids, sedatives (only occasionally) 8 ● Use the smallest amount of contrast material as possible ● Discontinue other nephrotoxic medications before procedure ● Allow 2-5 days between procedures requiring contrast material ● Check serum creatinine as necessary A. REPORTING ADVERSE REACTIONS ● Report adverse reactions occurring within 24 hours of contrast injection ○ Includes abnormal changes in urine output or blood pressure ● Evaluate patients for at least 48 hours after contrast injection for worsening function ○ Gauged by increases in serum creatinine of ≥ 0.5 mg/dL Active Recall Box 3. T/F. Diphenhydramine cannot be used to treat patients taking beta-blockers with adverse reactions to contrast material as it may cause hypertension. 4. Which of the following reactions to contrast media has an unknown cause? A. Compartment syndrome B. Nephrogenic systemic fibrosis C. Peritonitis Answers: 3F, 4B QUICK REVIEW QUESTIONS 1. Which of the following is not a risk factor for adverse reactions to contrast material? A. Diabetic neuropathy B. Intake of insulin C. Pregnancy D. Asthma 2. A pneumoarthrogram examines the lungs with the use of air as contrast media. Fluoroscopic examinations are done continuously to assess the patient in detail. A. Only statement 1 is true B. Only statement 2 is true C. Both statements are true D. Both statements are false 3. Which of the following statements does not describe ionic contrasts? A. Cheaper than non-ionic contrast B. Is radiopaque C. Has less risks than non-ionic contrast D. Has high osmolar content 4. Barium studies in the esophagus outline the lumen except at the following levels: A. C5, T4, T10 B. C5, T5, T9 C. C6, T4, T10 D. C6, T5, T9 5. T/F: Iodine contrast should be used sparingly because it can perforate the intestinal tracts YL6:01.35 Contrast Media in Radiology 6. Water is a type of positive contrast. Water is commonly used in Pneumoarthrograms wherein joints are being analyzed for pathology. A. Only statement 1 is true B. Only statement 2 is true C. Both statements are true D. Both statements are false 7. T/F: Barium sulfide is a crystalline compound that is highly soluble to water which makes it generally less toxic and safer to use. 8. What is the purpose of using sterile saline (water) in saline infusion sonohysterography? A. To enhance MRI image resolution B. To visualize joint spaces in arthrography C. To assess vascular structures in angiography D. To locate abnormalities in the endometrium 9. Which contrast material is used for double-contrast arthrography? A. Sterile saline (water) B. Gadopentetic acid C. Air D. Iodinated contrast medium 10. Which specific condition is a risk factor for Contrast agent-induced nephropathy? A. History of asthma B. Previous reactions to IV contrast media C. Diabetic Nephropathy D. Peritonitis ANSWER KEY 1B, 2D, 3C, 4C, 5F, 6D, 7F, 8D, 9C, 10C RATIONALE 1. B. Intake of insulin. Intake of Metformin, not insulin, is the risk factor for adverse reactions to contrast media. 2. D. Both statements are false. A pneumoarthrogram uses air to examine the joints, not the lungs. Fluoroscopic examinations are done intermittently to limit the patient’s exposure to radiation. 3. C. Has more risks than non-ionic contrast. Ionic contrasts have more, albeit small, risks compared to non-ionic contrasts. 4. C. C6, T4, T10. Contrast outlines the lumen of the esophagus except at the esophageal constrictions which can be found at the levels C6, T4, and T10. 5. F. It is Barium Sulfate that can cause perforation of the intestinal tracts. 6. D. Both statements are false. Water is a negative contrast, and it is Air that is used as contrast for pneumoarthrograms. 7. F. Barium sulfide is less soluble in water which renders it safer and less toxic to use. 8. D. To locate abnormalities in the endometrium. Saline infusion sonohysterography involves injecting sterile saline into the uterus to visualize the endometrial lining and detect abnormalities such as polyps or blood clots. The anechoic (black) appearance of the water-filled cavity helps identify lesions against the surrounding tissues.. 9. C. Air. Double-contrast arthrography involves using both air and a water-soluble iodinated medium to enhance the visualization of joint spaces. Air provides excellent contrast 9 in joint imaging and can be combined with other contrast agents for certain imaging studies, such as pneumoarthrograms. 10. C. Diabetic Nephropathy. Advanced age, pre-existing renal insufficiency, Diabetic nephropathy, Intake of medications, and Large doses of contrast media for a single study are risk factors for Contrast agent-induced nephropathy. REFERENCES REQUIRED 📄 ASMPH 2026. 01.31: Contrast Media in Radiology by Hernandez, R.B., MD, FPCR, FUSP ● 📄 ASMPH 2027. 01.35: Contrast Media in Radiology by Hernandez, R.B., MD, FPCR, FUSP (onsite) ● Concerns and Feedback form: http://bit.ly/YL6CFF2027 How’s My Transing? form: https://bit.ly/2027YL6HMT Mid-Semester Evaluation form: https://bit.ly/2027YL6MidSem End-of-Semester Evaluation form: https://bit.ly/2027YL6EndofSem Errata Points Trackers: https://bit.ly/YL62027EPT YL6 TransMap: https://bit.ly/2027YL6TransMap FREEDOM SPACE YL6:01.35 Contrast Media in Radiology 10