Contrast agent use in radiology newer technique
- 3. Dr. Alamgir Hossain DMRD Student(5th batch) Department of Radiology and Imaging Comilla Medical College
- 4. Contrast Agents: Transforming Diagnostic Imaging Department of Radiology and Imaging Comilla Medical College
- 5. • The difference in optical density between different parts of an image on a radiograph. • It is a reflection of the different absorption coefficients of different body parts being radiographed. Contrast
- 6. • It is a chemical substance of very high or very low atomic number or weight, therefor it increase or decrease the radiographic density of the organ under examination. Contrast Agent
- 7. • Contrast was discovered by Walter cannon Bradfold in 1896 (Air and water). • In 1910 Barium Sulfate was used safely for GIT contrast study. • In 1920s Syphilis was treated with high doses of sodium iodide, during this treatment urine in UB was observed radio- opaque owing to its iodine content. History
- 8. • In 1950 - modern ionic contrast agents were introduced still causing adverse effect due to high osmolarity. • In 1974 - first non ionic low osmolar contrast medium was introduced. • In 1984, gadolinium compound first used as a diagnostic intravascular MRI contrast agent. History contd…
- 10. Positive Contrast agents Negative Contrast agents • Contrast material is radio- opaque • High atomic number • White on film. Example: • Barium sulphate • Iodine Compounds. • Contrast material is not radio- opaque • Low atomic number • Black on film. • Example: • Air • Carbon dioxide • oxygen.
- 12. • Different absorptive power from tissue, thereby producing effective radiographic contrast. • Should not cross blood-brain barrier. • Inertness. • Persistence for sufficient time to take radiographs. • Total expulsion from body. Ideal Properties of Contrast Agents
- 13. Positive contrast agents Barium Sulphate High atomic number (56) Highly radio-opaque Can be used for double contrast studies Better coating resulting in better mucosal details in GIT contrast studies
- 14. Barium Sulphate Route: Oral/rectal Uses: • Barium swallow study • Barium meal study • Barium meal follow through study • Barium enema study Complications: • Chemical peritonitis • Extravasation into bronchial tree,urinary tract and other body cavities
- 15. Iodine based Contrast agent Oily/Non water soluble Iodinated Contrast Media Example: • Iophendylate (Myodil, Pantopaque). • Lipiodol ultrafluid (Ethiodol).
- 16. Use: 1. Sialography 2. Hysterosalpingography 3. Myelography 4. Lymphangiography 5. Bronchography 6. T Tube cholangiography Complication: Fat embolism
- 17. Water soluble iodinated contrast agents Based on osmolality High osmolality iodinated contrast agents Low osmolality iodinated contrast agents Iso osmolality iodinated contrast agents Approximately five to eight times the osmolality of serum. Less than three times the osmolality of human serum Osmolality almost equal to human serum Used for gastrointestinal and cystourethral administration. Used for intravascular and intrathecal administration. Ideal for intravascular administration Diatrizoate sodium Iothalamate sodium. Iohexol (Omnipaque) Iopromide (Ultravist) Iodixanol
- 18. • Ionic Contrast agents: Less cost High osmolality More adverse reaction Dissociates into charged particle Example: - Diatrizoate meglumine - Compound diatrizoate meglumine. Based on Ionicity • Nonionic contrast agents: High cost Low osmolality Less adverse reaction Does not dissociates into ionic particle Example: Iodinol, ioverol, iohexol, iodixanol(most ideal), iopamidol, iopromide, iotroram, gadopentetate dimeglumine.
- 19. Common uses of water soluble iodinated contrast agents • Contrast CTs. • Angiography (arterial investigations) • Venography (venous investigations) • HSG (hysterosalpingography) • IVU (intravenous urography) • RGU & MCU • T-tube cholangiography • Distal loopogram
- 20. Contrast agents used in CT scan Routes of administraion of contrast agents used in CT: • Intravenous injection • Oral • Per-rectal • Intra articular (arthrography) and inhaled as a gas and used for special lung and brain imaging. This technique (called Xenon CT) is only available at a small number of locations throughout the world and is only performed for rare cases.
- 21. Dose of IV contrast in CT Contrast: Iohexol Dosing (300 mg/ml) depends on area under examination • Head : 150 ml • Chest or abdomen : 100 ml • Children : 2 ml/kg
- 22. Contrast used in MRI GADOLINIUM • Gadolinium (Gd) is a toxic heavy metal with seven unpaired electrons. • It is rendered non-toxic and soluble by chelation with large organic molecules, forming a stable complex around the gadolinium. • Gadolinium chelates can either be injected intravenously or used as an oral preparation. • Dose For ECF gadolinium agents, usually 0.1 mmol kg−1 body weight. Up to 0.2 mmol kg−1 is given when used in low-field magnets.
- 24. MRI Contrast Agents in Pregnancy and Lactation • MRI contrast agents should not be routinely given to pregnant patients . Although there are no reports of teratogenic or mutagenic effects in humans. • Gadolinium chelates may accumulate in the amniotic fluid and remain there for an indefinite period of time, with potential dissociation of the toxic free gadolinium ion. • The decision to administer an MRI contrast agent to a pregnant patient should be made on risk–benefit analysis. • The use of gadolinium contrast agents is considered safe during lactation .
- 25. USG contrast agents: • USG contrast agents contain micro bubbles of air, nitrogen or fluorocarbon gas coated with a thin shell of material such as albumin, galactose or lipid. • The contrast agent is usually injected intravenously.
- 26. Adverse effect of IV contrast agents • High risk patients for anaphylactic reaction to IV contrast agents • Previous reaction to CA. • Asthma. • Allergies. • Special concern in patient with • Renal insufficiency eGFR < 30 ml/min, Serum creatinine > 130 µ mol/L • DM • Patients having Metformin drug • Old age, Cardiovascular disease • Thyrotoxicosis, Myasthenia gravis • Pheochromocytoma, Sickle cell disease.
- 27. Acute adverse reactions Rare and are classified as:(<1 hour) • Mild: Nausea, vomiting, headache, dizziness, shaking, altered taste, itching, rash, facial swelling. • Moderate: Tachycardia or bradycardia, hypertension, generalized erythema, dyspnoea, bronchospasm, wheezing, mild hypotension • Severe: Laryngeal oedema (severe or rapidly progressive), unresponsiveness, convulsions, cardiac arrhythmias, cardiac-arrest.
- 28. Delayed adverse reactions Occur in more than one hour to seven days • Contrast agent induced nephrotoxicity • Iodine induced hyperthyroidism • Extravasation.
- 29. Dr. Shahariar Hossain DMRD Student(4th batch) Department of Radiology and Imaging Comilla Medical College
- 30. Contrast agents used in common clinical practice
- 31. Neurological perspective Common modalities : • Contrast enhanced CT scan of brain. • Contrast enhanced MRI of brain.
- 32. Contrast enhanced CT and MRI allows to identify • Brain metastasis • Meningioma • Abscess • Meningitis • Lymphoma • Necrotic neoplasm –like glioblastoma. ……Etc.
- 39. Respiratory system perspective Modalities used: • Contrast enhanced CT of chest.
- 42. Barium Pharyngography • Area of interest: Pharynx • Indications: 1. Congenital malformation of pharynx. 2. Inflammatory and infiltrative disease. 3. Trauma. 4. Foreign body. 5. Laryngeal cyst….etc.
- 44. Barium swallow study • Area of interest : Oesophagus. • Indications : 1. Achalasia cardia. 2. Oesophageal diverticulum. 3. Oesophageal atresia. 4. Tracheo oesophageal fistula. 5. Oesophageal varices. 6. Oesophageal Ca.
- 49. Barium meal study • Area of interest : Stomach and duodenum. • Common Indications : 1. Gastric polyp. 2. Gastric CA. 3. Leiomyoma. 4. Gastric ulcer……etc.
- 51. Barium follow through study • Area of interest : Small Gut. • Indications: 1. Stricture 2. Obstruction. 3. Diverticulum. 4. Malignant growth……… Etc.
- 53. Barium enema study • Area of interest : Colon and rectum. • Indications : 1. Screening of colon Carcinoma. 2. Inflammatory bowel disease. 3. Hirschsprung disease. 4. Inconclusive colonoscopy. 5. Patency of distal loop.
- 57. Virtual colonoscopy/CT pneumocolon • Modality : Contrast enhanced CT or MRI. • Area of interest : Large intestine. • Oral contrast medium. • Indications : Pre cancerous growth like polyp, carcinoma.
- 60. Enteroclysis/ small bowel enema • Area of interest: Jejunum to ileocaecal junction. • Contrast : Single contrast: BaSo4. Double contrast: Air + BaSo4. • Indications: 1. Partial small bowel obstruction. 2. Crohn’s disease. 3. Meckel’s diverticulum. 4. Tumor .
- 62. Distal Loopogram: Indication : 1. To evaluate the integrity of colo-rectal or colo-anal anastomosis. 2. To confirm evidence of any leakage, stenosis or fistula. 3. To rule out any distal obstruction. • Time : Before loop ileostomy closure. Usually at 8-12 weeks after the initial surgery. • Area of interest : GIT, distal from stoma.
- 65. Dr. Mariam Akter DMRD Student(4th batch) Department of Radiology and Imaging Comilla Medical College
- 66. Hepatobiliary system perspective • Triple phase CT scan of liver • T-tube cholangiogram
- 67. • Triple phase CT of liver- is a non invasive tool and can be first line imaging modality for differentiating benign and malignant focal lesion. • Triple phases are: 1. Arterial phase : Usually image taken after 10-20 sec. 2. Redistribution or portal venous phase: taken about 30-40 sec. 3. Equilibrium or wash out phase: image taken at 5-10 min. Hepatobiliary approach
- 68. Triphasic CT evaluation of hepatic SOL SOL Pre contrast Arterial phase Portal venous phase Delayed phase HCC Low attenuation Heterogenous enhancement Wash out of contrast. Iso or hypoense to liver. Haemangioma low Peripheral ,nodular, discontinuous enhancement Centri-petal filling in Iso or hyper dense Hyper vascular metastasis Low Rim enhancement Central filling in Wash out Metastasis Low Rim enhancement Central filling in Wash out Abscess Low attenuation, may have irregular margin Transient regional enhancement. Ring enhancement. - Cyst Low No enhancement Adenoma Low Homogenous enhancement Iso or hypo dense Hypo Focal nodular hyperplasia Iso or low Homogenous enhancement Hypo Central scar retain contrast.
- 73. Urological perspective • IVU • RGU and MCU • Contrast CT urogram
- 74. IVU • Intravenous urography (IVU) is a radiographic study of the renal parenchyma, pelvicalyceal system, ureters and urinary bladder using intravenous contrast medium. • It can provide important information about: • Functioning or non functioning kidneys. • Ureteric obstruction. • Tumour. • Anatomical variants – such as horseshoe kidney, ectopic kidney. • The course of the ureters. • UB tumors, diverticulum etc.
- 78. CT Urogram • Hybrid CT Urogram: CT and IVU done together. • CT Urogram Phases with use: 1. Unenhanced phase: To detect calcification, calculi. 2. Corticomedullary phase: To differentiate renal cortex from renal medulla. 3. Nephrogram phase: To differentiate renal medulla from renal mass. 4. Excretory phase: To evaluate urothelial lesions of urinary tract.
- 80. MR Urogram • Contrast: Gadolinium • Indications: 1. Children and pregnant patient with dilated collecting system. 2. Post traumatic urinary tract status. 3. Suspected congenital anomalies. 4. Renal carcinoma.
- 81. MR Urogram
- 82. RGU and MCU • RGU ( Retrograde urethrogram) • Area of interest: Anterior urethra. • Indications: 1. Stricture urethra 2. Congenital anomalies • Post urethral valve. • Hypospadias. • Diverticulum • Bladder neck obstruction. 3. Prostatic enlargement….etc.
- 84. MCU ( Micturating cystourethrogram) • MCU ( Micturating cystourethrogram) • Area of interest: Posterior urethra. • Indications: 1. Vesico ureteric reflux. 2. Post urethral valve. 3. Urinary bladder • Diverticulum • Fistula • Sinus
- 88. Hysterosalpingography • Procedure : The uterine cavity is outlined by the injection of contrast medium through cervix. • Indications : 1. To study the patency of fallopian tubes in infertility. 2. To detect uterine anomalies. EX : septate , cornuate uterus. 3. To detect uterine polyp. 4. To detect uterine synechiae. 5. To study the incompetence of internal os , recurrent miscarriages…etc
- 92. Special uses of contrast medium
- 93. Sinogram/ Fistulogram: It is an X ray procedure to view an abnormal passage between two or more anatomical spaces or organs using contrast.
- 94. Sialogram
- 95. Myelogram
- 96. Lymphangiography
- 97. Bronchogram
- 98. Take home message 1. Understanding the different types of contrast media and their mechanisms of action is essential for undergraduate and post graduate students and clinicians for appropriate selection of contrast examinations. 2. It is important to be aware of potential adverse reactions and contraindications associated with contrast media, so that the honorable clinicians may counsel the patients about the benefit, effects and adverse effects before sending for the contrast examination.
- 99. References
- 100. Yearly Performance 2024 Department of Radiology & Imaging Dr. Moushumi Lucy Rahman Medical Officer Dept. of Radiology & Imaging CoMCH
- 101. Shifts / Service Hour • Morning • Evening
- 102. Organogram Name of post Sanctioned Posted Vacant 1 Professor 1 0 1 2 Associate Professor 1 0 1 3 Assistant Professor 2 2 0 4 Radiologist 5 5 0 5 Medical Officer 2 2 0
- 103. Supporting Staff Name of post Sanctioned Posted Vacant Radiographer 6 4 2 Dark room assistant 2 2 0 Outsourcing staff 8 8 0
- 104. Academic activities • Weekly departmental seminar/ case presentation – Sunday • Film discussion – Wednesday • X ray and USG expert review - Everyday • Journal review – Wednesday, Thursday
- 105. Diagnostic Modalities Name of Modality No. of units Current Status Xray CR 1 Inoperative. DR (500/1000 mA) 2 Running. USG 5 Running. CT scan 160 slice 1 Running. MRI 1.5 T 1 Inoperative due to mechanical problem since 05/09/24.
- 106. Special Services • Contrast X-Ray (Everyday) • USG guided Aspiration of pathological body fluids (Everyday) • USG guided therapeutic procedures(everyday) • USG guided FNAC (in collaboration of Pathology department-every Wednesday) • X-ray for age determination of medicolegal victims and other peoples for official needs(Everyday)
- 107. Annual Performance Modalities Total Patients Served Year 2024 (Upto October) X-Ray 38,685 X-Ray for age determination 1462 USG 26050 CT 3445 MRI 1979 Interventional Radiology (Aspiration + FNAC) 64 Total Patients served 71685
- 108. Thank You
- 110. Contrast study available in our department IVU RGU and MCU Barium pharyngography Barium swallow study Barium meal study Barium follow through study Invertogram Barium enema study Distal loopogram Sino/fistulogram T tube cholangiogram CECT Contrast enhanced MRI