RAD.CONT- PREFI

💧 CONTRAST MEDIA — TYPES & NAMES

Definition

A contrast medium is a substance used to enhance the visibility of internal organs or structures during radiographic exams.
Soft tissues have similar densities, so contrast media help differentiate them by absorbing or scattering X-rays differently.

⚖ CLASSIFICATION OF CONTRAST MEDIA

🧪 1. BARIUM SULFATE CONTRAST

💡 The most common positive contrast for GI tract studies.

🧫 Chemical Name:

Barium sulfate (BaSO₄) — an insoluble, inert, white powder mixed with water to form a suspension.

⚙ Used For:

• Esophagogram (Barium swallow)

• Upper GI series

• Small bowel series

• Barium enema (LGIS)

📋 Trade / Brand Names:

⚠ Contraindicated If:

• Suspected perforation of the GI tract

• Recent surgery on the intestines

• Obstruction or high risk of aspiration

💧 2. WATER-SOLUBLE IODINATED CONTRAST MEDIA

Used when barium is contraindicated, such as:

• Perforation of the intestine

• Post-surgery follow-up

• Suspected leaks or fistulas

These contain iodine, which absorbs X-rays well but can be absorbed and excreted by the kidneys, unlike barium.

⚙ Two Main Types:

🧫 Examples of Water-Soluble Iodinated Contrast for GI Use

3. NEGATIVE CONTRAST MEDIA

Used with positive contrast in double-contrast studies to enhance mucosal visualization.

🧠 Key Notes & WHYs

1. Why use barium if possible?
   → It provides the best coating and mucosal detail.
   → Not absorbed by the body, stays in the lumen for imaging.

2. Why switch to water-soluble iodinated contrast?
   → If perforation or leak is suspected.
   → Iodinated contrast can be absorbed safely by the body.

3. Why double contrast (barium + air)?
   → Air spreads the barium into a thin layer → shows fine mucosal detail.

4. Why avoid ionic contrasts in dehydration?
   → They pull water into the intestines, → may worsen dehydration or diarrhea.

📊 Summary Table

GROUP 3

☢ URINARY SYSTEM

(IVP • Nephrotomography • Percutaneous Renal Puncture • Hypertensive Pyelography • Retrograde Pyelography • Cystography)

🔷 1. INTRAVENOUS PYELOGRAPHY (IVP) / IVU

📌 Definition

A contrast study where iodinated contrast is injected intravenously, filtered by the kidneys, and excreted into the urinary tract for visualization.

📌 Purpose / Indications

• Evaluate renal function

• Detect kidney stones

• Assess hydronephrosis, strictures, obstruction

• Investigate flank pain, hematuria

• Visualize the bladder and ureters

📌 Contraindications

• Iodine contrast allergy

• Renal failure (↑ creatinine)

• Diabetes with metformin (risk of lactic acidosis)

• Pregnancy

• Severe dehydration

📌 Patient Preparation

• NPO 8 hours

• Laxative or cleansing enema (remove bowel gas)

• Void before exam

• Check creatinine and BUN

• Explain the warmth and metallic taste sensation

📌 Procedure (Sequence)

1. Pre-contrast KUB

2. Injection of iodinated contrast (50–100 mL)

3. 1-min nephrogram (renal parenchyma)

4. 5-minute renal pelvis images

5. 10–15 min ureters

6. 20–30 min bladder filling

7. Post-void film

📌 Contrast Used

• Non-ionic iodinated contrast(Omnipaque, Isovue, Optiray)

📌 Special Notes

• Always assess renal function first.

• Observe for a contrast reaction.

• Hydrate the patient post-procedure.

🔷 2. NEPHROTOMOGRAPHY (TOMO NEPHROGRAM)

📌 Definition

Tomographic imaging immediately after IV contrast to obtain slice-like images of the kidneys, improving visibility of renal parenchyma.

📌 Purpose

• Detect small renal masses

• Evaluate trauma

• Assess renal hypertension

• Identify cysts vs. solid tumors

📌 Patient Prep

Same as IVP (NPO 8 hrs, bowel cleansing).

📌 Procedure

• Performed during the early contrast phase (1–3 minutes post-injection).

• Multiple levels (3–5 slices) were taken by moving the tube and bucky during exposure.

📌 Special Notes

• Excellent for subtle renal lesions missed by routine IVP.

🔷 3. PERCUTANEOUS RENAL PUNCTURE

(Percutaneous Nephrostomy, Direct Renal Puncture)

📌 Definition

A needle is inserted directly through the skin into the renal pelvis to inject contrast or provide drainage.

📌 Purpose

• Evaluate obstruction when the IV route is impossible

• Drain hydronephrosis

• Place a nephrostomy catheter

• Deliver contrast directly to the collecting system

📌 Contraindications

• Bleeding disorders

• Uncooperative patient

• Severe hypertension

• Local infection at the puncture site

📌 Prep

• Informed consent

• Coagulation tests

• Local anesthesia

• Sterile technique

📌 Procedure

1. Patient prone or oblique.

2. Skin disinfected and anesthetized.

3. Needle guided under fluoroscopy or ultrasound.

4. Contrast is injected directly into the renal pelvis.

5. Images obtained immediately.

📌 Special Notes

• Done only when IVP and retrograde pyelography cannot be performed.

• Highest sterility required.

🔷 4. HYPERTENSIVE PYELOGRAPHY

📌 Definition

A rapid-sequence IVP to differentiate renal vs. essential hypertension.

📌 Purpose

• To check if renal ischemia or renal artery stenosis is causing high blood pressure.

📌 Prep

Same as IVP but with increased monitoring due to the patient’s hypertension.

📌 Procedure

• Very rapid filming (every 30 seconds to 1 minute).

• Focus on asymmetric kidney function, delayed nephrograms, and poor concentration of contrast.

📌 Special Note

• If one kidney enhances slowly, → may indicate renal artery stenosis.

🔷 5. RETROGRADE PYELOGRAPHY

📌 Definition

Contrast is injected upward from the bladder through catheters into the ureters and kidneys using a cystoscope.

📌 Purpose

• When IVP fails

• To visualize the ureters in obstruction or a tumor

• Evaluate hematuria

• Map the ureters before surgery

📌 Contraindications

• Active UTI

• Urethral trauma

• Contrast allergy (rare since minimal systemic absorption)

📌 Prep

• NPO 8 hours

• Urine test for infection

• Remove underwear and metal objects

• Patient in lithotomy position

📌 Procedure

1. Cystoscope inserted into the bladder.

2. Catheters advanced into the ureters.

3. Small amounts of iodinated contrast were injected retrograde.

4. Fluoroscopic imaging taken as contrast ascends.

📌 Contrast

• Water-soluble iodinated (Omnipaque, Isovue).

📌 Special Notes

• Best exam for ureteric strictures.

• Minimal contrast dose avoids systemic reaction.

• Requires a skilled urologist.

🔷 6. CYSTOGRAPHY

(including Retrograde Cystography already explained earlier)

📌 Definition

X-ray exam of the bladder using contrast, usually by filling the bladder through a catheter.

📌 Indications

• Bladder rupture

• Post-surgical leakage

• Vesicoureteral reflux

• Bladder tumors, diverticula

• Trauma

📌 Contraindications

• Active UTI

• Recent bladder/urethral injury

• Iodine allergy (rare)

📌 Patient Preparation

• Void before exam

• Check for UTI

• Explain procedure

• No major dietary restrictions

📌 Procedure (Retrograde Method)

1. Patient supine

2. Foley catheter inserted

3. 150–300 mL iodinated contrast instilled

4. Fluoroscopic imaging

5. AP, oblique, lateral views

6. Post-void film

📌 Contrast Used

• Only water-soluble iodinated
  (Never barium)

📌 Special Notes

• Post-void view is essential to detect small leaks.

• Avoid bladder overfilling.

⭐ QUICK MEMORY COMPARISON TABLE

GROUP 4

☢ HEPATOBILIARY SYSTEM

(Cholecystography • IVC • IOC • PTC • ERCP • T-tube Cholangiography • Oral Cholecystography)

🟩 OVERVIEW

The hepatobiliary system includes the liver, gallbladder, and bile ducts.
Contrast examinations are done to evaluate:

• Obstruction

• Stones

• Tumors

• Strictures

• Post-surgical leaks

• Function of the gallbladder and ducts

Most studies use iodinated water-soluble contrast because bile ducts may leak into the peritoneum if perforated.

🟦 1. ORAL CHOLECYSTOGRAPHY (OCG)

(Historical but still asked in exams)

📌 Definition

Patient swallows iodinated pills → absorbed → excreted by liver → taken up by gallbladder.

📌 Indications

• Gallstones

• Cholecystitis

• Non-functioning gallbladder

📌 Contraindications

• Iodine allergy

• Vomiting/diarrhea (poor absorption)

• Severe liver failure

• Pregnancy

📌 Patient Prep

• A low-fat diet the night before

• NPO after midnight

• Take 6 contrast tablets 14 hours before the exam

• Then NPO until imaging

📌 Procedure

• Scout film

• RUQ images in upright, supine, and LPO for the gallbladder neck

• A fatty meal may be given to test gallbladder emptying

📌 Special Notes

• Rare today → replaced by ultrasound and HIDA scan

• Still appears in board exam questions

🟦 2. INTRAVENOUS CHOLANGIOGRAPHY (IVC)

(IVC = Intravenous Cholecystocholangiography)

📌 Definition

IV injection of iodinated contrast → liver excretes it → ducts opacify.

📌 Indications

• Evaluate bile duct obstruction

• Detect stones

• Assess duct anatomy pre-surgery

📌 Contraindications

• Liver failure (won’t excrete contrast)

• Iodine allergy

• Pregnancy

• Kidney failure (contrast excretion)

📌 Prep

• NPO after midnight

• Check liver function tests

📌 Procedure

• IV contrast injection

• Serial RUQ images until ducts fill

📌 Special Notes

• Not preferred today because ducts must be working well to fill.

🟦 3. INTRAOPERATIVE CHOLANGIOGRAPHY (IOC)

📌 Definition

Imaging of the bile ducts during surgery (usually cholecystectomy) by injecting contrast into the cystic duct.

📌 Indications

• Identify bile duct anatomy during surgery

• Detect stones in the common bile duct

• Confirm the success of stone removal

📌 Contraindications

• None significant (already in sterile surgical environment)

📌 Procedure

1. The surgeon cannulates the cystic duct.

2. Injects iodinated contrast.

3. Fluoroscopy is used immediately.

4. Images taken AP and oblique.

📌 Special Notes

• Helps prevent surgical injury to ducts.

• Very common in laparoscopic cholecystectomy.

🟦 4. PERCUTANEOUS TRANSHEPATIC CHOLANGIOGRAPHY (PTC)

📌 Definition

A needle punctures the liver percutaneously → enters the bile duct, → contrast is injected.

📌 Purpose

• Best for high obstruction (near liver hilum)

• Visualize the biliary tree when ERCP is not possible

• Drainage via catheter (therapeutic)

📌 Indications

• Obstructive jaundice

• Strictures

• Stones

• Tumor of the bile ducts or pancreas

📌 Contraindications

• Bleeding disorders

• Ascites

• Infection at the puncture site

• Poor cooperation

📌 Patient Prep

• NPO 8 hours

• Coagulation tests

• Sterile technique

• Sedation may be given

📌 Procedure

1. Patient supine or RPO.

2. Right mid-axillary intercostal puncture.

3. Needle enters liver → bile duct.

4. Inject contrast slowly.

5. Fluoro images obtained.

📌 Special Notes

• Risk: bleeding, bile leak, and peritonitis.

• Excellent for dilated intrahepatic ducts.

🟦 5. ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY (ERCP)

📌 Definition

An endoscope is passed through the mouth → stomach, → duodenum; contrast is injected retrograde into the bile and pancreatic ducts.

📌 Indications

• Stones in CBD

• Tumors of the pancreas or ampulla

• Strictures

• Unexplained jaundice

• Therapeutic stone removal or stent placement

📌 Contraindications

• Acute pancreatitis

• Severe cardiopulmonary illness

• Contrast allergy

• Uncooperative patient

📌 Prep

• NPO 8 hours

• Remove dentures

• Obtain consent

• Sedation or anesthesia

📌 Procedure

1. The endoscope advanced into the duodenum.

2. Cannula inserted into ampulla of Vater.

3. Contrast injected retrograde.

4. Spot images taken of ducts.

📌 Special Notes

• Can be diagnostic AND therapeutic.

• Risk: pancreatitis, perforation, bleeding.

🟦 6. T-TUBE CHOLANGIOGRAPHY

(Post-operative Cholangiography)

📌 Definition

After gallbladder surgery, a T-shaped tube is left in the bile duct. Contrast is injected through this tube to check duct healing.

📌 Purpose

• Evaluate residual stones

• Check patency of ducts

• Detect leaks after surgery

📌 Contraindications

• Infection

• Allergy to contrast

📌 Prep

• Clamp tube 24 hours before the exam

• NPO for 6–8 hours

📌 Procedure

1. Patient supine.

2. Contrast is injected slowly via the T-tube.

3. Fluoroscopy or spot films are taken.

📌 Special Notes

• The tube should be clamped before the exam to prevent air entry.

⭐ QUICK MEMORY TABLE