Procedures · Fluoro and special studies3 min read5-question check
HSG, ERCP and Surgical Cholangiography
HSG checks the uterus and tubes after menses, ERCP enters the ducts through the ampulla, and an operative cholangiogram hunts for leftover stones.
Hysterosalpingography
Hysterosalpingography, or HSG, shows the uterine cavity and whether the fallopian tubes are open. It is most often done for infertility, repeated miscarriage, or after tubal surgery. It is scheduled after menstrual flow stops and before ovulation, usually about 7 to 10 days after the period begins, to avoid irradiating an early pregnancy. Pregnancy, active pelvic infection, and active bleeding are contraindications. With the patient in the lithotomy position, the physician places a speculum and a cannula or balloon catheter in the cervix and injects iodinated contrast under fluoroscopy. Contrast spilling freely into the peritoneal cavity means the tubes are patent. Images are centered about 2 inches above the symphysis pubis.
ERCP
Endoscopic retrograde cholangiopancreatography, or ERCP, is done by a gastroenterologist. An endoscope passes through the mouth, esophagus, and stomach into the duodenum. A catheter is placed into the hepatopancreatic ampulla, the ampulla of Vater, and contrast is injected backward, or retrograde, into the common bile duct and the pancreatic duct. ERCP can also treat: stones can be removed, the sphincter cut, and stents placed. The patient is NPO beforehand and sedated, and the throat is numbed. Nothing is given by mouth afterward until the gag reflex returns. Pancreatitis is the most common serious complication.
Surgical cholangiography
Operative, or surgical, cholangiography is done in the operating room during a cholecystectomy. The surgeon injects contrast through a catheter in the cystic duct while the radiographer takes images with a C-arm or mobile unit. The goal is to find stones left in the bile ducts before the incision is closed. A slight RPO, about 15 to 20 degrees, moves the common bile duct off the spine. A T-tube cholangiogram is a different exam, done in radiology days later through a T-shaped drain left in the common bile duct, to look for retained stones before the tube comes out.
The radiographer's role
In all three, the radiographer keeps the fluoroscopy time and dose low, covers the C-arm and IR to protect the sterile field, and follows sterile technique around the tray. Confirm pregnancy status for HSG, iodine allergy history, and consent, which the physician obtains. Use last image hold, tight collimation, and pulsed fluoroscopy. Record fluoro time and contrast amount.
Clinical Example
During a laparoscopic cholecystectomy, the surgeon asks for a cholangiogram. The radiographer drapes the C-arm, positions the patient in a slight RPO, and runs short pulsed fluoro as contrast is injected. A filling defect in the distal common bile duct shows a retained stone, and the surgeon plans its removal before closing.
Common Mistakes
- Scheduling an HSG during or just before menstruation instead of about 7 to 10 days after it starts.
- Thinking ERCP contrast is injected through the skin; it goes through the ampulla from the duodenum.
- Confusing an operative cholangiogram with a postoperative T-tube study.
- Giving fluids right after ERCP before the gag reflex returns.
Why It Matters
HSG, ERCP, and surgical cholangiography are named in the 2027 Thorax and Abdomen procedures. Questions focus on the purpose, timing, contrast route, and what a finding means.
Key Relationships
- HSG → uterine cavity and tubal patency, about days 7 to 10
- Free peritoneal spill on HSG → patent tubes
- ERCP → endoscope to duodenum, contrast through ampulla of Vater
- Operative cholangiogram → retained stones during surgery, slight RPO
- T-tube cholangiogram → postoperative, through a drain