What is a Tubogram?
A tubogram is a radiological procedure that evaluates fallopian tube patency, structure, and function by instilling contrast material through the uterus and observing its flow through the fallopian tubes using imaging techniques. This diagnostic test is primarily used in the evaluation of female infertility to assess tubal factors, which account for 25-35% of infertility cases 1.
Types of Tubograms
Hysterosalpingography (HSG)
- Most traditional and widely used tubogram method
- Uses fluoroscopy with iodinated contrast medium injected through the cervix
- Allows detection of tubal patency, tubal size, irregularity, and peritubal disease 2
- Can also detect intrauterine abnormalities like synechiae (adhesions)
- Has 65% sensitivity and 85% specificity for diagnosing tubal patency compared to laparoscopy 2
- Available with two types of contrast:
Sonohysterosalpingography (SonoHSG)
- Ultrasound-based tubogram techniques that avoid radiation exposure
- Several variations exist:
- Saline infusion sonohysterography (SIS) - limited for tubal assessment but fluid in posterior cul-de-sac may indicate patency 2
- Hysterosalpingo-contrast sonography (HyCoSy) - uses echogenic contrast (typically agitated air-saline mixture) 2, 1
- Hysterosalpingo-foam sonography (HyFoSy) - uses gel foam for better visualization 3
- HyCoSy has been shown to be 91% accurate compared to laparoscopy in diagnosing tubal patency 2
Other Tubogram Methods
- MR hysterosalpingography - investigational technique that combines MRI with contrast 3
- Virtual CT hysterosalpingography - specialized CT technique 3
Clinical Applications
Primary indication: Evaluation of female infertility
- Assessment of tubal patency as part of infertility workup
- Detection of tubal abnormalities including occlusion, hydrosalpinx, and peritubal adhesions
Secondary indications:
- Evaluation after tubal sterilization
- Assessment before fallopian tube recanalization
- Therapeutic effect: Tubal flushing during HSG has been shown to increase pregnancy rates up to 38% compared to 21% in women who did not undergo HSG 2
Advantages and Limitations
Advantages
- Non-invasive compared to laparoscopy
- HSG is widely available and considered a first-line test 3
- HyCoSy avoids radiation exposure and can be combined with other ultrasound evaluations 2, 3
- May have therapeutic benefits by flushing debris from tubes 2
Limitations
- HSG involves radiation exposure
- Less accurate than laparoscopy with chromopertubation (gold standard)
- HSG has only 65% sensitivity for tubal patency 2
- Standard transvaginal ultrasound alone cannot assess tubal patency 2
- Operator dependency for ultrasound-based techniques 4
Procedure Selection
The choice of tubogram technique should be based on:
- Availability of expertise: HyCoSy requires special training with a learning curve of at least 40 examinations 4
- Radiation concerns: Consider HyCoSy for patients where radiation exposure is a concern
- Need for comprehensive assessment: Consider combined approaches (e.g., TVUS with 3D imaging followed by SIS and HyCoSy) for comprehensive infertility examination 2
- Patient age and fertility status: HSG with oil-soluble contrast may be preferred in women younger than 38 years with unexplained subfertility 3
Laparoscopy with chromopertubation remains the gold standard for evaluating tubal patency but is more invasive and costly than tubogram techniques 5, 3.
Common Pitfalls
- Misinterpreting tubal spasm as pathologic occlusion
- Inadequate contrast filling due to technical factors
- Difficulty distinguishing between proximal and distal tubal occlusion
- False negative results in HSG due to its limited sensitivity
- Overreliance on standard TVUS which has significantly lower sensitivity compared to expanded protocol TVUS studies 4
Tubograms play a crucial role in the evaluation of female infertility by providing valuable information about fallopian tube structure and function, helping to guide appropriate treatment decisions.