Imaging Pathway — SIS, HSG, 3D Ultrasound, MRI

Key Takeaways

• The imaging pathway ensures a complete understanding of the uterus, ovaries, and fallopian tubes before IVF or surrogacy.
• SIS evaluates the uterine cavity in high detail; HSG checks tube patency; 3D ultrasound identifies subtle abnormalities; MRI offers deep, high-resolution mapping of complex issues.
• Using multiple imaging modalities prevents cycle cancellations, repeated failures, and missed diagnoses.
• The ideal sequence depends on age, symptoms, medical history, and prior fertility outcomes.

Before starting IVF, surrogacy, donor cycles, or embryo transfer, fertility specialists must ensure the reproductive anatomy is healthy, clear, and optimized. The Imaging Pathway—consisting of SIS (Saline Infusion Sonography), HSG (Hysterosalpingogram), 3D ultrasound, and MRI—provides a step-by-step approach to mapping the uterus and tubes thoroughly.

Each modality offers a different perspective. Together, they create a comprehensive picture that helps predict success and avoid preventable complications such as implantation failure, miscarriage, or ectopic pregnancy.

What Is the Imaging Pathway in Fertility Care?

The Imaging Pathway is a structured sequence of diagnostic tests used to assess the reproductive organs. It ensures no structural abnormality—however subtle—is missed before treatment begins.

The pathway commonly includes:

1. Baseline Ultrasound
2. SIS (Saline Infusion Sonogram)
3. HSG (Hysterosalpingogram)
4. 3D Pelvic Ultrasound
5. Pelvic MRI (as needed)

Each step increases diagnostic clarity and influences the treatment plan.

SIS — Saline Infusion Sonography

What It Shows

• Uterine lining
• Polyps
• Fibroids
• Adhesions
• Septum or cavity distortions

Why It Matters

SIS offers a dynamic view of the uterine cavity, making it invaluable for embryo transfer preparation. It helps confirm whether the uterus can support implantation.

HSG — Hysterosalpingogram

What It Shows

• Tubal patency (open or blocked)
• Spill of contrast into peritoneal cavity
• Hydrosalpinx (fluid-filled tube)

Why It Matters

Blocked tubes may require IVF, and hydrosalpinx must be treated before transfer to prevent toxic fluid from harming embryos.

3D Ultrasound

What It Shows

• Uterine shape (septate, arcuate, bicornuate)
• Depth and exact location of fibroids
• Adenomyosis features
• Ovarian cyst mapping

Why It Matters

3D ultrasound often detects abnormalities that 2D scans miss. This is critical for women with repeated failed cycles, miscarriages, or unexplained infertility.

Pelvic MRI

What It Shows

• Adenomyosis (gold standard)
• Deep fibroids
• Congenital uterine anomalies
• Scar tissue and anatomical distortions

Why It Matters

MRI is used when high-precision imaging is necessary, especially before surgical correction or when symptoms are complex.

Case Study: When Imaging Changed Everything

Patient: 34-year-old woman, 2 failed IVF cycles
Initial Testing: Standard ultrasound — “normal”
Plan: Proceed with another IVF cycle

Before restarting, her new clinic performed the full Imaging Pathway:

• SIS revealed a small intracavitary polyp.
• 3D ultrasound identified a mild uterine septum.
• HSG confirmed both tubes were open.
• MRI showed early adenomyosis.

Outcome:
She underwent polyp removal and corrective surgery. With a tailored protocol, her next IVF cycle resulted in a successful pregnancy.

Testimonials

1. Anita, 36

“I had tried for years without answers. The imaging sequence finally revealed a subtle septum no one had noticed. After correction, our embryo transfer worked on the first try.”

2. Saira, 32

“My HSG showed a hydrosalpinx that was sabotaging every cycle. Treating it changed everything.”

3. Rhea & Arjun, 38

“The clinic used MRI to map my fibroids precisely before surgery. It made IVF smoother and less stressful.”

Expert Quote

“Imaging is not just diagnostic—it is predictive. Proper mapping of the uterus and tubes significantly increases the likelihood of implantation and a healthy pregnancy.”
— Dr. Rashmi Gulati

Related Links

• Pain vs Fertility — Different Problems, Different Plans
• Thin Lining — What Helps and What Doesn’t
• Cervical Factors — When Access Is the Issue
• Endometritis — Diagnosis and Treatment Basics

Glossary

SIS: A saline-based ultrasound that evaluates the uterine cavity.
HSG: An X-ray test that checks whether fallopian tubes are open.
3D Ultrasound: Advanced imaging that provides multi-dimensional views of the uterus.
MRI: Magnetic scanning for complex uterine and pelvic issues.
Adenomyosis: Thickening of the uterine muscle that can affect fertility.
Fibroids: Benign growths that may interfere with implantation.
Polyp: Overgrowth of the endometrial lining.
Septum: Abnormal tissue dividing the uterus.
Hydrosalpinx: Fluid-filled, blocked fallopian tube.
Patency: Whether tubes are open.

FAQ 

Q. Do I need all four tests—SIS, HSG, 3D ultrasound, and MRI?

Ans. Not always. Most patients start with ultrasound + SIS + HSG.
MRI is added when abnormalities are suspected (fibroids, adenomyosis, septum) or when prior IVF attempts have failed. Your doctor personalizes the pathway.

Q. What is the difference between SIS and HSG?

Ans. SIS checks the uterine cavity, while HSG evaluates fallopian tube patency. They complement each other—one maps the space where the embryo implants, the other ensures the tubes aren’t leaking toxic fluid or blocking conception.

Q. Is HSG painful?

Ans. It can cause cramping, but discomfort varies. The procedure is short (2–4 minutes), and most women return to daily activities immediately. Taking ibuprofen before the test usually helps.

Q. Can imaging detect issues that cause miscarriages?

Ans. Yes. Polyps, fibroids, septum, adenomyosis, and chronic inflammation are common causes of recurrent miscarriage—and are often found during SIS, 3D ultrasound, or MRI.

Q. What happens if a hydrosalpinx is found on HSG?

Ans. A hydrosalpinx can reduce IVF success by up to 50%.
Treatment options include:

• Laparoscopic removal
• Tubal occlusion
• Draining the tube (less preferred)
  Repair is essential before embryo transfer.

Q. Why is 3D ultrasound preferred over standard ultrasound?

Ans. 3D ultrasound creates a volumetric view, which helps detect uterine anomalies, subtle septa, intracavity distortions, and adenomyosis patterns that regular 2D scans miss.

Q. When is MRI recommended in fertility evaluation?

Ans. MRI is suggested when the diagnosis is complex, such as:

• Deep adenomyosis
• Differentiating fibroids from other lesions
• Complex congenital anomalies
• Precise mapping for surgery

Q. Can these imaging tests improve IVF success?

Ans. Absolutely. The Imaging Pathway helps identify issues that could cause implantation failure, miscarriage, or cycle cancellation. Correcting them improves the likelihood of a successful transfer.

Q. How long does the full imaging pathway take?

Ans. SIS and 3D ultrasound can be done in the same cycle.
HSG is typically performed on cycle days 6–10.
MRI can be scheduled anytime unless cycle-specific timing is recommended.
Most patients complete all tests within 2–4 weeks.

Q. Can I start IVF without imaging?

Ans. Technically yes, but it is not advisable. Missing structural abnormalities often leads to failed cycles, wasted medications, and emotional stress.

Q. Are these procedures safe?

Ans. Yes. SIS and ultrasound use sound waves, HSG uses minimal radiation, and MRI uses magnetic fields with no radiation. All are considered safe for fertility evaluation.

Q. What if all imaging tests are normal but I still can’t conceive?

Ans. When imaging is normal, your doctor evaluates hormonal, genetic, ovarian, sperm, and immunological factors. A normal imaging pathway rules out structural barriers and guides your next steps in treatment.