What To Expect From An Undescended Testicle Ultrasound?

Why Is An Ultrasound Ordered For An Undescended Testicle?

Doctors order this ultrasound when a physical exam finds an empty scrotum on one or both sides. This condition, called cryptorchidism, affects about 3 percent of full-term baby boys and up to 30 percent of premature boys. Most cases resolve on their own by six months of age, but when they do not, imaging helps determine where the testicle is located.

The ultrasound is not the only tool doctors use. In many cases, the physical exam alone is enough to feel the testicle in the groin area. When the testicle cannot be felt during a physical exam, imaging becomes more valuable. The ultrasound attempts to find the missing testicle and measure its size and health. This information helps a pediatric urologist decide whether surgery is needed and what type of surgery will work best.

What Happens During The Ultrasound Procedure?

The procedure is straightforward and does not require sedation. Your child lies on an exam table, usually on their back. The technician applies a clear, water-based gel to the lower abdomen, groin, and upper scrotum. The gel ensures good contact between the skin and the ultrasound wand, called a transducer.

The technician moves the transducer slowly across these areas, pressing gently to get clear images. Your child may be asked to change positions slightly, such as bending the knees or turning to one side. This helps the technician see the inguinal canal and the area near the bladder more clearly. The entire scan typically lasts 20 to 30 minutes, depending on how easy it is to locate the testicle.

For infants and young children, parents usually stay in the room during the scan. Holding a child still is often the hardest part. Many hospitals provide a small screen or toys to help distract the child. The scan is completely painless, though the gel may feel cool against the skin. After the scan, the gel is wiped off, and there are no restrictions on eating, drinking, or activity afterward.

What Does The Ultrasound Actually Show?

The ultrasound creates real-time images of the soft tissues in the groin and abdomen. A testicle appears as an oval structure with a distinct internal pattern on the screen. The technician looks for this pattern in three main areas: the scrotum, the inguinal canal, and the lower abdomen.

When the testicle is found, the technician measures its length, width, and height. Size matters because an undescended testicle is often smaller than a normally descended one. The ultrasound also checks the blood flow to the testicle using a mode called Doppler imaging. Healthy blood flow is a good sign that the testicle is viable and has not twisted or suffered damage.

The ultrasound cannot always find the testicle. Sometimes the testicle is too small to see, or it is located deep inside the abdomen where sound waves cannot reach clearly. In about 20 percent of cases, the testicle is absent entirely, meaning it never formed or was lost early in development. When the ultrasound finds nothing, the doctor may order an MRI or perform a diagnostic laparoscopy, where a tiny camera is inserted through a small incision in the belly.

How Accurate Is The Ultrasound For This Condition?

Ultrasound is a useful tool, but it is not perfect. Its accuracy depends heavily on where the testicle is located. For testicles in the inguinal canal, ultrasound finds them correctly in most cases. For testicles inside the abdomen, the accuracy drops significantly.

Some research suggests ultrasound correctly identifies an intra-abdominal testicle in only about 20 to 40 percent of cases. This is because bowel gas and other abdominal structures can block the sound waves. The testicle may also be small and difficult to distinguish from surrounding tissue.

This limitation matters for treatment planning. A negative ultrasound does not mean the testicle is absent. It simply means the ultrasound could not see it. The physical exam remains the most important diagnostic step. If a testicle is not felt on exam and not seen on ultrasound, many surgeons go straight to laparoscopy, which is both diagnostic and therapeutic. The bottom line is that ultrasound helps, but it does not replace the judgment of an experienced pediatric urologist.

What Happens After The Ultrasound Results Come Back?

The radiologist reviews the images and sends a report to your child’s doctor. The report will describe whether a testicle was found, its location, its size, and its blood flow. Based on these findings, the doctor discusses the next steps.

If the testicle is found in the groin or lower scrotum, surgery may be scheduled. The standard procedure is called an orchiopexy. During this surgery, the testicle is moved into the scrotum and stitched into place. This surgery is usually done between six months and one year of age. Early surgery reduces the risk of future fertility problems and lowers the risk of testicular cancer, which is higher in undescended testicles.

If the testicle is not found on ultrasound, the doctor may order an MRI or proceed directly to laparoscopy. Laparoscopy allows the surgeon to look inside the abdomen and locate the testicle or confirm it is absent. If a healthy testicle is found, it can often be brought down in the same operation.

What Are The Risks And Limitations Of The Scan?

There are no known risks from the ultrasound itself. It uses no ionizing radiation, unlike X-rays or CT scans. The sound waves are safe for infants, children, and adults. There is no pain and no recovery time.

The main limitation is diagnostic uncertainty. A missed testicle on ultrasound does not rule out its presence. This uncertainty can cause anxiety for parents, but it should not. The ultrasound is one step in a careful evaluation process. Doctors expect that a certain number of scans will be inconclusive, and they have reliable tools to address that.

Another limitation is that ultrasound does not assess testicular function. It shows structure, not whether the testicle will produce sperm or hormones normally. Function is assessed through physical growth, hormone levels, and sometimes biopsy during surgery. The ultrasound is a structural map, not a functional report.

How Should Parents Prepare Their Child For The Scan?

Preparation is mostly about comfort and cooperation. No fasting or special diet is required. Dress the child in loose, comfortable clothing that is easy to remove from the waist down. Bring a favorite toy, book, or tablet to help keep the child calm.

Explain the procedure in simple terms if the child is old enough to understand. Tell them a camera will take pictures of their belly using a wand and warm gel. Avoid words like “needle” or “shot” because they are not part of this test. Reassure them that it will not hurt and that you will stay with them the whole time.

For babies, schedule the appointment around a nap time if possible. A sleeping baby is much easier to scan than an active one. If the child is very active, the technician may ask for help holding them still. This is normal and expected. The scan time is short, and most children tolerate it well.