Can You See Adhesions on an Ultrasound?

Adhesions themselves are thin bands of scar tissue, and they rarely show up as visible structures on a standard ultrasound image. What ultrasound can do, though, is reveal their presence indirectly by checking whether organs move the way they should. When organs that normally glide freely past each other appear stuck in place, the sonographer infers adhesions are holding them there. This approach turns out to be surprisingly accurate when performed by trained hands, and the techniques involved have become an important part of surgical planning over the past two decades.

How Ultrasound Finds Adhesions Without Directly Seeing Them

Most people picture an ultrasound as a snapshot, a still image of an organ’s shape or size. That kind of static image is not useful for detecting adhesions because scar tissue bands are often too thin or too similar in texture to surrounding tissue to stand out. The breakthrough in adhesion detection came from treating ultrasound as a real-time movie instead of a photograph. Rather than looking for the adhesion itself, clinicians watch how organs behave when nudged.

In the pelvis, the primary technique is called the “sliding sign.” During a transvaginal ultrasound, the examiner applies gentle pressure against the cervix with the ultrasound probe and, at the same time, uses the other hand to press on the lower abdomen. The goal is to see whether the rectum slides smoothly over the back of the cervix and uterus. If that smooth gliding motion is present, the sliding sign is positive, meaning no adhesions are binding those surfaces together. If the bowel stays fixed in place or drags the uterus along with it, the sign is negative, suggesting the area is stuck down by scar tissue.¹ The examiner checks multiple regions in the pelvis, including the space between the bladder and uterus and the tissue around each ovary.²

For the abdomen, a related technique called the visceral slide test works on a similar principle. The examiner places the ultrasound probe on the abdominal wall and asks you to breathe deeply or performs gentle compression. Normally, loops of bowel slide freely beneath the abdominal wall with breathing. When adhesions tether the bowel to the inner surface of the abdominal wall, that sliding motion is reduced or absent. This is particularly useful before repeat abdominal surgery, where adhesions from a previous incision might make a new entry point dangerous.

How Accurate Are These Techniques

The numbers are genuinely good, though they depend on which part of the body is being checked. For the pelvic sliding sign, a prospective multicenter study found a sensitivity of about 96% and specificity of about 93% for predicting pelvic adhesions in women who had previous surgery.² In plainer terms, the test correctly identified adhesions when they were there and correctly cleared patients when they were not, in the vast majority of cases.

A more recent study focusing on benign gynecologic surgery found that the retrocervical sliding sign had excellent specificity (96%) and accuracy (about 94%) for detecting obliteration of the pouch of Douglas, the deep pocket between the uterus and rectum where adhesions commonly form. However, sensitivity for the same sign was lower at 65%, meaning it missed about a third of cases. Adnexal mobility tests, which check whether the ovaries can be moved freely, had moderate sensitivity (roughly 53–64%) but similarly high specificity above 90%.³ The key detail here is that the study population included mostly loose adhesions. Thin, filmy adhesions are harder to detect because they may still allow partial movement, whereas dense, thick scar tissue is more reliably caught.

Another study reported transvaginal sonography achieving 77% sensitivity and 100% specificity for predicting pelvic organ adhesions confirmed during endoscopic surgery.⁴ That perfect specificity means no false alarms; when the ultrasound said adhesions were present, surgery confirmed them every time.

For abdominal wall adhesions, a systematic review and meta-analysis pooling data from multiple studies found the visceral slide test had a combined sensitivity of about 96% and specificity of about 93% for detecting bowel adhesions near the umbilicus. The negative predictive value was over 99%, meaning that when the test found no adhesions, there almost certainly were none.⁵ A separate prospective study found similar sensitivity (about 97%) with somewhat lower specificity (about 69%), suggesting some false positives.⁶ The pattern across these studies is consistent: ultrasound-based movement tests are very good at ruling out adhesions and reasonably good at confirming them, though the positive predictive value can be moderate because the test sometimes flags areas that turn out to be adhesion-free at surgery.

Indirect Signs That Point Toward Adhesions

Beyond movement-based tests, experienced sonographers look for anatomical clues that suggest adhesions have pulled organs out of position or fixed them in abnormal arrangements. None of these signs means you can see the adhesion band itself, but they reflect the downstream consequences of adhesions.

One well-recognized sign is “kissing ovaries,” where both ovaries are found touching or nearly touching behind the uterus rather than sitting in their normal positions on either side. A study of over 200 patients found that kissing ovaries were strongly associated with moderate to severe endometriosis. Among infertile patients with this finding, 80% had fallopian tube obstruction, compared with under 9% in those without kissing ovaries. Bowel and fallopian tube endometriosis were also significantly more common.⁷ The ovaries are drawn together and held in place by adhesions, making the finding a strong indirect marker of extensive pelvic scarring.

Other indirect signs include a uterus that is fixed in a retroverted (tipped backward) position and cannot be moved by the examiner, bowel that appears tethered to surrounding structures, and ovaries that are stuck to the side wall of the pelvis or to the uterus itself. A prospective validation study showed that fixed uterine retroflexion was associated with roughly double the odds of bowel involvement and nearly triple the odds of involvement of the rectovaginal septum. Bowel tethering was an even stronger predictor, with more than six times the odds of bowel lesions. And an ovary fixed in an abnormal position was associated with roughly 15–17 times the odds of endometriosis affecting that same ovary.⁸

The Operator Problem

The accuracy numbers cited above come from centers where the sonographers have specific training in these dynamic techniques. This is an important caveat, because the standard pelvic or abdominal ultrasound you might get at a general imaging center is not designed to check for adhesions. A routine scan focuses on organ size, shape, and structural abnormalities. The sonographer does not typically perform the sliding sign or the visceral slide test unless they have been trained to do so and the referring clinician requests it.

Research on the learning curve for these skills illustrates the gap. One study tracking a sonographer’s proficiency over time found that reaching a reliable level of competence required between 20 and 44 supervised examinations, depending on the specific anatomical site being assessed. Detecting adhesion-related obliteration of the pouch of Douglas required about 31 cases, while evaluating uterosacral ligament involvement took around 44.⁹ This means the technique is learnable, but it requires dedicated training that most general ultrasound technologists have not received. If you go to a clinic that does not specialize in endometriosis or complex pelvic conditions, the examination may not include any assessment for adhesions at all.

To improve consistency across different centers, an international consensus group called IDEA (International Deep Endometriosis Analysis) published a standardized set of terms, definitions, and measurement protocols for evaluating the pelvis by ultrasound.¹⁰ Centers that follow this protocol produce more consistent results, and a prospective study confirmed that expert-performed transvaginal ultrasound using the IDEA approach should be considered the preferred first-line imaging method for mapping deep endometriosis before surgery.¹¹

How Ultrasound Compares to MRI for Adhesion Detection

MRI is often considered the gold standard for soft-tissue imaging, so you might assume it would outperform ultrasound for adhesion detection. The reality is more nuanced. A head-to-head study comparing abdominal ultrasound with cine-MRI (a type of MRI that captures motion, similar in concept to the ultrasound sliding approach) found no significant difference between the two methods for detecting adhesions to the abdominal wall. Both had specificity of 100% and sensitivity above 90%. Where MRI pulled ahead was in detecting adhesions between internal organs, where it was superior to ultrasound.¹²

Ultrasound has practical advantages that often make it the first choice anyway: it is less expensive, widely available, involves no radiation, takes less time, and allows the examiner to interact with the patient in real time, pressing and repositioning to check different areas of movement. MRI is typically reserved for cases where ultrasound findings are unclear, where deep organ-to-organ adhesions are suspected, or where a more comprehensive surgical map is needed before a complex operation.

Why Surgeons Want Adhesion Maps Before Operating

Knowing where adhesions are before surgery changes the entire operative plan. For laparoscopic procedures (keyhole surgery), the first step is inserting a trocar through the abdominal wall, usually near the umbilicus. If bowel loops are stuck to the inner surface of the abdominal wall at that location, the trocar can perforate them, a serious complication. One study found that among patients undergoing repeat abdominal procedures, ultrasound-guided entry site selection allowed safe trans-umbilical laparoscopy in about 74% of patients. In roughly 20% of cases, midline adhesions detected by ultrasound prompted the surgeon to use an alternative entry point in the upper left quadrant, and those adhesions were confirmed once inside.¹³

For endometriosis surgery, preoperative ultrasound mapping helps in a different way. By documenting which organs are stuck together, whether the bowel is involved, and how extensively the disease has spread, the surgeon can counsel you about what to expect, arrange for the right specialists to be in the operating room (a colorectal surgeon if bowel resection might be needed, for example), and choose the approach most likely to remove disease completely while minimizing complications.¹⁴

Adhesions After Cesarean Section and Chronic Pain

One area where adhesion detection by ultrasound has direct relevance for a large number of people is after cesarean delivery. Adhesions forming between the bladder and the lower uterine segment or between the uterus and the anterior abdominal wall are common after C-sections, and they can cause chronic pelvic pain that is otherwise difficult to explain. A study examining women with a history of cesarean section found that the presence of adhesions on ultrasound was an independent predictor of chronic pelvic pain, with roughly two and a half times the odds compared with women whose ultrasound showed no adhesions. Anterior abdominal wall adhesions showed a similar association.¹⁵

This matters because chronic pelvic pain after surgery is frequently dismissed or attributed to vague causes when no obvious pathology shows up on routine imaging. A targeted ultrasound examination that includes the sliding sign can provide an explanation and, potentially, a path forward through surgical adhesion removal. Ultrasound has also been used in pediatric surgical contexts to monitor whether anti-adhesion treatments are working, by comparing organ movement before and after interventions.¹⁶

Emerging Tools That May Improve Detection

Two newer technologies are beginning to push adhesion detection further. The first is ultrasound elastography, which measures tissue stiffness rather than just shape. Deep endometriotic nodules and adhesion-related scar tissue tend to be much stiffer than normal tissue. A systematic review found that increased stiffness measured by elastography correlated well with the fibrotic content of deep pelvic endometriosis lesions confirmed by pathology, with sensitivity ranging from 78% to 100%.¹⁷ Elastography is still used mainly as a complement to standard ultrasound rather than a standalone test, but it adds another layer of information that can help characterize suspicious areas.¹⁸

The second is machine learning. Researchers have begun building algorithms that combine ultrasound findings with clinical data to predict pelvic adhesions. One model used four predictors: obstructed ovarian activity, surgical history, endometriosis, and gynecological inflammation. It achieved an area under the curve of about 0.87 for identifying patients with adhesions, and in a validation set it caught every case (100% sensitivity), though specificity was only 60%, meaning it generated a fair number of false positives.¹⁹ These models are in early stages, but the direction is clear: combining what the ultrasound shows with a patient’s clinical history can improve prediction beyond what either source of information provides alone.

What Ultrasound Cannot Reliably Detect

For all its strengths in detecting adhesions through organ movement, ultrasound still has blind spots. Adhesions between organs deep within the abdomen, such as loops of bowel stuck together far from the abdominal wall, are difficult to assess because the probe cannot apply targeted pressure to test movement in those regions. This is where MRI, and particularly cine-MRI, has an advantage. Very thin, filmy adhesions that allow some residual organ sliding may be missed even by experienced operators, which partly explains the lower sensitivity numbers seen in some studies for loose adhesions. And adhesions between the liver and the abdominal wall present their own challenge: they can mimic a mass on ultrasound because the affected portion of the liver does not slide normally during breathing, an appearance that has to be carefully distinguished from a tumor.²⁰

Another limitation is access. If your doctor orders a “pelvic ultrasound” or an “abdominal ultrasound” without specifying that adhesion assessment is needed, the examination protocol at most facilities will not include the sliding sign or visceral slide test. You may need to ask specifically for an adhesion-focused examination or seek out a center with expertise in dynamic ultrasound techniques. In endometriosis care, this often means going to a specialist unit, since general radiology practices may not have staff trained in the IDEA protocol or its equivalents.

The gap between what is technically possible and what is routinely available remains wide. Ultrasound can detect adhesions with impressive accuracy when the right techniques are used by the right people. But that “when” is doing heavy lifting. If you suspect adhesions are causing your symptoms, pushing for a referral to a center that performs dynamic ultrasound assessment may be the most important step you can take to get a clear picture before anyone mentions surgery.