The Acute Abdomen and Pregnancy - SD

Introduction

Hello everyone.

Thank you for taking a moment to come join me as we look at acute complications in pregnancy.

My name's Dr. Phyllis Glands and I'm from the University of Toronto in Toronto, Ontario, Canada.

I have a special interest in perinatal imaging with a focus on maternal complications of pregnancy.

Thank you very much.

Hello everyone. We're gonna spend the next little while speaking about the acute abdomen in pregnancy with a focus on ultrasound and the management of non obstetric complications of pregnancy.

Definition of Acute Abdomen

Before beginning, I just wanted to look at the definition of an acute abdomen and when we look it up in Steadman's medical dictionary, it's defined as any serious intraabdominal condition in which emergency surgery must be considered.

I think that this may be modified in pregnancy to include conditions which may result in preterm labor or in emergency cesarean section for fetal wellbeing.

Challenges in Diagnosing Acute Abdomen in Pregnancy

Looking and understanding the acute abdomen and pregnancy is a challenge and it's a challenge for a number of reasons.

The first of which is as the gravid uterus expands, it displaces structures and compresses structures making the clinical examination very challenging and the referral of pain is changed as structures are moved and the visceral and parietal peritoneum separate.

Our usual imaging algorithms are modified by a concern about the use of ionizing radiation.

Certainly we've all heard jokes about the hormonal changes in pregnancy and certainly the laboratory values are altered in pregnancy.

In particular those in the white blood cell count and liver function tests.

Our clinical exam, our clinical history, our usual imaging algorithms and our laboratory values are all of less use in the pregnant state.

Then we have the challenge of not only considering the usual spectrum of surgical, gynecological and medical diseases, but we also have to think about conditions which are specific to pregnancy and balance them in the context of both patients.

Nonetheless, as usual, we can think about what are the big ones.

The commonest surgical emergencies are appendicitis and acute cholecystitis.

The commonest medical request is to try and distinguish between obstructive versus non-obstructive renal disease.

Specific to pregnancy, we really wanna consider the various forms of hepatic diseases and trauma is an important consideration as it's the commonest non obstetrical cause of maternal death.

Acute Cholecystitis

We'll begin with acute cholecystitis as this is an area in which most of us are very familiar with.

From a sonographic perspective, is it altered in pregnancy?

It is in the sense that there's an actual increased incidence of gallstone formation in pregnancy, and this is because estrogen decreases bowel salt concentrations and increases cholesterol secretion into bile.

Progesterone relaxes the smooth muscle, the gallbladder decreasing its contractility, thus promoting bile stasis and stone formation.

Ultrasound is terrific, 95% sensitive in the detection of gallstones at two millimeters or larger.

The findings that we associate with acute cholecystitis in order of importance as gallstones in the setting of a positive ultrasound Murphy sign.

Then the secondary signs are distension of the gallbladder, thickened gallbladder wall, pericholecystic fluid and increased wall flow.

This appearance of the gallbladder is the one where happiest to see where there's a nice undulating curvature to the gallbladder wall so that we can be confident that there's no obstruction present.

Often we'll see a fluid debris level within the gallbladder, the debris representing echogenic bile or sludge.

We can confirm this by moving the patient and watching that sludge move.

Echogenic biliary sludge in and of itself does not constitute gallstones but is a precursor to gallstone formation.

Calculi are identified as a rounded echogenic object which has good acoustic shadowing.

As in this particular picture.

We like to see them mobile, but in cases of acute cholecystitis, they're quite often impacted within the gallbladder neck or cystic duct.

We wanna make sure to not confuse them with tumor effective sludge as we see here.

How can we do this?

By simply repositioning the patient, we begin to see the layering out of that sludge and can feel quite confident that we're not looking at true gallstones.

The other mimicker that can be present is that of small gallbladder polyps and we distinguish this by the lack of mobility.

It's adherence to the wall and if we can see a vascular pedicle as in this case, we can feel confident that we're looking at a small gallbladder polyp rather than a gallstone.

Just as a sidebar, we see the intact underlying gallbladder wall.

So we feel fairly confident that this is not a metastatic deposit.

The hallmark of acute cholecystitis in or out of pregnancy is gallstones with a positive ultrasound Murphy sign.

So again, the gallstone with acoustic shadowing, the thickening of the gallbladder wall, sometimes an impacted gallstone, little bit of pericholecystic fluid and increased flow to the wall are all signs that we can look for.

Should we be operating on these patients that we have no good prospective evidence, but we are seeing that intrapartum surgery via the laparoscopic cholecystectomy is turning out to be a relatively safe modality for these patients.

This is the kind of exam that is a very classic acute cholecystitis where we see the thickening of the gallbladder wall.

We see tiny gallstones coming in and out of view.

There's good flow to the gallbladder wall consistent with inflammation and is often the case.

The lumen is not very distended.

So here we have our patient with gallstones, positive ultrasound Murphy sign and some of the secondary signs such as increased flow to the wall and thickening consistent with the diagnosis of acute cholecystitis.

This patient presented to us at 32 weeks gestational age with fever and poorly localized pain.

Her background history included insulin dependent diabetes mellitus and we see a very similar appearance to the gallbladder as in the preceding case with a grossly thickened wall.

Some small gallstones present but a negative ultrasound Murphy sign.

Does this patient have acute cholecystitis?

When we investigate a little further and we put the color flow on, we recognize that there's no vascularity to the wall.

So we think about ischemia to the gallbladder wall with denervation resulting in a negative Murphy sign.

In fact when we look a little closer at the gallbladder, you may appreciate the sloughing of the membranes into the gallbladder lumen as well as a small pericholecystic fluid collection.

This patient in fact has a gangrenous gallbladder with localized perforation.

Although our key is a positive ultrasound Murphy sign in the setting of gallstones when it's negative, we need to consider gangrenous changes.

Appendicitis

We're gonna move gears a little bit and think about appendicitis.

Appendicitis remains the commonest non obstetrical surgical emergency in pregnancy affecting about one in 1500 deliveries.

It's a challenging diagnosis due to the gravid lab migration of the appendix and the poor localization of symptoms.

CT is generally considered the screening examination of choice in the non pregnant adult patient.

How should we be approaching this with the pregnant patient?

Our signs and symptoms and lab values remain relatively nonspecific graded compression ultrasound is limited by the gravid uterus and although there's no actual increased incidence of appendicitis, the associated delay in diagnosis leads to an increased perforation rate.

In uncomplicated acute appendicitis, the fetal loss rate is less than 2%, whereas once perforation has occurred, it's over 30% fetal wastage and in fact that perforation rate increases in third trimester to about 70%.

We would really like to make this diagnosis in the early phases prior to perforation and when we're lucky, it looks like this, the line is outlining the cecum and then we can visualize the blind ending appendix mildly dilated at eight millimeter in cross section.

The signs on ultrasound of acute appendicitis are the identification of a dilated or more than six millimeter diameter, non-compressible blind ending tubular structure, which is tender and aperistaltic.

Secondary signs may include appendicolith, inflamed adjacent fat, and per appendiceal collections.

Here we have an example of a distended appendix in cross section with the adjacent echogenic fat, which is inflamed with increased vascularity.

The appendix itself has increased flow in the wall and we often see some local lymph nodes which have responded to the inflammation.

Acute appendicitis, we always, whenever we bring up appendicitis, we wanna comment on watching the appendix all the way to the end to ensure that we're not missing a case of distal tip appendicitis as in this image.

Renal Complications in Pregnancy

One of our most common clinical requests is this one mild flank tenderness rule out pyelonephritis.

This particular patient was a 49-year-old female, nine weeks pregnant who had a bit of fever, an elevated white blood cell count, urine dipstick positive and pyuria.

How would we approach a patient with these findings?

Our process is to consider both patients, we'll begin with examining the kidney and bladder where the initial clinical indication is.

If they're negative or we're not sure that they're responsible for the symptoms, we'll go on to examine the right upper quadrant looking for biliary colic, hepatitis, pancreatitis, we'll examine the right lower quadrant for bowel disease.

We'll examine the right adnexa thinking about ovarian torsion to ovarian abscess rupture or hemorrhage of a cyst, perhaps thinking about a pedunculated degenerating or torted uterine fibroid.

We'll also wanna rule out placental abruption or cervical shortening with preterm labor in later pregnancy.

We wanna ensure fetal wellbeing.

In this particular case, looking in the right lower quadrant, we did identify a normal appearing cecum and appendix, but immediately adjacent the terminal ileum was quite thickened and we did have some inflammatory lymph nodes locally.

What is our diagnosis?

In fact, our diagnosis will remain pyelonephritis.

The kidney ultrasound is typically normal and there was enough clinical evidence to confirm pyelonephritis and our role was to rule out an obstructive etiology.

Our second diagnosis, however was terminal ileitis and in this particular patient we had a postpartum confirmation of Crohn's disease.

About a one third of women with known inflammatory bowel disease will relapse during the pregnancy, often related to the discontinuation or decrease in medications.

This patient is a 47-year-old female with right lower quadrant pain and fever.

It's her first pregnancy.

She's been an infertility patient for a long time and has made it up to 12 weeks gestational age when she presents.

When we examine the right lower quadrant, we appreciate there's a tender mass inferior to the junction of the cecum in the appendix and we thought, well perhaps this is a perforated appendiceal abscess.

The patient refused surgery, wanted to take no chances with this very precious pregnancy, was put on antibiotics, responded well and was discharged home.

Her symptoms however recurred the repeat ultrasound was unchanged and she was booked for surgery.

At surgery an aggressive adenocarcinoma originating from the base of the appendix, which had perforated was found and she had an unfortunate course and died within two months from the combination of aggressive spread of tumor and postoperative complications.

The take home lesson for us here was in the older population particularly we need to think beyond appendiceal abscess and consider other abnormalities such as cancers and tumors of the bowel.

This patient is a 46-year-old infertility patient again who has successfully gone out to 33 weeks gestation with a twin pregnancy and presents with our somewhat familiar sounding right lower quadrant pain and the requisition read acute pain right sided increasing for two days.

When the sonographer attempted to examine the patient, they were very unsuccessful due to pain.

We came into the room and on talking to the patient a bit more, we realized that in fact she had had low grade pain for two to three months now, but thought it was normal in the context of this first pregnancy for her, she had gained 13 pounds weight, which in fact is a weight loss for a patient at 33 weeks gestation with twins.

She had absolutely no GI symptoms in the sense there was no nausea or vomiting, normal bowel movements, no fever or bleeding.

She had had a prior appendectomy which was reassuring for us not to have to try and find one at this late stage of gestation.

She was extremely tender diffusely on the right side.

It was a challenging exam but we could say that the kidneys were essentially unremarkable a little right hydronephrosis may be physiological.

We did not identify the right ovary.

We did see a normal left ovary.

We confirmed there was no placental abruption, the cervix was in normal length and there were two babies alive and well.

But as we examined the right flank, we saw this vertically oriented abnormal structure which we felt likely represented the right colon.

We moved our probe up into the liver where we saw a number of lesions and then here on the surface of the uterus surrounded by a bit of ascites is what we felt likely represented a drop metastasis.

Our concern was that this patient had primary colon carcinoma metastatic and that night shortly after the ultrasound and upright x-ray was done to rule out perforation or free air.

Then in the morning she went to MRI for confirmation.

Our upper images here show at least two discrete lesions within the liver, the hydronephrosis in the right kidney that was felt to be physiological and this abnormally thickened loop of bowel in coronal imaging we can see a picture very similar to that noted on the ultrasound of this long segment of abnormal thickening of the right colon as well as one of the deposits within the liver.

Did we really need the MRI for the patient who was very emotional as one might imagine it was important before agreeing to surgery to have a second mode of confirmation for the surgeon.

He wanted a roadmap as well as confidence to go in on this pregnant patient with very, very major disease.

During the discussion as to the best timing for surgery in this patient, she developed a bowel obstruction and so underwent an emergency C-section with resection of the primary tumor with primary anastomosis.

She started chemotherapy at four weeks and has done fairly well with a response.

Chemotherapy usually doesn't start until six weeks.

Hoping for healing of the cesarean incision and just to show that not all of our patients are elderly primips.

Here we have a 29-year-old who presents at 19 weeks gestational age with very severe diffuse abdominal pain.

Her ultrasound basically demonstrated large amounts of complex fluid and we see in the upper right hand picture, fair amount of fluid surrounding the surface of the liver going down the flank, we can appreciate the complexity of the fluid with fibril strands and debris.

Very non-specific gallbladder wall thickening debris along the small bowel.

Here's the pregnancy within the uterus with fluid debris levels on either side.

No diagnosis, non-specific findings, but extremely high risk findings in a critically ill pregnant patient.

She went directly from the table to CT.

Her final diagnosis was gastric volvulus with perforation and contamination of intraabdominal and thoracic contents.

This diagnosis was in fact not made from the CT examination and she went to surgery without a clear diagnosis.

Unfortunately there was an intrauterine fetal demise which occurred sometime between the CT examination and the surgery.

Our take home lesson I think from this case is that ultrasound may not always be diagnostic, even a preoperative CT was not diagnostic, but certainly should be performed if appropriate and surgery may be required without a diagnosis.

Role of the Kidney in Pregnancy

We're gonna shift gears a little bit now and look at the role of the kidney in pregnancy.

The very typical request that we receive is to rule out obstruction and the key differential is between obstruction or ascending infection with or without acute pyelonephritis.

It's fairly common urinary tract infections and pyelonephritis in pregnancy occurring in one to 2% and the risk is its association with preterm labor.

An ultrasound is typically negative.

Just to demonstrate a little bit about what's referred to as the normal or physiological hydronephrosis of pregnancy in the right kidney we see a moderate hydronephrosis, none really on the left and a distension of the ureter until the pelvic brim.

It's extremely common occurring in 70 to 90% of patients by third trimester and is in this case more common on the right than the left.

Why does it happen? There are two components at play here.

One is a mechanical component where the ureter is compressed between the pelvic brim and the sacral promontory and the gravid enlarging uterus.

The other component is a hormonal one where the progesterone levels result in diminished contractility of the smooth muscle of the collecting system.

This appearance of the tapering ureter as it passes over the pelvic brim is a hint to consider that this is physiological hydronephrosis almost 90% by third trimester occurrence.

Here we have a patient a little earlier in pregnancy, 20 weeks gestational age with right flank pain and the arrows pointing to a small urinary calculus with discreet acoustic shadowing behind it.

I just bring this to your attention because this is a very subtle and easy to miss finding and sometimes when we're unsure we'll put the color on to look for this twinkle sign.

The twinkle sign occurs in about 80% of urinary calculi with a sensitivity and specificity in the eighties.

This is good to help us minimize false positive and false negatives.

What happens here is you have an artifact due to the variation of the incident beam at the interface of that stone where there are many rough edges resulting in multiple reflections.

You may think that there's color, but the spectral tracing will always be flat.

The twinkle sign is one that we do use, particularly when we wanna confirm the presence of a calculus.

If we look here at this particular case, we can appreciate there's not much hydronephrosis associated with this calculus present in the proximal ureter.

The twinkle sign is very helpful for picking it out for us.

This case is a 26 week gestational age with twins admitted for our now somewhat common right flank pain.

What do we see when we look well?

The right kidney has a mild hydronephrosis and there is bilateral ureteric jets present.

We thought the hydronephrosis was likely physiological.

We could identify the left ovary normal in appearance.

However, the right ovary was enlarged with a loss of the normal architectural structure and relatively hypovascular little bit of free fluid was present and possibly a twisted pedicle.

We thought that the patient likely had ovarian torsion and indeed she underwent laparotomy with removal of a necrotic right ovary.

Hydronephrosis may be present but may not always be the etiology of the pain.

This particular case is a 32 week gestation with triplets who now presents with severe left-sided flank pain.

We can appreciate a moderate hydronephrosis on the right, very mild on the left and there are bilateral ureteric jets present.

What's going on?

Can we solve the problem by staying and looking at the urinary system?

If we take a little bit closer look at the right kidney, we do have some blunting of the calyces, but when we look at the left kidney, we're concerned because we're appreciating between the arrows thickening of the ureteral epithelium and if we take a look at that kidney and we draw a cross section through it, what do we see?

Well over here is the ureter, which in cross-section is nicely demonstrated ureteric wall thickening and some inflammatory changes in the adjacent fat and some fluid.

It was felt that there was inflammation or infection involving the ureteral epithelium on the left.

The patient underwent left ureteral stenting and then C-section as her symptoms did not resolve.

In summary, hydronephrosis and urinary tract infections are common findings in pregnancy and the ultrasound typically will be negative in pyelonephritis.

In our first case of right flank pain, we had minimal hydronephrosis but a stone identified in the proximal ureter.

Mechanical obstruction.

In our second case of right flank pain, we had a moderate right hydronephrosis which was felt to be physiological and the right ovary had undergone torsion and necrosis.

In the third case where there was left flank pain, the hydronephrosis was significantly greater on the right than the left.

But as we examined it closely we could see some left-sided perirenal fluid and thickening of the epithelium consistent with infection and likely a degree of mechanical obstruction.

Some tips and hints if you can't identify the calculus, sometimes looking for a stone at the UVJ with transvaginal sonography can be quite useful.

If the ureteric jet is not identified by palpation repositioning the patient in a contralateral decubitus position, you may avoid compression of the ureter by the enlarging uterus and be able to identify a ureteric jet.

Sometimes we see surrounding the kidney as in the left case a hypoechoic area.

We put the color doppler on and we can appreciate that these are distended renal capsular veins.

A not uncommon finding during pregnancy.

Perinephric hematomas on the other hand are uncommon.

The case on the right, we're seeing a similar black hypoechoic rim surrounding the kidney with no vascularity.

We need to keep looking to try and determine why do we have this.

We see here the usual physiological narrowing of that ureter and no right ureteric jet.

We're concerned that there is in fact an obstruction to that right kidney.

We haven't defined the level of the obstruction, but we can appreciate on this cine loop the amount of fluid dissecting around that kidney.

Although we've gone up and down the ureter nicely, we appreciate only the distended ureter to the level of the physiological level of obstruction.

In very rare cases, physiological obstruction can result in a true mechanical obstruction with perirenal fluid.

This patient required stenting for resolution of her relative obstruction.

Hepatic Diseases in Pregnancy

We're going to look now at pregnancy and the liver.

Hepatic disease complicates about 3% of all pregnancies and there are four key hepatic diseases specific to pregnancy.

The one associated with PIH or pregnancy induced hypertension, the HELLP syndrome hemolysis, elevated liver enzymes and low platelets, acute fatty liver of pregnancy, an intrahepatic cholestasis of pregnancy.

What they all have in common is that the only treatment is prompt delivery.

Pregnancy induced hypertension and HELLP syndrome as they affect the liver are believed to be a spectrum of the same disease with vasospasm as the underlying pathology and simply on a continuum of increasing severity, the treatment is prompt delivery.

Maternal mortality is relatively low at one to 3%, but perinatal mortality is approximately 30%.

It is a rare syndrome and it becomes multifactorial as the vasospasm increases with progressive endothelial damage and fibrin deposition.

Subsequent hepatic destruction due to hepatic microemboli distension of the liver due to impeded blood flow and occasionally rare hepatic rupture.

There can be associated renal failure, bleeding, stroke, and death.

The clinical presentation is quite non-specific with the only truly consistent one being right upper quadrant tenderness.

This is related to swelling of the hepatic capsule or stretching of the hepatic capsule as the liver swells and in a sense is an ultrasound positive Murphy sign, but over the liver, the best diagnostic feature however, are by the lab values, looking for elevated LDH a drop in the platelets below a hundred thousand and hemolysis on blood smears.

There are very serious complications as we've mentioned, including DIC abruption, hepatorenal failure, and pulmonary edema.

The liver can be affected by hepatic infarctions hemorrhage, and hepatic rupture.

Acute fatty liver of pregnancy is a very rare entity.

However, it has 18% maternal morbidity and 23% fetal mortality.

An acute fatty hepatic infiltration may rapidly progress to hepatic failure and death.

Again, the treatment is prompt delivery.

Intrahepatic cholestasis of pregnancy, again a rare disease, but the commonest liver disorder, which is peculiar to pregnancy, it is actually the second commonest cause of jaundice in third trimester following viral hepatitis.

Its pathogenesis is unclear, but the key risks are to the fetus who experiences distress premature labor and intrauterine fetal death.

So although maternal mortality is low, there is a significant fetal mortality and treatment is prompt delivery.

What's the role of ultrasound in hepatic diseases specific to pregnancy?

It's really quite minimal because most of these are laboratory diagnoses.

However, what they would like us to do is to rule out alternate hepatic or bile duct pathology, in particular obstruction of the biliary system.

We certainly can look for high-risk sequelae of the HELLP syndrome such as heterogeneous liver on the basis of infarct or hemorrhage, parenchymal or subcapsular rupture or as in the bottom examination a subcapsular hematoma.

But the role remains somewhat limited.

Maternal Trauma

The last sector that we're going to look at is maternal trauma.

There are several key principles which we need to be aware of.

There is no fetal survival without maternal survival, with the exception being third trimester trauma where immediate C-section may save the fetus.

There are two patients and their connection to consider minor maternal trauma may cause fetal death.

This is generally due to placental abruption where there's a shear injury between the relatively non-elastic placenta and the uterine wall.

We amend trauma protocols in the pregnant patient to include an observation period in labor and delivery for fetal monitoring and potential delivery.

In the setting of blunt abdominal trauma, the routine in hemodynamically stable patients is to undergo a screening CT exam.

Typically 90% of these are negative in the pregnant patient.

It is difficult to justify an ionizing exposure examination with ionizing radiation, which is going to be typically negative.

Does ultrasound have a role to play?

Unfortunately, the sensitivity of ultrasound for detection of intraabdominal injury in pregnant patients is not good about 60%.

But alternatively, it is highly specific and can function to rapidly triage a group of patients who need additional evaluation.

As one might expect it's most sensitive in first trimester.

The key and most common injury is placental abruption followed by splenic, then liver and then bowel injury.

How big a problem is trauma in pregnancy?

Well, it remains the leading non obstetric cause of maternal death in pregnancy occurring in about 5% of pregnancies.

The first line examination is ultrasound followed by MRI as appropriate.

Unfortunately in the setting a trauma MRI may take too long and so in many cases the second line would be a radiological examination.

How serious is the exposure?

Induction of congenital malformations, the assumed threshold is in the range of five to 15 rads.

The risk of a pelvic CT is likely below the threshold for induction of congenital malformations.

The average multi detector pelvic CT examination will give an exposure of about three and a half rads, and certainly the period of organogenesis between two and 15 weeks may be expected to be more sensitive than later in pregnancy.

Are their childhood cancer risks?

We assume if we assume five rads exposure for a pelvic CT, it doubles the relative risk of developing a childhood cancer.

So we go from a risk of one in 2000, our baseline to two in 2000.

So this is not a highly significant excess risk and we need to balance the risk of exposure to that of not doing the examination.

While keeping in mind that risks are cumulative when it comes to ionizing radiation.

Our maxim is to do the clinically appropriate examination in a timely fashion.

Direct fetal exposure from the common examinations in a chest x-ray is almost negligible at 0.02 to 0.07 rads one plain film of the abdomen would provide an exposure of about a hundred rads CT of the head, virtually zero, a CT of the thorax.

Thinking about really pulmonary embolism protocol about 16 millirads fetal exposure.

Quite low. So the key exposure is in the CT of the abdomen, which is about 3.5 rads.

The concept here is that we should use ionizing radiation when medically indicated, but minimize exposure without compromising patient care.

In practice, it is unlikely that any single diagnostic study would deliver a dose sufficient to justify termination, but affects are cumulative.

What is the role of MRI?

Although it is not fully evaluated with respect to safety, efficacy, pitfalls or limitations, it has a rapidly expanding role in pregnancy due to the excellent cross-sectional evaluation it provides without ionizing radiation.

So essentially it's to be used when benefit outweighs risk when the ultrasound is non-contributory or fails to provide an answer or, and the information will be likely to alter patient care during that pregnancy.

Gadolinium however, is a category C drug, which means it's to be used when benefit outweighs risk.

However, its safety has not been proven.

We do know that it crosses the placenta and the long-term effects are unknown.

Gadolinium is potentially excreted and reabsorbed in a recurring cycle so that the half-life in fetal circulation remains unknown.

There are preliminary studies suggesting that there is an increase in skeletal malformations, in animal studies and possibly retarded development.

Conclusion

In conclusion, can we use ultrasound in the setting of an acute abdomen?

In the pregnant woman in the setting of acute cholecystitis, a positive and negative result are both excellent and reliable in the setting of bile duct stones, which we did not address during this talk.

If we do see a stone, it's excellent.

If we don't see it, it's of negative value in the setting of acute appendicitis, a positive ultrasound is very good, but of limited value when negative in the setting of a hydronephrosis and a renal calculi, a positive finding is excellent.

A negative one is of limited value for pyelonephritis.

Ultrasound is rarely positive.

It's a clinical diagnosis, but our role is to rule out an obstructive etiology in hepatic disease.

Specific to pregnancy, ultrasound does not play a major role and in trauma, the best we can categorize it as good as its sensitivity is only in the 60% range, although highly specific once positive.

In conclusion, can we rely on the ultrasound findings?

Ultrasound does remain a first line screening tool.

Pregnancy does not rule out less common disease.

Pathology just makes it harder to diagnose as in the case of perforated adenocarcinoma at the base of the appendix or the gastric volvulus and perforation.

When the clinical picture and the ultrasound picture do not match or provide a solution, we keep going and there is clearly a role for both MRI and CT in the appropriate setting.

Thank you very much for your time and attention.