GI Practice Cases

FORWARD

In clinical practice abdominal radiographs have more or less been replaced with computed tomography (CT) as the test of choice to diagnose pathology. Consequently as a community of Radiologists our CT interpretation skills are continuously developing but our plain film interpretation skills are sadly diminishing. Being less confident at plain film reporting is less of a problem in real life but unfortunately for the FRCR 2B viva exam, plain films form an important component of this assessment. To make matters more challenging the same condition can look very different on different radiographs, for example I have a collection of approximately 20 different examples of perforation! Some of these I have displayed on this website, a large number I use in my course and a few are used in lectures. To be able to satisfactorily navigate the exam you need to see hundreds of abdominal radiographs and need to practice presenting in the months leading to the viva.  In the section I have tried to show a variety of different pathologies and highlight a style of how to present. Please note that this is the technique that I used when I did the exam in 2012 and teach on my courses. I have highlighted the technique in this section because delegates who attend my courses find this enhances the course learning experience if they have exposure to a structured style before the exam. I will emphasise that if you have your own technique do not divert too much. On the other hand if you are struggling and unclear on how to present, please use these cases as an example to build a solid base for your FRCR skyscraper. I emphasise again this is a drop in the ocean to what you need to see. Spotting pathology on plain films is about getting your eye in for the abnormality!

Please drop me a line if you found this collection of cases helpful or not! I always need cases so if you have any good examples you want to donate please also let me know. 

I would like to acknowledge Dr Ciaron Healey, Dr Mohammed Mohammed and Dr Abhijit for the contribution of cases for this section.

Finally Good Luck to you!


CASES

 


Case 1: 55 Year old Male with abdominal pain presented to A&E

 

Case1sbowithhernialabelled

Case 1: Model Answer and Analysis

Description This is an abdominal radiograph of an adult patient whom has presented with pain. The first abnormality that draws my eye is that small and large bowel loops are dilated.  I note that loops of dilated bowel projected over the left groin are also dilated. I therefore suspect a mechanical obstruction due to a left groin hernia. I am looking for evidence of complications such as perforation or ischaemia but cannot see any radiological features of these conditions. No bone destruction or lung base abnormality. In summary mechanical bowel obstruction due to a hernia. This is a surgical emergency and in my normal working practice I would urgently convey the findings to the referring team. 

What are the features of bowel ischaemia on a plain film ? Pneumatosis coli. Featureless bowel within a geographic distribution but not necessarily. Portal vein gas, visualised as lucencies over the liver

Would a CT scan be helpful in this instance ? Although, unable to exclude bowel ischaemia on CT, it may show signs of ischaemia such as reduced perfusion or pneumatosis. CT may also be helpful to look for content of the hernia in the groin.

Commentary Left groin hernia with obstruction.

GI Practice Cases 1 Case 2 Image 2

Tips This is a case where the abnormality and cause are present on the film. Look for obstruction and think about the three common causes hernia, adhesions or neoplasia and look for signs to support the cause i.e. clips for adhesions or additional signs of neoplasia. A complication of hernia is bowel strangulation and this should be thought of and mentioned in the discussion. Useful to mention acidosis on blood gas as a clinical supportive parameter for ischaemia.


Case 2: 67 year old off legs with hypotension

 

Case2perforationlabelled

 

Case 2: Model Answer and Analysis

Description Supine Radiograph of the Abdomen in a skeletally mature individual showing increased lucency within the upper abdomen. The appearance is in the configuration of a ‘football.’ Image features are consistent with Pneumoperitoneum. I cannot appreciate any dilated loops of bowel, pneumobilia or dense lesions to represent gallstones within the abdomen. No clips are visualised to suggest recent surgery. Differentials include perforated gastric ulcer, diverticulitis and recent instrumentation.

What would you do next If this was an inpatient film I would inform the referring team immediately. If this was an outpatient film I would contact the referrer and inform them of the finding.

What if the referrer is unavailable I would inform the oncall surgical team of the findings.

Would you perform a CT scan next No. I would ask the clinical team to assess the patient and discuss the case. However, if it helps the management then I would perform a CT scan. The clinicians may want to operate but if they wanted to perform a CT scan one option is to perform a scan with water soluble oral contrast to try to identify the leak point if it is at the duodenum. Also if there is evidence of diverticulitis on the CT, this would point to the potential point of problem. Occasionally dilated bowel loops are better appreciated on CT then plain film.

Commentary This is an example of perforation on an abdominal x ray

GI Practice Cases 1 Case 1 Image 2

 

Tips This is an obvious case of a ‘football’ sign-massive pneumoperitoneum. There are a number of differential diagnosis for this but all likely due to perforation of a hollow viscous-duodenum, stomach, bowel or secondary to mechanical obstruction. The description recognises the findings and in the significant negatives highlights to the examiner that you are thinking of the differential diagnosis. As part of being safe the automatic next answer is not to organise a CT scan but to speak to the clinician and gain more information.  Abdominal x rays are difficult and modern Radiology is more CT/MRI orientated. It is very important note to make up signs. To help with practice, it is useful to look at cases of free air and practice presenting the findings to yourself in a room or with a colleague. The differentials are very different in a paediatric population.


Case 3 69 year old admitted with two day history of bowels not open

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Case 3: Model Answer and Analysis

Description Abdominal radiograph of an adult patient demonstrates dilated loops of small bowel. The large bowel is normal calibre. No free air is demonstrated. No pneumatosis. No small bowel obstruction. A calcified density is noted within the lower abdomen over the pelvis. The appearance on imaging is suggestive of gallstone ileus. No visible air in the biliary tree. No bony abnormalities. No hernia is noted. I would urgently convey the report to the surgical team.

Would you do a CT scan next Gallstone ileus is a mechanical obstruction and requires urgent intervention as patient may compromise very quickly. If it will benefit management I would organise a CT scan next.

How would CT scan help Can show the point of fistulation with the small bowel. CT has more sensitivity to assess for signs of ischaemia such as reduced mural enhancement, portal venous gas and pneumobilia then plain film. CT can be used as a prognostic tool to determine how sick the patient is and can influence when they have management.

Commentary This is a case of gallstone ileus.

Tips The triad of signs are pneumobilia, small bowel obstruction and a radio-opaque stone. Look for evidence of complications of this condition. The examiner may then go on to show a CT scan with evidence of ischaemia or even perforation


Case 4 75 year old admitted with epigastric pain. Concern for perforation.

Case4psoasshadowlabelled

Case 4: Model Answer and Analysis

Description Abdominal radiograph of an adult patient. The left psoas shadow is absent. There is increased density within the left side of the abdomen. The right psoas shadow is normal. No bowel obstruction.  No free air. No bony abnormality is identified. In particular the lumbar and thoracic vertebrae height is maintained. No cortical destruction. No organomegaly in particular the spleen is normal size. Differentials for the appearance include retroperitoneal abnormality such as ruptured aorta, lymphadenopathy and psoas abscess or a paraspinal abnormality. The patient will require additional imaging but the test performed will be guided by the clinical scenario

What could you do next A CT scan of the abdomen and pelvis as this is easier to do then a MRI lumbar spine.

If a psoas abscess was visualised on a CT what would you do next MRI lumbar spine with intravenous contrast

Commentary This is an example of a left psoas lesion.

Tips Abdominal radiographs are difficult. The first step is to ensure that the abnormality is identified. Pay attention to the history for example the examiner may say “young person with history of fever and back pain.”  When looking at the film think about the differential diagnosis and when presenting the case offer significant negatives and positives to back up your thinking i.e. is there splenomegaly to go with the psoas shadow that will push you towards lymphoma or is there abnormality of the adjacent vertebral bodies. This might make you suggest discitis. The cases often have two findings that point towards a diagnosis. The examiner may then move onto either a CT, ultrasound or MRI to further discuss the case.

 


Case 5 GP referral for distended abdomen in a 54 year old lady.

Case5asciteslabelled

Description An IUCD is present in the pelvis. There is increased density of the abdomen with a double density outline in both flanks. The more lateral density is fat and the medial larger density is more suggestive of fluid. The appearance on imaging is suggestive of ascites. No evidence of splenomegaly. No hepatomegaly. The bones are unremarkable. Differential diagnosis includes malignancy, chronic conditions such as liver disease, infections such as TB.

What would you do next Least invasive test is an ultrasound to look for ascites, but I would be guided by the clinical history and information. If there was concern for malignancy then I would perform a CT scan.

If LFT were deranged what would you do If there was concern for liver disease I would perform an ultrasound scan. This would enable for the confirmation of ascites and also for the assessment of the liver for conditions such as budd chiari syndrome.

Commentary This is an example of ascites on a plain film. The eventual diagnosis was peritoneal cancer.

Case5asciteswithlabels

Tips Ascites is a difficult diagnosis on abdominal film but the density is there. The examiner may help you by telling you there is a history of abdominal distension or weight loss. Importantly do not make up signs. You might get a plain film with 2 abnormalities i.e. ascites and splenomegaly. Common causes of ascites are malignancy look for evidence of bony destruction or liver disease in which case look for evidence of enlarged spleen or previous liver surgery. The value of ultrasound in liver disease is that you can look at the vessels. Ultrasound is also non invasive.


Case 6: 34 year old lady with right iliac fossa pain. 

Case6axrdermoidlabelled

 

 

Case 6: Model Answer and Analysis

Description Abdominal radiograph in a adult patient demonstrates a low density lesion in the right iliac fossa projected over the sacro-iliac joint. This contains high density foci which have the configuration of teeth. There is surrounding low density. The appearance on imaging is suggestive of a dermoid. No bowel obstruction. No bony abnormality demonstrated. 

Where is a dermoid located? Ovaries are located intra-peritoneally (although this is difficult to identify on a plain film)

How do you diagnose this lesion? CT and MRI are the most sensitive. The key feature is the presence of fat.

Which sequence on MRI is most helpful T1 fat sat sequences-to help distinguish between an endometrioma and dermoid.

What would you do next Dermoids are typically benign lesions, with a very low malignant potential. If the patient had no acute symptoms, I would recommend an outpatient MRI for further assessment. However, if the patient has pelvic pain dermoids can occasionally rupture. If there was concern for this then a CT scan would be the most sensible next option.

Commentary This is an example of an ovarian dermoid in the right iliac fossa. I had a similar case in one of my actual exam viva. This is difficult to distinguish from bowel loops.

Case6axrdermoidabelledCase6ctdermoid

Tips Abdominal radiographs are difficult to interpret at the best of times. The key in this type of case is to be systematic. If the abnormality is not obvious go through the case systematically with significant positives and then negatives. Lock at the solid organs and then look in the pelvis and suggest you are looking for adnexal mass lesions. Listen to the examiners cues!!!!


Case 7: 45 year old lady with distended abdomen and pelvic pain referred by the GP. 

Case7ovariancystlabelled2

Case 7: Model Answer and Analysis

Description Abdominal Radiograph in an adult patient demonstrates opacification of the lower abdomen with displacement of small bowel loops superiorly. The psoas shadows are visible, suggesting this is not a retroperitoneal abnormality. The large bowel is normal calibre. No bony abnormality is appreciated. The appearance on imaging is suggestive of an intra-peritoneal mass of likely ovarian origin. Differentials include ovarian cyst, ovarian neoplasm and dermoid. I would suggest CT for further characterisation and tumour marker levels.

What would you do next Management of ovarian cysts depends on the size of the lesion. Below 3cm are likely physiological. This is a very large lesion and needs further evaluation with tumour markers and MRI

If tumour markers are normal and this is a simple cyst how would you manage. This would be a clinical decision either to monitor or resect but given the size most likely option is resection.

Commentary  This is an example of a large ovarian cyst.

Case7ctCase7ovariancystlabelled

Tips This is a case where the abnormality and cause are present on the film. Look for obstruction and think about the three common causes hernia, adhesions or neoplasia and look for signs to support the cause i.e. clips for adhesions or additional signs of neoplasia. A complication of hernia is bowel strangulation and this should be thought of and mentioned in the discussion. Useful to mention acidosis on blood gas as a clinical supportive parameter for ischaemia.


Case 8:83 year old diabetic patient admitted with abdominal pain

Case8axremphasematouscystitislabelled

Case 8: Model Answer and Analysis

Description Abdominal radiograph of a skeletally mature patient demonstrates curvilinear lucency surrounding the wall of the bladder. No bowel obstruction. No intra-abdominal free air visualised. There is extensive calcification of the abdominal aorta and iliac vessels. Degenerative change of the lumbar spine. The appearance on imaging is suggestive of gas in the bladder wall. Differential diagnosis include emphysematous cystitis. The alternate differential diagnosis is a fistula with the adjacent bowel. The vascular calcification makes me suspicious for underlying diabetes.

What would you do next Recommend either a CT scan of the abdomen and pelvis or a cystogram to demonstrate a fistula communication with the adjacent bowel. The advantage of the CT is intramural bladder gas is better appreciated.

Management of emphysematous cystitis Ensure no bladder rupture has occurred. Potential causes are bacterial and fungal infections. These would need to be treated, as well as the underlying cause.

Tips Be aware of the difference between emphysematous cystitis and air in the bladder! Look for evidence of a cause for this, in this case it is likely diabetes but the patient maybe immunocompromised so look for evidence of an underlying neoplasia.


Case 9: 69 year old referred for abdominal pain into hospital

Case9pneumatosisaxrlabelled

Case 9: Model Answer and Analysis

Description Abdominal radiograph of an adult patient demonstrates prominent loop of large bowel in the right upper quadrant which contains air within the bowel wall-intra mural air. No evidence of free intraperitoneal air. No bowel obstruction demonstrated. No bony abnormalities. Differential diagnosis include bowel ischaemia, infection, medication induced causes and asymptomatic pneumatosis intestinalis. I would urgently convey the results to the referring clinician and organise appropriate tests based on clinical concern.

What investigations would you do next If there was clinical concern I would organise a CT scan of the abdomen and pelvis.

How would you protocol the scan I would include an arterial and portal venous phase examination. I would only use intravenous contrast.

What are the image features of bowel wall ischaemia on CT scans

  • Visualise clot within superior mesenteric artery or vein
  • Gas within the portal vasculature
  • Bowel wall hyperdensity-for early ischaemia
  • Reduced/absent bowel enhancement
  • Bowel wall thickening
  • Target sign for venous infarction

Commentary This is an example of pneumatosis coli.

Case9pneumatosisaxr2.docxCase9pneumatosisaxrct.docx

Tips Identify the abnormality and present it on the abdominal radiograph. Look for evidence of ancillary support signs such as portal venous gas on the plain film. It is important to offer differential diagnosis rather then immediately recommend a CT scan for assessment. Remember the causes for intramural air include benign causes as well as a neoplastic pathology. Enter into a discussion with the examiner and if presented with a CT scan be aware of the findings to look for


Case 10: History of abdominal pain with change in bowel habit.

Case10colitis And Hernia2labelled2)

Case 10: Model Answer and Analysis

Description Abdominal radiograph in a skeletally mature patient demonstrating a right groin hernia containing bowel loops as well as a distended transverse colon devoid of haustra. It is difficult to determine if the hernia contains large or small bowel but the absence of valvulae coniventae makes me suspect this is large bowel. The appearance of the large bowel in the transverse colon is concerning for obstruction and a geographic colitis. I would be concerned about the possibility of ischaemia. No evidence of perforation.  I would recommend clinical correlation in the first instance, if there was any doubt I would suggest organising a contrast enhanced CT for further assessment.

What type of hernia can you identify in the groin Direct, indirect or femoral-it is difficult to determine the type on a plain film

Direct; protrusion through a weakness in the posterior wall of the inguinal canal, medial to inferior epigastric vessels, lateral to the rectus sheath muscle (Hasselbach’s triangle). The inguinal canal is usually compressed or displaced.

Indirect; Lateral and superior to the course of the inferior epigastric artery. This enters the inguinal ligament in the deep ring and extends out through the superficial ring. This can occasionally enter the scrotum.

Femoral hernia; exit below the inguinal ligament, this is an inverted cone shaped fascial space medial to the femoral vein usually the space for the femoral and lymphatic vessels.

Borders of the femoral ring Medial-lucanar ligament, anterior-medial inguinal ligament, lateral-femoral vein, posterior-pectineal ligament.

Commentary This is a case of a right groin hernia containing bowel loops with a distended thickened transverse with concern for ischaemia 

Tips If you saw the right groin hernia immediately then great, alternatively include that in your review area for looking at the abdominal radiograph.


Case 11: 84 year old emergency referral for abdominal pain. History of warfarin use.

 

Case11rectus Sheath Soft Tissue Haematomalabelled2

Case 11: Model Answer and Analysis

Description Abdominal radiograph of an adult patient demonstrates increased density over the left lower abdomen project over the iliac wing. The right flank demonstrates normal tissue density. There is a calcified density projected over the gallbladder. This is presumed to represent a gallstone. No bowel obstruction. No bony abnormality is appreciated. Incidental note is made of vascular calcification. I would recommend a CT scan for further assessment of this lesion.

What are the differential diagnosis for the soft tissue lesion Haematoma or soft tissue neoplasm.

How can you distinguish between your two differential diagnosis on imaging In the first instance I would recommend a CT scan to assess for haematoma. If this is not conclusive, we can perform an MRI scan.

Commentary Soft tissue haematoma of the left rectus sheath muscle

Case 11.ctimageCase11rectus Sheath Soft Tissue Haematoma Labelled

Tips This is an example of a haematoma of the left rectus muscle. The finding on abdominal x ray is subtle but once you see it on CT, it is more apparent. If you see this then great, if unsure the examiner can offer you guidance. Remember do not make up signs.


Case 12:  62 year old presented with back pain. Concern for kidney stones. 

 

Case12horseshoe Kidney Axrllsbelled

Case 12: Model Answer and Analysis

Description Abdominal radiograph in an adult patient demonstrates increased soft tissue density adjacent to the medial poles of the kidneys. No renal tract calculus. No bowel obstruction. No bony abnormality. Differential diagnosis for the appearances include horse shoe kidney as the most likely cause but it is difficult to exclude local nodes or a retroperitoneal mass.

What would you do next Check if there is a history of known horseshoe kidney. If there are previous films or ultrasound I would compare the current findings to older studies. Alternatively if there is no known history of this, I would suggest an ultrasound scan for further assessment.

Would you be concerned with a horseshoe kidney This is a common developmental anomaly for which there is no increased association of malignancy. However, if the reason for requesting the plain film was an acute abdomen in the first place, then this x ray does not answer that question. The patient may require a CT scan to assess for a cause of the acute abdomen.

Commentary This is an example of a horseshoe kidney on an abdominal radiograph.

Case12horseshoekidneyaxrlablled

Tips As with the previous case if you spotted the horseshoe quickly great (without prompting), then look for potential causes of the request i.e. renal stones, soft tissue mass lesions to suggest renal neoplasm. If you didn’t spot it immediately review the abdominal film systematically i.e. bowel gas patterns, soft tissue densities, bone review etc….


Case 13: 55 Year old Male with abdominal pain presented to A&E

Case13sickle Cell Labelled

Case 13: Model Answer and Analysis

Description The spleen is massively distended and there is evidence of previous cholecystectomy. I cannot see any evidence of free fluid in the abdomen. No bowel obstruction. No visible bony abnormalities. The differential diagnosis for splenomegaly is vast but in view of the cholecystectomy I will include sickle cell disease as a differential diagnosis. Other potential causes include liver disease, lymphoma and inherited conditions such as Gauchiers’ disease.

What is the upper limit of a normal spleen size Usually the cut of is 13cm, however the context of a patient needs to be considered. For example if the spleen is long measuring 13.6cm but not widened and the patient is tall, this can be normal.

What would you do next Ideally check if there is any supportive old images to determine if this is an acute event or long standing. If there was a previous x ray that was normal perhaps in the last year I would be more concerned about this appearance. If previous examinations demonstrate splenomegaly I would be more inclined towards a chronic condition such as Gauchiers or Sickle Cell Disease

Commentary This is an example of splenomegaly in a patient with Sickle Cell Anaemia.

Case13ctimage

Tips Differential diagnosis for splenomegaly is wide. Listen to the history, the examiner might give a clue i.e. the patient is unwell-think sickle cell crisis or an infection which has caused splenomegaly or there is increased lethargy and weight loss-consider lymphoma. This is an example of gross splenomegaly and the cholecystectomy is a clue to the diagnosis. Look for signs to support sickle cell such as a hip prosthesis.


Case 14: 55 Year old Male with abdominal pain presented to A&E

Case14porceleingallbladderlsbelled

 

Case 14: Model Answer and Analysis

Description Abdominal radiograph in an adult patient demonstrates a catheter in the bladder. There is a calcified density in the right upper quadrant. The appearance on imaging is suggestive of a porcelain gallbladder. There is degenerative change of the lumbar spine. No bowel obstruction. The management depends on the clinical presentation. If there is suspicion of cholecystitis I would recommend an ultrasound. Alternatively if the gallbladder is an incidental finding then non urgent referral to a upper GI surgeon is suggested for assessment. 

What are the image features of cholecystitis on ultrasound Positive sonographic murphy’s sign in a gallbladder with visible calculi, gallbladder wall thickening greater then 4mm, pericholecystic fluid and hyperaemia on ultrasound.

Commentary This is an example of a porcelain gallbladder.

Tips The traditional method of managing porcelain gallbladder is surgical resection because of an association with malignancy established from studies in the 1930s, recent studies spread some doubt on this but it is still reasonable to suggest a non urgent referral to a surgeon.    


Case 15: 75 Year old lady with abdominal pain presented to A&E

Case15abdo X Ray Ascites Labelled(1)

 

Case 15: Model Answer and Analysis

Description: There is increased opacification of the abdomen with an apparent ‘double density’ appearance in the flanks. This makes it difficult to clearly see the psoas shadows. There is also bulging of the flanks. The more lateral density is fat, the medial density has higher opacification and the appearance is suggestive of fluid. No associated bowel obstruction. No visible hepatosplenomegaly. No bony abnormalities. Differential causes of ascites are malignancy, chronic liver disease and inflammatory conditions such as TB. I would suggest a CT scan or ultrasound of the abdomen and pelvis to further characterise depending on the clinical presentation.

Which is better CT or Ultrasound Depends on the clinical concern. If there is suspicion of chronic liver disease, then ultrasound is valuable to assess for volume of ascites, contour irregularity of the liver, patency of vessels and splenomegaly. If there is concern for malignancy then CT would be more ideal.

What are the different types of ascites Transudate-protein low fluid, exudate-protein rich fluid and haemoperitoneum-blood.

How do you distinguish Difficult to identify blood on ultrasound but this may possible be increased in echogenicity on ultrasound. A more reliable method is to either measure the HU on CT, below 15 is transudate, above that is exudate and above 45 is likely blood.

Commentary This is an example of ascites on an Abdominal Film

Case15ct

Tips This is an example of ascites. In this case this is secondary to liver disease. However, differentials can be due to leakage from operations such as cholecystectomy-look for cholecystectomy clips and if you see any enquire about recent surgery. The other common differential diagnosis is malignancy. You may see bowel obstruction with this due to soft tissue deposits or bony destruction. The key to identifying the abnormality is the double density. Low density widened abdomens indicate an obese patient, but the key is the double density.