- Email: [email protected]
Lower GI radiology quiz
quizzes
Lower GI radiology quiz
Case 2 A single radiographic image (Figure 2) in a 65-year-old man admitted with distal large bowel obstruction. 1 What has been done? 2 What is the likely pathology? 3 What are the indications for this procedure?
Alan Freeman Anna Gomez
Questions Case 1 Single-contrast barium enema examination (Figure 1a) and contrast enhanced abdominal CT image (Figure 1b) in a 55-year-old man who presented with weight loss, altered bowel habit and lower abdominal pain. 1 What do the images show? 2 What is the diagnosis? 3 What is the role of imaging in this condition?
Figure 2
Case 3 A single radiographic image (Figure 3) in a 50-year-old woman with altered bowel habit. 1 What is this examination? 2 What does it show? 3 What is its role in clinical practice?
Figure 1
Figure 3
Alan Freeman FRCR is a Consultant Radiologist at the Department of Radiology, Addenbrooke’s Hospital, Cambridge, UK. Competing interests: none declared. Anna Gomez MRCP FRCR is a Specialist Registrar at the Department of Radiology, Addenbrooke’s Hospital, Cambridge, UK. Competing interests: none declared.
MEDICINE 35:6
337
© 2007 Published by Elsevier Ltd.
quizzes
Case 4 Figure 4a is a plain abdominal radiograph of a patient with diarrhoea and Figure 4b is a contrast-enhanced CT image of a 50- year-old hospitalized female patient on antibiotics with acute abdominal pain. 1 Describe the findings on imaging. 2 What is the diagnosis, taking into account the clinical history? 3 What is the role of imaging?
Figure 4
Case 5 Double-contrast barium enema examination (Figure 5a) and contrast-enhanced abdominal CT study (Figure 5b) in a 65-yearold man who presented with an acute episode of left iliac fossa pain. 1 What is the diagnosis? 2 Figures 5c and d show contrast-enhanced pelvic CT images in another patient with the same diagnosis before and after undergoing a CT-guided procedure. What has been done? 3 What is the most appropriate imaging test for this condition?
MEDICINE 35:6
Figure 5
338
© 2007 Published by Elsevier Ltd.
quizzes
Case 6 Contrast-enhanced lower abdominal CT image (Figure 6) in a 38year-old female with acute right iliac fossa pain. 1 What does the image show? 2 What is the diagnosis? 3 What is the most appropriate imaging test for this condition?
Answers Case 1 1 The barium enema demonstrates an ‘apple core’ constricting lesion of the sigmoid colon; the lumen is markedly narrowed. The CT image show a soft tissue mass narrowing the sigmoid colon. 2 Sigmoid cancer 3 Imaging may actually detect primary colon cancer.1 Imaging is also used for staging; three separate questions must be addressed – the extent of local disease, the detection of lymph node metastases and the detection of distant metastases. CT of the thorax, abdomen and pelvis is the primary staging imaging investigation. CT is also used for monitoring the response to treatment, for confirmation of disease remission and for evaluating possible disease recurrence. PET-CT is an accurate modality for detecting local recurrence as well as hepatic and extrahepatic recurrence.2
‘Apple core’ stricture of sigmoid
Figure 6 Rectum
Case 7 Figure 7 is a plain abdominal radiograph of a 40-year-old woman with acute cramping severe abdominal pain, vomiting and constipation. On examination, she is tachycardic with a rigid abdomen. 1 What does the plain abdominal radiograph show? 2 What surgical emergency is this the classic appearance of? 3 What other imaging investigations would be useful to confirm the diagnosis?
Small bowel
Right colon
Case 2 1 A stent has been placed in the sigmoid colon. 2 Sigmoid cancer 3 The approach to acute colonic obstruction has traditionally been staged surgery consisting of colostomy, tumour resection, and colostomy take-down. However, emergency surgery in an unprepared colon is associated with high morbidity and mortality rates. Metallic colonic stent placement has gained acceptance as an initial treatment of acute colonic obstructions, giving time to resuscitate the patient and perform accurate staging and allowing bowel preparation and one-stage surgery with
Figure 7
MEDICINE 35:6
Soft tissue mass in sigmoid
339
© 2007 Published by Elsevier Ltd.
quizzes
end-to-end anastomosis in surgical candidates. Stent placement has also been used as palliation in nonsurgical candidates; stent patency rates in patients treated for palliation vary but average 17 weeks. Colonic stenting is performed with radiological and endoscopic guidance from a retrograde approach.3,4
Case 4 1 The plain abdominal radiograph shows wall thickening of the transverse colon with extraluminal free air (perforation). The CT image shows gross wall thickening and abnormal wall enhancement of the right and left colon. 2 Ulcerative colitis with perforation and antibiotic-related (pseudomembranous) colitis. 3 CT is often used as the initial diagnostic test in colitis as many patients present with non-specific abdominal pain. Imaging features are helpful in differentiating the various types of colitis. Ulcerative colitis is distinguished from Crohn’s colitis in terms of location, extent and appearances of colonic wall thickening and type of complications. Pseudomembranous colitis demonstrates marked bowel wall thickening and is associated with broad-spectrum antibiotic treatment. Neutropenic colitis is characterized by right-sided colonic and ileal involvement. Ischaemic colitits is characterized by vascular distribution and history. However, while imaging features can help narrow the differential diagnosis or suggest a specific diagnosis, the final diagnosis is often based on clinical and laboratory data and colonoscopic and biopsy findings.7
Lumbar spine Metallic sigmoid stent
Hip joints
Case 3 1 This is an image from a computed tomographic colonography. This procedure involves full bowel preparation followed by rectal gas insufflation and helical CT examination of the distended colon. The resulting image data set is then displayed on a workstation with complex image analysis software which produces images that simulate those obtained at conventional colonoscopy.5 2 The image shows a colonic polyp. 3 The role of CT colonography in clinical practice has not yet been established. CT colonography has good accuracy for detection of medium and large colorectal polyps and colorectal cancer in symptomatic or high-risk patients but is less sensitive and specific in detecting smaller lesions. It offers an excellent alternative to double-contrast barium enema in patients in whom colono scopy cannot be performed and new developments in technology may increase its accuracy.5,6
Extraluminal free air perforation
Thick-walled enhancing right colon
Thick-walled transverse colon
Thick-walled enhancing left colon
Colonic polyp Wall of large bowel
Large bowel lumen
MEDICINE 35:6
340
© 2007 Published by Elsevier Ltd.
quizzes
Case 5 1 Acute sigmoid diverticulitis. The double-contrast barium enema shows a narrow spiculated lumen of a segment of sigmoid colon. The CT study shows sigmoid diverticula, localized wall thickening, inflammation of the pericolonic fat and an enhancing pericolonic abscess. 2 The patient has undergone CT-guided percutaneous drainage of a large pericolonic diverticular abscess. 3 CT is now widely advocated as the primary imaging test for evaluating acute sigmoid diverticulitis (which occurs in 20 to 25% of patients with diverticulosis) due to its high sensitivity (70–99%) and specificity, its ability to determine the extent of disease and the presence of disease that might warrant further intervention (associated abscesses, fistulas, obstruction, or perforation). When abscesses are present, it has been shown that CT-guided percutaneous drainage of abscess collections can eliminate multi-stage operative procedures and may eliminate the need for surgery entirely. CT is also able to demonstrate extra-colonic disease (e.g. genitourinary and gynaecological abnormalities) that may mimic diverticulitis.8,9
Case 6 1 The appendix is fluid filled and enlarged with an enhancing wall and there is inflammation in the surrounding fat. 2 Acute appendicitis 3 Both ultrasound and CT are used in the diagnosis of acute appendicitis. Ultrasound, using the technique of graded compression sonography with a high-frequency transducer has the advantage of lack of ionizing radiation risk to the patient and it is the first modality of choice in pregnant women and paediatric patients. However, ultrasound is limited in large patients and patients with a retro caecal or perforated appendix and it is also operator dependent. CT is the most accurate study for evaluating patients without a clear clinical diagnosis of acute appendicitis. CT can be used to choose among different therapeutic options, including antibiotic treatment (with small abscesses), percutaneous drainage (with one to three well-defined medium-sized abscesses), and surgery (with extensive abnormality not amenable to percutaneous drainage).10–12
Barium in left colon CT guided percutaneous drain in abscess Narrowed segment of sigmoid colon Sigmoid diverticula Air in rectum
Pericolonic abscess
Thick-walled sigmoid colon Large sigmoid diverticular abscess
Stranding in the pericolonic fat Diverticula
MEDICINE 35:6
341
© 2007 Published by Elsevier Ltd.
quizzes
References 1 Schwartz LH. Advances in cross-sectional imaging of colorectal cancer. Semin Oncol 1999; 26: 569–576. 2 The Royal College of Radiologists. Recommendations for crosssectional imaging in cancer management. London: Royal College of Radiologists, 2006. 3 Lopera JE, Ferral H, Wholey M, Maynar M, Castaneda-Zuniga WR. Treatment of colonic obstructions with metallic stents: indications, technique, and complications. AJR 1997; 169: 1285–90. 4 Ahmed T. Expandable metal stents in malignant colorectal obstruction. BMJ 2000; 321: 584–85. 5 Halligan S, Altman D, Taylor A, et al. CT colonography in the detection of colorectal polyps and cancer: systematic review, metaanalysis and proposed minimum data set for study level reporting. Radiology 2005; 237: 893–904. 6 Solomon MJ, Lord S, Walleser S. Review: computed tomographic colonography is accurate for medium and large colorectal polyps and cancer. EBM 2006; 11: 153. 7 Thoeni RF, Cello JP. CT Imaging of colitis. Radiology 2006; 240: 623–38. 8 Kircher MF, Rhea JT, Kihiczak D, Novelline RA. Frequency, sensitivity, and specificity of individual signs of diverticulitis on thin-section helical CT with colonic contrast material: experience with 312 cases. AJR 2002; 178: 1313–18. 9 Levine MS, Bree RL, Foley WD, et al. Expert Panel on Gastrointestinal Imaging. Evaluation of left lower quadrant pain. [online publication]. Reston (VA): American College of Radiology (ACR), 2005. 10 Jacobs J. CT and Sonography for suspected acute appendicitis: a commentary. AJR 2006; 186: 1094–96. 11 Bree RL, Blackmore CC, Foley WD, et al. Expert Panel on Gastrointestinal Imaging. Evaluation of acute right lower quadrant pain. [online publication]. Reston (VA): American College of Radiology (ACR), 2005. 12 Raman SS, Lu DSK, Kadell BM, Vodopich DJ, Sayre J, Cryer H. Accuracy of nonfocused helical CT for the diagnosis of acute appendicitis: a 5-year review. AJR 2002; 178: 1319–25. 13 Moore C, Corl FM, Fishman EK. CT of caecal volvulus. AJR 2001; 177: 95–98. 14 Consorti ET, Liu TH. Diagnosis and treatment of caecal volvulus. Postgrad Med J 2005; 81: 772–76.
Oral contrast medium in caecum
Enlarged appendix with enhancing wall Stranding in the periappendiceal fat
Case 7 1 There is a grossly dilated loop of large bowel in the left upper quadrant extending down towards the left iliac fossa. There are also dilated loops of small bowel. 2 Caecal volvulus 3 The traditional imaging modality for caecal volvulus confirmation has been a contrast enema with reported diagnostic accuracy rates of 88% for acute volvulus. However, abdominal CT is increasingly been used for the evaluation of acute abdominal pain and for this reason CT is replacing the contrast enema as the preferred imaging modality. CT shows the presence and location of the volvulus and has the added benefit of allowing early identification of potentially fatal complications, such as ischaemia and perforation. Three-dimensional (3D) reconstructions may further improve diagnostic capabilities by allowing visualization of the entire bowel in a single image.13,14 ◆
Massively dilated caecum
Dilated small bowel
Acknowledgements The authors would like to thank Dr N Carroll for providing the image of the sigmoid stent, and Mr Julian Evans for help with image preparation.
MEDICINE 35:6
342
© 2007 Published by Elsevier Ltd.
Lower GI radiology quiz
Case 2 A single radiographic image (Figure 2) in a 65-year-old man admitted with distal large bowel obstruction. 1 What has been done? 2 What is the likely pathology? 3 What are the indications for this procedure?
Alan Freeman Anna Gomez
Questions Case 1 Single-contrast barium enema examination (Figure 1a) and contrast enhanced abdominal CT image (Figure 1b) in a 55-year-old man who presented with weight loss, altered bowel habit and lower abdominal pain. 1 What do the images show? 2 What is the diagnosis? 3 What is the role of imaging in this condition?
Figure 2
Case 3 A single radiographic image (Figure 3) in a 50-year-old woman with altered bowel habit. 1 What is this examination? 2 What does it show? 3 What is its role in clinical practice?
Figure 1
Figure 3
Alan Freeman FRCR is a Consultant Radiologist at the Department of Radiology, Addenbrooke’s Hospital, Cambridge, UK. Competing interests: none declared. Anna Gomez MRCP FRCR is a Specialist Registrar at the Department of Radiology, Addenbrooke’s Hospital, Cambridge, UK. Competing interests: none declared.
MEDICINE 35:6
337
© 2007 Published by Elsevier Ltd.
quizzes
Case 4 Figure 4a is a plain abdominal radiograph of a patient with diarrhoea and Figure 4b is a contrast-enhanced CT image of a 50- year-old hospitalized female patient on antibiotics with acute abdominal pain. 1 Describe the findings on imaging. 2 What is the diagnosis, taking into account the clinical history? 3 What is the role of imaging?
Figure 4
Case 5 Double-contrast barium enema examination (Figure 5a) and contrast-enhanced abdominal CT study (Figure 5b) in a 65-yearold man who presented with an acute episode of left iliac fossa pain. 1 What is the diagnosis? 2 Figures 5c and d show contrast-enhanced pelvic CT images in another patient with the same diagnosis before and after undergoing a CT-guided procedure. What has been done? 3 What is the most appropriate imaging test for this condition?
MEDICINE 35:6
Figure 5
338
© 2007 Published by Elsevier Ltd.
quizzes
Case 6 Contrast-enhanced lower abdominal CT image (Figure 6) in a 38year-old female with acute right iliac fossa pain. 1 What does the image show? 2 What is the diagnosis? 3 What is the most appropriate imaging test for this condition?
Answers Case 1 1 The barium enema demonstrates an ‘apple core’ constricting lesion of the sigmoid colon; the lumen is markedly narrowed. The CT image show a soft tissue mass narrowing the sigmoid colon. 2 Sigmoid cancer 3 Imaging may actually detect primary colon cancer.1 Imaging is also used for staging; three separate questions must be addressed – the extent of local disease, the detection of lymph node metastases and the detection of distant metastases. CT of the thorax, abdomen and pelvis is the primary staging imaging investigation. CT is also used for monitoring the response to treatment, for confirmation of disease remission and for evaluating possible disease recurrence. PET-CT is an accurate modality for detecting local recurrence as well as hepatic and extrahepatic recurrence.2
‘Apple core’ stricture of sigmoid
Figure 6 Rectum
Case 7 Figure 7 is a plain abdominal radiograph of a 40-year-old woman with acute cramping severe abdominal pain, vomiting and constipation. On examination, she is tachycardic with a rigid abdomen. 1 What does the plain abdominal radiograph show? 2 What surgical emergency is this the classic appearance of? 3 What other imaging investigations would be useful to confirm the diagnosis?
Small bowel
Right colon
Case 2 1 A stent has been placed in the sigmoid colon. 2 Sigmoid cancer 3 The approach to acute colonic obstruction has traditionally been staged surgery consisting of colostomy, tumour resection, and colostomy take-down. However, emergency surgery in an unprepared colon is associated with high morbidity and mortality rates. Metallic colonic stent placement has gained acceptance as an initial treatment of acute colonic obstructions, giving time to resuscitate the patient and perform accurate staging and allowing bowel preparation and one-stage surgery with
Figure 7
MEDICINE 35:6
Soft tissue mass in sigmoid
339
© 2007 Published by Elsevier Ltd.
quizzes
end-to-end anastomosis in surgical candidates. Stent placement has also been used as palliation in nonsurgical candidates; stent patency rates in patients treated for palliation vary but average 17 weeks. Colonic stenting is performed with radiological and endoscopic guidance from a retrograde approach.3,4
Case 4 1 The plain abdominal radiograph shows wall thickening of the transverse colon with extraluminal free air (perforation). The CT image shows gross wall thickening and abnormal wall enhancement of the right and left colon. 2 Ulcerative colitis with perforation and antibiotic-related (pseudomembranous) colitis. 3 CT is often used as the initial diagnostic test in colitis as many patients present with non-specific abdominal pain. Imaging features are helpful in differentiating the various types of colitis. Ulcerative colitis is distinguished from Crohn’s colitis in terms of location, extent and appearances of colonic wall thickening and type of complications. Pseudomembranous colitis demonstrates marked bowel wall thickening and is associated with broad-spectrum antibiotic treatment. Neutropenic colitis is characterized by right-sided colonic and ileal involvement. Ischaemic colitits is characterized by vascular distribution and history. However, while imaging features can help narrow the differential diagnosis or suggest a specific diagnosis, the final diagnosis is often based on clinical and laboratory data and colonoscopic and biopsy findings.7
Lumbar spine Metallic sigmoid stent
Hip joints
Case 3 1 This is an image from a computed tomographic colonography. This procedure involves full bowel preparation followed by rectal gas insufflation and helical CT examination of the distended colon. The resulting image data set is then displayed on a workstation with complex image analysis software which produces images that simulate those obtained at conventional colonoscopy.5 2 The image shows a colonic polyp. 3 The role of CT colonography in clinical practice has not yet been established. CT colonography has good accuracy for detection of medium and large colorectal polyps and colorectal cancer in symptomatic or high-risk patients but is less sensitive and specific in detecting smaller lesions. It offers an excellent alternative to double-contrast barium enema in patients in whom colono scopy cannot be performed and new developments in technology may increase its accuracy.5,6
Extraluminal free air perforation
Thick-walled enhancing right colon
Thick-walled transverse colon
Thick-walled enhancing left colon
Colonic polyp Wall of large bowel
Large bowel lumen
MEDICINE 35:6
340
© 2007 Published by Elsevier Ltd.
quizzes
Case 5 1 Acute sigmoid diverticulitis. The double-contrast barium enema shows a narrow spiculated lumen of a segment of sigmoid colon. The CT study shows sigmoid diverticula, localized wall thickening, inflammation of the pericolonic fat and an enhancing pericolonic abscess. 2 The patient has undergone CT-guided percutaneous drainage of a large pericolonic diverticular abscess. 3 CT is now widely advocated as the primary imaging test for evaluating acute sigmoid diverticulitis (which occurs in 20 to 25% of patients with diverticulosis) due to its high sensitivity (70–99%) and specificity, its ability to determine the extent of disease and the presence of disease that might warrant further intervention (associated abscesses, fistulas, obstruction, or perforation). When abscesses are present, it has been shown that CT-guided percutaneous drainage of abscess collections can eliminate multi-stage operative procedures and may eliminate the need for surgery entirely. CT is also able to demonstrate extra-colonic disease (e.g. genitourinary and gynaecological abnormalities) that may mimic diverticulitis.8,9
Case 6 1 The appendix is fluid filled and enlarged with an enhancing wall and there is inflammation in the surrounding fat. 2 Acute appendicitis 3 Both ultrasound and CT are used in the diagnosis of acute appendicitis. Ultrasound, using the technique of graded compression sonography with a high-frequency transducer has the advantage of lack of ionizing radiation risk to the patient and it is the first modality of choice in pregnant women and paediatric patients. However, ultrasound is limited in large patients and patients with a retro caecal or perforated appendix and it is also operator dependent. CT is the most accurate study for evaluating patients without a clear clinical diagnosis of acute appendicitis. CT can be used to choose among different therapeutic options, including antibiotic treatment (with small abscesses), percutaneous drainage (with one to three well-defined medium-sized abscesses), and surgery (with extensive abnormality not amenable to percutaneous drainage).10–12
Barium in left colon CT guided percutaneous drain in abscess Narrowed segment of sigmoid colon Sigmoid diverticula Air in rectum
Pericolonic abscess
Thick-walled sigmoid colon Large sigmoid diverticular abscess
Stranding in the pericolonic fat Diverticula
MEDICINE 35:6
341
© 2007 Published by Elsevier Ltd.
quizzes
References 1 Schwartz LH. Advances in cross-sectional imaging of colorectal cancer. Semin Oncol 1999; 26: 569–576. 2 The Royal College of Radiologists. Recommendations for crosssectional imaging in cancer management. London: Royal College of Radiologists, 2006. 3 Lopera JE, Ferral H, Wholey M, Maynar M, Castaneda-Zuniga WR. Treatment of colonic obstructions with metallic stents: indications, technique, and complications. AJR 1997; 169: 1285–90. 4 Ahmed T. Expandable metal stents in malignant colorectal obstruction. BMJ 2000; 321: 584–85. 5 Halligan S, Altman D, Taylor A, et al. CT colonography in the detection of colorectal polyps and cancer: systematic review, metaanalysis and proposed minimum data set for study level reporting. Radiology 2005; 237: 893–904. 6 Solomon MJ, Lord S, Walleser S. Review: computed tomographic colonography is accurate for medium and large colorectal polyps and cancer. EBM 2006; 11: 153. 7 Thoeni RF, Cello JP. CT Imaging of colitis. Radiology 2006; 240: 623–38. 8 Kircher MF, Rhea JT, Kihiczak D, Novelline RA. Frequency, sensitivity, and specificity of individual signs of diverticulitis on thin-section helical CT with colonic contrast material: experience with 312 cases. AJR 2002; 178: 1313–18. 9 Levine MS, Bree RL, Foley WD, et al. Expert Panel on Gastrointestinal Imaging. Evaluation of left lower quadrant pain. [online publication]. Reston (VA): American College of Radiology (ACR), 2005. 10 Jacobs J. CT and Sonography for suspected acute appendicitis: a commentary. AJR 2006; 186: 1094–96. 11 Bree RL, Blackmore CC, Foley WD, et al. Expert Panel on Gastrointestinal Imaging. Evaluation of acute right lower quadrant pain. [online publication]. Reston (VA): American College of Radiology (ACR), 2005. 12 Raman SS, Lu DSK, Kadell BM, Vodopich DJ, Sayre J, Cryer H. Accuracy of nonfocused helical CT for the diagnosis of acute appendicitis: a 5-year review. AJR 2002; 178: 1319–25. 13 Moore C, Corl FM, Fishman EK. CT of caecal volvulus. AJR 2001; 177: 95–98. 14 Consorti ET, Liu TH. Diagnosis and treatment of caecal volvulus. Postgrad Med J 2005; 81: 772–76.
Oral contrast medium in caecum
Enlarged appendix with enhancing wall Stranding in the periappendiceal fat
Case 7 1 There is a grossly dilated loop of large bowel in the left upper quadrant extending down towards the left iliac fossa. There are also dilated loops of small bowel. 2 Caecal volvulus 3 The traditional imaging modality for caecal volvulus confirmation has been a contrast enema with reported diagnostic accuracy rates of 88% for acute volvulus. However, abdominal CT is increasingly been used for the evaluation of acute abdominal pain and for this reason CT is replacing the contrast enema as the preferred imaging modality. CT shows the presence and location of the volvulus and has the added benefit of allowing early identification of potentially fatal complications, such as ischaemia and perforation. Three-dimensional (3D) reconstructions may further improve diagnostic capabilities by allowing visualization of the entire bowel in a single image.13,14 ◆
Massively dilated caecum
Dilated small bowel
Acknowledgements The authors would like to thank Dr N Carroll for providing the image of the sigmoid stent, and Mr Julian Evans for help with image preparation.
MEDICINE 35:6
342
© 2007 Published by Elsevier Ltd.