Small Intestine Flashcards
A 25-year-old male presents following blunt abdominal trauma following a motor vehicle accident. Which is the most common CT finding in the ‘shock bowel’?
A. Small bowel luminal dilation
B. Fluid-filled loops of small bowel
C. Colonic involvement greater than small bowel
D. Increased small bowel mucosal enhancement
E. Focal involvement of the small bowel
D. Increased small bowel mucosal enhancement
Increased small bowel mucosal enhancement (HU > psoas) and mural thickening > 3mm are the most common signs. Colon involvement is infrequent and the small bowel is typically diffusely involved.
@# The CT of a 50-year-old man with abdominal pain shows a stellate enhancing mesenteric mass with a radiology pattern of linear densities emanating from the mass. Adjacent small bowel loops show tethering and thickening. Which is the most likely diagnosis?
A. Primary mesenteric mesothelioma
B. Desmoid tumour
C. Non-Hodgkin’s Lymphoma (NHL)
D. Metastatic carcinoid tumour
E. Abdominal TB
D. Metastatic carcinoid tumour
The stellate pattern is characteristic for carcinoid tumor.
A duodenal diverticulum is noted on CT as an incidental finding. Which is the single best answer?
A. Commonly symptomatic with high risk of inflammation
B. Reported in up to 5% of upper Gastrointestinal (GI) fluoroscopic studies
C. Mostly located on the lateral wall of the duodenum
D. Mostly arise from the third or fourth part of the duodenum
E. If perforated is easy to distinguish from a perforated duodenal ulcer
B. Reported in up to 5% of upper Gastrointestinal (GI) fluoroscopic studies
Common acquired outpouchings of the mucosa and submucosa located along the medial wall of the duodenum within 2cm of the ampulla of Vater.
25% arise from D3/4.
Reported in 1-5% of upper GI fluoroscopic studies.
Which of the following is a cause of smooth, regular and thickened folds in non-dilated small bowel?
A. Crohn’s
B. Zollinger-Ellison
C. Intraluminal haematoma
D. Tuberculosis
E. Carcinoid
C. Intraluminal haematoma
B-D are cases of irregular and thickened distal folds in non- dilated small bowel.
Which of the following is a case of decreased/absent duodenal folds:
A. Pancreatitis
B. Lymphoma
C. Melanoma metastases
D. Whipples disease
E. Scleroderma
E. Scleroderma
Scleroderma, strongyloides, and cystic fibrosis are causes of decreased/absent folds. Crohn’s and amyloidosis can cause decreased or increased folds.
- A 34-year-old woman with a history of steatorrhea and weight loss undergoes a small bowel follow-through examination that demonstrates dilatation of the proximal small bowel with flocculation and segmentation of the barium column. Fold thickness is normal. What is the most likely diagnosis?
A. Crohn’s disease
B. Zollinger–Ellison syndrome
C. coeliac disease
D. small bowel lymphoma
E. Whipple’s disease
C. coeliac disease
Coeliac disease is characterized by malabsorption due to intolerance to the alpha-gliadin component of gluten, which causes small intestinal villous atrophy.
Typical findings are of dilatation of the proximal small bowel, together with dilution of the barium column due to hypersecretion of fluid.
Artefacts such as segmentation (breaking up of the barium column) or flocculation (clumping of disintegrated barium) were traditionally classic features of coeliac disease, but are less often seen nowadays with improved barium suspensions.
In Whipple’s disease the small bowel is typically non-dilated, and shows moderate fold thickening.
Crohn’s disease usually causes nodular fold thickening, and predominantly involves the distal small bowel.
Zollinger–Ellison syndrome results in dilatation of proximal small bowel due to hypersecretion, but typically causes thickened folds.
Small bowel lymphoma is usually associated with fold thickening.
- A 25-year-old woman presents with cramping abdominal pain and bleeding per rectum. On examination she has mucocutaneous pigmentation of her mucous membranes and face. A small bowel follow-through examination demonstrates small-bowel intussusception. Which other finding is most likely to be demonstrated?
A. separation and displacement of small bowel loops
B. localized outpouching of the antimesenteric border of the distal ileum
C. generalized irregular fold thickening
D. multiple filling defects in the small bowel
E. generalized dilatation of the small bowel
D. multiple filling defects in the small bowel
Peutz–Jegher syndrome is characterized by multiple benign hamartomata’s intestinal polyps and mucocutaneous pigmentation. It is familial in 50% of cases, with an autosomal dominant inheritance, and sporadic in 50%. It is the most common polyposis syndrome to involve the small intestine, and frequently presents with intussusception.
Typical findings are of multiple hamartomatous polyps in the small bowel, and less commonly the colon and stomach. Patients are at increased risk of gastrointestinal malignancy, but also of tumours of the pancreas, breast, ovary, endometrium and testis.
A 46-year-old man presents with severe abdominal pain. An erect chest radiograph shows free intraperitoneal air below the diaphragm. What is the most likely cause?
A. perforated anterior wall duodenal ulcer
B. perforated posterior wall duodenal ulcer
C. perforated gastric ulcer
D. perforated appendix
E. diverticulitis with perforation
A. perforated anterior wall duodenal ulcer
The commonest cause of a free intraperitoneal perforation is an anterior wall duodenal ulcer.
However, free peritoneal air is only apparent on an erect chest radiograph in 60%of perforated duodenal ulcers. Possible causes include sealing of the perforation, adhesions preventing the gas reaching the subphrenic space or insufficient time being allowed for gas to collect under the diaphragm.
Anterior wall gastric ulcers also perforate into the peritoneal cavity but are a less common cause of pneumoperitoneum.
Posterior wall duodenal and gastric ulcers perforate into the lesser sac or retroperitoneal region rather than the peritoneal cavity.
Perforated appendix and diverticulitis may produce localized collections of extraluminal gas, but pneumoperitoneum is rare.
- A 20-year-old woman with anorexia nervosa presents with intermittent abdominal pain and vomiting relieved by lying prone. Barium meal examination reveals a vertical band-like narrowing of the third part of the duodenum, with proximal duodenal dilatation and vigorous to-and-fro peristalsis. What is the most likely diagnosis?
A. duodenal duplication cyst
B. annular pancreas
C. Ladd’s bands
D. superior mesenteric artery syndrome
E. duodenal atresia
D. superior mesenteric artery syndrome
The third part of the duodenum is bounded posteriorly by the aorta, and anteriorly by the root of the mesentery carrying the superior mesenteric artery.
In superior mesenteric artery syndrome, the third part of the duodenum is compressed by the superior mesenteric artery, and the angle between it and the aorta narrows to 10–22° (normal 45–65°).
The condition is associated with severe weight loss, prolonged bedrest (particularly in a body cast), lumbar lordosis and pregnancy.
Patients report intermittent abdominal pain and vomiting, relieved by lying prone or in the knee–elbow position.
Duodenal atresia causes complete obstruction usually distal to the ampulla of Vater, and presents in neonates with a ‘double-bubble’ sign on plain abdominal radiograph.
Annular pancreas is usually asymptomatic but may present with abdominal pain and vomiting, and barium meal demonstrates narrowing of the second part of the duodenum.
Duodenal duplication cysts cause extrinsic compression of the first and second portions of the duodenum.
Ladd’s bands are congenital peritoneal bands occurring in association with malrotation that may cause obstruction of the second part of the duodenum, but presentation is usually in infants and children.
- A 67-year-old man presents with abdominal pain, distension and vomiting. Multiple dilated loops of small bowel are seen on plain abdominal radiograph. A contrast-enhanced CT of the abdomen and pelvis is performed, which shows small bowel dilatation to the terminal ileum, where there is a nodular calcified mass with surrounding desmoplastic reaction. What is the most likely cause of small bowel obstruction?
A. adhesions
B. carcinoid tumour
C. Crohn’s disease
D. previous irradiation
E. small bowel lymphoma
B. carcinoid tumour
The commonest cause of small bowel obstruction in adults is adhesions, which are diagnosed on CT when there is an abrupt caliber transition without an associated mass, surrounding inflammatory changes or bowel wall thickening. Carcinoid tumours comprise 25% of all tumours of the small bowel. They are commonly asymptomatic but may present with pain or obstruction, or with carcinoid syndrome in 7% of patients. Most occur in the ileum, and typical appearances are of a calcified mass with surrounding desmoplastic reaction, retraction of the mesentery and thickening of surrounding loops of bowel. Small bowel obstruction complicates Crohn’s disease in approximately 15% of patients, due to thickening and submucosal oedema of the bowel wall. Previous irradiation may result in adhesions and fibrotic changes in the mesentery that can cause bowel obstruction. Lymphomatous involvement of the small bowel causes circumferential bowel wall thickening, but this rarely results in obstruction.
@# 5. A 60-year-old woman presents with weight loss and diarrhoea. CT of the abdomen demonstrates multiple, enlarged, low-attenuation mesenteric lymph nodes containing fat–fluid levels and splenic atrophy. What is the most likely diagnosis?
A. tuberculosis
B. coeliac disease
C. Whipple’s disease
D. lymphoma
E. metastatic squamous cell carcinoma
B. coeliac disease
Cavitating mesenteric lymph node syndrome is a rare complication of coeliac disease, in which multiple enlarged lymph nodes are seen in the jejunoileal mesentery.
The nodes have central low attenuation and may contain fat or fluid, or fat–fluid levels.
Splenic atrophy is usually seen,
and jejunal or duodenal biopsy confirms villous atrophy of the small bowel mucosa.
Low-attenuation lymphadenopathy may also be seen in tuberculosis, Whipple’s disease, lymphoma & necrotic mets,
but fat–fluid levels have been reported only in coeliac disease.
- A 68-year-old woman presents with abdominal pain, distension and vomiting. Plain abdominal radiograph demonstrates bowel obstruction, gas within the biliary tree, and an ectopic, calcified, 3 cm gallstone. What is the most likely site of bowel obstruction?
A. pylorus
B. duodenum
C. proximal ileum
D. terminal ileum
E. sigmoid
D. terminal ileum
Gallstone ileus accounts for up to 5% of intestinal obstruction, increasing in prevalence with age. It involves erosion of a large gallstone from the gallbladder or common bile duct into the bowel, which goes on to cause obstruction.
The classic appearance on plain film (Rigler’s triad) is only seen in 10% of cases, and consists of partial or complete intestinal obstruction (usually small bowel), gas in the biliary tree and an ectopic calcified gallstone.
The most common site of fistulous communication is between the gallbladder and the duodenum, seen in 60%, and this may be demonstrated on barium meal as a contrast collection lateral to the first part of the duodenum representing barium within the gallbladder.
Fistulas occur less commonly between the common bile duct and duodenum, gallbladder and colon.
The ectopic gallstone most often causes obstruction at the terminal ileum (60–70%), followed by the proximal ileum, distal ileum, pylorus, sigmoid and duodenum.
- What is the most common site of involvement in tuberculosis of the gastrointestinal tract?
A. stomach
B. duodenum
C. ileocaecal region
D. splenic flexure
E. rectum
C. ileocaecal region
Tuberculosis of the gastrointestinal tract may occur through ingestion of infected sputum, or by haematogenous spread to submucosal lymph nodes from a pulmonary tuberculous focus. It most commonly affects the ileocaecal region due to its abundance of lymphoid tissue and relative stasis of gut contents. Typical features at this site include circumferential thickening of the terminal ileum and caecum, a thickened ileocaecalvalve and ulceration following the orientation of lymphoid follicles (longitudinal in the terminal ileum and transverse in the colon). Marked enlargement of adjacent mesenteric lymph nodes with central areas of low attenuation may be seen.
@# Enteropathy-associated T-cell lymphoma is most commonly associated with which of the following conditions?
(a) Coeliac disease
(b) Crohn’s disease
(c) Lymphangiectasia
(d) Whipple’s disease
(e) Peutz-Jegher’ssyndrorme
(a) Coeliac disease
This is invariably seen in the underlying bowel in patients this condition, although it may not have been diagnosed prior to the lymphoma. The other conditions do not predispose to lymphomas.
With regard to radiation enteropathy, which of the following is not true?
(a) Acute changes occur in patients have received 1,000cGy or more
(b) Acute changes are due to damage to the blood supply
(c) Chronic changes may be seen in up to 15% Of patients
(d) Multiple stenoses are a feature of chronic disease
(e) Acute radiation enteropathy refers to changes within the first 2 months
(b) Acute changes are due to damage to the blood supply
Acute radiation enteropathy is due to death of the mucosal cells which are dividing rapidly. Chronic enteropathy is due to the effect on the vasculature, resulting in strictures, adhesions and fistulae.
A 45-year-old with a history of diarrhoea and weight loss undergoes endoscopy and has a duodenal biopsy. The biopsy is reported to show foamy macrophages. Granules the cytoplasm of these macrophages stain positively with periodic acid-Schiff (PAS) stain. What additional feature might you expect on a SI enema in this patient?
(a) Multiple polyps
(b) Ulceration of the mucosa
(c) Reduced mucosal folds with dilatation of the small bowel
(d) Pseudosacculation
(e) Thickening of the mucosal folds
(e) Thickening of the mucosal folds
These are the clinical, pathological and radiological features Of Whipple’s disease. This is an uncommon condition of the small bowel caused by a bacterial infection, thought to be Tropheryma whippelli. Antibiotic therapy needs to continue for at least a year and relapses may involve the CNS.
A 56-year-old patient presents with carcinoid syndrome and is found to have liver metastases. What is the most likely site of the primary lesion?
(a) Stomach
(b) Duodenum.
(c) Small Bowel
(d) Appendix.
(e) Rectum
(c) Small Bowel
Over 40% of carcinoid tumours arise within the small intestine, rectum (27%), appendix (24%) and stomach (8%) next most common. Duodenal carcinoids are rare. Small intestinal carcinoid tumours are often symptomatic.?
A 57-year-old man presents with diarrhoea and is noted to have elevated ACTH levels. A small bowel enema demonstrates no ulceration or strictures but there is sharp angulation of loops of distal ileun. What is the most likely diagnosis?
(a) Cushing’s disease
(b) Cushing’s syndrome
(c) Crohn’s disease
(d) Desmoid tumour Carcinoid
(e) Carcinoid
(e) Carcinoid
Carcinoid syndrome commonly presents with non-specific symptoms, with obstruction, bleeding pain or diarrhoea all seen. A polypoid nodule may be seen in the wall of the bowel but the desmoplastic reaction in the adjacent mesentery causes sharp angulation Of bowel loops.
In the assessment of small bowel disease, for which of the following criteria is MRI superior to other imaging modalities?
(a) Shorter imaging time
(b) Better depiction of early disease
(c) Superior spatial resolution
(d) Better mucosal detail
(e) Superior tissue contrast
(e) Superior tissue contrast
Small bowel enema has the best resolution and better depicts early disease. CT is the fastest study to perform. MRI has superior tissue contrast.
You are asked to supervise a CT enterography study for inflammatory bowel disease which has been protocolled for a single ‘enteric phase’. Approximately how long after the commencement of the i.v. injection of contrast medium should the study be acquired?
(a) 20 secs
(b) 45 secs
(c) 70 secs
(d) l00 secs
(e) 180 secs
(b) 45 secs
This optimises mural enhancement. By contrast, in the evaluation of small bowel neoplasia or obscure GI bleeding, an unenhanced, arterial and portal venous study are usually used. Neutral oral contrast agents are usually favoured, although positive agents may have a role when intravenous contrast medium is contraindicated.
A 53-year-old lady undergoes a small bowel enema study. This shows delayed transit with a marked increase in the number of mucosal folds. What is the most likely diagnosis?
(a) Systemic sclerosis
(b) Whipple’s disease
(c) Intestinal lymphangiectasis
(d) Eosinophilic gastroenteritis
(e) Mastocytes
(a) Systemic sclerosis
The ‘wire-sprung’ or ‘hidebound’ appearances are characteristic. Dilatation of the duodenum and jejunum, decreased peristalsis and sacculations (pseudodiverticulae) are also features. The remaining conditions cause a non-specific thickening of the mucosal folds.
Which of the following primary tumours is least likely to metastasize to the small bowel?
(a) Bronchus
(b) Thyroid
(c) Melanoma
(d) Renal cell carcinoma
(e) Breast
(b) Thyroid
The remaining are the commonest tumours to have blood-borne metastases to the small bowel. Direct invasion may be seen from the prostate, uterus, ovary, colon or kidney; lymphatic spread is less common but may be seen from caecum to terminal ileum.
A 32-year-old man weight loss is referred for a barium follow through. This is reported to show mild jejunal dilatation. There is a reduction in the number of jejunal folds, an increase in the ileal folds, but only very slight fold thickening. What is the most likely diagnosis?
(a) Whipple’s disease
(b) Coeliac disease
(c) Eosinophilic enteritis
(d) Scleroderma
(e) lymphangiectasia
(b) Coeliac disease
This appearance, as jejunisation of the ileum, is typical of coeliac disease. There is an associated increase in the frequency of both epithelial tumours and NHL in patients with coeliac disease.
Amyloid deposition in the smooth muscle of the small bowel would most likely present with which of the following?
(a) Pseud-obstruction
(b) Volvulus
(c) Bleeding
(d) Pain
(e) Watery diarrhoea
(a) Pseud-obstruction
Pain, bleeding or diarrhoea might be seen with deposition in the bowel wall. Volvulus is not a feature of amyloidosis. Both primary and secondary amyloidosis may affect the bowel, as well as other organs.
What is the most common cause for small bowel intussusception in adults?
(a) Meckel’s diverticulum
(b) Lymphoma
(c) Crohn’s disease
(d) Gastrointestinal stromal tumour
(e) Polypoid tumour
(e) Polypoid tumour
Polypoid tumours are the most common cause for small bowel intussusceptions in adults and these may have one of a number of histopathological diagnoses. Crohn’s disease does not cause an intussusception but the other conditions can on occasion.
A 67-year-old man presents with abdominal pain, weight loss, fever and diarrhoea. The small bowel demonstrates discrete ulcers, both circumferential and longitudinal, with mucosal fold thickening. Which of the following conditions is most likely?
(a) Actinomycosis
(b) Tuberculosis
(c) Giardiasis
(d) Yersiniosis
(e) Strongyloidiasis
(b) Tuberculosis
Lesions are often multiple, and stricture formation is also commonly seen. When the terminal ileum is involved, a rigid and gaping ileocaecal valve may be seen. Cross-sectional imaging may low attenuation lymph nodes (due to caseous liquefaction), ascites and peritoneal nodules.
A 27 year old male has recurrent admissions for intermittent low-grade small bowel obstruction of unknown cause. Which one of the following investigations would be most appropriate?
a. Contrast-enhanced CT abdomen and pelvis
b. Barium meal
c. Small bowel enteroclysis
d. Serial abdominal plain films
e. Barium follow-through
c. Small bowel enteroclysis
Small bowel enteroclysis is the most appropriate examination. CT is sensitive for high-grade obstruction as it will readily identify the level of obstruction and can demonstrate complications such as ischaemia and perforation. Enteroclysis is the preferred investigation for recurrent low-grade obstruction as it is more likely to demonstrate the presence of a transition point (for example from non-obstructing adhesions) because the bowel is distended. The examination involves passing a nasojejunal tube just distal to the duodenojejunal flexure and distending the small bowel using either dilute barium or a double-contrast examination with high-density barium and methylcellulose.
A 31 year old male is investigated as an outpatient for diarrhoea. A small bowel meal study reveals jejunal dilatation with thickened valvulae conniventes. In the ileum an increased number of mucosal folds are seen. Which of the following diagnoses is most likely?
a. Lymphoma
b. Crohn’s disease
c. Coeliac disease
d. Whipple disease
e. Behcet syndrome
c. Coeliac disease
Jejunal dilatation and jejunisation of the ileal loops are characteristic features of coeliac disease. This is an immunological intolerance to gluten that causes villous atrophy in the small intestine. In Whipple disease there is thickening of the jejunal and duodenal mucosal folds but typically no luminal dilatation. Dilatation of the small bowel does occur with lymphoma but jejunisation of the ileum is not a feature.
A 34 year old female is investigated for intermittent abdominal pain and malabsorption. Small bowel meal shows dilatation of the proximal small bowel loops but a normal mucosal fold pattern. Which one of the following is the most likely underlying diagnosis?
a. Coeliac disease
b. Amyloid
c. Whipple disease
d. Giardiasis
e. Eosinophilic gastroenteritis
a. Coeliac disease
All of these may cause malabsorption. Amyloid can cause dilatation but also causes diffuse thickening of the valvulae conniventes throughout the small bowel. With Whipple disease and eosinophilic gastroenteritis, one would not see dilatation of the bowel, but thickening of the mucosa is again a prominent feature. Giardiasis causes thickening and marked distortion of the mucosal folds in the duodenum and jejunum. One of the hallmark features of untreated coeliac disease is jejunal dilatation. Typically the mucosal folds are of normal thickness
A 38 year old patient with AIDS presents with diarrhoea and steatorrhoea. As part of the work-up, small bowel enteroclysis shows thickened jejunal folds with nodularity and evidence of marked jejunal spasm. The ileum has normal appearances. Which one of the following is the most likely underlying cause?
a. Cytomegalovirus
b. Tuberculosis
c. Mycobacterium avium intracellulare
d. Cryptosporidium
e. Giardiasis
e. Giardiasis
All the stems are potential causes for these symptoms in a patient with AIDS, however giardiasis is the most likely cause given these imaging appearances. Cytomegalovirus most typically affects the caecum, and tuberculosis affects the caecum and ileocaecal valve. Mycobacterium avium intracellularecan affect the ileum and jejunum but does not usually cause spasm. Cryptosporidium affects the duodenum and the jejunum can be affected, but dilatation is more common than spasm.
A 45 year old female has a CT for abdominal pain and weight loss. Findings include a soft-tissue mass at the root of the small bowel mesentery with eccentric calcifications and tethering of adjacent small bowel loops resulting in a moderate degree of small bowel obstruction. There is a desmoplastic reaction within the surrounding mesentery. Which one of the following is the most likely diagnosis?
a. Lymphoma
b. Carcinoid tumour
c. Melanoma metastases
d. Tuberculosis
e. Paraganglioma
b. Carcinoid tumour
These features are typical of carcinoid tumour. The desmoplastic reaction appears on CT as thickened mesentery in a radiating pattern away from the soft-tissue mass, with beading of the mesenteric vascular bundles.