Radiological imaging of the Small Bowel diseases.

Dr/ Abd Allah Nazeer. MD.

Small Intestine.Small Intestine, one of the most important organs for the immune defense.Largest endocrine organs of the body.Start from the pylorus and ends at the cecum.

3 Parts: 1. Duodenum(20 cm), retroperitoneal and supplied by the celiac artery and SMA.2. Jejunum(100 to 110 cm). Occupies upper left of the abdomen , thicker wall and wider then the ileum, Mesentery has less fat and forms only 1-2 arcades. 3. Ileum(150 to 160 cm). Occupies the lower right: Has more fat and forms more arcuates. Contain Payer,s patches. Ileum and jejunum and supplied by the SMA.

Congenital Anomalies of the Small Intestine.

Congenital abnormalities involving the small bowels are detected in neonates only when they are the direct cause of obstruction. Such abnormalities must be rectified surgically if the patient is to survive. Clinical signs and symptoms including abdominal distention, vomiting, and obstipation prompt the clinician to consult the radiologist, who must determine the presence, location, and cause of an obstruction.In a healthy neonate, air can usually be identified in the stomach within minutes of birth, and within 3 hours the entire small bowel usually contains gas. After 8–9 hours, healthy neonates demonstrate sigmoid gas. The diagnosis of obstruction is based on some interruption in this dispersion of air. Delayed passage of gas through the neonatal gut may occur as a result of traumatic delivery, septicemia, hypoglycemia, or brain damage. Absence of gas in the bowel may be noted in neonates with severe respiratory distress who are undergoing mechanical ventilation and in cases of continuous nasogastric suction .Radiography is the most valuable means of determining whether obstruction is present. This modality is often diagnostic; even if it is not, however, it may help determine the next most useful diagnostic procedure

Congenital anomalies causing incomplete obstruction ( e. g, stenosis, webs, duplications, malrotations, peritoneal bands, aganglionosis) may not manifest until later in life, and other types of examinations (e. g, barium enema studies, ultrasonography [US], computed tomography [CT], magnetic resonance [MR] imaging) are generally needed for diagnosis.In this article, we discuss the importance of pediatric radiation protection and various means of ensuring adequate protection. We also discuss and illustrate a variety of congenital anomalies affecting the small bowel. evaluate the efficacy of various imaging modalities in the diagnosis and management of these conditions; and discuss the embryologic and pathologic basis of radiologic findings in appropriate cases as well as differential diagnoses and diagnostic pitfalls.

Jejunal atresia. (a) Supine radiograph in a neonate with associated esophageal atresia shows three dilated loops of bowel. st = stomach.

Ileal atresia. (a) Upright radiograph shows multiple air-fluid levels occupying the entire abdominal cavity. (b) Image from a barium

enema study shows numerous dilated, air-filled loops of bowel and a small, unused colon (functional microcolon).

Non-rotation. Images from a contrast material-enhanced gastrointestinal examination show the small intestine on the right side of the abdomen and the colon and cecum on the left side. The ileum is seen crossing the midline from right to left (arrows in b).

Midgut volvulus. Image from a contrast-enhanced upper gastrointestinal series clearly demonstrates the “corkscrew” appearance of the proximal small bowel (arrows) as it twists around the superior mesenteric artery

Malrotation. Abdominal CT scan shows the superior mesenteric vein (+) lying anterior to the superior mesenteric artery. The superior mesenteric vein normally lies on the right side of the superior mesenteric artery; in

malrotation, it lies either in front or on the left side

Ileal duplication. (a) Image from a barium enema study shows extrinsic compression of the cecum by an extraluminal mass. (b) US image shows a cystic

mass (C) that corresponds to a surgically proved duplication cyst. k = kidney.

Tumors of the Small Bowel.Tumors of the small bowel are rare. They are usually single, but may be multiple particularly in certain syndromes (i.e. intestinal polyposis syndrome). Tumors can be benign or malignant. Some benign tumors can progress and become malignant (i.e. adenomas, leiomyomas). Most small intestine tumors are clinically silent for long periods; nearly half of all benign small intestine tumors are found only incidentally either during an operation or an investigation to visualize the intestine for other reasons. Symptoms can be chronic and/or intermittent and include abdominal pain, nausea, weight loss and bleeding. The larger the tumor, the more likely the patient will experience symptoms of bowel obstruction. Tumors can also become ulcerated and bleed.

Benign Tumors :Leiomyoma – Leiomyomas are tumors of one of the muscle layers of the bowel wall. Some can grow into the lumen of the bowel and become ulcerated and cause bleeding or anemia, which is the most common symptom and finding. They can be very difficult to diagnose, especially when they occur in the small intestine. Endoscopic ultrasound is a useful way to determine the site of the tumor within the bowel wall. Some leiomyomas do have malignant potential. Biopsy sampling and surgical resection are usually advised. Adenomas – Adenomas are benign tumors that do have malignant potential. They cause symptoms due to blockage. When they arise in the region of the papilla or the area of the duodenum where the bile duct and pancreas drain they can cause jaundice. Because of the risk of malignant degeneration, adenomas are usually removed (by surgery or endoscopy). Lipomas – Lipomas are collections of fatty tissue within the wall of the intestine. They are characterized by a soft yellowish appearance when viewed endoscopically. These are completely benign tumors with no malignant potential. Lipomas do not need to be removed unless they become very large and cause obstructive symptoms (or bleeding due to ulceration).

Hemangiomas – Hemangiomas are collections of blood vessels that form a benign vascular tumor in the wall of the stomach or intestine. They are benign and sometimes found in conjunction with other syndromes (i.e. Turners syndrome, Tuberous sclerosis, blue-rubber-bleb syndrome and Osler-Weber-Rendu syndrome). Hemangiomas can cause gastrointestinal bleeding and anemia. They are detected by endoscopy. They can be treated endoscopically with application of a heater probe to burn the vessels. Patients may need resection of areas of intestine heavily involved with hemangiomas if they cause significant bleeding. Various medicinal therapies (i.e. estrogens) have been tried to reduce the amount of bleeding from hemangiomas. Reports of success have been variable. Neurogenic Tumors – Neurogenic tumors are benign growths arising from neural (nerve) tissue. The most common variety is neurofibroma. They are usually solitary. When multiple and found diffusely in the intestine they are more likely to be associated with neurofibromatosis. The diagnosis can be confirmed by their microscopic appearance after biopsy sampling.

Malignant Tumors : Adenocarcinoma of the small intestine probably develops mainly from adenomas. Most tumors occur at the ampulla in the duodenum. Other risk factors for adenocarcinoma include Crohn's disease, celiac sprue, different types of previous surgery (i.e. surgery joining the urinary system with the intestines), and neurofibromatosis. Patients can present with obstruction or bleeding. The tumor may be diagnosed by radiologic techniques (barium studies), endoscopy or surgery, and confirmed by biopsy sampling.

Intestinal Lymphoma – Intestinal lymphoma of the small intestine is a recognized complication of celiac sprue, and can occur in immunodeficiency syndromes. Symptoms include crampy-like abdominal pain, weight loss, features of malabsorption, bleeding, or even bowel obstruction. Leiomyosarcoma – This is a malignant tumor arising from the muscle wall of the intestine and can also arise from a benign leiomyoma. Treatment should involve complete surgical resection, wherever possible. Chemotherapy and radiation are also used. Metastatic Malignancy from Other Organs – (i.e. lung, breast or melanoma).

CARCINOID TUMOR.

Carcinoid of the small bowel arise from enterochromaffin or Kulchitsky cells found in the base of crypts of lieberkuhn. These cells are also known as argentaffin cells because of their staining by silver compounds. While secrete hormone serotonin and substance P. Carcinoid tumor occurs throughout the GIT, but particularly in the appendix, terminal ileum and rectum. The lesion is hard, white nodules arise from deep aspect of the mucosa and small in size. They metastases to regional LN and liver.

Coronal and axial CT showing low density clearly delineated mass in duodenum/jejunum. Low intensity of the mass on MR T1 fat sat. Macroscopic image of lipoma.

Intraluminal lipoma.

Small bowel lipoma (black arrow).

Schwannoma of the stomach.

Leiomyoma of stomach.

Extra-luminal jejunal leiomyomas.

Small bowel leiomyoma.

Benign hamartomatous polyps.

Giant Brunner’s Gland Adenoma of the Duodenal Bulb.

Barium study showing a well-defined lobular large adenoma.

Jejunal adenoma.

Axial CT shows large clearly delineated mesenterial mass compressing the IVC, PA proven desmoid tumor

Small hemangioma.

Coronal T1 fat sat and coronal T2 shows enhancing clearly delineated luminal mass in the right upper quadrant, PA proven small bowel hemangioma.

Axial T2 images. Multifocal small bowel intussusceptions in patient with Peutz Jeghers syndrome.

Homogenously enhancing polypoid lesions (arrows) in Peutz Jeghers syndrome

Axial T2 image. Unilocular benign mass with shouldering margins in the duodenum.

Adenocarcinoma of the small bowel.

Adenocarcinoma arising from the jejunal loops with para-aortic lymph nodes (arrowheads).

Adenocarcinoma of the ileum Adenocarcinoma of the Jejunum.

Axial CT. Thick walled jejunal mass with dilated lumen, PA: adenocarcinoma

Adenocarcinoma causing typical apple coreapple core lesion.

Duodenal and jejunal GIST

(Two cases of GIST).

Small Bowel Lymphoma

Small Bowel Lymphoma.

Burkett's lymphoma.

Leiomyosarcoma of small bowel.

Leiomyosarcoma of small bowel.

Carcinoid tumour of the small bowel.

Carcinoid tumour of the small bowel and liver.

Axial CT. Speculated calcified mesenterial mass and dilated small bowel loops, consistent with small bowel carcinoid.

Satellite mesenteric mass although the

primary carcinoid tumor.

Axial nonenhanced CT images and fused FDG-PET images. Two sites of wall thickening in the small bowel with marked FDG uptake, in a patient

with metastasized melanoma

Axial and coronal CT of intussuscepting luminal mass of small bowel on right side in patient with melanoma

Metastasis from carcinoma breast.

Thank You.