Presentation on theme: "Imaging Diagnosis Of Parasitic Helminthes 4 Gastrointestinal and Abdominal Diseases By Sh.Ghaffary January 2008."— Presentation transcript:
Imaging Diagnosis Of Parasitic Helminthes 4 Gastrointestinal and Abdominal Diseases By Sh.Ghaffary January 2008
Gastrointestinal and Abdominal Diseases Predominantly Small Bowel Ascariasis Intestinal Strongyloidiasis Ancylostomiasis (Hookworm Disease) Intestinal Capillariasis Trichinosis (Trichinellosis)
Ascariasis Intestinal Ascariasis Individual worms are seen as longitudinal tubular structures. If the alimentary tract of the worm is empty, the worm may appear as a filling defect. If its alimentary tract is distended, the worm appears as parallel bands (arrow). On transverse sections, the worm appears as a target sign (arrowhead) with body wall and a central dot representing its gut.
Intestinal Ascariasis Clinical presentation: An african male with lower abdominal discomfort. The bowel mucosal pattern and lumen calibre is normal throughout. There is a linear gap in the barium column which lies along the lumen of the ileum and has a line of barium at its centre Ascariasis
Ultrasound has been advocated as a highly sensitive and specific, quick, safe, noninvasive, and relatively inexpensive modality for suspected biliary ascariasis. Various appearances of roundworms in the biliary tract and gallbladder have been described. It can be used in symptomatic patients and can be repeated frequently to monitor movement of worms in the ducts or exit from the ducts.
Ascariasis biliary ascariasis The reported sonographic appearances of roundworm are: "Stripe" sign: A single, long linear or curved echogenic nonshadowing structure without an inner tube, located within the CBD or gallbladder "Spaghetti" sign: Multiple, long linear overlapping echogenic structures due to coiling of a single worm or several worms in the CBD
Ascariasis biliary ascariasis Other sonographic appearances that have been described in patients with biliary ascariasis include dilatation of the bile duct, gallbladder distension with edematous wall, and presence of echogenic sludge within the gallbladder
Ascariasis a case of biliary ascariasis A sonographic examination of the abdomen was performed first. On placing the probe over the right hypochondriac region, a tubular, tram-like echogenic structure with wriggling motions was noticed in the common bile duct (CBD)
During the ultrasound examination, the patient suddenly became restless as she experienced a severe agonizing colicky pain in the right hypochondrium. She also had tachycardia, palpitations and perspiration. At this time, the tubular echogenic structure in the CBD was moving with active wriggling motion from the CBD through the cystic duct and reached the gall bladder lumen. A similar tubular structure was noted in the duodenum which was confirmed by a high frequency superficial probe
Ascariasis Acute pancreatitis due to round worm in main pancreatic Duct A twenty six year old female patient presented with abdominal pain (in epigastgric region radiating to back) and vomiting (vomitus contained two round worms). USG abdomen was performed which showed two echogenic parallel lines in main pancreatic duct. Small bowel loops duodenum and stomach showed multiple moving linear structures within them, which on transverse scan appeared as target lesions. USG abdomen showing dilated pancreatic duct with echogenic lesion within it
Strongyloidiasis Radiology plays an important role in the diagnosis and management of patients with intestinal and pulmonary strongyloidiasis. Some patients will be referred with the clinical diagnosis of pneumonia, peptic ulceration, sprue, giardiasis, hookworm disease, amebiasis, and other gastrointestinal diseases. Recognition of the various clinical and radiological disease patterns seen in strongyloidiasis may suggest the correct diagnosis. The radiological changes correlate well with the pathological process and, therefore, provide an index for grading the disease and for planning therapy.
Intestinal Strongyloidiasis During the early stages of the disease, or in less severe infections, the radiological findings will be somewhat nonspecific, An upper gastrointestinal and small bowel series may show prominent mucosal folds in the gastric antrum and an irritable, spastic, tender duodenal bulb and C-loop with prominent, thickened, spiked transverse mucosal folds. There may be flocculation of barium in the duodenum and proximal jejunum from excess fluid and mucous secretions and rapid peristalsis and irritability. The radiographic appearance of the duodenum and jejunum is typical of inflammation and irritability, such as may be seen also with giardiasis. spasm and inflammatory changes are unusual beyond the jejunum.
Intestinal Strongyloidiasis Upper GI series :Strongyloidiasis in the early stages of the disease, when the clinical presentation may mimic duodenitis and peptic ulceration.
Intestinal Strongyloidiasis Many patients, especially those who present with clinical symptoms of diarrhea and malabsorption suggesting sprue, will also show radiological findings similar to those seen in nontropical or, especially, tropical sprue. In these patients with second-stage disease, the radiographic pattern usually suggests an inflammatory process in the duodenum and proximal jejunum, as well as a malabsorption pattern in the jejunum and ileum There is an increase in diameter of the lumen of the small intestine, and there is considerable hypomotility as evidenced by delayed gastric emptying and transit time throughout the small bowel
Intestinal Strongyloidiasis Strongyloidiasis of the small bowel, with malabsorption, in a patient from India.Small bowel series demonstrates dilated proximal jejunal loops with thickening of the transverse mucosal folds. Peristalsis was slow throughout the small bowel and the radiological appearance resembles that of sprue.
Intestinal Strongyloidiasis Still another radiographic pattern is seen in the third stage of strongyloidiasis in severe, often fatal infections and reflects more chronic and usually irreversible disease. Plain films of the abdomen, as well as small bowel series, may reveal multiple dilated small bowel loops, suggesting a paralytic ileus or even partial small bowel obstruction in some patients
Intestinal Strongyloidiasis there is toxic dilatation of the small bowel caused by an overwhelming infection which did not respond to treatment, leading to the patient's death a few days later. In such patients, the changes are irreversible at this stage, with diminished or absent peristalsis resulting in hypomotility and delay in transit of barium, in part due to edema and/or fibrosis of the bowel wall and involvement of the myenteric plexi
Intestinal Strongyloidiasis In other patients with advanced strongyloidiasis, there will be rigidity of multiple segments of proximal small bowel as a result of edema and fibrosis of the intestinal wall and involvement of the myenteric plexi produced by a severe inflammatory and fibrotic response to Strongyloides larvae (and often superimposed infection with other organisms). Fluoroscopically, there is strikingly decreased or absent peristalsis in the duodenum and proximal jejunum. The stomach may be somewhat small, with mucosal atrophy in about one- third of the patients
Intestinal Strongyloidiasis Chronic strongyloidiasis involving the stomach. Advanced narrowing and rigidity of the antrum and, to a lesser extent, the body of the stomach in another patient with strongyloidiasis. There is moderate spasm and mucosal edema with spiking of the valvulae conniventes of the small bowel.
Intestinal Strongyloidiasis case report: 37 year old Iranian man with anaemia and eosinophilia. There is mucosal thickening in duodenum and proximal jejunum. The thickening is greater proximally and decreases towards the ileum. The nodular swelling of the mucosa is particularly marked in the duodenum
Hookworm Disease Most patients with hookworm infection show no radiographic abnormality on barium examination of the upper gastrointestinal tract. early investigators found small bowel abnormalities in 60% of examined hookworm patients, with the changes generally being proportional to the severity of the patient's disease. Mucosal folds of the jejunum were described as irregular and two to three times normal thickness. The ileum was usually normal except that, in patients with marked jejunal changes, the ileal folds also appeared unusually prominent and wide. There was increased tone in several loops and the intestinal lumen was narrowed in the more advanced infections. Peristalsis was observed to be vigorous and rapid and the small intestine appeared constantly in motion and unable to relax.
Hookworm Disease ( A) Throughout the small bowel series, there was slight dilatation of the mid-jejunal loops with coarsening of the folds. Also note flocculation and segmentation of barium in several ileal loops in the right abdomen, suggesting a mild "deficiency" or "malabsorption" pattern occasionally seen in patients with severe hookworm disease. (B) Spot film showing slight dilatation of the mid-jejunal loops and edema and thickening of the valvulae conniventes. Hookworm Disease
A broad spectrum of parasitic infections (eg, amebiasis, malaria, trypanosomiasis, ascariasis, strongyloidiasis, dirofilariasis, cystic echinococcosis, schistosomiasis, paragonimiasis) frequently affect the lungs, mediastinum, and thoracic wall, manifesting with abnormal imaging findings that often make diagnosis challenging. Although most of these infections result in nonspecific abnormalities, familiarity with their imaging features as well as their epidemiologic, clinical, and physiopathologic characteristics may be helpful to the radiologist in formulating an adequate differential diagnosis.
Intestinal Capillariasis The radiological findings in intestinal capillariasis have been well documented by Paulino and Wittenberg, based on their analysis of small bowel series performed on 14 patients at the Philippine General Hospital in Luzon in 1968-1969. Most of their patients were teenaged boys who represent the group at highest risk because they swim and fish in infected waters. The following classical signs of a malabsorption pattern were identified in varying degrees in their patients:
Intestinal Capillariasis 1. Dilatation :Dilatation was present in slightly over half of the patients, usually involved only a short segment of bowel, and was rarely pronounced. As with other malabsorption syndromes, there was a changing pattern of dilatation of the loops during the examination. 2. Segmentation:In approximately one-third of the patients, delayed segmentation of the barium column was noted, most commonly in the ileum. 3. Fragmentation :Scattering or fragmentation of the barium column into numerous small clumps or globules was the most common radiographic abnormality. It was seen to at least some degree in all 14 patients.
Intestinal Capillariasis 4. Hypersecretion:Increased fluid in the small bowel, as manifested by the presence of diluted or flocculated barium (amorphous large clumps within a barium-filled loop), was noted in the majority of patients, but was usually of minimal degree and seen in only one or two loops. 5. Abnormal Fold Pattern: There was thickening of the valvulae conniventes of mild to moderate degree (folds wider than 1.5 mm) in all patients. Usually this pattern presented as a uniform thickening of the folds with normal contour, and was most extensive in the distal jejunum and proximal ileum. This finding may be related to the hypoalbuminemia universally present in these patients.
Two films from a small bowel series taken at 30-minute intervals on a Filipino infected with Capillaria philippinensis. marked thickening of the valvulae conniventes in the proximal and mid-jejunum (A) and the slight seperation of the loops and slight thickness of the bowel wall seen best in B. The malabsorptive changes include areas of slight dilatation over a short segment with a changing pattern seen between the two films, as well as moderate segmentation and fragmentation of the barium in the distal jejunum and ileum. There is evidence of slight hypersecretion
Trichinosis The tiny size of the calcified Trichinella larvae (less than 1 mm) in the striated musculature of infected patients is beneath the resolution of conventional radiography and thus the larvae remain invisible on plain film examinations. cerebral CT scans, after onset of neurological signs (mean 6 days), showed two principal abnormal findings felt most likely to be the result of small infarcts from ischemia: small hypodense areas in the white matter and small cortical hypodensities.
Neurotrichinosis: cerebral CT scan findings (A) Multiple small hypodense areas in the hemispheric white matter, probably representing tiny infarcts from ischemia. (B) Enhancement of similar small hypodense areas after infusion of contrast medium.
Gastrointestinal and Abdominal Diseases Predominantly Colon Diseases Trichuriasis
Trichuriasis Radiology should really play no significant role in the diagnosis, but the worms may well be found as part of an investigation of rectal bleeding or other colonic disease. A routine barium enema may be unremarkable or may show a granular mucosal pattern throughout the colon. An air contrast barium enema is the definitive imaging study and will demonstrate the wavy radiolucent outlines of numerous small trichurids against the air- barium background of the colon and rectum. The characteristic uncurled curvilinear pattern or S- shaped configuration of the female worm and the tightly coiled "pinwheel" or "target" pattern of the male worm will be recognized.
(A) Air contrast barium enema reveals the outline of innumerable small trichurids on the erect view. (B) Magnification of the rectosigmoid colon shows the tightly coiled outlines of multiple male parasites and the semilunar or whiplike configuration of numerous female trichurids contrasted against the air-barium background.
Postevacuation film from a routine barium enema examination shows flocculation of barium and poor mucosal coating, probably due to excessive mucous secretions surrounding the numerous whipworms.
Massive Trichuris infestation in a Brazilian child. Air contrast examination of the colon, including the spot film of the rectosigmoid colon shown here, identifies the typical wavy outlines of innumerable trichurids; some are tightly coiled in a "target" pattern typical of male parasites, whereas others are unfurled in the curvilinear configuration of female trichurids.
Liver flukes Ultrasound is particularly useful in the detection of bile duct dilatation and fibrous thickening of the duct walls with increased wall echogenicity CT demonstrates intra- and extrahepatic ductal dilatation, abscesses, atrophy and hyperattenuated stones or sludge. In a heavy infection, the common bile duct may be dilated. MRI shows findings that parallel CT, though it may be useful in detecting subtle cases of cholangiocellular carcinoma
Opisthorchiasis and cholangiocarcinoma the parasites have caused a severe cholangitis with marked distortion and dilatation of the visualized bile ducts, especially in the left lobe of the liver Opisthorchiasis
ERCP: dilatation of the intrahepatic bile ducts. These are numerous oval, elliptical or crescentic filling defects representing adult C. sinensis flukes in small and medium-sized bile ducts Clonorchiasis
A )dilatation of the intra- and extrahepatic bile ducts and irregular thickening of their walls. Shown here is the scan of the dilated common bile duct with wall thickening (open arrows). B) The ultrasound scan of the gallbladder shows sludge and vermiform nonshadowing images of Fasciola hepatica flukes (arrows), which showed active motility. Biliary fascioliasis
The cholangiogram shows multiple linear, crescent-shaped lucencies in the distal common duct, which represent F. hepatica flukes. Biliary fascioliasis
CT scan in a patient with fascioliasis shows multiple hypodense nodular lesions in the right lobe of the liver and tiny dot-like filling defects (small black arrows) within several dilated bile ducts which may represent flukes in the ducts. Fascioliasis
Hepatic Capillariasis Capillaria hepatica, a common parasite in rats, is very rarely found in humans. The majority of the 25 or more reported human infections have been in children. The parasite can cause an acute or subacute hepatitis with marked eosinophilia and persistent fever. Hepatomegaly (which is non-specific on radiography or sonography) may develop, with eggs in the liver parenchyma inducing necrosis and abscess formation.