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Imaging Diagnosis Of Parasitic Helminthes 2 Major Multi-System Diseases

Imaging Diagnosis Of Parasitic Helminthes 2 Major Multi-System Diseases. By Sh.Ghaffary January 2008. Major Multi-System Diseases Schistosomiasis Hydatid Disease Taeniasis , Cysticercosis Sparganosis. Schistosomiasis. Acute Schistosomiasis ( The Katayama Syndrome)

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Imaging Diagnosis Of Parasitic Helminthes 2 Major Multi-System Diseases

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  1. Imaging Diagnosis Of Parasitic Helminthes 2Major Multi-System Diseases By Sh.Ghaffary January 2008

  2. Major Multi-System DiseasesSchistosomiasis Hydatid Disease Taeniasis, Cysticercosis Sparganosis

  3. Schistosomiasis • Acute Schistosomiasis ( The Katayama Syndrome) • The chest radiograph is either normal or shows increased vascular and interstitial markings and minimal enlargement of the hilar lymph nodes. • Miliary tuberculosis in its early stages or a simple virus infection may be suspected. The changes are not specific (history and eosinophilia). • The chest radiograph returns to normal with or without treatment

  4. Katayama stage of an acute S. haematobium infection. This young adult had not previously been exposed to schistosomiasis when he bathed in a Central African lake 4 weeks before this radiograph. The chest radiograph shows an increase in vascular markings with a faint nodular pattern throughtout both lungs; the hila are prominent. There were no focal lesions and the findings were transient.

  5. Schistosomiasis Acute Schistosomiasis ( The Katayama Syndrome): • In the abdomen there are three sonographic (and CT) findings which contribute to the diagnosis of the Katayama stage of acute schistosomiasis. • nonspecific hepatosplenomegaly. The left lobe of the liver may be more enlarged than the right. liver is sonographically homogeneous or, in a few cases, hyperechoic. • At the same time there may be periportal and juxtapancreatic lymphadenopathy, particularly in children. The lymph nodes are sharply outlined and round or oval, with a thin surrounding hypoechoic halo.

  6. Schistosomiasis Acute Schistosomiasis ( The Katayama Syndrome): • Ultrasonography may also show multiple small nodules throughout the liver parenchyma. These nodules may persist in spite of adequate therapy: they may be 4-5 mm in diameter and are well shown on CT scanning, being hypodense with delayed contrast enhancement. (In subacute schistosomiasis, echogenic lesions in the liver are thought to be due to portal vein branches (in cross-section). It probably takes from 3 to 5 years to develop stage one periportal (Symmers) fibrosis when patients have a high-intensity infection. With low infection rates, it may take much longer. There is no evidence of portal hypertension during the Katayama stage. )

  7. Schistosomiasis Acute Schistosomiasis ( The Katayama Syndrome): • The acute phase of S. japonicuminfection results in CNS involvement in about 2% of patients. • CT scans of the brain may show edema around low-density inflammatory foci, which are often multiple and contrast-enhancing with edema. • In some cases there may be a mass effect , causing shift with pressure on any part of the ventricular system. (This pattern of CNS involvement must be distinguished from the mass effect which is found in chronic cerebral schistosomiasis affecting patients who have been previously and often repeatedly infected.)

  8. Chronic Schistosomiasis • Imaging changes other than in the acute state are different with each type of infection and will be discussed separately. • The clinical and laboratory investigations for each patient depends on the symptoms.

  9. Chronic Schistosomiasis • All three major species of schistosome may affect the kidneys. • Infection with S. mansoni, S. japonicum, and S. intercalatumparticularly may affect the liver, causing cirrhosis, portal hypertension, and splenomegaly. Espohagealvarices develop, with resulting hemorrhage, and pulmonary hypertension may be an added complication. • In S. haematobium infection, as well as urinary tract involvement, there may be granulomatous disease of the colon; the latter often occurs in conjunction with mucosal polyps and causes diarrhea. • In S. japonicuminfection, the disease may affect the small bowel as well as the colon, liver, and lungs; cerebral infections may cause epilepsy.

  10. Chronic Schistosomiasis Schistosomiasis Haematobium: • When there is hematuria caused by S. haematobium, ultrasound and subsequently intravenous urography may be indicated. Cystoscopy may show multiple papillomas within the bladder. • There is individual variation between populations, even villages, seemingly infected with the same schistosome to the same extent. • Anyone working in a particular country or locality must determine the effect of schistosomiasis in their own patients, but it is possible to give a general review.

  11. Chronic Schistosomiasis • Schistosomiasis Haematobium: • Ultrasonography • In the urinary tract, ultrasonography can detect hypertrophy of the bladder mucosa, thickening of the bladder wall (which is normally less than 5 mm when the bladder is distended), and bladder calcification. • If the ureters are easily demonstrated by ultrasound, they are probably thickened and abnormal; in some patients calcification will be seen, but ultrasound is not a reliable way to demonstrate early ureteric changes. • Dilatation of the renal collecting system can be detected very early, and represents the result of significant ureteric dysfunction.

  12. Chronic Schistosomiasis • Schistosomiasis Haematobium: • Radiography • Plain radiography of the abdomen is of no assistance until calcification has developed in the bladder and ureters, although in severe infections calcified eggs may also be seen in the soft tissues. ( Early calcification is much more clearly seen by CT.) • Intravenous (contrast) urography will provide very useful diagnostic information. All the early findings will be in the ureters and bladder; the kidneys remain normal until later in the disease.

  13. Chronic Schistosomiasis Schistosomiasis Haematobium: Radiography changes in the ureters • persistent filling of the lower segment in all films of the urography series, not dilated or otherwise abnormal • Dilatation of the filled distal, intrapelvic segment • Earliest ureteric constriction is within the bladder wall • Changes in ureteric peristalsis • Ureter will have a ragged outline and a beaded internal appearance, with some irregular dilatation because of acute "pseudotubercles" in the submucosa. • As they heal these may cause strictures. In more advanced cases there are multiple strictures, and gross irregularity .

  14. Intravenous urograms of two African men. Kidneys are normal, but both ureters are filled throughout their length and the lower thirds are dilated, irregular, and show beading due to multiple intrinsic constrictions. Their bladders do not show any calcification

  15. C .In another patient there is narrowing of both ureters close to bladder and in the right ureter there is a segment of dilatation between two areas of stenosis. D. Persisitent filling in the lower half of both ureters, with a long constriction in the right ureter just above the bladder.

  16. C: Ascending urography in another patient shows stenosis of the distal segment of the left ureter within the bladder wall and marked dilatation above it. B: marked dilatation of left ureter, showing the typical narrowing as the ureter enters the bladder wall. The right ureter is not distended or even filled, so it may be normal

  17. Schistosomiasis Schistosomiasis Haematobium:Radiography Blader and renal changes • The bladder outline first becomes hazy and indistinct, due to submucosal edema and pseudotubercles . • As the granulomas become fibrotic, the bladder wall shows calcification, but the calcium is not within the fibrous tissue. rather, it is entirely submucosal, in the eggs. • As the calcification spreads up the ureter, there will be a matching reduction in the rate of peristalsis. • By the time there is hydronephrosisand hydroureter, renal function is decreased with marked dilatation of the whole system. • secondary infection will hasten these changes.

  18. The ureters can calcify in schistosomiasis haematobium, with (or, rarely, without) bladder calcification. Calcified ureters may be narrowed or dilated

  19. Gross bilateral hydronephrosis and hydroureter demonstrated by reflux from a retrograde cystogram. The ureters are atonic and have lost the beaded appearance. Extremely heavy bladder calcifcation in schistosomiasis haematobium The heavily calcified (empty) bladder of an Egyptian male patient.

  20. Ultrasound scans showing gross thickening of the bladder wall and of the ureter multi-layered calcification of the entire bladder wall

  21. Schistosomiasis Schistosomiasis Haematobium: Lungs Radiological abnormalities in the chest are uncommon in patients infected with S. haematobium • the Katayama syndrome. • reaction around the larvae. This is a local immune reaction similar to others in the Loeffler syndrome. There will be scattered hazy foci of consolidation in both lungs, changing in both size and position at short intervals, and without any specific distribution. There is no lymphadenopathy . • The third pattern is often found by chance in the elderly : a pattern of fine, generalized interstitial fibrosis, distributed equally throughout both lungs.

  22. late stage of schistosomiasis . Both lungs show marked interstitial fibrosis and there is enlargement of the main pulmonary arteries. Pulmonary hypertension has many causes and there is no way to distinguish schistosomiasis, nor, at this stage, will specific therapy have any effect.

  23. Chronic Schistosomiasis • Schistosomiasis Haematobium: Colon S. haematobium can cause a granulomatous reaction in the large bowel. A Superficial ulceration and edema causing irregularity of the right half of the transverse colon Rectal and colonic calcification may be seen

  24. Chronic Schistosomiasis • Schistosomiasis Mansoni: • The main imaging findings in S. mansoni infections reflect the pathological changes in the bowel, portal system, and lungs. • Large Bowel • Changes follow as: • 1) An edematous mucosal pattern with tiny ulcers leading to spasm and incomplete distention .

  25. there are many tiny punctate mucosal ulcerations, a double contrast barium enema will show a fine granular mucosa, as in this hepatic flexure

  26. Chronic Schistosomiasis • Schistosomiasis Mansoni • Large Bowel (continue) • loss of haustration, chiefly in the descending and sigmoid colon, most marked in the distribution of the inferior mesenteric artery. • heavier infection and chronic exposure leads to multiple granulomatous polyps, usually 1-2 cm in diameter, especially in the rectum, sigmoid and descending colon. • Strictures may develop , and can be mistaken for carcinoma or Crohn's disease. • Calcification in the eggs may be seen

  27. Schistosomiasis Mansoni Schistosomal polyposis (arrows) extending from the rectum to the transverse colon (air-barium enema).

  28. Schistosomiasis Mansoni A barium enema . a polypoid mass arising from the left lateral rectal wall in the frontal view (E), more clearly seen in the post evacuation film (F).

  29. Schistosomiasis Mansoni This barium enema shows stenosis of the rectum and a stricture in the midsigmoid colon. Throughout the rectosigmoid there is loss of haustral markings and the bowel has become tubular and rigid.

  30. Schistosomiasis Mansoni: small bowel S. mansonidoes not commonly cause radiological changes in the small bowel . All varieties of schistosomiasis can affect the duodenum; patients present clinically with vague symptoms suggesting peptic ulceration. A) Marked deformity and narrowing of the pylorus and duodenum. B )The edematous second and third parts of the duodenum

  31. Chronic Schistosomiasis • Schistosomiasis Mansoni • Biliary Tract and Pancreas: • Tubular and irregular calcification may be seen in the main hepatic ducts, the common hepatic, cystic, and common bile ducts, and also the pancreatic duct. • There is seldom ductal obstruction. • The tubular calcification may be seen on plain radiographs , It is well shown by CT as calcified ring densities or, depending on the section, parallel tubular lines.

  32. Schistosomiasis Mansoni: Biliary Tract and Pancreas The CT scan showing dense calcification in the neck of the gallbladder (arrows) heavy calcification in the common hepatic duct (arrows), cystic duct (open arrow), and pancreas (curved arrows).

  33. Chronic Schistosomiasis Schistosomiasis japonica • The radiological findings are different because eggs are smaller and more in number. • The S. japonicum worms live in mesenteric veins and their eggs are deposited predominantly within small bowel venules and in the mesentery. Small Bowel: • The mucosa of the duodenum and the upper jejunum becomes edematous, coarse and irregular; motility is decreased and there may be some dilatation. The terminal ileum may show similar changes .

  34. Schistosomiasis japonica: Small Bowel Four views of the first and second part of the duodenum of a Chinese patient with schistsomiasis japonica.

  35. Chronic Schistosomiasis • Schistosomiasis japonica • Colon and Rectum: • Schistsoma japonicum infection produces changes very similar to those seen in schistosomiasis mansoni. • Retroperitoneum • Granulomas located in the retroperitoneal space may become large enough to resemble malignant disease. • Although CT, and occasionally ultrasound, can demonstrate multiple eggs, the exact differential diagnosis may only be possible by biopsy.

  36. Chronic Schistosomiasis • Hepatic Schistosomiasis • Hepatomegaly and an often massive splenomegaly is common wherever there is schistosomiasis. • Periportal fibrosis occurs in any type of schistosomiasis. • Changes in the liver : • thickening around the portal vein and its main branche • when portal hypertension develops, there is usually splenomegaly • multiple varicosities and collateral veins will develop.

  37. Chronic Schistosomiasis Hepatic Schistosomiasis • Schistosomiasis japonica may cause little clinical evidence of liver damage . • In schistosomiasis japonica the eggs are frequently deposited along the fibrous septa of the liver with only a mild inflammatory response. The eggs are more common in the peripheral or subcapsular regions. • The hepatic changes of schistosomiasis japonica are characteristic .The background picture of periportal fibrosis is similar to S. mansoniinfections, but the extent of hepatic calcification is quite different

  38. periportal fibrosis due to S. mansoni

  39. S. japonica Nonenhanced CT shows septal calcification close to the top of the liver, better seen with contrast enhancement

  40. Nonenhanced CT scan of a 79-year-old Japanese male with S. japonicum in his stool.

  41. Hydatid Disease Hydatid cysts are classified into four types on the basis of their appearance : Type I: Simple Cyst with No Internal Architecture Type II: Cyst with Daughter Cyst(s) and Matrix Type III: Calcified Cyst Type IV: Complicated HC ultrasound, CT, or MRI provides the best images. All methods of scanning can provide images in multiple planes and no added contrast is necessary, except in CT imaging. Used alone, or in combination, an almost 100% positive diagnosis of hydatid disease can be made in the majority of cases. Imaging may even provide a strong diagnostic probability when immunodiagnosis is equivocal or even (rarely) inaccurate.

  42. Hydatid Disease • Sonography should be the first method used to scan the patient, with a chest radiograph added. sonography is highly accurate (except in the chest, skeleton and CNS). • CT and MRI often provide additional valuable information. • Pulmonary lesions are usually detected on the chest radiograph but, when it is available, CT is helpful • Brain hydatids can be imaged by either CT or MRI • Plain films are often adequate for imaging bone hydatids, but CT and MRI yield more information as to extent of the lesion and possible soft tissue involvement. • Angiography, Doppler sonography and nuclear medicine are only occasionally useful in the diagnosis of cystic hydatid disease and are utilized only when the other modalities are unavailable.

  43. Hydatid Disease Type I: Simple Cyst appear as a well-defined anechoic mass with or withouthydatid sand and septa. Unilocular cysts are considered to bean initial stage in the development of the parasite. The pericyst is rarely identified by US and is seen by CT only if it is calcified . However, it is demonstrable by MRI, particularly on T2-weighted images which produce a low intensity rim. Neither the cyst nor the pericyst enhance by CT or MRI as they are avascular

  44. Hydatid Disease Type I: Simple Cyst • At CT, a typeI hydatid cyst appears as a well-defined, water-attenuation mass. Frequently,the septa and cyst wall enhance after injection of contrastmaterial at CT and MRI, a finding that helps differentiate type I hydatid cyst from a simple liver cyst. • MRI features are also similar to those of a simple livercyst and include hypointensity on T1-weighted images and markedhyperintensity on T2-weighted images. • A low-signal-intensityrim ("rim sign"), which is more evident on T2 MRI,has been described as characteristic of hydatidosisas opposedto nonparasitic cysts in the liver and lungs. This finding representsthe parasitic membranes and pericyst. However, it is a nonspecificfinding that can also be seen in amebic abscess, hepatocellularcarcinoma, and hematoma.

  45. Hydatid Disease Type I lesions have a non-specific cystic appearance but if the patient is rotated immediately before US scanning the settling hydatid sand produces signals which have been likened to falling snow Ultrasound scan reveals echos at bottom of a liver hydatid caused by hydatid sand (arrows).

  46. Univesicular uncomplicated type I cyst

  47. Type I: Simple Cyst Incidentally found type I HCs in a 45-year-old woman. Computed tomographic (CT) scan shows multiple unilocularhypoattenuating lesions in the liver (maximum lesion diameter, 15 mm) and spleen (maximum lesion diameter, 30 mm).

  48. MRI of a simple viable type I hydatid cyst of liver. (A) T1-weighted image (SE 733/20). Cyst wall is isointense relative to cyst contents. (B) T2-weighted image (SE 2000/100). Cyst wall, consisting of both intact parasitic membranes and pericyst, is of low signal intensity compared with high signal of cyst contents.

  49. Hydatid Disease Large hypermaturehydatid cyst filled with debris. Some detachment of the cyst wall from the host pericyst is noted

  50. Hydatid Disease Type II: Cyst with Daughter Cyst(s) and Matrix • Daughter cysts are seen inside the mother cyst. floating membranesor vesicles can also be seen in the cyst • Sometimesmultiple cysts and echogenic areas that are enclosed togetherwithin a single capsule give rise to a "racemose" or "wheelspoke" appearance. • Consolidation of the daughter cysts may produceechogenic solid lesions. Type II lesions usually have a characteristic appearance due to daughter cysts whether or not fluid or matrix are present

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