Utility of Diagnostic Imaging in the Diagnosis and Management of Schistosomiasis

Abstract

Diagnosis of schistosomiasis is made by demonstration of the parasite ova in stools, urine,and biopsy specimens from affected organs, or presence of antibodies to the different stages of the parasite or antigens circulating in body fluids by serologic techniques. DNA of schistosomes can now also be detected in serum and stool specimens by molecular technique.However, these tests are unable to determine the severity of target organ pathology and resultant complications. Accurate assessment of schistosome-induced morbidities is now made with the use of imaging techniques like ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI). US has made major contributions in the diagnosis of hepatosplenic and urinary form of disease. This imaging method provides real time results, is portable (can be carried to the bed side and the field) and is lower in cost than other imaging techniques. Typical findings in hepatosplenic schistosomiasis by US include: hyperechoic fibrotic bands along the portal vessels (Symmer’s fibrosis), reduction in the size of the right lobe, hypertrophy of the left lobe, splenomegaly, and ascites. More advanced ultrasound equipment like the colour Doppler ultrasound can characterize portal vein perfusion, a procedure that is critical for the prediction of disease prognosis and for treatment options for complicated portal hypertension. Although CT and MRI are more expensive, are hospital based, and require highly additional specially-trained personnel, they provide more accurate description of the pathology, not only in hepatosplenic and urinary forms of schistosomiasis, but also in the diagnosis of ectopic forms of the disease,particularly involving thebrain and spinal cord. MRI demonstrates better tissue differentiation and lack of exposure to ionizing radiation compared with CT.

Advances in the Diagnosis of Human Schistosomiasis

“…These tests are useful in the clinical management of patients, especially in situations where the clinical evidence may be suggestive of schistosomiasis but not confirmed by other diagnostic tests, such as the KK test (18). Such procedures are very sensitive and are extremely helpful in complicated case management, where a prompt diagnosis is critical (18,82).…”

Morbidity Associated with Schistosomiasis Before and After Treatment in Young Children in Rusinga Island, Western Kenya

“…The major tool for assessing S. mansoni infection-associated morbidity in older patients is ultrasound [22][23][24][25][26][27][28] using the WHOrecommended Niamey scoring system. 29,30 It includes assessment of expected morbidities such as splenomegaly and left lobe hepatomegaly, as well as successively more pronounced liver ultrasound changes scored as image patterns (IP) A (normal), B ("starry sky," abnormal linear opacities of unclear significance), and C through F (progressive hepatic fibrosis).…”

En utenlandsk mann med hodepine og ryggsmerter

“…Somatisk antigen er et kroppslig antigen fra selve ikten og ses typisk ved kroniske infeksjoner der noen ikter har begynt å dø eller etter Vurdering av schistosomiasisinfeksjon i hepatospleniske og urogenitale organer kan gjøres ved bruk av ultralyd, CT-og MRundersøkelser. Ultralyd kan gjøres på sengepost og i felten og krever betydelig mindre økonomiske investeringer enn de andre modalitetene (8). CT-undersøkelse er spesielt bra for å vise forkalkninger i urinveiene, noe som er typisk for urogenital schistosomiasis (9).…”