Disagreement between ultrasound and magnetic resonance imaging in the identification of schistosomal periportal fibrosis

Abstract

Abdominal ultrasound (US) has been widely used in the evaluation of patients with schistosomiasis mansoni. It represents an important indirect method of diagnosis and classification of the disease, and it has also been used as a tool in the evaluation of therapeutic response and regression of fibrosis. We describe the case of a man in whom USshowed solid evidence of schistosomal periportal fibrosis and magnetic resonance imaging revealed that periportal signal alteration corresponded to adipose tissue which entered the liver togheter with the portal vein.Key words: schistosomiasis -Schistosoma mansoni -ultrasound -magnetic resonance imaging Abdominal ultrasound (US) has been widely used in the evaluation of patients with schistosomiasis mansoni. It represents an important indirect method of diagnosis and classification of the disease (Abdel-Latif et al. 1981, Hussain et al. 1984, Fataar et al. 1984, Cerri et al. 1984, Homeida et al. 1988a, b, Abdel-Wahab et al. 1989, PintoSilva et al. 1994, Gerspacher-Lara et al. 1998, GerspacherLara 1999, Niamey Working Group 2000, Ritcher et al. 2001. US has also been used as a tool in the evaluation of therapeutic response and regression of fibrosis in schistosomiasis (Massoud et al. 1986, Homeida et al. 1988c, Homeida et al. 1991, DoehringSchwerdtfeger et al. 1992, Boisier et al. 1998, Frenzel et al. 1999, De Jesus et al. 2000, Cota et al. 2006. Ultrasonographic examination of subjects with hepatosplenic schistosomiasis has detected a characteristic pattern of abnormalities, quite different from the aspects observed in liver cirrhosis (Homeida et al. 1988a, Abdel-Wahab et al. 1989) and in acute schistosomiasis (Barata et al. 1999, 1997. The most important finding was echogenic thickening of the walls of the portal vein and its branches. Field studies in endemic areas have shown that the sum of total thickening of three peripheral branches of the portal vein, thickening of gallbladder wall, enlargement of the left lobe of the liver, and thickening of the portal vein in its bifurcation are the best variables for ultrasonographic diagnosis of schistosomiasis mansoni (Gerspacher-Lara 1999).Magnetic resonance imaging (MRI) has been described in four cases of hepatosplenic schistosomiasis mansoni (Patel et al. 1993, Willemsen et al. 1995, Lambertucci et al. 2002, 2004 puted tomography (CT) and MRI in the evaluation of a patient with hepatosplenic schistosomiasis mansoni. The findings of the different methods were in agreement in both studies. Periportal echogenic thickening on US, suggestive of fibrosis, and low attenuation bands about the portal vessels, which markedly enhanced with contrast CT were described. MRI demonstrated the same periportal bands that were seen on liver US and CT scans. These bands showed hiperintense signal on T2-weighted sequences, and were isointense in T1-weighted sequences, with enhancement after contrast administration. The studies of Lambertucci et al. (2002Lambertucci et al. ( , 2004 evaluated patients with advanced forms of hepatosplenic schistosom...

Schistosoma mansoni: magnetic resonance analysis of liver fibrosis according to WHO patterns for ultrasound assessment of schistosomiasis-related morbidity

“…In a patient without portal hypertension and with intense periportal thickening diagnosed by US, MRI described a normal liver (Silva et al 2006). In fact, MRI identified fat tissue around the main portal vein that was seen as fibrosis by US.…”

“…MRI has been described in hepatosplenic schistosomiasis mansoni (Patel et al 1993, Willemsen et al 1995, Lambertucci et al 2002, Bezerra et al 2004, 2007, 2008, Silva et al 2006), but there is no standardisation of the method in the evaluation of liver periportal fibrosis. The aim of this paper was to analyse MRI using an adaptation of the WHO patterns for US assessment of schistosomiasisrelated morbidity.…”

Revisiting the concept of hepatosplenic schistosomiasis and its challenges using traditional and new tools

“…It uses strong magnetic fi elds and non-ionizing radiation in the radio frequency range, in contrast to CT scans and traditional X-rays, which both use ionizing radiation. Contrast agents may be injected intravenously to enhance the appearance of blood vessels, tumors or infl ammation [36][37][38][39][40][41][42][43] . …”

“…The World Health Organization (WHO) grading of liver fi brosis by US should be reevaluated and used carefully in the defi nition of the severity of hepatosplenic schistosomiasis. Papers published using the WHO classifi cation should also be revised 37,38,41 . The characteristic periportal fi brosis (diagnosed by US, MRI or histology) associated with evidence of portal hypertension (large spleen, esophageal varices and collateral vessels) should be suffi cient to defi ne disease severity and indicate surgical intervention, as necessary.…”

Imaging techniques and histology in the evaluation of liver fibrosis in hepatosplenic schistosomiasis mansoni in Brazil: a comparative study

“…In schistosomiasis, MR alterations have already been described in case reports and in series of cases (Patel et al 1993, Willemsen et al 1995, Lambertucci et al 2002, 2004, Silva et al 2006, Bezerra et al 2007, Silva 2007. However, to our knowledge, no study has compared US and MR to liver histology in patients with hepatosplenic schistosomiasis.…”