Objective To explore the diagnostic value of abdominal aortic aneurysm (AAA) with 16-slice spiral CT.Methods Forty patients with AAA were examinated with 16-slice spiral CT. Multiplanar reformation (MPR), maximal intensity projection (MIP) and volume rendering (VR) were performed in all cases.Results Forty patients with AAA included seven cases of cystiform, twenty-three cases of shuttle and ten cases of shuttle-cystiform aneurysm. There were three cases of multiple abdominal aortic aneurysm. There was one case of pseudoaneurysm after the rupture of true aneurysm. MPR definitely revealed the site, modality and extent of aortic disease and demonstrated the mural thrombus in the aneurysm. The calcifications of abdominal aortic aneurysm’s wall or in mural thrombus were well depicted by MIP. VR definitely showed the relationship between aneurysm and arterial branches with three-dimension form.Conclusion 16-slice spiral CT is the optimal imaging technique in diagnosing, following up pre-and post-operation of abdominal aortic aneurysms.

Objective To observe the morphological changes in the testes and ovaries of adult 12th-generation Oncomelania hupensis bred for 12 winters in Weishan Lake areas. Methods The offspring of the adult O. hupensis snails bred in the Weishan Lake that were originated from the Yangzhou section of the Yangtze River was defined as the experiment group, while uninfected, adult O. hupensis snails captured from the marshland of the Yangzhou section of the Yangtze River served as the control group. Snails were dissected and intact testicular and ovarian specimens were sampled, routinely fixed, dehydrated, embedded, polymerized in an oven and sliced on an ultramicrotome. The sections were visualized under a transmission electron microscope, and the ultrastructure of the snail gonad was compared between the experiment and control groups. Results Transmission electron microscopy showed “9 + 2” microtubules on the transverse sections of the tails of sperm cells in the testes of male snails in the control group, with triangular acrosomes and spiral, dense nuclei seen in the tip, while in the experiment group, the “9 + 2” microtubules disappeared on the transverse sections of the tails of sperm cells in the testes of male snails, with low chromatin density found in the tip. Transmission electron microscopy revealed clear nucleolus and nuclear membranes in the ova of female snail ovaries, and displayed yolk body, liposomes and endoplasmic reticulum in the cytoplasm, bilayer twists of nuclear membrane and a uniform nucleolus in the control group, while in the experiment group, smooth nuclear membrane and unclear nucleolus were observed in the ova of female snail ovaries, with few contents seen within cells. Conclusions Following breeding for 12 winters in the Weishan Lake, the 12th-generation O. hupensis snails fail to fully adapt to the natural environment in northern China, and the remarkable changes in the ultrastructure of the snail gonad may be a cause of gradual decline and even extinction of O. hupensis in the Weishan Lake areas.