Importance of b value in diffusion weighted imaging for the diagnosis of pancreatic cancer

AIM:To investigate the use of multi-b-value diffusionweighted imaging in diagnosing pancreatic cancer.METHODS:We retrospectively analyzed 33 cases of pancreatic cancer and 12 cases of benign pancreatic tumors at the Second Affiliated Hospital of Kunming Medical University from December 2008 to January2011.The demographic characteristics,clinical presentation,routine magnetic resonance imaging and diffusion weighted imaging(DWI)features with different b values were reviewed.Continuous data were expressed as mean±SD.Comparisons between pancreatic cancer and benign pancreatic tumors were performed using the Student’s t test.A probability of P<0.05 was considered statistically significant.RESULTS:Thirty-three patients with pancreatic cancer were identified.The mean age at diagnosis was 60±5.6 years.The male:female ratio was 21:12.Twenty cases were confirmed by surgical resection and 13 by biopsy of metastases.T1 weighted images demonstrated a pancreatic head mass in 16 patients,a pancreatic body mass in 10 cases,and a pancreatic tail mass with pancreatic atrophy in 7 cases.Eight patients had hepatic metastases,13 had invasion or envelopment of mesenteric vessels,4 had bone metastases,and 8had lymph node metastases.DWI demonstrated an irregular intense mass with unclear margins.Necrotic tissue demonstrated an uneven low signal.A b of 1100s/mm2was associated with a high intensity signal with poor anatomical delineation.A b of 700 s/mm2was associated with apparent diffusion coefficients(ADCs)that were useful in distinguishing benign and malignant pancreatic tumors(P<0.05).b values of 50,350,400,450 and 1100 s/mm2were associated with ADCs that did not differentiate the two tumors.CONCLUSION:Low b value images demonstrated superior anatomical details when compared to high b value images.Tumor tissue definition was high and contrast with the surrounding tissues was good.DWI was useful in diagnosing pancreatic cancer.

Next-generation sequencing technology for diagnosis and efficacy evaluation of a patient with visceral leishmaniasis: A case report

BACKGROUND Visceral leishmaniasis(VL)is a parasitic disease caused by Leishmania and transmitted by infected sand flies.VL has a low incidence in China,and its clinical presentation is complex and atypical.This disease is easily misdiagnosed and can become life-threatening within a short period of time.Therefore,early,rapid and accurate diagnosis and treatment of the disease are essential.CASE SUMMARY A 25-year-old male patient presented with the clinical manifestations of irregular fever,hepatosplenomegaly,increased polyclonal globulin,and pancytopenia.The first bone marrow puncture biopsy did not provide a clear diagnosis.In order to relieve the pressure and discomfort of the organs caused by the enlarged spleen and to confirm the diagnosis,splenectomy was performed,and hemophagocytic syndrome was diagnosed by pathological examination of the spleen biopsy.Following bone marrow and spleen pathological re-diagnosis and metagenomic next-generation sequencing(mNGS)technology detection,the patient was finally diagnosed with VL.After treatment with liposomal amphotericin B,the body temperature quickly returned to normal and the hemocytes recovered gradually.Post-treatment re-examination of the bone marrow puncture and mNGS data showed that Leishmania was not detected.CONCLUSION As a fast and accurate detection method,mNGS can diagnose and evaluate the efficacy of treatment in suspicious cases of leishmaniasis.

New monoterpene phenyl ethers from Illicium micranthum

Seven new monoterpene phenyl ethers,namely micranthumnins A-G(1-7),were isolated from the stem bark of Illicium micranthum(Illiciaceae).Their structures were elucidated by comprehensive spectroscopic analyses including MS,IR,1D and 2D NMR.All compounds were evaluated for their anti-AChE activities.