In vivo assessment of the vascular disrupting effect of M410 by DCE-MRI biomarker in a rabbit model of liver tumor.

The present study aimed to prospectively monitor the vascular disrupting effect of M410 by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in rabbits with VX2 liver tumors. Twenty-eight rabbits bearing VX2 tumors in the left lobe of the liver were established and randomly divided into treatment and control groups, intravenously injected with 25 mg/kg M410 or sterile saline, respectively. Conventional and DCE-MRI data were acquired on a 3.0-T MR unit at pretreatment, 4 h, 1, 4, 7 and 14 days post-treatment. Histopathological examinations [hematoxylin and eosin (H&E) and CD34 immunohistochemisty staining] were performed at each time point. The dynamic changes in tumor volume, kinetic DCE-MRI parameter [volume transfer constant (Ktrans)] and histological data were evaluated. Tumors grew slower in the M410 group 4-14 days following treatment, compared with rapidly growing tumors in the control group (P<0.05). At 4 h, 1 and 4 days, Ktrans significantly decreased in the M410 group compared with that in the control group (P<0.05). However, Ktrans values were similar in the two groups for the other time points studied. The changes in DCE-MRI parameters were consistent with the results obtained from H&E and CD34 staining of the tumor tissues. DCE-MRI parameter Ktrans may be used as a non-invasive imaging biomarker to monitor the dynamic histological changes in tumors following treatment with the vascular targeting agent M410.

Heroin body packing: clearly discerning drug packets using CT.

BACKGROUND: To determine if heroin body packing has occurred using computed tomography (CT), and to evaluate the role of CT in screening such cases. METHODS: We collected 158 cases of suspected drug packers' imaging materials (all underwent CT, 42 cases were imaged using plain x-ray film) from September 5, 2005 to April 23, 2008. Abdominal-pelvic CT appearances (shape, size, number, location and density) and abdominal plain x-ray film manifestations were retrospectively observed for those who were finally confirmed as heroin body packers through the passing of evacuated drug packets. RESULTS: Among 158 cases of suspected drug packers in our study, 124 cases were finally diagnosed as heroin body packers. This was consistent with the CT results. However, there were 2 false-negative cases of abdominal imaging taken with plain x-ray film. All of the evacuated heroin body packets were produced mechanically. CT and plain film characteristic findings included the presence of uniform shape, varied density, and well-defined round or ovoid intra-luminal foreign-body shadows arranged closely along the gastrointestinal (GI) tract and/or vagina. We also found that the "air-ring sign" and "onion sign" were valuable characteristics that were seen on the CT scan, which helped to positively confirm the detection of heroin packets. CONCLUSION: Heroin body packing has clearly defined diagnostic features that can be seen with CT. Furthermore, conventional abdominal-pelvic CT is the imaging modality of choice in the evaluation of suspected body packers.