This paper describes a calibration phantom system for QCT bone mineral density determination, which consists of 4-standard-solid-sample calibration phantom, a quality assurance (QA) phantom and the bone mineral density analysis software. The system adds to the new applications of CT systems, and provides a new method with a good accuracy and reliability for the examination, diagnosis, prevention, treatment of osteoporosis diseases and the observation of curative effect of drugs.
Absorptiometry, Photon ; instrumentation ; methods ; Algorithms ; Animals ; Bone Density ; Calibration ; Equipment Design ; Humans ; Image Processing, Computer-Assisted ; methods ; Imaging, Three-Dimensional ; methods ; Osteoporosis ; diagnostic imaging ; Phantoms, Imaging ; Software ; Tomography, X-Ray Computed ; instrumentation ; methods

BACKGROUNDAccurate evaluation of response following chemotherapy treatment is essential for surgical decision making in patients with breast cancer. Modalities that have been used to monitor response to neo-adjuvant chemotherapy (NAC) include physical examination (PE), ultrasound (US), and magnetic resonance imaging (MRI). The purpose of this study was to evaluate the accuracy of PE, US, and MRI in predicting the response to NAC in patients with breast cancer.

METHODSAccording to the response evaluation criteria in solid tumors guidelines, the largest unidimensional measurement of the tumor diameter evaluated by PE, US, and MRI before and after NAC was classified into four grades, including clinical complete response, clinical partial response, clinical progressive disease, clinical stable disease, and compared with the final histopathological examination.

RESULTSOf the 64 patients who received NAC, the pathologic complete response (pCR) was shown in 13 of 64 patients (20%). The sensitivity of PE, US, and MRI in predicting the major pathologic response was 73%, 75%, and 80%, respectively, and the specificity was 45%, 50%, and 50% respectively. For predicting a pCR, the sensitivity of PE, US, and MRI was 46%, 46%, and 39%, respectively, and the specificity was 65%, 98%, and 92% respectively.

CONCLUSIONSCompared with final pathologic findings, all these three clinical and imaging modalities tended to obviously underestimate the pCR rate. A more appropriate, universal, and practical standard by clinical and imaging modalities in predicting the response to neo-adjuvant chemotherapy in vivo is essential.

Adult ; Aged ; Breast Neoplasms ; diagnostic imaging ; drug therapy ; pathology ; Chemotherapy, Adjuvant ; Female ; Humans ; Magnetic Resonance Imaging ; Middle Aged ; Physical Examination ; Ultrasonography

[Abstract] Objective To investigate the effects of the downregulation of draxin expression on the projection characteristics of 23C10-positive neural fibers in the chick embryonic hindbrain. Methods The vitro incubation of HH stages 21-22 chick embryonic hindbrain biopsy with alkaline phosphatase (ALP) protein was used as control group. The incubation of HH stages 21-22 chick embryonic hindbrain biopsy with draxin-ALP fusion protein was used as experimental group. The number of embryonic hindbrain for each group was 10. To detect whether 23C10-positive neural fibers could directly bind to draxin protein or not;In ovo electroporation using empty vector in the chick embryonic hindbrain was used as control group. In ovo electroporation with small interfering RNA(siRNA) expressing vector for reducing draxin expression in the chick embryonic hindbrain was used as experimental group. The number of embryonic hindbrain for each group was 18. The effect of the down-regulation of draxin expression and the change of projection characteristics of 23C10-positive neural fibers were observed to check whether the down-regulation of draxin expression would affect the distribution of 23C10-positive fibers. Results Most portion of draxin protein could overlap with 23C10-positive neural fibers in HH stages 21-22 chick embryonic hindbrain biopsies; After expression of the siRNA plasmid against draxin by electroporation, the expression level of draxin protein was significantly reduced, and the distribution of 23C10-positive fibers was scattered in the dorsal hindbrain on the electroporated side at HH stages 25-26 of chick embryos (P < 0. 05) . Conclusion Draxin protein may directly bind to 23C10-positive fibers in hindbrain, and it plays an important regulatory role in the fasciculation of 23C10-positive fibers during chick embryonic development.