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Object: To investigate the relationship of the different diffusion tensor imaging (DTI) parameters (ADC, FA, and first eigenvector (EV)) to the constituents (proteoglycans and collagen), the zonal arrangement of the collagen network, and mechanical loading of articular cartilage., Material and Methods: DTI of eight cartilage-on-bone samples of healthy human patellar cartilage was performed at 17.6 T. Three samples were additionally imaged under indentation loading. After DTI, samples underwent biomechanical testing, safranin-O staining for semiquantitative proteoglycan estimation, and scanning electron microscopy (SEM) for depicting collagen architecture., Results: From the articular surface to the bone-cartilage interface, ADC continuously decreased and FA increased. Cartilage zonal heights calculated from EVs strongly correlated with SEM-derived zonal heights (P < 0.01, r (2)=0.87). Compression reduced ADC in the superficial 30% of cartilage and increased FA in the superficial 5% of cartilage. Reorientation of the EVs indicative of collagen fiber reorientation under the indenter was observed. No significant correlation was found between ADC, FA, and compressive stiffness., Conclusions: Correlating ADC and FA with proteoglycan and collagen content suggests that diffusion is dominated by different depth-dependent mechanisms within cartilage. Knowledge of the spatial distribution of the DTI parameters and their variation contributes to form a database for future analysis of defective cartilage.

Introduction: CT plays an important role in depicting gunshot wounds in parenchymal and hollow organs in the abdomen. Relative to other techniques and to emergency laparotomy, CT permits good assessment of abdominal content, major injuries and changes in other districts, such as chest, pelvis and skull. We investigated the yield and role of CT in diagnosing abdominal gunshot wounds, with their rich and varied radiological signs and associated injuries., Material and Methods: We retrospectively reviewed the findings of 30 patients with abdominal gunshot wounds examined in 4 years at Loreto-Mare Hospital, Naples. All patients were men, age ranging 19-54 years (mean: 35); 6 of them were not from the European Union. Examinations were carried out from diaphragm to pubis with i.v. contrast injection and the CT angiography technique. CT was integrated with chest studies in 6 cases and with skull studies in 5. Subsequent CT follow-ups were necessary in 12 cases submitted to conservative treatment., Results: Liver was the most damaged parenchyma, with hemorrhage and lacerocontusion in 7 cases and mashed in 1 case; spleen was involved in 4 cases; hemoperitoneum was found in 18 cases. Diaphragm was involved in 5 cases and pancreas in 2; gallbladder, stomach and duodenum were involved in 1 case each and jejunum-ileum and colon in 3 and 6 cases, respectively. CT showed renal injury in 3 cases and bladder injury in 2. Eight patients had vertebral gunshot damage. Pneumothorax, hemothorax and lacerocontusion were found in 7 cases; brain was injured in 4 cases and limbs in 16., Discussion and Conclusions: Tissue damage extent depends on the speed and kinetic energy the bullet carries into the abdomen. Abdominal radiography shows the bullet and its site, pneumoperitoneum from gastrointestinal perforation, crash bone injuries, vertebral trauma and subcutaneous emphysema. Instead, CT depicts early parenchymal damage and vascular injury and thus becomes a complete and necessary tool for imaging gunshot wounds. CT provides early diagnostic information which help plan emergency treatment and thus decrease mortality. As for angiography and US, we suggest they be used subsequently because in emergency they may delay the diagnosis. Moreover, vessel rupture and active intraabdominal bleeding are easily detected with spiral CT, which appears the best tool for prompt assessment of the injuries associated with gunshot wounds in other districts such as, the skull. To conclude, CT permits adequate planning of emergency surgery and helps select the cases for follow-up, intensive care and conservative treatment.