Predictive geometric factors in a standardized model of femoral neck fracture. Experimental study of cadaveric human femurs

An experimental study was performed on 20 cadaveric human proximal femurs to investigate both the reproducibility of their mechanical behavior under uniaxial compression and the correlation of mechanical properties with geometric dimensions and bone density. These variables were assessed by radiography, physical measurement, and dual-energy X-ray absorptiometry (DEXA). The specimens were immobilized, loaded to the point of fracture, and analyzed with the help of a materials testing machine. The fractures invariably showed a similar pattern both in location (i.e. at the femoral neck) and in nature (i.e. "axial-shear" type according to the AO classification system). The mechanical properties of the tested proximal femurs correlated negatively with age (r = -0.39) and positively with sex (male femurs were stronger and correlated more closely than female femurs, P = 0.005). They showed a strong positive correlation with head diameter (r = 0.713, P = 0.0004), a moderate positive correlation with both neck axis length (r = 0.63) and neck diameter (r = 0.502), and a slight positive correlation with femoral neck-shaft angle (r = 0.326). All DEXA-based densitometry measures turned out to be powerful predictors of fracture force. The establishment of this solidly reproducible fracture model based on standardized loading conditions should have implications for future research on osteopenia/osteoporosis and preventive stabilization techniques.     

Local staging of pancreatic carcinoma with multi-detector row CT: use of curved planar reformations initial experience

PURPOSE: To evaluate the utility of curved planar reformations compared with standard transverse images in the assessment of pancreatic tumors. MATERIALS AND METHODS: Forty-three patients suspected of having pancreatic tumors underwent contrast material-enhanced biphasic multi-detector row computed tomography (CT). Curved planar reformations were generated along the pancreatic duct, common bile duct, and major mesenteric vessels. Three blinded independent readers assessed the curved planar reformations and transverse images separately for the presence of tumor, resectability, and vascular involvement. The results were compared with those of a consensus panel who evaluated the curved planar reformations and transverse images together along with clinical data and surgical findings. RESULTS: Of 43 patients, 20 had pancreatic malignancies as judged by the consensus panel and proven at biopsy and/or clinical follow-up. For tumor detection, transverse images and curved planar reformations had an average sensitivity of 95.0% and 98.4% (P >.05), respectively, and an average specificity of 90.9% and 91.3% (P >.05), respectively. For tumor resectability, transverse images and curved planar reformations had an average sensitivity of 85.7% and 71.4% (P >.05), respectively, and an average specificity of 85.2% and 84.3% (P >.05), respectively. Average interpretation time was 6.4 minutes with transverse images and 4.1 minutes with curved planar reformations. CONCLUSION: Curved planar reformations are equivalent to transverse images in the detection of pancreatic tumors and determination of surgical resectability.     

Alagille's syndrome associated with cystic renal disease

Although renal abnormalities have been described in children with Alagille's syndrome, cystic kidney disease has not often been documented, and then usually only at necropsy. Three children with Alagille's syndrome are described, in two of whom a unilateral multicystic dysplastic kidney was detected by prenatal ultrasound; in the other, a solitary cortical cyst was found later in childhood. All have normal renal function, growth, and liver synthetic function but continue to have clinical and biochemical signs of cholestasis. These cases show that unilateral cystic kidney disease with or without renal dysplasia may be associated with Alagille's syndrome, that the clinical course is not necessarily unfavourable, and that Alagille's syndrome should be included in the differential diagnosis of cystic kidney disorders associated with cholestatic liver disease. Patients with Alagille's syndrome should be evaluated by renal ultrasound.     

Computed tomography colonography: feasibility of computer-aided polyp detection in a "first reader" paradigm

OBJECTIVE:: To determine the feasibility of a computer-aided detection (CAD) algorithm as the "first reader" in computed tomography colonography (CTC). METHODS:: In phase 1 of a 2-part blind trial, we measured the performance of 3 radiologists reading 41 CTC studies without CAD. In phase 2, readers interpreted the same cases using a CAD list of 30 potential polyps. RESULTS:: Unassisted readers detected, on average, 63% of polyps > or =10 mm in diameter. Using CAD, the sensitivity was 74% (not statistically different). Per-patient analysis showed a trend toward increased sensitivity for polyps > or =10 mm in diameter, from 73% to 90% with CAD (not significant) without decreasing specificity. Computer-aided detection significantly decreased interobserver variability (P = 0.017). Average time to detection of the first polyp decreased significantly with CAD, whereas total reading case reading time was unchanged. CONCLUSION:: Computer-aided detection as a first reader in CTC was associated with similar per-polyp and per-patient detection sensitivity to unassisted reading. Computer-aided detection decreased interobserver variability and reduced the time required to detect the first polyp.     

Delirium Tremens

The varied clinical manifestations and management of 14 male patients with delirium tremens (DT) have been studied. Eight patients were initially hospitalised for diseases unrelated to ethanol abuse i.e. 2 each for gun shot wound, myocardial infarction and stroke, and one each for pneumonia and gastroenteritis. One patient was going through withdrawal because of prodrome of viral hepatitis before he was hospitalised for uncontrolled agitation and delirium. Two known cases of mild essential hypertension on dietary therapy reported for agitation, abnormal behaviour, a single episode of tonic clonic seizure and hypertensive encephalopathy as they could not/did not get alcohol for 3 days. Three patients presented denovo with DT without concomitant illness. The other features besides delirium and hallucinations were tremulousness in 10, tachycardia in 12, fever in 3, diaphoresis in 2 and tonic clonic seizures in 4 patients. The symptoms fluctuated markedly at short intervals and 2 patients did not have any features of sympathetic overactivity. Altered hepatic biochemical parameters and ketonuria with normal blood sugar were noted in 4 and one patients respectively. Other biochemical parameters including serum electrolytes were normal. CT scan brain done for 5 patients revealed subdural haematoma in one. Cerebro spinal fluid (CSF) and EEG findings were noncontributory. All made good recovery with heavy doses of intravenous vitamin B complex, glucose and oral benzodiazepine. Short course of haloperidol was used in 2 patients. Two patients developed pancreatitis during follow up. All patients made complete recovery, and 8 patients have been followed for 8 to 12 months without relapse. The reason for hospitalisation in such cases is often unrelated to alcohol abuse; hence a detailed history of alcoholism is mandatory to identify those at risk as well as for prompt treatment and decreasing the mortality.Key Words: Alcohol withdrawal, Concomitant illnesses, Delirium, Precipitating events     

Line scan diffusion imaging of the spine

BACKGROUND AND PURPOSE: Recent findings suggest that diffusion-weighted imaging might be an important adjunct to the diagnostic workup of disease processes in the spine, but physiological motion and the challenging magnetic environment make it difficult to perform reliable quantitative diffusion measurements. Multi-section line scan diffusion imaging of the spine was implemented and evaluated to provide quantitative diffusion measurements of vertebral bodies and intervertebral disks. METHODS: Line scan diffusion imaging of 12 healthy study participants and three patients with benign vertebral compression fractures was performed to assess the potential of line scan diffusion imaging of the spinal column. In a subgroup of six participants, multiple b-value (5-3005 s/mm(2)) images were obtained to test for multi-exponential signal decay. RESULTS: All images were diagnostic and of high quality. Mean diffusion values were (230 +/- 83) x 10(-6) mm(2)/s in the vertebral bodies, (1645 +/- 213) x 10(-6) mm(2)/s in the nuclei pulposi, (837 +/- 318) x 10(-6) mm(2)/s in the annuli fibrosi and ranged from 1019 x 10(-6) mm(2)/s to 1972 x 10(-6) mm(2)/s in benign compression fractures. The mean relative intra-participant variation of mean diffusivity among different vertebral segments (T10-L5) was 2.97%, whereas the relative difference in mean diffusivity among participants was 7.41% (P <.0001). The estimated measurement precision was <2%. A bi-exponential diffusion attenuation was found only in vertebral bodies. CONCLUSION: Line scan diffusion imaging is a robust and reliable method for imaging the spinal column. It does not suffer as strongly from susceptibility artifacts as does echo-planar imaging and is less susceptible to patient motion than are other multi-shot techniques. The different contributions from the water and fat fractions need to be considered in diffusion-weighted imaging of the vertebral bodies.