Automated volumetry at CT colonography: a phantom study

RATIONALE AND OBJECTIVES: To assess the performance of a computer-aided detection (CAD) algorithm for measuring polyp-like structures on CT colonography (CTC) images of a phantom. MATERIALS AND METHODS: We constructed a Plexiglas phantom to which we affixed a series of idealized Plexiglas polyp-like objects, including spheres and hemispheres. We imaged the phantom in a four-channel detector CT scanner at a 1.3 mm slice thickness with a reconstruction interval of 0.6 mm, using combinations of 100 mAs, 30 mAs, horizontal and vertical orientation. For each set of CT images, the interior surface of the phantom was segmented. The CAD algorithm was applied to the resulting surface to identify the polypoid regions of interest and to calculate their volume and maximum linear dimension. Calculated values were then compared with actual values to yield percent error in each measurement. RESULTS: The mean error in volume for the subgroups of spheres and hemispheres was 3% and 5% respectively. Mean error in linear dimension was approximately 2% for both shape subgroups. All CAD-calculated values were closely correlated with their respective actual values. Parameter selection did not significantly affect the accuracy of the calculated measurements. CONCLUSIONS: Our CAD software accurately measured the greatest linear dimension and the volume of each of the polyp-like structures in our phantom. Results were largely independent of phantom orientation and the CT exposure factors.     

Bone density and hemoglobin levels in older persons: results from the InCHIANTI study

Hypoxemia has been recognized as a risk factor for bone loss. The aim of the present study is to investigate the relationship of bone mass and density measures with anemia and hemoglobin levels in a large sample of older community-dwelling persons. The study is based on data from 950 participants enrolled in the Invecchiare in Chianti (Aging in the Chianti area, InCHIANTI) study. All the analyses were performed considering continuous hemoglobin levels as well as the dichotomous anemia variable (defined according to WHO criteria as hemoglobin <12 g/dl in women and <13 g/dl in men). A peripheral quantitative computerized tomography (pQCT) scan of the right calf was performed in all participants to evaluate total bone density, trabecular bone density, cortical bone density, and the ratio between cortical and total bone area. Linear regression analyses were used to assess the multivariate relationship of pQCT bone measures with anemia and hemoglobin levels after adjustment for demographics, chronic conditions, muscle strength and biological variables. Participants were 75.0 (SD 6.9) years old. In our sample, 101 participants (10.6%) were anemic. In women, coefficients from adjusted linear regression analyses evaluating the association between pQCT bone measures (per SD increase) and hemoglobin levels/anemia showed significant associations of anemia with total bone density (=–0.335, SE=0.163; P=0.04) and cortical bone density (=–0.428, SE=0.160; P=0.008). Relationships with borderline significance were found for the associations of anemia with trabecular bone density and the ratio between cortical and total bone area. Significant associations were found between hemoglobin levels and trabecular bone density (=0.112, SE=0.049; P=0.02), total bone density (=0.101, SE=0.046; P=0.03), cortical bone density (=0.100, SE=0.046; P=0.03) and the ratio between cortical bone and total area (=0.092, SE=0.045; P=0.04). In men, significant associations were found for hemoglobin levels with total bone density (=0.076, SE=0.036; P=0.03) and cortical bone density (=0.095, SE=0.41; P=0.02). A borderline significance was reported for the association between anemia and cortical bone density. We concluded that anemia and low hemoglobin levels are negatively and independently associated with bone mass and density. The bone loss associated with hemoglobin levels mainly occurs in the cortical bone. Women with lower hemoglobin levels demonstrate a higher bone loss than male counterparts.     

The occurrence of fluid collections following routine abdominal surgical procedures: sonographic survey in asymptomatic postoperative patients

To investigate the frequency and appearance of reactive effusions following abdominal surgery, a prospective real-time sonographic survey of 80 asymptomatic postoperative patients was conducted. Serial scans on the 4th, 8th, and 12th postoperative days disclosed localized abdominal fluid collections in 19% (15/80), 6% (5/80), and 2.5% (2/80) of cases, respectively. The only collection that enlarged was an abscess. Knowledge of the natural history of reactive postoperative effusions should help the ultrasonographer to detect pathologic fluid collections and abscesses in postsurgical patients.     

Biliary pressure: manometric and perfusion studies at percutaneous transhepatic cholangiography and percutaneous biliary drainage

Manometric pressure recordings were attempted during percutaneous transhepatic cholangiography (PTC) and after percutaneous biliary drainage (PBD) in 203 cases. Successful readings were achieved at PTC in 85% (104/122) of patients. Pressure measurements were also obtained through 56 biliary drainage catheters, and controlled perfusion challenges were performed in 12 patients (on 18 occasions). Documentation of the occasionally poor correlation between the caliber of ducts and the degree of obstruction (i.e., pressure) was shown, and it was suggested that very high pressures may be predictive of a bile leak after PTC. Adequacy of percutaneous drainage and stricture dilatation were further assessed with these manometric techniques. Pressure and perfusion data aided in detecting and determining the significance of the nondilated obstructed duct, the dilated nonobstructed ductal system, and subtle distal ductal strictures. The knowledge obtained from percutaneous pressure recordings may help to determine appropriate therapy.     

Environmental demands associated with community mobility in older adults with and without mobility disabilities

BACKGROUND AND PURPOSE: In this study, the influence of 8 dimensions of the physical environment on mobility in older adults with and without mobility disability was measured. This was done in order to identify environmental factors that contribute to mobility disability. SUBJECTS: Subjects were 36 older adults ((> or = 70 years of age) who were recruited from 2 geographic sites (Seattle, Wash, and Waterloo, Ontario, Canada) and were grouped according to level of mobility function (physically able [ability to walk 1/2 mile (0.8 km) or climb stairs without assistance], physically disabled). METHODS: Subjects were observed and videotaped during 3 trips into the community (trip to grocery store, physician visit, recreational trip). Frequency of encounters with environmental features within each of the 8 dimensions was recorded. Differences in baseline characteristics and environmental encounters were analyzed using an analysis of variance or the Fisher exact test, as appropriate. RESULTS: Mobility disability among older adults was not associated with a uniform decrease in encounters with environmental challenges across all dimensions. Environmental dimensions that differed between subjects who were physically able and those with physical disability included temporal factors, physical load, terrain, and postural transition. Dimensions that were not different included distance, density, ambient conditions (eg, light levels and weather conditions), and attentional demands. DISCUSSION AND CONCLUSION: Understanding the relationship of the environment to mobility is crucial to both prevention and rehabilitation of mobility disability in older adults. Among older adults, certain dimensions of the environment may disable community mobility more than others.     

Systemic sclerosis could mask the presentation of psoriasis in a patient with symptomatic and bilateral sacroiliitis

Psoriasis is rarely associated with systemic sclerosis (SSc), and sacroiliitis associated to Connective Tissue Diseases is also rather rare. In this report we describe a case of a young woman with SSc who developed symptomatic and bilateral sacroiliitis. The clinical pattern of sacroiliac involvement of this patient resembles that of psoriatic sacroiliitis. HLA typing was compatible with both SSc and psoriasis. Psoriatic sacroiliitis could not be diagnosed, but, on the basis of these observations, the patient described could represent a case of PsA without psoriasis. and psoriatic cutaneous involvement masked by the presence of SSc.