Multidetector spiral computed tomography (CT) has opened the possibility of quantitative evaluation of emphysema extent in the whole lung. Visual assessment can be used for such a purpose, but its ...reproducibility has not been established.
To assess agreement of detailed assessment of pulmonary emphysema on whole-lung CT using a visual scale.
Thirty patients with chronic obstructive pulmonary disease underwent whole-lung inspiratory CT. Four chest radiologists rated the same 22 ± 2 thin sections using a visual scale which defines a range of emphysema extent between 0 and 100. Two of them repeated the rating two months later. Inter- and intra-operator agreement was evaluated with the Bland and Altman method. In addition, the percentage of emphysema at -950 Hounsfield units in the whole lung was determined using fully automated commercially available software for 3D densitometry.
In three of six operator pairs and in one of two intra-operator pairs the Kendall τ test showed a significant correlation between the difference and the average magnitude of visual scores. Among different operators the half-width of 95% limits of agreement (95% LoA) was wide ranging between a score of 14.2-27.7 for an average visual score of 20 and between 18.5-36.8 for an average visual score of 80. Within the same operator the half-width of 95% LoA ranged between a score of 10.9-21.0 for an average visual score of 20 and between 25.1-30.1 for an average visual score of 80. The visual scores of the four radiologists were correlated with the results of densitometry (P < 0.001; r = 0.65-0.81).
The inter- and intra-operator agreement of detailed assessment of emphysema in the whole lung using a visual scale is low and decreases with increasing emphysema extent.
AIM： To report our experience with computed tomography colonography （CTC） systematically performed in subjects with positive faecal occult blood test （FOBT） and an incomplete colonoscopy in the ...setting of a population-based screening for colorectal cancer （CRC）.
METHODS： From April 2006 to April 2007, 43 290 individuals （age range 50-70） who adhered to the regional screening program for the prevention of CRC underwent immunochemical FOBT. FOBT was positive in 1882 subjects （4.3%）. 1463 （77.7%） of these subjects underwent colonoscopy, 903 performed in a single center. Of 903 colonoscopies 65 （7.2%） were incomplete. Forty-two of these subjects underwent CTC. CTC was performed with a 16-MDCT scanner after standard bowel prep （polyethyleneglycole） in both supine and prone position. Subjects whose CTC showed polyps or masses were referred to the endoscopist for repeat colonoscopy under sedation or underwent surgery. Perlesion and per-segment positive predictive values （PPV） were calculated.
RESULTS： Twenty-one （50%） of 42 CTCs showed polyps or masses. Fifty-five of these subjects underwent a repeat colonoscopy, whereas 2 subjects underwent surgery for colonic masses of indeterminate nature. Four subjects refused further examinations. CTC correctly identified 2 colonic masses and 20 polyps. PPV for masses or polyps greater than 9 mm was of 87.5%. Per-lesion and per-segment PPV were, respectively, 83.3% and 83.3% for polyps greater or equal to 10 mm, and 77.8% and 85.7% for polyps of 6-9 mm.
CONCLUSION： In the context of a screening program for CRC based on FOBT, CTC shows high per-segment and per-lesion PPV for colonic masses and polyps greater than 9 mm. Therefore, CTC has the potential to become a useful technique for evaluation of the non visualized part of the colon after incomplete colonoscopy.
We assessed with computed tomography (CT) densitometry the prevalence of emphysema in 266 (175 men and 91 women; mean age 64 ± 4 years) smokers and former smokers enrolled in the ITALUNG trial of ...lung cancer screening with low-dose thin-slice CT. Whole-lung volume and the relative area at −950 Hounsfield units (RA
950
) and mean lung attenuation (MLA) in 1 of every 10 slices (mean, 24 slices per subject) were measured. Lung volume, MLA and RA950 significantly correlated each other and with age. Average RA950 >6.8% qualifying for emphysema was present in 71 (26.6%) of 266 subjects, with a higher prevalence in men than in women (30.3% vs 19.8%; p = 0.003). Only in smokers was a weak (r = 0.18; p = 0.05) correlation between RA950 and packs/year observed. In multiple regression analysis, the variability of RA950 (R2 = 0.24) or MLA (R2 = 0.34) was significantly, but weakly explained by age, lung volume and packs/year. Other factors besides smoking may also have a significant role in the etiopathogenesis of pulmonary emphysema.
Previous fMRI studies using motor tasks yielded conflicting results concerning the activation pattern in Parkinson's disease (PD) patients. Possible explanations of these discrepancies include ...differences in the clinical features of the examined patients and in the executed tasks and incomplete task monitoring. We evaluated with fMRI 20 patients with untreated de-novo PD and 11 healthy controls with a simple motor task consisting of self-paced continuous right hand-tapping. The task was monitored on-line with a dedicated device which measures the strength and frequency of the tapping. Fifteen patients performed the task correctly. The frequency was not significantly different, whereas force was slightly different between patients (26.4
±
3.0
N) and controls (28.5
±
2.4
N) (
p
=
0.046, Mann–Whitney
U-test). After insertion of the subject's frequency and force as covariate variables in the model, PD patients compared to controls showed areas of significantly
Z statistic image
>
5.1 and
p
≤
0.05 (corrected) cluster significance lower activation in the left primary sensorimotor (SM1) cortex and cerebellum and higher activation in the left temporal–parietal cortex adjacent to the SM1 and in right SM1. Furthermore in PD patients the disease severity evaluated with the Hoehn and Yahr staging system correlated significantly
Z statistic image
>
2.3 and
p
≤
0.05 (corrected) cluster significance with activation of left SM1 and supplementary motor area and cingulum, bilaterally. The mixed pattern of decreased and increased cortical activation in de novo PD patients possibly reflects the coexistence of cortical deafferentation, and compensatory phenomena by cortico-cortical circuits.
The cerebral cortex manifests an inherent structural complexity of folding. The fractal geometry describes the complexity of structures which show self-similarity in a proper interval of spatial ...scales. In this study, we aimed at evaluating in-vivo the effect of different criteria for selecting the interval of spatial scales in the estimation of the fractal dimension (FD) of the cerebral cortex in T
-weighted magnetic resonance imaging (MRI). We compared four different strategies, including two a priori selections of the interval of spatial scales, an automated selection of the spatial scales within which the cerebral cortex manifests the highest statistical self-similarity, and an improved approach, based on the search of the interval of spatial scales which presents the highest rounded R
coefficient and, in case of equal rounded R
coefficient, preferring the widest interval in the log-log plot. We employed two public and international datasets of in-vivo MRI scans for a total of 159 healthy subjects (age range 6-85 years). The improved approach showed strong associations of FD with age and yielded the most accurate machine learning models for individual age prediction in both datasets. Our results indicate that the selection of the interval of spatial scales of the cerebral cortex is thus critical in the estimation of FD.
Leukoencephalopathy with calcifications and cysts (LCC) is an uncommon condition of unknown etiology occurring in children and adults. Pathological findings include obliterative hyalinosis of the ...small vessels, myelin loss, intense gliosis, Rosenthal fiber formation, microcalcifications, and hemosiderin deposits. Herein we report a 55-year-old man with LCC documented 10 years ago, in whom we examined brain perfusion by pseudocontinuous arterial spin labeling technique. We demonstrated diffused hypoperfusion of the affected white matter (WM) and of the subcortical gray matter (GM) and cortical GM in the patient in comparison to a group of healthy control subjects, using both qualitative evaluation and region of interest analysis. WM and subcortical GM hypoperfusion reflects the known distribution of LCC microangiopathy. We speculate that cortical hypoperfusion may be related to cerebral atrophy or may reflect deafferentation secondary to severe leukoencephalopathy, and may possibly contribute to severe motor and cognitive impairment. Further studies addressing cerebral blood flow in LCC are necessary.
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