Bernhard L. Partik

3D versus 2D ultrasound: accuracy of volume measurement in human cadaver kidneys.

Partik B, Stadler A, Schamp S, et al. 3D versus 2D ultrasound. Accuracy of volume measurement in human cadaver kidneys. Invest Radiol 2002;37:489–495. Rationale and Objectives.Comparison of the accuracy of 3D and 2D ultrasound in assessing the volume of human cadaver kidneys. Materials and Methods.Before autopsy the volume of 22 kidneys was assessed from a 3D data set after manually tracing organ contours (3D volumetry) and by applying a 3D ellipsoid formula both on a 3D data set and 2D images. Measurements by water-displacement served as the gold standard. Results.3D volumetry showed a mean absolute deviation of 31 mL (18.5%) compared with the mean gold standard measurement (168 mL), yielding a concordance correlation (Lin’s &rgr;c) of 0.71. Calculation based on the ellipsoid formula revealed a mean absolute deviation of 37 mL (22.0%) when applied on the 3D data set (&rgr;c = 0.65) and of 42 mL (25.0%) when applied on 2D images (&rgr;c = 0.61), respectively. Conclusions.3D volumetry showed a satisfactory concordance correlation and is superior to volume calculation based on the ellipsoid formula either applied to a 3D data set or to conventional 2D images in assessing the volume of human cadaver kidneys.

Primary Interpretation of Thoracic MDCT Images Using Coronal Reformations

OBJECTIVE The objective of this study was to evaluate the accuracy and efficiency of primary interpretation of thoracic MDCT using coronal reformations as compared with transverse images. SUBJECTS AND METHODS Fifty patients (18 females, 32 males; age range, 15-93 years; mean age, 63.6 years) underwent 4-MDCT of the chest (detector width, 1 mm; beam pitch, 1.5). Contrast material was administered in 20 of the 50 patients. Coronal and transverse sections were reformatted into 5-mm-thick sections at 3.5-mm intervals. All available image and clinical data consensually reviewed by two thoracic radiologists served as the reference standard. Subsequently, three other thoracic radiologists independently evaluated reformatted coronal and transverse images at two separate review sessions. Each image set was assessed in 58 categories for abnormalities of the lungs, mediastinum, pleura, chest wall, diaphragm, abdomen, and skeleton. Interpretation times and number of images assessed were recorded. Sensitivity, specificity, and interobserver concordance were calculated. Differences in mean sensitivities and specificities were evaluated with Wilcoxons signed rank test. RESULTS The most common findings identified were pulmonary nodules (n = 73, transverse images; n = 72, coronal images) and emphysema (n = 45, transverse; n = 40, coronal). The mean detection sensitivity of all lesions was significantly (p = 0.001) lower on coronal (44% +/- 26% [SD]) than on transverse (51% +/- 22%) images, whereas the mean detection specificity was significantly (p = 0.005) higher (96% +/- 5% vs 95% +/- 6%, respectively). Reporting findings for significantly (p < 0.001) fewer coronal images (mean, 63.0 +/- 4.6 images) than transverse images (mean, 91.9 +/- 8.8 images) took significantly (p = 0.025) longer (mean, 263 +/- 56 sec vs 238 +/- 45 sec, respectively). CONCLUSION Primary interpretation of thoracic MDCT is less sensitive and more time-consuming using 5-mm-thick coronal reformations as compared with transverse images.

Bildgebende Verfahren: Röntgen, Ultraschall, CT, Nuklearmedizin

Auszug In der Intensivmedizin findet die radiologische Diagnostik überwiegend am Krankenbett statt (»bedside radiology«). Etwa 90% der radiologischen Untersuchungen in der Intensiv- und Notfallmedizin stellen projektionsradiographische Röntgenaufnahmen des Thorax, des Abdomens und des Skelettsystems dar. In zunehmendem Maße werden neben den klassischen Aufnahmen auch die Schnittbildverfahren eingesetzt. Hier kommt der Ultraschalldiagnostik eine führende Rolle zu, gefolgt von der Computertomographie (CT).