Computational quantitative MR image features - a potential useful tool in differentiating glioblastoma from solitary brain metastasis.

PURPOSE: Glioblastomas (GBM) and metastases are the most frequent malignant brain tumors in the adult population. Their presentation on conventional MRI is quite similar, but treatment strategy and prognosis are substantially different. Even with advanced MR techniques, in some cases diagnostic uncertainty remains. The main objective of this study was to determine whether fractal, texture, or both MR image analyses could aid in differentiating glioblastoma from solitary brain metastasis. METHOD: In a retrospective study of 55 patients (30 glioblastomas and 25 solitary metastases) who underwent T2W/SWI/CET1 MRI, quantitative parameters of fractal and texture analysis were estimated, using box-counting and gray level co-occurrence matrix (GLCM) methods. RESULTS: All five GLCM parameters obtained from T2W images showed significant difference between glioblastomas and solitary metastases, as well as on CET1 images except correlation (SCOR), contrary to SWI images which showed different values of two parameters (angular second moment-SASM and contrast-SCON). Only three fractal features (binary box dimension-Dbin, normalized box dimension-Dnorm and lacunarity-λ) measured on T2W and Dnorm measured on CET1 images significantly differed GBMs from solitary metastases. The highest sensitivity and specificity were obtained from inverse difference moment (SIDM) on T2W and SIDM on CET1 images, respectively. Combination of several GLCM parameters yielded better results. The processing of T2W images provided the most significantly different parameters between the groups, followed by CET1 and SWI images. CONCLUSIONS: Computational-aided quantitative image analysis may potentially improve diagnostic accuracy. According to our results texture features are more significant than fractal-based features in differentiation glioblastoma from solitary metastasis.

Transabdominal and transrectal ultrasonography of fetuses in Württemberg ewes: Correlation with gestational age.

It is useful to determine the gestational age in sheep to provide essential information for effective flock management practices. The aims of this study were to evaluate the efficacy and practical aspects for using two ultrasound techniques, transabdominal and transrectal, in determining the gestational age in Württemberg ewes. Monitoring of embryo and fetus developmental stages during the ewes' gestation was carried out with real time ultrasound using a transabdominal convex probe, frequency 3.5 MHz, and a transrectal linear probe, frequency 7.5 MHz. The size of the embryonic vesicle during the period from the 23rd to the 38th day of gestation can be used as a confirmational indicator of gestational age when the transrectal probe is used. The occipital nasal diameter correlated with the gestational age with both transabdominal (P < 0.05) and transrectal probes (P < 0.01) from the 46th to the 63rd day of gestation. The biparietal diameter of the fetal head measured by transabdominal probe during the period from the 46th to the 63rd day of gestation correlates with gestation age (P < 0.05). The diameter of the fetal eye orbit monitored by transrectal probe from the 46th to the 63rd day of gestation also correlated well with gestational age (P < 0.05).