Tehran University Medical Journal

Background: Due to intrinsic heterogeneity of cellular distribution and density within diffusion weighted images (DWI) of glioblastoma multiform (GBM) tumors, differentiation of active tumor and peri-tumoral edema regions within these tumors is challenging. The aim of this paper was to take advantage of the differences among heterogeneity of active tumor and edematous regions within the glioblastoma multiform tumors in order to discriminate these regions from each other.
Methods: The dataset of this retrospective study was selected from a database which was collected at the medical imaging center, Imam Khomeini Hospital, Tehran University of Medical Sciences, Iran. The quantification was performed as a part of a research study being supported by the Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Iran, between May and September 2017. Twenty patients with histopathologically-confirmed GBM tumors who had been imaged on a 3T MRI scanner prior to their surgery, were included. Conventional and diffusion weighted MR images had been carried out on the patients. The regions of interest including the regions of active tumor and edema were identified on MR images by an expert and overlaid on ADC-maps of the same patients. Histogram analysis was performed on each of these regions and 14 characteristic features were calculated and the best feature combination for discrimination of active tumor from edema was obtained.
Results: It was shown that by combining 8 out of 14 histogram features, including median, normalized mean, standard deviation, skewness, energy, 25th, 75th, and 95th percentiles, differentiation with accuracy of 96.4% and diagnostic performance of 100% can be achieved. Furthermore, by combining mean, energy, and 75th percentile features of histograms, the active tumor region can be discriminated from the edematous region by 92.7% of accuracy and 98.9% of diagnostic performance.
Conclusion: The present study confirms that the heterogeneity of cellular distribution can be a predictive biomarker for differentiation of edematous regions from active tumor part of GBM tumors.

Background: Prostate cancer (PCa) has been one of the most prevalent cancers in men in recent years. Multi-parametric magnetic resonance imaging (mp-MRI) has been increasingly applied in the diagnosis, localization and staging of prostate cancer. This approach uses a combination of morphology information obtained from T2-weighted image along with at least two functional imaging modalities, such as diffusion-weighted (DWI), dynamic-contrast-enhancement (DCE), and magnetic-resonance-spectroscopy (MRS). This review gives a comprehensive overview of the theories and methodologies of the mp-MRI for diagnosing prostate cancer. The search was fulfilled using a list of search engines.
Methods: In this study, with a systematic review of studies conducted during February 2015 to October 2021, the role and potential of integrating the results of morphological and functional imaging in a multi-parameter approach were evaluated and the optimal combination was introduced. This article collected studies that have employed mp-MRI in prostate cancer including: peer-reviews, research articles, academic reports and conferences. This review has been studied from September 2016 to January 2022.

Results: According to the reported results, the optimum combination of T2-w, DWI and DCE in the mp-MRI approach provides the highest sensitivity and specificity in the diagnosis, localization and staging of prostate cancer. Applying the field strength of 3T versus 1.5T improves detection accuracy including improving sensitivity and specificity as well, and also the application of endorectal coils does not provide much advantage compared to pelvic phased-array coil in term of prostate cancer detection accuracy.  Conclusion: MP-MRI as a precision instrument plays a valuable role in the diagnosis of prostate cancer. The most suitable combination of the pulse sequences to achieve the goals of this approach is T2-w, DWI and DCE. This review is comprehensive overview covered previous articles of mp-MRI in prostate cancer for all the researchers in this field and expresses the positive and negative points of each modality. Moreover, this article reports the sensitivity and the Specificity of the recent researches.