Chromaticity Matrix to Tristimulus Matrix Conversion for RGB Color Spaces – Even In the Dark

Two methods to transform primary chromaticities and white point into primary tristimulus values are examined and compared. One method appears in numerous places in the literature; we refer to this as the familiar\u27\u27 method, and provide a novel interpretation of it. The second is much less well-known and is referred to as the unfamiliar\u27\u27 method. Necessary and sufficient conditions for computing primary tristimulus values from their chromaticities are identified; in brief, the triangle in the (x,y) chromaticity diagram must have non-zero area. The computational burdens for the methods were compared; the familiar method required slightly more arithmetical operations. Two problems with the familiar method were identified: high potential for rounding error and the inability to contend with a non-luminous primary. The unfamiliar method is less prone to rounding error, and is able to contend with primaries on the alychne. It is recommended that the unfamiliar method be preferred

Radiomics and prostate MRI: Current role and future applications

Multiparametric prostate magnetic resonance imaging (mpMRI) is widely used as a triage test for men at a risk of prostate cancer. However, the traditional role of mpMRI was confined to prostate cancer staging. Radiomics is the quantitative extraction and analysis of minable data from medical images; it is emerging as a promising tool to detect and categorize prostate lesions. In this paper we review the role of radiomics applied to prostate mpMRI in detection and localization of prostate cancer, prediction of Gleason score and PI-RADS classification, prediction of extracapsular extension and of biochemical recurrence. We also provide a future perspective of artificial intelligence (machine learning and deep learning) applied to the field of prostate cancer

Deep learning-based methods for prostate segmentation in magnetic resonance imaging

Magnetic Resonance Imaging-based prostate segmentation is an essential task for adaptive radiotherapy and for radiomics studies whose purpose is to identify associations between imaging features and patient outcomes. Because manual delineation is a time-consuming task, we present three deep-learning (DL) approaches, namely UNet, efficient neural network (ENet), and efficient residual factorized convNet (ERFNet), whose aim is to tackle the fully-automated, real-time, and 3D delineation process of the prostate gland on T2-weighted MRI. While UNet is used in many biomedical image delineation applications, ENet and ERFNet are mainly applied in self-driving cars to compensate for limited hardware availability while still achieving accurate segmentation. We apply these models to a limited set of 85 manual prostate segmentations using the k-fold validation strategy and the Tversky loss function and we compare their results. We find that ENet and UNet are more accurate than ERFNet, with ENet much faster than UNet. Specifically, ENet obtains a dice similarity coefficient of 90.89% and a segmentation time of about 6 s using central processing unit (CPU) hardware to simulate real clinical conditions where graphics processing unit (GPU) is not always available. In conclusion, ENet could be efficiently applied for prostate delineation even in small image training datasets with potential benefit for patient management personalization

CT imaging findings of abdominopelvic vascular compression syndromes: what the radiologist needs to know

Abdominopelvic vascular compression syndromes include a variety of uncommon conditions characterized by either extrinsic compression of blood vessels by adjacent anatomical structures (i.e., median arcuate ligament syndrome, nutcracker syndrome, May-Thurner syndrome) or compression of hollow viscera by adjacent vessels (i.e., superior mesenteric artery syndrome, ureteropelvic junction obstruction, ureteral vascular compression syndromes, portal biliopathy). These syndromes can be unexpectedly diagnosed even in asymptomatic patients and the predisposing anatomic conditions can be incidentally discovered on imaging examinations performed for other indications, or they can manifest with atypical abdominal symptoms and acute complications, which may lead to significant morbidity if unrecognized. Although computed tomography (CT) is an accurate noninvasive technique for their detection, the diagnosis remains challenging due to the uncommon clinical presentation and often overlooked imaging features. Dynamic imaging may be performed in order to evaluate patients with inconstant symptoms manifesting in a specific position. The purposes of this paper are to review the CT imaging findings of abdominopelvic vascular compression syndromes, correlating with anatomical variants and to provide key features for the noninvasive imaging diagnosis

T-L technique for HoLEP: perioperative outcomes of a large single-centre series

Introduction: The aim of this article was to describe, step-by-step, an original technique (T-L technique) in a single centre series of patients who underwent holmium laser enucleation of the prostate (HoLEP) for symptomatic benign prostatic hyperplasia and analyze perioperative outcomes. Material and methods: We retrospectively analyzed data of 567 patients who underwent HoLEP. The T-L technique consists of a series of incisions used as landmarks, performed at the beginning of the procedure before enucleation. Two T-shape incisions are performed at the level of bladder neck (at the 5-7 and 12 o'clock positions); two L-shape incisions are performed at the level of verumontanum, bilaterally, to mark the apex and to limit the sphincter. Another T-shape incision is performed on the bladder neck at the 12 o'clock position posterior to the level of verumontanum. Results: The median operative time (OT) was 80 minutes (IQR 64-105); 50 minutes (IQR 35-70) and 15 minutes (IQR 10-20) for enucleation and the morcellation phase, respectively. Conversion to transurethral resection of the prostate (TURP) was necessary in 3/567 (0.6%) patients. Intraoperative complications occurred in 3.4% of cases, capsule perforation occurred in 12/567 (2%) of cases, while bladder perforation during morcellation occurred in 8/567 (1.4%) of cases. Postoperative complications were observed in 20/567 (3.5%) of patients. Specifically, grade 1-2 occurred in 19/567 (3.3%) and grade 3 was recorded in 1/567 (0.2%). Conclusions: The T-L technique for HoLEP is safe and reproducible with a low rate of perioperative complications. The positioning of some landmarks before enucleation allows for the better orientation during enucleation and could be very useful in case of large prostates

Clinical and genetic factors associated with kidney tubular dysfunction in a real-life single centre cohort of HIV-positive patients

BACKGROUND: Tenofovir (TDF) is one of the most widely used antiretroviral drug. Despite the high degree of tolerability a small percentage of patients experienced alteration in tubular function during TDF use. Intracellular TDF disposition is regulated by ATP-binding cassette (ABC) drug efflux transporters and, a reduced transport activity may be implicated in accumulation of TDF into the cells. The aim of our study was to assess the major determinants of TDF associated tubular dysfunction (KTD) in a real-life setting including the usefulness of single-nucleotide polymorphisms (SNPs) mapping into ABCC2, ABCC4 and ABCC10 genes. METHODS: We retrospectively analyzed all HIV positive patients who were followed at the Infectious Diseases Unit, DIBIC Luigi Sacco, University of Milan from April 2013 to June 2016. All patients treated with TDF who underwent a genotypization for the functional variants mapping in ABCC2 rs717620 (-24 C > T), ABCC4 rs1751034 (3463 A > G) and ABCC10 rs2125739 (T > C) were evaluated. KTD was defined as the presence of urine phosphate wasting and/or proteinuria at 24 h urine analysis. RESULTS: One hundred fifty-eight patients were genotyped, of which 42 (26.6%) experienced signs of KTD. No statistical significant differences were observed among patients with or without KTD regarding age, gender, ethnicity and comorbidities (hypertension and diabetes). The percentage of patients with KTD was higher among those with "GG" genotype at rs1751034 of ABCC4 compared to patients without KTD [6 (14.3%) vs 4 (3.5%), p = 0.01]. No statistical significant differences were observed regarding the distribution of ABCC2 and ABCC10 SNPs. Carriers of "G" allele in homozygous status at rs1751034 of ABCC4 showed a significant association with KTD (Odds Ratio 4.67, 95% CI 1.25-17.46, p = 0.02) in bivariate analysis, but this association was lost in multivariable analysis. A significant association between bone diseases and KTD was observed (Odds Ratio 3.178, 95%CI 1.529-6.603, p = 0.002). CONCLUSIONS: According to our results ABCC4 rs1751034 could be a genetic determinant of KTD; however validation studies are needed for therapy personalization. Noteworthy, a strong association between bone disease and KTD was also observed

A new Ultraluminous X-ray source in the galaxy NGC 5907

We report on the serendipitous discovery of a new transient in NGC 5907, at a peak luminosity of 6.4x10^{39} erg/s. The source was undetected in previous 2012 Chandra observations with a 3 sigma upper limit on the luminosity of 1.5x10^{38} erg/s, implying a flux increase of a factor of >35. We analyzed three recent 60ks/50ks Chandra and 50ks XMM-Newton observations, as well as all the available Swift observations performed between August 2017/March 2018. Until the first half of October 2017, Swift observations do not show any emission from the source. The transient entered the ULX regime in less than two weeks and its outburst was still on-going at the end of February 2018. The 0.3-10 keV spectrum is consistent with a single multicolour blackbody disc (kT~1.5 keV). The source might be a ~30 solar mass black hole accreting at the Eddington limit. However, although we did not find evidence of pulsations, we cannot rule-out the possibility that this ULX hosts an accreting neutron star.Comment: Accepted on MNRAS, 5 pages, 2 figure, 1 tabl

ANATOMICAL DISSECTION AND ANALYSIS OF THE STRUCTURES OF THE UPPER LIMB

In 2015, a whole body dissection course was proposed by the University of Palermo, Palermo, Italy, thanks to the cooperation with the University of Malta, Msida, Malta. The purpose of this study was to show the the difference between the studyof anatomy on books and on corpses. The article focuses its attention on the dissection method of the upper limb. The astudy was performed on two corpses, a male and a female, by using a basic surgeon kit. Blunt dissection method was used for fasciae, innards and to isolate vascular-nervous structures from the fat; we used scalped for cutis, sub cutis, muscles, fasciae, veins, arteries and nerves of the upper limb from the shoulder to the hand. The upper limb dissection shows the difference between how a real body appears and shows the difference between how a real body appears and how books represent it