Francesco Ria

Duke University | DU · Radiology Department - Clinical Imaging Physics Group

Purpose: Modern CT systems adjust x-ray flux accommodating for patient size to achieve certain image noise values. The effectiveness of this adaptation is an important aspect of CT performance and should ideally be characterized in the context of real patient cases. The objective of this study was to characterize CT performance with a new metric t...

OBJECTIVE. Diagnostic reference levels were developed as guidance for radiation dose in medical imaging and, by inference, diagnostic quality. The objective of this work was to expand the concept of diagnostic reference levels to explicitly include noise of CT examinations to simultaneously target both dose and quality through corresponding referen...

Purpose: Phantoms are useful tools in diagnostic CT, but practical limitations reduce phantoms to being only a limited patient surrogate. Furthermore, a phantom with a single cross sectional area cannot be used to evaluate scanner performance in modern CT scanners that use dose reduction techniques such as Automated Tube Current Modulation (ATCM)...

Objective. The outbreak of coronavirus SARS-COV2 disease 2019 (COVID-19) necessitates fast and accurate diagnostic tools. RT-PCR has been identified as gold standard test with Chest-CT and Chest-Radiography showing promising results as well. However, several institutions are discouraging the use of radiological procedures for COVID-19 diagnosis, pa...

Objectives Quantifying radiation burden is essential for justification, optimization, and personalization of CT procedures and can be characterized by a variety of risk surrogates inducing different radiological risk reflections. This study compared how twelve such metrics can characterize risk across patient populations.Methods This study included...

A comparative assessment of the absorbed doses resulted from computed tomography (CT) examinations, and the dose resulted from occupational external gamma exposure of the “Mayak” workers was carried out. The patients’ diagnostic radiation dose was reconstructed using Monte-Carlo simulation on a population of 58 virtual adult phantoms across 13 CT p...

The evaluation of radiation burden in vivo is crucial in modern radiology as stated also in the European Directive 2013/59/Euratom—Basic Safety Standard. Although radiation dose monitoring can impact the justification and optimization of radiological procedure, as well as effective patient communication, standardization of radiation monitoring soft...

Objective: To devise a patient-informed time series model that predicts liver contrast enhancement, by integrating clinical data and pharmacokinetics models, and to assess its feasibility to improve enhancement consistency in contrast-enhanced liver CT scans. Methods: The study included 1577 Chest/Abdomen/Pelvis CT scans, with 70-30% training/va...

Purpose: The gold-standard method for estimation of patient-specific organ doses in digital tomosynthesis (DT) requires protocol-specific Monte Carlo (MC) simulations of radiation transport in anatomically accurate computational phantoms. Although accurate, MC simulations are computationally expensive, leading to a turnaround time in the order of...

Purpose To estimate cumulative organ doses and age- and gender-stratified cancer mortality risks in patients undergoing recurrent computed tomography (CT) exams. Methods Cohorts of patients who received cumulative effective dose ≥100 mSv were stratified into age and gender groups. Organ doses of 27 organs using Monte Carlo methods were available,...

Purpose: Accurate classification of COVID-19 in chest radiographs is invaluable to hard-hit pandemic hot spots. Transfer learning techniques for images using well-known convolutional neural networks show promise in addressing this problem. These methods can significantly benefit from supplemental training on similar conditions, considering that the...

Purpose. Recent studies have shown that it is not uncommon for a patient to undergo multiple CT exams resulting in high cumulative dose above 100 mSv, the radiation risk associated with which is not negligible. The purpose of this study was to compare the estimated radiation risk in a large population of such cases based on effective dose to estima...

Purpose. Risk in medical imaging is a combination of radiation risk and clinical risk, which is largely driven by the effective diagnosis. While radiation risk has traditionally been the main focus of Computed Tomography (CT) optimization, such a goal cannot be achieved without considering clinical risk. The purpose of this study was to develop a c...

A Correction to this paper has been published: https://doi.org/10.1007/s00330-021-07903-z

Image quality estimation is crucial in modern CT with noise magnitude playing a key role. Several methods have been proposed to estimate noise surrogates in vivo. This study aimed to ascertain the accuracy of three different noise-magnitude estimation methods. We used ensemble noise as the ground truth. The most accurate approach to assess ensemble...

OBJECTIVE. The purpose of this study is to comprehensively implement a patient-informed organ dose monitoring framework for clinical CT and compare the effective dose (ED) according to the patient-informed organ dose with ED according to the dose-length product (DLP) in 1048 patients. MATERIALS AND METHODS. Organ doses for a given examination are c...

In a highly technological discipline like medical physics, even the highest education needs to be integrated with specific competencies sufficient to practice imaging physics independently. To this end, the American Board of Radiology (ABR) provides an alternate pathway to board certification for medical physicists trained in countries other than t...

Objective To determine the correlation between patient attributes and contrast enhancement in liver parenchyma and demonstrate the potential for patient-informed prediction and optimization of contrast enhancement in liver imaging. Methods The study included 418 chest/abdomen/pelvis computed tomography scans, with 75% to 25% training-testing spl...

Objective: The outbreak of coronavirus SARS-COV2 affected more than 180 countries necessitating fast and accurate diagnostic tools. Reverse transcriptase polymerase chain reaction (RT-PCR) has been identified as a gold standard test with Chest CT and Chest Radiography showing promising results as well. However, radiological solutions have not been...

Purpose: Patient radiation burden in CT can best be characterized through risk estimates derived from organ doses. Organ doses can be estimated by Monte Carlo simulations of the CT procedures on computational phantoms assumed to emulate the patients. However, the results are subject to uncertainties related to how accurately the patient and CT pro...

Computed tomography (CT) is a leading advanced imaging modality today. Its use, however, has raised concerns regarding utilization costs, appropriate applications, and the associated potential radiation risks. Programmatic radiation dose reporting software has emerged to monitor radiation exposure towards proper CT imaging. Proper imaging implies b...

Purpose. Radiological risk is a combination of radiation and clinical risk (likelihood of not delivering a proper diagnosis), which together may be characterized as a total risk index (TRI). While many strategies have been developed to ascertain radiation risk, there has been a paucity of studies assessing the clinical risk. This knowledge gap make...

Purpose: Automated assessment of perceptual image quality on clinical Computed Tomography (CT) data by computer algorithms has the potential to greatly facilitate data-driven monitoring and optimization of CT image acquisition protocols. The application of these techniques in clinical operation requires the knowledge of how the output of the compu...

Purpose: The purpose of this study was to simulate and validate organ doses from different CT localizer radiograph geometries using Monte Carlo methods for a population of patients. Methods: A Monte Carlo method was developed to estimate organ doses from CT localizer radiographs using PENELOPE. The method was validated by comparing dosimetry est...

Purpose. Automated Tube Current Modulation (ATCM) systems are implemented in modern CT scanners adjusting X-ray flux for patient size to save patient dose and achieve uniform image quality. Different vendors developed different ATCM strategies that offer different relationship between dose, noise, and patient size. Therefore, there is a need to ass...

Purpose. Diagnostic Reference Level (DRL) is a typical radiation metric reported for achieving optimum dose and patient safety. DRLs represent "only a first step in the overall optimization process" (IAEA). Therefore, the concept of DRL needs to be expanded to incorporate diagnostic quality. The objective of this work was to expand DRL to new dose...

Introduction: The European Directive 2013/59/EURATOM requires patient radiation dose information to be included in the medical report of radiological procedures. To provide effective communication to the patient, it is necessary to first assess the patient's level of knowledge regarding medical exposure. The goal of this work is to survey patients...

A new social role for medical physicists: the Italian Association of Medical Physics (AIFM) free web section 'ilfisicomedicorisponde' to convey the clear and scientific information to public

Purpose: Radiologic procedures are optimized based on a benefit-to-risk. However, risk has been the primary focus of radiology optimization and dose monitoring. Such programs are typically based on the concept of Diagnostic Reference Level (DRL). The term “diagnostic” implies image quality, yet DRL refers to radiation dose. The purpose of this stud...

Purpose: Iodinated contrast agents are commonly used in computed tomography (CT) to delineate vasculature and blood perfusion by enhancement of Hounsfield unit values. Contrast-enhancement is affected by anatomical and physiological factors, and varies across patients. The purpose of this study was to quantify the variability of the contrast-enhanc...

Purpose: Current radiation dose estimation for CT localizer exams report a single CTDIvol value. Localizer exams with the same CTDIvol can be acquired as AP, PA, or lateral geometries, each of which carry different radiation burdens. The Purpose of this study was to quantify radiation burden from different CT localizer geometries using Monte-Carlo...

Purpose: Evolution in European and American legislations and scientific initiatives, such as IAEA_Rpop, Image Wisely, and Image Gently, are leading to a new multidisciplinary approach in radiology, and to an increase in patient awareness. In this scenario, there is a need of a new social role for medical physicists. This work describes the Italian...

Purpose: To develop a robust and accurate automated solution for measuring image noise, spatial resolution, contrast, and radiation dose using clinical patient CT images. Methods: An automated infrastructure has been developed to measure the image quality and radiation dose metrics from daily clinical CT images data routed through the picture archi...

Purpose: American and European legislation, as well as scientific initiative such IAEA RPOP and Image Wisely, have described a new approach to optimization and patient awareness in radiology. Therefore, there is a need for a new medical physicist role that can convey correct and effective information to patients. This work describes a four-year rad...

Abstract In the radiolabelling process, the frequency of routine analytical testing must be defined with a risk assessment based on different factors (Pharmeuropa Vol. 26 No. 2, 5.19). Aim of this study is to define the criteria based on the risk assessment required for setting the frequency of analytical controls. 331 preparations of three differe...

Purpose:Inconsistency in the scan range for a given protocol can be a source of variability in patient dose. The purpose of this study was to determine the variability in the over-scan length in clinical CT operation for chest and abdominopelvic (A&P) protocols. Methods:A total of 51 abdomen-pelvis and 121 chest CT exams were randomly selected from...

Background: The gold standard treatment for early stage non small-cell lung cancer (NSCLC) is surgical resection. For patients (pts) considered medically or functionally not amenable with surgery, radiotherapy is the alternative treatment. In the last years impressive local control (LC) rates have been reported using stereotactic radiotherapy treat...

An assessment of the new monograph chapter Compounding of Radiopharmaceuticals has been conducted on the basis of the first period of implementation of Italian legislation on Good Radiopharmaceuticals Practice (NBP) in the preparation of radiopharmaceuticals, in keeping with Decree by the Italian Ministry of Health dated March 30, 2005. This approa...