A straightforward method for assessing the technical image quality of reconstructed and synthetic 2D images for Digital breast tomosynthesis systems.

Purpose: Digital Breast Tomosynthesis (DBT) is an advanced mammography technique for which there are currently no internationally agreed methods and reference values for image quality assessment. The aim of this multicentre study was to evaluate a simple method to assess the technical image quality of reconstructed and synthetic 2D (SM) images of different models of DBT systems using commercially available phantoms.

Methods: The signal difference to noise ratio (SDNR) was chosen as an index of technical image quality and was evaluated for three commercial phantoms, Tomophan, Tormam and CIRS model 015, on 55 DBT systems (six vendors, nine models).

In vivo dosimetry of total body irradiation patients: A 10 year retrospective analysis.

Myeloablative Total Body Irradiation (TBI) used in our Institution, as part of the conditioning scheme for haematopoietic stem cell transplantation, is an extended-distance supine technique that has been implemented using a 15 MV LINAC beam, lead lung compensators, PMMA, and water bolus to improve homogeneity. This study reviews in-vivo dosimetry (IVD) over 10 years of treatments, assessing the technique's robustness, accuracy, and efficiency. A 2-lateral opposite fields plan was calculated from planning CT with validated Oncentra TPS (Elekta AB, Sweden).

Typical values of z-resolution for different Digital Breast Tomosynthesis systems evaluated in a multicenter study.

Purpose: The aim of the present study, conducted by a working group of the Italian Association of Medical Physics (AIFM), was to define typical z-resolution values for different digital breast tomosynthesis (DBT) models to be used as a reference for quality control (QC). Currently, there are no typical values published in internationally agreed QC protocols.

Methods: To characterize the z-resolution of the DBT models, the full width at half maximum (FWHM) of the artifact spread function (ASF), a technical parameter that quantifies the signal intensity of a detail along reconstructed planes, was analyzed.

Spatio-temporal generalized Model Observers methods for Low Contrast Detectability assessment in digital angiography: Application to moving targets.

The purpose of this work is to investigate the feasibility of spatio-temporal generalized Model Observer methods for protocol optimization programs in the field of interventional radiography. Two Model Observers were taken under examination: a Channelized Hotelling Observer with 24 spatio-temporal Gabor channels and a Non Pre-Whitening Model Observer with two different implementations of the spatio-temporal contrast sensitivity function. The images of targets, both stationary and in motion, were acquired in fluoroscopic mode using a CDRAD phantom for signal-present images and an homogenous slab of PMMA for signal-absent ones.

Statement of the Italian Association of Medical Physics (AIFM) task group on radiation dose monitoring systems.

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 software is far to be achieved. Toward this goal, the Italian Association of Medical Physics (AIFM) published a report describing the state of the art and standard guidelines in radiation dose monitoring system quality assurance.

A single phantom, a single statistical method for low-contrast detectability assessment.

Purpose: The assessment of low-contrast-details is a part of the quality control (QC) program in digital radiology. It generally consists of evaluating the threshold contrast (Cth) detectability details for different-sized inserts, appropriately located in dedicated QC test tools. This work aims to propose a simplified method, based on a statistical model approach for threshold contrast estimation, suitable for different modalities in digital radiology.

Model observers for Low Contrast Detectability evaluation in dynamic angiography: A feasible approach.

Purpose: To evaluate the feasibility of spatio-temporal generalisation of mathematical methods for protocol optimisation in interventional radiology.

Materials And Methods: Two model observers were considered:Furthermore, Low Contrast Detectability (LCD) was evaluated with a generalised statistical method by taking into account the noise integration capability of the human eye. A series of two alternative force choices (2AFC) experiments performed by four observers were used to evaluate the reliability of the proposed models.

Patient dose in angiographic interventional procedures: A multicentre study in Italy.

Purpose: The Council Directive 2013/59/EURATOM considers interventional radiology to be a special practice involving high doses of radiation and requiring strict monitoring to ensure the best quality assurance programs. This work reports the early experience of managing dose data from patients undergoing angiography in a multicentre study.

Materials And Methods: The study was based on a survey of about 15,200 sample procedures performed in 21 Italian hospitals centres involved on a voluntary basis.

Evaluation of a commercial Model Based Iterative reconstruction algorithm in computed tomography.

Introduction: Iterative reconstruction algorithms have been introduced in clinical practice to obtain dose reduction without compromising the diagnostic performance.

Purpose: To investigate the commercial Model Based IMR algorithm by means of patient dose and image quality, with standard Fourier and alternative metrics.

Materials And Methods: A Catphan phantom, a commercial density phantom and a cylindrical water filled phantom were scanned both varying CTDI and reconstruction thickness.

Quality assurance multicenter comparison of different MR scanners for quantitative diffusion-weighted imaging.

Purpose: To propose a magnetic resonance imaging (MRI) quality assurance procedure that can be used for multicenter comparison of different MR scanners for quantitative diffusion-weighted imaging (DWI).

Materials And Methods: Twenty-six centers (35 MR scanners with field strengths: 1T, 1.5T, and 3T) were enrolled in the study.

Simultaneous liver iron and fat measures by magnetic resonance imaging in patients with hyperferritinemia.

Objective: Hyperferritinemia is frequent in chronic liver diseases of any cause, but the extent to which ferritin truly reflects iron stores is variable. In these patients, both liver iron and fat are found in variable amount and association. Liver biopsy is often required to quantify liver fat and iron, but sampling variability and invasiveness limit its use.

Dosimetric evaluation of a 256-slice computed tomography scanner.

Purpose: This study evaluated the effectiveness of patient dose reduction tools on a 256-slice computed tomography scanner (Brilliance iCT, Philips).

Materials And Methods: The performance of the Brilliance iCT scanner was described in terms of cumulative dose and dose-normalised contrast-to-noise ratio (CNRD). The efficiency of automatic tube current modulation (Z-Dom and D-Dom), shaping filters (SmartShape and IntelliBeam) and asymmetric collimator (Eclipse) was evaluated using appropriate phantoms.

Acceptance tests of diagnostic displays in a PACS system according to AAPM TG18.

In a filmless environment it is necessary to execute acceptance and constancy tests on monitors used for interpretation of medical images. Performances of Barco CRT MGD521 MKII, Barco LCD L685EX monitors have been evaluated. Acceptancepress were executed following AAPM Task Group 18 guidelines.

Grayscale calibration and quality assurance of diagnostic monitors in a PACS system.

Purpose: The aim of this study was to calibrate monitors used in soft-copy review of diagnostic images in a pictures archiving and communication system (PACS) and to assess critical quality assurance (QA) parameters through appropriate checks.

Materials And Methods: Barco [cathode ray tube (CRT) and liquid crystal display (LCD)] and EIZO (LCD) monitors were evaluated. Calibration and QA controls were carried out during acceptance tests on the systems and every 6 months according to the Task Group 18 (TG18) report by the American Association of Physicists in Medicine (AAPM).

[The evaluation of the physical characteristics of a volumetric computer tomograph].

Spiral or volumetric computed tomography (CT) is a new scanning technique which allows the scanning of body regions with a continuously rotating system based on the slip ring technology; the patient is also moved continuously, synchronously with data acquisition. The physical characteristics of spiral CT image acquisition were compared with those of conventional CT images. The modulation transfer function (MTF) has the same values for medium-resolution filters, but lower values for spiral CT for high-resolution and frequency-enhancement filters.

[The spatial resolution of the digital storage phosphor system. The monitor and film compared].

The physical characteristics of radiographic images, namely spatial resolution and contrast, have obvious effects upon diagnostic image usefulness. We investigated the spatial resolution of both radiographs and magnified digital obtained with a storage phosphor system, in comparison with a film-screen combination. This study was carried out on the conventional radiographs of a phantom grid 0.

[Dosimetric evaluations in dental radiology: comparison of the digital system and the conventional system].

The dosimetric values measured on digital dental examinations (panoramic radiography and cephalography) were compared with those obtained with screen-film combinations. The X-ray dose was measured at the critical organs (lens, thyroid, cervical cord) on an anthropomorphic phantom, using thermoluminescence dosimeters and an ionization chamber: the radiographic unit was set at the same exposure values used for standard human studies in adults and children. The mean thyroid dose for screen-film panoramic radiographs was 0.

[Radiographic enlargement in the study of hand diseases. Digital versus conventional techniques].

The electronic magnification of digital images was compared with direct digital magnification and with plain radiograph magnification. A whole-body computed radiographic system with photostimulable phosphor plates contained inside standard X-ray cassettes was used. The small bones of the hands and wrists of 18 patients with traumatic (10 cases) or degenerative (8 cases) bone conditions mainly due to chronic renal failure were studied.

[The detectability of osteoarticular lesions of the extremities on the television monitor].

The diagnostic accuracy of the light-box reading of conventional (film screen) radiographs of the extremities was compared with that of the same set of images displayed on a 1 k x 1 k interactive monitor after laser digitization. 389 alterations (23 nondisplaced fractures, 129 soft-tissue calcifications and 237 articular bone erosions), identified by two experienced radiologists on 66 conventional radiographs, were the reference standard. ROC statistical analysis was performed on 1,556 observations expressed by four readers.

[Detection of small bone lesions with digital radiography using storage phosphors].

To date, the skeletal imaging capabilities of digital radiography with storage phosphors have been poorly investigated, and the diagnostic accuracy of this technique has not been thoroughly assessed. To evaluate the performance of storage phosphor digital radiography we compared 66 conventional and 66 digital radiographs of small abnormalities of the extremities (fractures, erosions, calcifications). Conventional images were obtained with a low-speed screen-film system while digital ones were acquired with high-resolution (5 lp/mm max) phosphors and laser-printed on a 8" x 10" film.