Giacomo Aringhieri

Evaluation of Dosimetric Properties in Full Field Digital Mammography (FFDM) - Development of a New Dose Index

According to the World Health Organization (WHO), breast cancer is the most common cancer in women, constituting 29% of all cancers related to the female population. In this context, Full Field Digital Mammography (FFDM) is the reference imaging technique for breast cancer early detection and diagnosis and it is widely employed in screening programs. Therefore, the absorbed radiation dose for each examination shall be evaluated in order to ensure proper radiation exposures for the patient. In addition, the new European Directive 59/2013/EURATOM requires that dosimetric data referred to the radiation exposure should be inserted in the radiological report. For these reasons, we designed a multidisciplinary research project with the intention of realizing and validating a new method for calculating the Average Absorbed Breast Dose (2ABD) by the patient during a mammography procedure. The innovative aspect regards the availability of a quantitative and personalized dosimetric parameter, providing an index that is patient-specific rather than related to the X-ray machine output, directly related to the risk of radiation. Specifically, in this work we present our scientific approach as well as the initial results.

Radiation dose exposure in patients affected by lymphoma undergoing repeat CT examinations: how to manage the radiation dose variability

PurposeTo assess the variability of radiation dose exposure in patients affected by lymphoma undergoing repeat CT (computed tomography) examinations and to evaluate the influence of different scan parameters on the overall radiation dose.Materials and methodsA series of 34 patients (12 men and 22 women with a median age of 34.4 years) with lymphoma, after the initial staging CT underwent repeat follow-up CT examinations. For each patient and each repeat examination, age, sex, use of AEC system (Automated Exposure Control, i.e. current modulation), scan length, kV value, number of acquired scans (i.e. number of phases), abdominal size diameter and dose length product (DLP) were recorded. The radiation dose of just one venous phase was singled out from the DLP of the entire examination. All scan data were retrieved by our PACS (Picture Archiving and Communication System) by means of a dose monitoring software.ResultsAmong the variables we considered, no significant difference of radiation dose was observed among patients of different ages nor concerning tube voltage. On the contrary the dose delivered to the patients varied depending on sex, scan length and usage of AEC. No significant difference was observed depending on the behaviour of technologists, while radiologists’ choices had indirectly an impact on the radiation dose due to the different number of scans requested by each of them.ConclusionsOur results demonstrate that patients affected by lymphoma who undergo repeat whole body CT scanning may receive unnecessary overexposure. We quantified and analyzed the most relevant variables in order to provide a useful tool to manage properly CT dose variability, estimating the amount of additional radiation dose for every single significant variable. Additional scans, incorrect scan length and incorrect usage of AEC system are the most relevant cause of patient radiation exposure.

Traumatic Chest Wall Injuries

A chest wall injury can occur as the result of a blunt or a penetrating trauma and more than two-thirds of cases are determined by motor vehicle collisions (MVC). Other less common causes include falls from height, sport injuries, or blows from blunt objects. Minor chest wall injuries are represented by rib fractures (the most common findings), soft-tissue contusions, and hematomas that may be produced by arterial or venous bleeding. Major chest wall injuries include deep organs laceration and flail chest syndrome (seen in 6% of patients with rib fractures), an immediate life-threatening injury that require evaluation and treatment during the primary survey. Imaging plays a fundamental role in the diagnosis. Chest X-ray (CXR) is typically used as the first and, in most cases, as the only diagnostic technique. Multi-detector computed tomography (MDCT) must be performed in stable polytrauma patients or in doubtful cases at initial plain film study and has a very high sensibility and specificity; it can demonstrate significant disease in patients with negative initial CXR images, thus changing their clinical management. MRI plays a limited role in the diagnosis in the ED. In this chapter, we will treat imaging findings, natural history, and treatment of different traumatic conditions included in chest trauma such as rib fractures, first rib and lateral rib fractures, costochondral injuries, flail chest, sternal fractures, sternochondral injuries, and sternoclavicular dislocation; costovertebral dislocation, scapulo-thoracic dissociation, scapular fractures, and chest wall hematoma.

Average absorbed breast dose in mammography: a new possible dose index matching the requirements of the European Directive 2013/59/EURATOM

BackgroundThe new European Directive 2013/59/EURATOM requires that patients are informed about the risk associated with ionising radiation and that detailed information on patient exposure is included in the radiological report. This implies a revision of the routinely used dose indexes to obtain quantities related to individual exposure evaluable from acquisition parameters. Here we propose a new mammography dose index consistent with the average glandular dose (AGD).MethodsAn equation has been developed for calculating the average absorbed breast dose (2ABD). It depends on incident air kerma ka,i and on energy absorption coefficient μen; ka,i can be calculated for each anode-filter combination, based on kVp, mAs, the yield of the tube used Ytb, and the breast thickness d; μen depends on kVp and has been evaluated for each anode-filter combination. 2ABD has been compared to AGD evaluated by Dance or Wu methods, which represent the reference standards, for 20 patients of our university hospital.ResultsThe incident air kerma ka,i, calculated as a function of kVp, mAs, Ytb and d, was in good agreement with the same quantity directly measured: the relative uncertainty is < 0.10. The results of the comparison between 2ABD and AGD evaluated by both Dance and Wu methods appear to be consistent within the uncertainties.Conclusions2ABD is easily evaluable for each mammogram from the acquisition parameters. It can be proposed as a new suitable dose index, consistent with AGD, matching the requirements of the 2013 European Directive.

Hydronephrosis and Pyonephrosis

Urinary tract infections (UTIs) are a frequent clinical problem in infants and children, and they may develop into serious complications with long-term sequelae. Their prevalence varies according to age and sex: males are more interested in the neonatal period and in the first year of age, while females are more involved after that time. The clinical outcome and the severity of UTIs depend on many risk factors including urinary tract malformations and dysfunctions, virulence and properties of the pathogen, host response to the infection, and promptness of diagnosis and management.