95 / 146
Correct Response
Dose reduction
90%
4%
85%
15%
80%
22%
Conclusions:
For very high and very low dose levels, the Radiology De-
partment performance was similar for both ASIR and FBP algorithms. It has
been found that there is a certain dose level at which ASIR enhances the
“diagnostic capability” with respect to FBP and shows its maximum
performance.
http://dx.doi.org/10.1016/j.ejmp.2016.01.308B.304
ANALYSIS ON PHANTOM IMAGES BETWEEN 2D SYNTHESIZED
MAMMOGRAPHY (SM) FROM DIGITAL BREAST TOMOSYNTHESIS (DBT)
AND FLAT FIELD MAMMOGRAPHY (FFDM)
R. Rosasco
*
, F. Bisi, N. Canevarollo.
Fisica Sanitaria A.S.L. 3 Genovese, Genova,
Italy
Introduction:
In mammography DBT, combined with 2D mammography
(combo), has better performance than conventional FFDM, improving cancer
detection by reducing the superimposition of breast structures.
In recent years companies have developed software to generate SM views
from a DBT dataset. Clinical retrospective studies, analyzing the perfor-
mance of SM associated to DBT compared to conventional 2D alone,
underline that SM offers a dosimetric benefit to the patients, since the ra-
diation dose comes only from DBT instead of combo exposure, and a contrast
improvement in calcifications. No significant differences in diagnostic ac-
curacy appear between SM and FFDM.
The aim of this study is to compare FFDM and SM, acquiring different phan-
toms, with some objective representative parameters.
Materials and Methods:
In order to compare FFDM with SM generated by
DBT, we acquired phantom images in combo mode, using a Hologic unit
with a dedicated software (C-view) to obtain SM.
We used different types of phantoms: contrast, geometric and details phan-
toms and PMMA slabs of different thicknesses with Al details placed on
the surface and at various depths in the phantom. Initially we defined the
most representative acquisition configurations and which physical param-
eters to study.
Results:
The exposures have beenmade with the phantoms positioned hor-
izontally and skewed on the detector plane in order to have the inside
phantoms details at different depths, to simulate the condition of a real breast.
2D and C-View images have been processed with ImageJ to obtain quan-
titative assessments of contrast and resolution of details, evaluating also
the trend of SNR by increasing the thickness of PMMA slabs.
Conclusion:
This preliminary work shows a better performance of SM than
FFDM in contrast values but a loss in spatial resolution parameters, espe-
cially when details contrasts decrease. The results obtained in phantoms
become significant in the clinical setting; moreover there is an agree-
ment with literature data.
http://dx.doi.org/10.1016/j.ejmp.2016.01.309B.305
EVALUATION OF OPERATOR AND PATIENT DOSE DURING
INTERVENTIONAL CARDIOLOGY PROCEDURES
V. Salamone
* , a ,G. Mannino
a ,C. Stancampian
o b ,S. Inserilli
a ,A. La Manna
c ,S. Imm
e c .a
A.O.U Policlinico Vittorio Emanuele, Catania, Italy;
b
ASST Nord,
Milano, Italy;
c
Divisione Cardiologia, A.O.U. Policlinico Vittorio Emanuele,
Catania, Italy
Introduction:
Purpose of this study is the evaluation of patient and op-
erators dose, in order to optimize the clinical protocols of X-ray
investigations. The study was carried out in reference to some interventional
cardiology procedures and in particular: Transcatheter Aortic Valve System
(TAVI) and Chronic Total Occlusion (CTO). The procedures selected are those
which present greater run times and consequently greater radiation ex-
posure for both the patient and the operators.
Material and Methods:
For the evaluation of the maximum skin dose (MSD)
to the patient radiochromic film (GafChromic XR-RV3) placed to the skin,
has been used, by the entry point of the X-ray beam. The operators dose
have been estimated by using thermoluminescent dosimeters (TLD type
GR200A to LiF (Mg, Cu, P)). A set of three dosimeters have been used for
each operator, one for the whole body, one for the extremity and one for
the eye lens. To optimize the operating protocols was necessary to record
the parameters of exposure, and the position occupied by operators, rel-
ative to the X-ray source. The recorded exposure parameters were: voltage,
current, fluoroscopy time and number of images, and was also written down
the dose-area product (DAP), whose main application is the ability to create
a database of values reference, to be used as a guide for the purposes of
procedures optimization.
Conclusion and Results:
The measurements have allowed the construc-
tion of a correlation between the evaluation of the MSD to the patient, and
the DAP, recorded from the radiological equipment, which allows us to es-
timate the maximum skin dose for each patient. The dose to the two
monitored operators, has been correlated with the patient dose. This allowed
us to estimate, from the values obtained for the patient, the dose to the
operator for each specific procedure, optimizing the operating modes.
http://dx.doi.org/10.1016/j.ejmp.2016.01.310B.306
IMAGE QUALITY IN SYNCHROTRON RADIATION BREAST CT
A. Sarno
* , a ,G. Mettivie
r a ,F. Di Lillo
a ,B. Golosio
b ,P. Oliva
b ,R. Longo
c ,P. Russo
a .a
Dipartimento di Fisica, Università di Napoli Federico II and INFN
Sez. Napoli, Napoli, Italy;
b
Universita’ di Sassari and INFN Sez. di Cagliari,
CagliarI, Italy;
c
Dipartimento di Fisica and INFN Sezione di Trieste, Universita’
di Trieste, Trieste, Italy
Introduction:
The goal of the SYRMA-CT project is the first in vivo, free-
space propagation-based phase-contrast 3D imaging of the pendant
uncompressed breast with monochromatic X-ray synchrotron radiation (SR)
at the ELETTRA facility (Trieste, Italy), for breast cancer diagnosis. The
imaging performance of the CT scanner and the dosimetry protocol was
investigated.
Materials and Methods:
The uncompressed breast is scanned with laminar
X-ray beam at 38 keV. The breast-to-detector distance is 2 m and pixel pitch
of the single-photon counting CdTe detector is 60 μm. The modulation trans-
fer function (MTF) of the scanner was evaluated together with the contrast
to noise ratio (CNR) and microcalcification visibility in a mammographic
phantom (CIRS phantom BR50/50 mod. 014AD) at a low radiation dose
(about 4.5 mGy glandular dose in the irradiated section), eligible for in vivo
breast imaging. The influence of phase retrieval (transport-of-intensity al-
gorithm) on the 3D images was evaluated. The CT slices were reconstructed
via filtered-back projection algorithm.
Results:
The system spatial resolution (at 10% MTF) was 6.7 1/mm for at-
tenuation imaging and 2.5 1/mm in the phase-retrieved images. The CNR
increased by one order of magnitude after phase retrieval; microcalcifications
with diameter down to 0.130 mm were visible in both cases. A global index
indicated the superior performance of phase imaging compared to atten-
uation imaging.
Conclusions:
The SR CT scans of the test object and breast phantom showed
the technical feasibility of SR breast CT in terms of spatial resolution and
contrast for in vivo 3D imaging with a dose comparable to that of two-
viewmammography. Phase-retrieved images showed the best performance
in the trade-off between spatial resolution and image noise.
Acknowledgments:
Thanks to all members of the SYRMA-CT collabora-
tion for the useful discussions and contribution to the measurements.
http://dx.doi.org/10.1016/j.ejmp.2016.01.311B.307
PERSONNEL REAL TIME DOSIMETRY IN INTERVENTIONAL RADIOLOGY
L. Servoli
*
, a ,M. Paolucci
a , b ,A. Pentiricci
c ,P. Placidi
d , a ,D. Magalotti
e , a ,S. Fabiani
f , a ,A. Calandra
g ,L. Bissi
h , a ,A. Maselli
b, M. Scarpignato
b ,R. Di Lorenzo
a , b ,R. Cicion
i g ,A. Scorzoni
d , a ,L. Colleluori
d ,S. Chiocchini
g ,N. Forini
g , a ,A.C. Di Pilato
g ,F.P. Cappotto
b .a
Istituto Nazionale di Fisica
Nucleare, Sezione Perugia, Perugia, Italy;
b
ASL 2 Umbria, Foligno (PG), Italy;
c
ASL 1 Umbria, Città di Castello (PG), Italy;
d
University of Perugia, Dip. di
Ingegneria, Perugia, Italy;
e
University of Modena e Reggio Emilia, Dip.
e90
Abstracts/Physica Medica 32 (2016) e71–e96