25 research outputs found
Diffusion tensor magnetic resonance imaging of prostate cancer
Purpose: To explore the feasibility of 3 T magnetic resonance (MR)
diffusion tensor imaging (DTI) and fiber tracking (FT) in patients
with prostate cancer.
Materials and methods: Thirty consecutive patients (mean age,
62.5 years) with biopsy proven prostate cancer underwent 3 T-MR
imaging (MRI) and DTI using a 6-channel external phased-array
coil before radical prostatectomy. Regions of interest of 14 pixels
were defined in tumors and nonaffected areas in the peripheral zone
(PZ) and central gland (CG), according to histopatology after radical
prostatectomy. Apparent diffusion coefficient (ADC) and fractional
anisotropy (FA) values were determined. Differences in mean ADC
and FA values among prostate cancer, normal PZ and CG were
compared by 2-sided Student t test. The predominant diffusion
direction of the prostate anisotropy was color coded on a directionally
encoded color (DEC) map. A 3D reconstruction of fiber tract
orientations of the whole prostate was determined using the continuous
tracking method. The overall image quality for tumor localization
and local staging was assessed in retrospective matching
with whole-mount section histopathology images. Nodules detected
at MRI were classified as matched lesions if tumor presence and
extension were evidenced at histopathology.
Results: For all the patients, the DTI sequence images were suitable
for the evaluation of the zonal anatomy of the prostate gland and the
tumor localization. Quantitative evaluation of the regions of interest
(ROIs) showed a mean ADC value significantly lower in the peripheral
neoplastic area (1.06 0.37 10 3 mm2/s) than in the
normal peripheral portion (1.95 0.38 10 3 mm2/s) (P 0.05).
The mean FA values calculated in the normal peripheral (0.47
0.04) and central area (0.41 0.08) were very similar (P 0.05).
The mean FA values in the neoplastic lesion (0.27 0.05) were
significantly lower (P 0.05) than in the normal peripheral area and
in the normal central and adenomyomatous area. DEC showed a
top-bottom type preferential direction in the peripheral but not in the
central area, with the tumor lesions reducing the diffusion coding
direction represented as color zones tending toward gray. Tractographic
analysis permitted good delineation of the prostate anatomy
(capsule outline, peripheral and central area borders) and
neoplastic lesion extension and capsule infiltration compared
with histopathology.
Conclusions: Three tesla DTI of the prostate gland is feasible and
has the potential for providing improved diagnostic information
Painful constipation: a neglected entity?
Functional chronic constipation is a common symptom in daily clinical practice. Although the definition of constipation may be variable, there is usually agreement that (at least for research purposes) the definition given by the Rome Committee are useful. However, some blind spots or hidden angles remain, even in the more thorough classifications; among these, there is painful constipation, a poorly defined yet clinically encountered entity. The present article reviews the current knowledge about painful constipation, trying to put together the scarce data available, and to frame it in the more general context of chronic constipation
Focal therapy for prostate cancer: revolution or evolution?
The face of prostate cancer has been dramatically changed since the late 1980s when PSA was introduced as a clinical screening tool. More men are diagnosed with small foci of cancers instead of the advanced disease evident prior to PSA screening. Treatment options for these smaller tumors consist of expectant management, radiation therapy (brachytherapy and external beam radiotherapy) and surgery (cryosurgical ablation and radical prostatectomy). In the highly select patient, cancer specific survival employing any of these treatment options is excellent, however morbidity from these interventions are significant. Thus, the idea of treating only the cancer within the prostate and sparing the non-cancerous tissue in the prostate is quite appealing, yet controversial. Moving forward if we are to embrace the focal treatment of prostate cancer we must: be able to accurately identify index lesions within the prostate, image cancers within the prostate and methodically study the litany of focal therapeutic options available
A 3D Web-GIS for the Historical Centre of Rome
Trattamento dei dati topografici del'area centrale della città antica mediante sistemi informatici avanzati, che tengano conto della pluristratificazione del sito in esame
Integrated multislice CT and Tc-99m Sestamibi SPECT-CT evaluation of solitary pulmonary nodules
Abstract
Purpose. The purpose of this study was to evaluate efficacy of
multislice computed tomography (MSCT) and single photon
emission computed tomography (SPECT)-CT with Tc-99m
Sestamibi in the assessment of solitary pulmonary nodules of
uncertain significance. Scintigraphy was performed using a
‘hybrid’ g-camera that allows simultaneous acquisition of SPECT
and CT images, with interesting results in diagnostic oncology.
Materials and methods. Between September 2003 and August
2004, 23 patients with a solitary pulmonary nodule detected on CT
underwent SPECT-CT using Tc-99m Sestamibi as a radiotracer.
Nodules with positive scintigraphy were immediately subjected to
biopsy or surgical resection. Nodules with negative scintigraphy
were followed up after 3–4 months by MSCT with automatic
segmentation software (Advanced Lung Analysis, ALA) and
histological characterisation.
Results. Of the 23 nodules (size range 0.8–2 cm) discovered with
MSCT, 11 showed intense uptake of Tc-99m Sestamibi. Ten
lesions were true positive: seven adenocarcinomas, one squamous
cell carcinoma, one large cell carcinoma and one metastasis. The
only false positive was histologically classified as a large cell
granuloma. Twelve lesions had negative scintigraphy: five fibrous
lesions, three hamartomas, three granulomas and one
adenocarcinoma (false negative). Benign nodules without tracer
uptake underwent another CT scan 3–4 months later, which
confirmed stability of the nodule size. Correlation of Sestamibi
SPECT with histology showed sensitivity (Se) of 90.9 %,
specificity (Sp) of 91.6 %, diagnostic accuracy of 91.3 %,
positive predictive value (PPV) of 90.9% and negative predictive
value (NPV) of 91.6 %.
Conclusions. The integrated use of MSCT and Tc-99m Sestamibi
SPECT-CT could be very useful in the management of solitary
pulmonary nodules (SPNs). In particular, in our preliminary study,
scintigraphy provided significant diagnostic information to
differentiate benign from suspicious pulmonary nodules. The use
of scintigraphy could be helpful to anticipate histological
assessment and surgical treatment of SPNs identified at CT
Combined morphological, [1H]-MR spectroscopic and contrast-enhanced imaging of human prostate cancer with a 3-Tesla scanner: preliminary experience
Purpose. The objective of this study was to explore the feasibility of combined morphological magnetic resonance imaging (MRI), [H-1]magnetic resonance spectroscopic imagine, (MRSI) and quantitative dynamic contrast-enhanced MRI (DCE-MRI) of human prostate cancer at 3 Tesla using a pelvic phased-array coil. Materials and methods. MRI, MRSI and DCE-MRI with a 3-Tesla whole-body scanner were. performed in 30 patients with biopsy-proven prostate cancer before radical prostatectoray. High-resolution T2-weighted turbo spin echo (TSE) images were evaluated for visualisation of the peripheral zone, central gland, visibility of the cancer lesion, prostatic capsule delineation and overall image quality according to a five-point scale. Relative levels of the prostate metabolites citrate, choline and creatine were determined in cancer and in the normal peripheral zone (PZ) and central gland (CG). Spectra were also evaluated for the separation of the signal of citrate, choline and creatine and suppression of lipid and water signals. Time-intensity curves were obtained for prostatic cancer and healthy PZ and CG from DCE-MRI. Finally, time of arrival, time to peak, maximum enhancement and wash-in rate in cancer, normal PZ and CG were calculated. Results. The high signal-to-noise ratio (SNR) at 3 Tesla provided T2-weighted TSE images with excellent anatomical detail (in-plane voxel size of 0.22x0.22 mm) and good T2 contrast. The increased spectral resolution was sufficient to separate the choline and creatine resonances and allow delineation of the four peaks of citrate resonance. The (choline + creatine)/citrate ratio was elevated in cancer in comparison with PZ and CG (p<0.001). Dynamic contrast-enhanced images showed good temporal resolution. All parameters obtained from DCE-MRI showed a statistically significant (P<0.05) difference between cancer tissue and normal PZ and CG. Wash-in rate and (choline+creatine)/citrate ratio were significantly correlated (r=0.713, P=0.001) in PZ cancer, whereas the correlation was not significant (r=0.617, P=0.06) in CG and in PZ (r=0.530, P=0.08). Conclusions. It is possible to perform MRI of prostate cancer at 3 Tesla using a pelvic phased-array coil with high spatial, temporal and spectral resolution. The combination of vascular information from DCE-MRI and metabolic data from MRSI has excellent potential for improved accuracy in delineating and staging prostate carcinoma. These results suggest that high magnetic field strengths offer the possibility of studying prostate cancer without use of an endorectal coil
The Cosmo-Skymed Second Generation Sar Antenna Electrical Power Chain and Platform Power Distribution
This paper presents the Electrical power Subsystem (EPS) of the COSMO-SKYMED SECOND GENERATION (CSG) spacecraft, regarding the design and development of the electronics for power generation, conditioning and distribution. It provides a detailed description of the power equipment’s and of the Photovoltaic Assembly (PVA).
It will be also shown how the design of the power conditioning and distribution electronics has taken advantage of the Leonardo (former Finmeccanica) heritage on Power Management and Distribution (PMD) for scientific platforms [1], [3].
The design characteristics of the EPS elements are described. A summary of the main performances is given, including a glance to the EMC aspects, which are very important in the definition and characterization of the design of a high power SAR system
Misurazione in vivo del coefficiente apparente di diffusione nel tessuto prostatico sano e maligno con l'utilizzo di sequenze EPI a strato sottile
Combined morphological, [1H]-MR spectroscopic and contrast-enhanced imaging of human prostate cancer with a 3-Tesla scanner:preliminary experience. Imaging combinato morfologico, spettroscopico e dinamico post-contrastografico del cancro prostatico con apparecchiatura di risonanza magnetica a 3 Tesla: esperienza preliminare
Painful constipation: a neglected entity?
Functional chronic constipation is a common symptom in daily clinical practice. Although the definition of constipation may be variable, there is usually agreement that (at least for research purposes) the definition given by the Rome Committee are useful. However, some blind spots or hidden angles remain, even in the more thorough classifications; among these, there is painful constipation, a poorly defined yet clinically encountered entity. The present article reviews the current knowledge about painful constipation, trying to put together the scarce data available, and to frame it in the more general context of chronic constipation