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Purpose. To evaluate signal intensity (SI) differences between 3.0 T and 1.5 T on T2-weighted (T2w), diffusion-weighted imaging (DWI), and apparent diffusion coefficient (ADC) in rectal cancer pre-, during, and postneoadjuvant chemoradiotherapy (CRT). Materials and Methods. 22 patients with locally advanced rectal cancer were prospectively enrolled. All patients underwent T2w, DWI, and ADC pre-, during, and post-CRT on both 3.0 T MRI and 1.5 T MRI. A radiologist drew regions of interest (ROIs) of the tumor and obturator internus muscle on the selected slice to evaluate SI and relative SI (rSI). Additionally, a subanalysis evaluating the SI before and after-CRT (∆SI pre-post) in complete responder patients (CR) and nonresponder patients (NR) on T2w, DWI, and ADC was performed. Results. Significant differences were observed for T2w and DWI on 3.0 T MRI compared to 1.5 T MRI pre-, during, and post-CRT (all P < 0.001 ), whereas no significant differences were reported for ADC among all controls (all P > 0.05 ). rSI showed no significant differences in all the examinations for all sequences (all P > 0.05 ). ∆SI showed significant differences between 3.0 T and 1.5 T MRI for DWI-∆SI in CR and NR ( 188.39 ± 166.90 vs. 30.45 ± 21.73 and 169.70 ± 121.87 vs. 22.00 ± 31.29 , respectively, all P 0.02) and ADC-∆SI for CR ( − 0.58 ± 0.27 vs. − 0.21 ± 0.24 P value 0.02), while no significant differences were observed for ADC-∆SI in NR and both CR and NR for T2w-∆SI. Conclusion. T2w-SI and DWI-SI showed significant differences for 3.0 T compared to 1.5 T in all three controls, while ADCSI showed no significant differences in all three controls on both field strengths. rSI was comparable for 3.0 T and 1.5 T MRI in rectal cancer patients; therefore, rectal cancer patients can be assessed both at 3.0 T MRI and 1.5 T MRI. However, a significant DWI-∆SI and ADC-∆SI on 3.0 T in CR might be interpreted as a better visual assessment in discriminating response to therapy compared to 1.5 T. Further investigations should be performed to confirm future possible clinical application.

The purpose of this study was to assess the impact of adaptive statistical iterative reconstruction (ASiR) on half-dose coronary artery calcium scoring (CACS) acquisition protocol.Between September 2016 and October 2017, 89 patients (54 male patients, mean age 64.6±10.7 y) with a clinically indicated coronary computed tomography angiography were prospectively enrolled. On a 64-row computed tomography scanner, patients underwent a standard CACS protocol (120 kVp, 170 mAs) reconstructed by filtered-back projection, and a half-dose CACS protocol (120 kVp, 85 mAs) reconstructed by ASiR at different percentages, from 10% to 100%, in 10% increments. CACS determinants (Agatston score, number of plaques, volume, and mass), signal-to-noise ratio, contrast-to-noise ratio, and radiation dose of both protocols were calculated. Patient risk categories based on CACS were determined for each protocol, and analysis of risk reclassification of half-dose protocol was performed. Depending on their body mass index (BMI), patients were divided into nonobese (BMI30 kg/m) and obese (BMI≥30 kg/m) groups to investigate the influence of BMI on CACS determinants and risk reclassification.Half-dose protocol reconstructed with ASiR 70% showed no significant differences in any CACS determinant compared with the standard protocol for both nonobese and obese patients (all P≥0.070 and ≥0.066, respectively) and reclassified 1 (1.7%) and 6 (20.0%) patients, respectively, with excellent (κ=0.91) and good (κ=0.74) agreement with standard protocol, respectively. ASiR 70% also resulted in a higher signal-to-noise ratio (1.88±0.78) and contrast-to-noise ratio (7.10±2.73) compared with standard protocol (all P≤0.001). Half-dose protocol provided 52% less radiation dose than standard acquisition (0.31±0.06 vs. 0.64±0.10 mSv; P0.001).ASIR 70% coupled with reduction of tube current by 50% allowed for significant dose reduction and no detrimental effects on image quality, with minimal patient reclassification in nonobese patients. In obese patients, excessive noise may lead to a clinically significant reclassification rate.

To investigate whether diet restriction affects quality of colon cleansing and patient tolerance during reduced bowel preparation for CT colonography (CTC). Asymptomatic and symptomatic patients were enrolled in this pragmatic, single-centre, randomised trial. All patients were randomly assigned (1:1 ratio, blocks of ten) to receive a reduced bowel preparation and faecal tagging with (Diet-Restriction-Group [DR]) or without (No-Diet-Restriction-Group [NDR]) dietary restriction. Five readers performed a blinded subjective image analysis, by means of 4-point Likert-scales from 0 (highest score) to 3 (worst score). Endpoints were the quality of large bowel cleansing and tolerance to the assigned bowel preparation regimen. The trial is registered at ClinicalTrial.gov (URomLSDBAL1). Ninety-five patients were randomly allocated to treatments (48 in NDR-group, 47 in DR-group). Both groups resulted in optimal colon cleansing. The mean residual stool (0.22, 95%CI 0.00-0.44) and fluid burden (0.39, 95%CI 0.25-0.53) scores for patients in DR-group were similar to those in patients in NDR-group (0.25, 95%CI 0.03-0.47 [p = 0.82] and 0.49, 95%CI 0.30-0.67 [p = 0.38], respectively). Tolerance was significantly better in NDR-group. A reduced bowel preparation in association with faecal tagging and without any dietary restriction demonstrated optimal colon cleansing effectiveness for CTC, providing better patient compliance compared with dietary restriction. • Dietary restriction in reduced bowel preparation regimen can be avoided. • The quality of colon cleansing is not affected by dietary restriction. • The quality of faecal tagging is not affected by dietary restriction. • Avoidance of dietary restriction improves patients’ tolerance for CTC.

To prospectively compare two different approaches for estimating the amount of intravenous contrast media (CM) needed for multiphasic MDCT of the liver in obese patients. This single-center, HIPAA-compliant prospective study was approved by our Institutional Review Board. Ninety-six patients (55 men, 41 women), with a total of 42 hypovascular liver lesions, underwent MDCT of the liver. The amount of contrast medium injected was computed according to the patient’s lean body weight which was estimated using either a bioimpedance device (Group A) or the James formula (Group B). The following variables were compared between the two groups: the amount of contrast medium injected (in grams of Iodine, gI), the contrast enhancement index (CEI) and the lesion-to-liver contrast-to-noise ratio. Protocols A and B yielded significant differences in the amount of CM injected (mean values 41.9 ± 4.41 gI in Group A vs. 35.9 ± 5.75 gI in Group B; P = 0.021). The mean CEI value and lesion-to-liver contrast-to-noise ratio measured on the portal phase were significantly higher with protocol A than with protocol B (P

We compared 2-[fluorine-18] fluoro-2-deoxy- d -glucose PET-CT and contrast-enhanced computed tomography (CECT) in 62 consecutive patients with newly diagnosed Hodgkin Lymphoma (HL), aiming to provide evidences that may spare CECT from the staging procedures of HL patients. Among a total of 1448 nodal sites examined, disease involvement was detected in 232 (16%) and 280 (19.3%) nodal areas by CECT and PET-CT, respectively (P A total of 248 extranodal areas were examined. CECT and PET-CT identified disease involvement in 19 (7.7%) and 25 (10.1%) extranodal areas, respectively (P = n.s). Compared to PET-CT, CECT detected a lower number of cases with bone and/or bone marrow involvement (P = 0.05), whereas no differences were detected at the level of lung. By contrast, CECT identified liver lesions in four patients versus three identified by PET-CT. In comparison to CECT, PET-CT upstaged 6 patients (9.7%) and downstaged 1 patient (1.6%). We showed that PET-CT modified treatment strategy in five (8.1%) cases not only as a result of stage advancement (2 cases) but also of a different prognostic stratification in patients with localized disease (3 cases), due to the better sensitivity in detecting nodal involvement. In conclusion, our data, confirm the superiority of PET-CT in detecting disease involvement at diagnosis of HL, and further supports the possibility to replace CECT with PET-CT in the initial staging of HL.

We compared 2-[fluorine-18] fluoro-2-deoxy-d-glucose PET-CT and contrast-enhanced computed tomography (CECT) in 62 consecutive patients with newly diagnosed Hodgkin Lymphoma (HL), aiming to provide evidences that may spare CECT from the staging procedures of HL patients. Among a total of 1448 nodal sites examined, disease involvement was detected in 232 (16%) and 280 (19.3%) nodal areas by CECT and PET-CT, respectively (P 0.01). Sensitivity of CECT in detecting disease involvement ranged from 0% for internal mammary region (7 cases) and Waldayer's ring (1 case) to 100% for mediastinum. A total of 248 extranodal areas were examined. CECT and PET-CT identified disease involvement in 19 (7.7%) and 25 (10.1%) extranodal areas, respectively (P = n.s). Compared to PET-CT, CECT detected a lower number of cases with bone and/or bone marrow involvement (P = 0.05), whereas no differences were detected at the level of lung. By contrast, CECT identified liver lesions in four patients versus three identified by PET-CT. In comparison to CECT, PET-CT upstaged 6 patients (9.7%) and downstaged 1 patient (1.6%). We showed that PET-CT modified treatment strategy in five (8.1%) cases not only as a result of stage advancement (2 cases) but also of a different prognostic stratification in patients with localized disease (3 cases), due to the better sensitivity in detecting nodal involvement. In conclusion, our data, confirm the superiority of PET-CT in detecting disease involvement at diagnosis of HL, and further supports the possibility to replace CECT with PET-CT in the initial staging of HL.

Purpose. To prospectively compare the performance of James and Boer formula in contrast media (CM) administration, in terms of image quality and parenchymal enhancement in obese patients undergoing CT of the abdomen. Materials and Methods. Fifty-five patients with a body mass index (BMI) greater than 35 kg/m2 were prospectively included in the study. All patients underwent 64-row CT examination and were randomly divided in two groups: 26 patients in Group A and 29 patients in Group B. The amount of injected CM was computed according to the patient’s lean body weight (LBW), estimated using either Boer formula (Group A) or James formula (Group B). Patient’s characteristics, CM volume, contrast-to-noise ratio (CNR) of liver, aorta and portal vein, and liver contrast enhancement index (CEI) were compared between the two groups. For subjective image analysis readers were asked to rate the enhancement of liver, kidneys, and pancreas based on a 5-point Likert scale. Results. Liver CNR, aortic CNR, and portal vein CNR showed no significant difference between Group A and Group B (all P≥0.177). Group A provided significantly higher CEI compared to Group B (P=0.007). Group A and Group B returned comparable overall subjective enhancement values (3.54 and vs 3.20, all P≥0.199). Conclusions. Boer formula should be the method of choice for LBW estimation in obese patients, leading to an accurate CM amount calculation and an optimal liver contrast enhancement in CT.

Over the past three years Italy has seen a rapid growth in the PV (photovoltaic) energy market, followed by an equally sudden decline when the government decided to reduce the incentives. This sharp change in the trend of the market calls into question the achievement of the so called Grid Parity and the possibility that the market is able to develop independently. The motivation of this paper is to evaluate the effects that uncertainties surrounding both the energy prices and PV module costs have on forecasting the dynamics of the Italian PV market. Using the Real Option approach we calculate “the best time to invest” in a PV system by a maximizing investor. We show that these sources of uncertainty can delay the optimal investment decision of several years compared to current Grid Parity forecasts, well describing the current market situation in Italy.