Search

Purpose: To evaluate the diagnostic accuracy of computed tomography (CT)-based radiomic algorithms and deep learning models to preoperatively identify lymph node metastasis (LNM) in patients with pancreatic ductal adenocarcinoma (PDAC)., Methods: PubMed, CENTRAL, Scopus, Web of Science and IEEE databases were searched to identify relevant studies published up until February 11, 2024. Two reviewers screened all papers independently for eligibility. Studies reporting the accuracy of CT-based radiomics or deep learning models for detecting LNM in PDAC, using histopathology as the reference standard, were included. Quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2, the Radiomics Quality Score (RQS) and the the METhodological RadiomICs Score (METRICS). Overall sensitivity (SE), specificity (SP), diagnostic odds ratio (DOR), and the area under the curve (AUC) were calculated., Results: Four radiomics studies comprising 213 patients and four deep learning studies with 272 patients were included. The average RQS total score was 12.00 ± 3.89, corresponding to an RQS percentage of 33.33 ± 10.80, while the average METRICS score was 63.60 ± 10.88. A significant and strong positive correlation was found between RQS and METRICS (p = 0.016; r = 0.810). The pooled SE, SP, DOR, and AUC of all the studies were 0.83 (95 %CI = 0.77-0.88), 0.76 (95 %CI = 0.62-0.86), 15.70 (95 %CI = 8.12-27.50) and 0.85 (95 %CI = 0.77-0.88). Meta-regression analysis results indicated that neither the study type (radiomics vs deep learning) nor the dataset size of the studies had a significant effect on the DOR (p = 0.09 and p = 0.26, respectively)., Conclusion: Based on our meta-analysis findings, preoperative CT-based radiomics algorithms and deep learning models demonstrate favorable performance in predicting LNM in patients with PDAC, with a strong correlation between RQS and METRICS of the included studies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Purpose: Radiation doses to adult patients submitted to cerebral angiography and intracranial aneurysms treatments were assessed by using DICOM Radiation Dose Structured Reports (RDSR) and Monte Carlo simulations. Conversion factors to estimate effective and organ doses from Kerma-Area Product (P KA ) values were determined., Methods: 77 cerebral procedures performed with five angiographic equipment installed in three Italian centres were analyzed. Local settings and acquisition protocols were considered. The geometrical, technical and dosimetric data of 16,244 irradiation events (13305 fluoroscopy, 2811 digital subtraction angiography, 128 cone-beam CT) were extracted from RDSRs by local dose monitoring systems and were input in MonteCarlo PCXMC software to calculate effective and organ doses. Finally, conversion factors to determine effective and organ doses from P KA were determined. Differences between centres were assessed through statistical analysis and accuracy of dose calculation method based on conversion factors was assessed through Bland-Altman analysis., Results: Large variations in P KA (14-561 Gycm 2 ) and effective dose (1.2-73.5 mSv) were observed due to different degrees of complexity in the procedures and angiographic system technology. The most exposed organs were brain, salivary glands, oral mucosa, thyroid and skeleton. The study highlights the importance of recent technology in reducing patient exposure (about fourfold, even more in DSA). No statistically significant difference was observed in conversion factors between centres, except for some organs. A conversion factor of 0.09 ± 0.02 mSv/Gycm 2 was obtained for effective dose., Conclusions: Organ and effective doses were assessed for neuro-interventional procedures. Conversion factors for calculating effective and organ doses from P KA were provided., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Associazione Italiana di Fisica Medica e Sanitaria. Published by Elsevier Ltd. All rights reserved.)

Purpose: Thermal ablation procedures represent an alternative treatment option for patients with T1a renal tumors. Radiofrequency ablation (RFA) and cryoablation (CA) are the most used and studied techniques, while microwave ablation (MWA) has progressively emerged in recent years. Our aim was to assess the effectiveness and safety of MWA in comparison to RFA and CA for the treatment of primary renal tumors., Method: Pubmed, CENTRAL, Web of Science and Scopus were searched until March 2023 to identify studies aimed at comparing the efficacy and safety of MWA with those of RFA and CA for the treatment of patients with primary renal tumors. We compared MWA and RFA/CA primary technique efficacy, local recurrences, overall and cancer-specific survival, major and overall complications, and eGFR changes. Moreover, subgroup analyses were conducted (MWA vs RFA; MWA vs CA; MWA vs RFA/CA in T1a renal tumors)., Results: Ten retrospective studies with 2258 thermal ablations were included (508 MWA and 1750 RFA /CA). MWA had fewer local recurrences (OR = 0.31; 95% CI, 0.16, 0.62; p = 0.0008) than RFA/CA; the other outcomes were not significantly different. In subgroup analyses, MWA resulted to have fewer overall complications than RFA (OR = 0.60; 95% CI, 0.38, 0.97; p = 0.04) and CA (OR = 0.49; 95% CI, 0.28, 0.85; p = 0.01); moreover, MWA was associated with fewer recurrences than CA (OR = 0.30; 95% CI, 0.11, 0.84; p = 0.02). In T1a renal tumors subgroup analysis, the outcomes were not significantly different., Conclusions: MWA is an ablative procedure as effective and safe as RFA or CA for the treatment of renal tumors., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Even though many types of stents have been tested in superficial femoral artery (SFA) and popliteal artery (PA), most of these devices have provided an unsatisfactory outcome, probably due their unsuitable anatomical and physiological characteristics. The Supera peripheral stent (Abbott Vascular, Santa Rosa, CA, USA) is a braided interwoven nitinol device specifically designed for treating atherosclerotic lesions of the femoro-popliteal segment. The aim of this multicenter retrospective study was to describe the effectiveness of Supera stents in the management of femoral-popliteal atherosclerotic lesions and to critically analyze our findings in the context of current and past literature., Design and Methods: In this study we enrolled only patients who satisfied the inclusion criteria: i) patients affected by chronic obstructive arterial disease (COAD) grade II, as per Rutherford classification; ii) patients treated with endovascular revascularization and Supera stent implantation in the femoro-popliteal axis. We retrospectively analyzed the Doppler Ultra-sound (US) follow-up at 12-24 and 36 months to detect the vascular occlusions. The primary patency, primary patency assisted and TLR were described statistically analyzed by survival analysis and the demographic data, clinical data, device safety following stenting were described as frequency and mean value., Results: 105 endovascular procedures on 99 patients for femoro-popliteal stenting with Supera were performed in four Italian hospitals. The median follow-up was 39 months (range 6-72), with primary patency rate of 83.1%, 74.3% and 69.5% at 12, 24 and 36 months after the procedure. The primary patency assisted was 89.9%, 76.8% and 73.4% in the same period, while the freedom from TLR values were 92.7%, 91.5% and 89.5% at 12, 24 and 36 months after the procedure, respectively. The mortality rate recorded at 12 months from the Supera implantation was 2.8% (3 out of 99 patients enrolled)., Conclusions: Our data were in agreement with the current literature, showing the non-inferiority Supera stent in relation to the other stent available. Supera stent showed an excellent safety, effectiveness profile and high durability for the treatment of PAD patients with femoro-popliteal artery disease.

Purpose: To identify the risk factors associated with patency loss after bailout stenting with third-generation hybrid heparin-bonded nitinol stent of the femoropopliteal segment., Methods: Prospective, multicenter, single-arm registry including 156 patients (50 females, mean age 72 ± 11 years) subjected, from February 2017 to December 2018, to provisional stenting with Gore Tigris vascular stent of the distal superficial femoral artery, with or without involvement of the popliteal artery, in 9 different centers. The 194 lesions, with Rutherford score ≥ 3, were stented in case of recoil, dissection or residual stenosis not responding to percutaneous trans-luminal angioplasty (PTA). The follow-up (FU) was performed with clinical evaluation and duplex ultrasound (DUS) at 1, 6 and 12 months., Results: The primary patency rate was 99(95%CI 98-100)% at 1 month, 86(80-92)% at 6 months and 81(74-88)% at-12 months. After patency loss, 13/23 (56.5%) patients were re-treated, yielding a primary assisted patency of 91(86-96)% at 6 months and 88(82-94)% at 12 months and a secondary patency of 94(90-98)% at 6 months and 90(84-95)% at 12 months. Rutherford score ≥ 4 (p = 0.03) and previous severe treatments (p = 0.01) were identified as risk factors for early patency loss during FU. The involvement of the popliteal artery was not an independent risk factor for loss of patency., Conclusions: The bailout stenting of the femoropopliteal segment with third-generation nitinol stents is a safe and effective option in case of recoil, dissection or residual stenosis not responding to PTA. Critical limb ischemia and history of previous major treatment at the same level are significant prognostic factors for patency loss during FU., (© 2021. Italian Society of Medical Radiology.)

Background: The flow-diverter devices (FDDs) safety and effectiveness have been demonstrated by large series and meta-analyses. Due to the high occlusion rates and the acceptable morbidity rates of FDDs, the indications for their use are continuously expanding. We presented our Italian multicentric experience using the second generation of DERIVO® Embolization Device (DED ® ; Acandis, Pforzheim, Germany) to cure cerebral aneurysms, evaluating both middle and long-term safety and efficacy of this device., Methods: Between July 2016 and September 2017 we collected 109 consecutive aneurysms in 108 patients treated using DED ® during 109 endovascular procedures in 34 Italian centers (100/109 aneurysms were unruptured, 9/109 were ruptured). The collected data included patient demographics, aneurysm location and characteristics, baseline angiography, adverse event and serious adverse event information, morbidity and mortality rates, and pre- and post-treatment modified Rankin Scale scores. Midterm and long-term clinical, angiographic and cross-sectional CT/MR follow-up were recorded and collected until December 2018., Results: In 2/109 cases, DED ® placement was classified as technical failures. The overall mortality and morbidity rates were respectively 6.5% and 5.5%. Overall DERIVO® related mortality and morbidity rates were respectively 0% and 4.6% (5 out of 108 patients). Midterm neuroimaging follow-up showed the complete or nearly complete occlusion of the aneurysm in 90% cases, which became 93% at long-term follow-up. Aneurysmal sac shrinking was observed in 65% of assessable aneurysms., Conclusions: Our multicentric experience using DED ® for endovascular treatment of unruptured and ruptured aneurysms showed a high safety and efficacy profile, substantially equivalent or better compared to the other FDDs.

Background: Mechanical thrombectomy is now standard of care for treatment of acute ischemic stroke secondary to large vessel occlusion in the setting of high NIHSS. We analysed a large nationwide registry focusing on patients with large vessel occlusion and low NIHSS on admission to evaluate the efficacy and safety of thrombectomy in this patient population METHODS: 2826 patients treated with mechanical thrombectomy were included in a multicentre registry from January 1, 2011 to December 31, 2015. We included patients with large vessel occlusion and NIHSS ≤ 6 on admission. Baseline characteristics, imaging, clinical outcome, procedure adverse events and positive and negative outcome predictors were analysed., Results: 134 patients were included. 90/134 had an anterior circulation and 44 a posterior circulation stroke. One patient died before treatment. Successful revascularization (mTICI 2b-3) was achieved in 73.7% (98/133) of the patients. Intraprocedural adverse event was observed in 3% (4/133) of cases. Symptomatic intracranial haemorrhage rate was 5.3% (7/133). At three months, 70.9% (95/134) of the patients had mRS score 0-2, 15.7% (21/134) mRS 3-5 and 13.4% (18/134) mRS 6. Age and successful recanalization were significant predictors of a good clinical outcome on both univariate (p= 0.005 and p=0.007) and multivariable (p=0.0018 and p=0.009 [nat log]) analysis. Absence of vessel recanalization and symptomatic intracranial hemorrhage were independent predictors of poor outcome (p=0.021) ., Conclusions: Our study suggests that patients with large vessel occlusion and low NIHSS score on admission can benefit from mechanical thrombectomy. Randomized trials are warranted., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The first waveguide coupled phosphide-based UTC photodiodes grown by Solid Source Molecular Beam Epitaxy (SSMBE) are reported in this paper. Metal Organic Vapour Phase Epitaxy (MOVPE) and Gas Source MBE (GSMBE) have long been the predominant growth techniques for the production of high quality InGaAsP materials. The use of SSMBE overcomes the major issue associated with the unintentional diffusion of zinc in MOVPE and gives the benefit of the superior control provided by MBE growth techniques without the costs and the risks of handling toxic gases of GSMBE. The UTC epitaxial structure contains a 300 nm n-InP collection layer and a 300 nm n ++ -InGaAsP waveguide layer. UTC-PDs integrated with Coplanar Waveguides (CPW) exhibit 3 dB bandwidth greater than 65 GHz and output RF power of 1.1 dBm at 100 GHz. We also demonstrate accurate prediction of the absolute level of power radiated by our antenna integrated UTCs, between 200 GHz and 260 GHz, using 3d full-wave modelling and taking the UTC-to-antenna impedance match into account. Further, we present the first optical 3d full-wave modelling of waveguide UTCs, which provides a detailed insight into the coupling between a lensed optical fibre and the UTC chip.

Purpose: The aim of our study is to assess the effectiveness of popliteal artery aneurysm (PAA) endovascular treatment., Basic Procedures: We retrospectively evaluated 48 high-surgical-risk patients that presented at our three departments with evidence of popliteal artery aneurysms, both symptomatic and asymptomatic, and were therefore treated by deployment of stent graft. Immediate technical success was 100%. No periprocedural complications occurred., Main Findings: During a mean follow-up of 24.5 months (range 6-72), 12/48 occlusions of stent graft occurred, five of which occurred in the first 30 days after the procedure while other seven occurred during long-term follow-up. Primary stent patency rate was 70.8% and secondary stent patency rate was 89.6% at 1 year. No limb amputation was witnessed., Conclusions: According to our experience, endovascular approach appeared as an effective treatment for popliteal artery aneurysms, as it appeared affected by a low rate of peri- and post-procedural complications. It could be proposed as treatment of choice in patients with high surgical risk.

We report the first demonstration of a uni-traveling carrier photodiode (UTC-PD) used as a 5 Gbps wireless receiver. In this experiment, a 35.1 GHz carrier was electrically modulated with 5 Gbps non-return with zero on-off keying (NRZ-OOK) data and transmitted wirelessly over a distance of 1.3 m. At the receiver, a UTC-PD was used as an optically pumped mixer (OPM) to down-convert the received radio frequency (RF) signal to an intermediate frequency (IF) of 11.7 GHz, before it was down-converted to the baseband using an electronic mixer. The recovered data show a clear eye diagram, and a bit error rate (BER) of less than 10 -8 was measured. The conversion loss of the UTC-PD optoelectronic mixer has been measured at 22 dB. The frequency of the local oscillator (LO) used for the UTC-PD is defined by the frequency spacing between the two optical tones, which can be broadly tuneable offering the frequency agility of this photodiode-based receiver.

Midwives and nurses have a key role in monitoring postpartum period. They represent the first line professional figure in quantifying blood loss, initiating early diagnosis of obstetric hemorrhage, and mobilizing a team response, if needed. These actions are crucial in determining maternal outcome in postpartum hemorrhage (PPH). In our review we aimed to: (1) Provide a picture of PPH including its pathophysiology, epidemiology, and associated complications; (2) Discuss diagnosis of this dangerous postpartum event; and, (3) Especially evaluate the efficiency of the employment of visual blood loss estimation as a rapid way to suspect PPH and activate the patient assessment.

We propose and characterize a scattering probe for terahertz (THz) near-field microscopy, fabricated from indium, where the scattering efficiency is enhanced by the dipolar resonance supported by the indium probe. The scattering properties of the probe were evaluated experimentally using THz time-domain spectroscopy (TDS), and numerically using the finite-difference time-domain (FDTD) method in order to identify resonant enhancement. Numerical measurements show that the indium probes exhibit enhanced scattering across the THz frequency range due to dipolar resonance, with a fractional bandwidth of 0.65 at 1.24 THz. We experimentally observe the resonant enhancement of the scattered field with a peak at 0.3 THz. To enable practical THz microscopy applications of these resonant probes, we also demonstrate a simple excitation scheme utilizing a THz source with radial polarization, which excites a radial mode along the length of the tip. Strong field confinement at the apex of the tip, as required for THz near-field microscopy, was observed experimentally.

Background: Intraprocedural aneurysm sac embolization (embo-EVAR) during endovascular abdominal aneurysm repair (EVAR) using coils and fibrin glue is a technique for preventing type II endoleak (EII). Our aim is to evaluate feasibility, safety and clinical outcome of this promising approach., Materials and Methods: A retrospective clinical case analysis of 72 patients who underwent EVAR during the period 2011-2014. Two groups were compared at 6 and 12 months follow-up with contrast media computed tomography scan and contrast-enhanced ultrasound (CEUS) imaging: consecutively, 36 patients (group A) treated with classic EVAR and 36 patients (group B) treated with embo-EVAR. Coils were released filling better as possible the aneurysm sac; the embolization was completed by injecting fibrin glue. Device and materials used, differential systemic and sac pressures, presence of any endoleak, and complication were registered., Results: In our experience, we had 100% technical success without surgical conversion. Embo-EVAR was performed, after endograft deployment, in group B patients, all with ratio of Δ-pressures (obtained from Δ-sac pressure/Δ-differential pressure) > 0.16. No early or late complications occurred and mortality was nil. Follow-up was performed with computed tomography-angiography and CEUS at 6 and 12 months. We observed 9 type II and 1 type Ia endoleak in group A and 2 type II and 1 type Ib endoleaks in group B. Mean radiation exposure time was 30.3 min in group A and 43.3 min in group B. EVAR procedure average cost was 9,000 €. The average cost of sac embolization was 1,500€., Conclusions: Although a randomized study is necessary, embo-EVAR may be a valid approach to prevent type II endoleaks and further complications. Mild costs and exposure-dose increase could be accepted to avoid reinterventions, and in our experience, it could be routinely performed with excellent results., (Copyright © 2017 Elsevier Inc. All rights reserved.)

We report the generation mechanism associated with nano-grating electrode photomixers fabricated on Fe-doped InGaAsP substrates. Two different emitter designs incorporating nano-gratings coupled to the same broadband antenna were characterized in a continuous-wave terahertz (THz) frequency system employing telecommunications wavelength lasers for generation and coherent detection. The current-voltage characteristics and THz emission bandwidth of the emitters is compared for different bias polarities and optical polarisations. The THz output from the emitters is also mapped as a function of the position of the laser excitation spot for both continuous-wave and pulsed excitation. This mapping, together with full-wave simulations of the structures, confirms the generation mechanism to be due to an enhanced optical electric field at the grating tips resulting in increased optical absorption, coinciding with a concentration of the electrostatic field.