Gene fusions in poroma, porocarcinoma and related adnexal skin tumours: An update.

Poroma is a benign sweat gland tumour showing morphological features recapitulating the superficial portion of the eccrine sweat coil. A subset of poromas may transform into porocarcinoma, its malignant counterpart. Poroma and porocarcinoma are characterised by recurrent gene fusions involving YAP1, a transcriptional co-activator, which is controlled by the Hippo signalling pathway. The fusion genes frequently involve MAML2 and NUTM1, which are also rearranged in other cutaneous and extracutaneous neoplasms. We aimed to review the clinical, morphological and molecular features of this category of adnexal neoplasms with a special focus upon emerging differential diagnoses, and discuss how their systematic molecular characterisation may contribute to a standardisation of diagnosis, more accurate classification and, ultimately, refinement of their prognosis and therapeutic modalities.

Early results of ultra-low-dose CT-scan for extremity traumas in emergency room.

Background: Ultra-low dose computed tomography (ULD-CT) was shown to be a good alternative to digital radiographs in various locations. This study aimed to assess the diagnostic sensitivity and specificity of ULD-CT versus digital radiographs in patients consulting for extremity traumas in emergency room. Methods: Digital radiography and ULD-CT scan were performed in patients consulting at the emergency department (February-August 2018) for extremity traumas. Fracture detection was evaluated retrospectively by two blinded independent radiologists. Sensitivity and specificity were evaluated using best value comparator (BVC) and a Bayesian latent class model (LCM) approaches and clinical follow-up. Image quality, quality diagnostic and diagnostic confidence level were evaluated (Likert scale). The effective dose received was calculated. Results: Seventy-six consecutive patients (41 men, mean age: 35.2±13.2 years), with 31 wrists/hands and 45 ankles/feet traumas were managed by emergency physicians. According to clinical data, radiography had 3 false positive and 10 false negative examinations, and ULD-CT, 2 of each. Radiography and ULD-CT specificities were similar; sensitivities were lower for radiography, with BVC and Bayesian. With Bayesian, ULD-CT and radiography sensitivities were 90% (95% CI: 87-93%) and 76% (95% CI: 71-81%, P<0.0001) and specificities 96% (95% CI: 93-98%) and 93% (95% CI: 87-97%, P=0.84). The inter-observer agreement was higher for ULD-CT for all subjective indexes. The effective dose for ULD-CT and radiography was 0.84±0.14 and 0.58±0.27 µSv (P=0.002) for hand/wrist, and 1.50±0.32 and 1.44±0.78 µSv (P=NS) for foot/ankle. Conclusions: With an effective dose level close to radiography, ULD-CT showed better detection of extremities fractures in the emergency room and may allow treatment adaptation. Further studies need to be performed to assess impact of such examination in everyday practice. Trial Registration: ClinicalTrials.gov Identifier: NCT04832490.

A national dose analysis of guided tumor destruction: influence of sex, age, localization and destruction technique used.

Background: Percutaneous destructions of tumor lesions by ablation (microwave, radiofrequency or cryoablation) under computed tomography (CT) guidance allow high efficiency with minimally-invasive techniques, and acute needle placement and follow-up during procedure. This study investigated the impact of patient and technique parameters on the dose delivered during these procedures under CT guidance. Methods: Data were extracted from a previous nationwide retrospective study. Patients who underwent percutaneous destruction of bone lesions, abdominal and lung tumors were included. Univariate and multivariate linear regression of the dose length product (DLP) log were performed, according to patient's gender, age, lesion location, destruction technique, adjusted to the participating center. Results: A total of 822 patients (556 men), of mean age 62±14 years, were included: 150 patients had bone lesions, 463 abdominal and 209 thoracic tumors. The mean DLP was 991.6±979.0 mGy·cm for patients with bone lesions, 2,130.7±2,051.8 mGy∙cm for abdominal tumors and 825.2±545.4 mGy·cm for lung tumors. In multivariate analysis, the age was significantly associated with higher DLP for bone (P=0.0082) but not for abdominal and thoracic lesions; the DLP was significantly higher in men for abdominal tumors (P<0.0001) while sex had no impact on the dose for bone and thoracic lesions. The dose depended on the lesion location only for bone (P<0.0001) percutaneous destructions. The technique was not correlated to DLP for all lesions. Conclusions: Patient and tumor characteristics such as sex, age and lesion location impacted on the dose delivered during percutaneous destructions of bone, abdominal and thoracic lesions, but not the destruction technique used. Further studies are needed to propose sharper reference dose levels.

Effect of a new deep learning image reconstruction algorithm for abdominal computed tomography imaging on image quality and dose reduction compared with two iterative reconstruction algorithms: a phantom study.

BACKGROUND: New reconstruction algorithms based on deep learning have been developed to correct the image texture changes related to the use of iterative reconstruction algorithms. The purpose of this study was to evaluate the impact of a new deep learning image reconstruction [Advanced intelligent Clear-IQ Engine (AiCE)] algorithm on image-quality and dose reduction compared to a hybrid iterative reconstruction (AIDR 3D) algorithm and a model-based iterative reconstruction (FIRST) algorithm. METHODS: Acquisitions were carried out using the ACR 464 phantom (and its body ring) at six dose levels (volume computed tomography dose index 15/10/7.5/5/2.5/1 mGy). Raw data were reconstructed using three levels (Mild/Standard/Strong) of AIDR 3D, of FIRST and AiCE. Noise-power-spectrum (NPS) and task-based transfer function (TTF) were computed. Detectability index was computed to model the detection of a small calcification (1.5-mm diameter and 500 HU) and a large mass in the liver (25-mm diameter and 120 HU). RESULTS: NPS peaks were lower with AiCE than with AIDR 3D (-41%±6% for all levels) or FIRST (-15%±6% for Strong level and -41%±11% for both other levels). The average NPS spatial frequency was lower with AICE than AIDR 3D (-9%±2% using Mild and -3%±2% using Strong) but higher than FIRST for Standard (6%±3%) and Strong (25%±3%) levels. For acrylic insert, values of TTF at 50 percent were higher with AICE than AIDR 3D and FIRST, except for Mild level (-6%±6% and -13%±3%, respectively). For bone insert, values of TTF at 50 percent were higher with AICE than AIDR 3D but lower than FIRST (-19%±14%). For both simulated lesions, detectability index values were higher with AICE than AIDR 3D and FIRST (except for Strong level and for the small feature; -21%±14%). Using the Standard level, dose could be reduced by -79% for the small calcification and -57% for the large mass using AICE compared to AIDR 3D. CONCLUSIONS: The new deep learning image reconstruction algorithm AiCE generates an image-quality with less noise and/or less smudged/smooth images and a higher detectability than the AIDR 3D or FIRST algorithms. The outcomes of our phantom study suggest a good potential of dose reduction using AiCE but it should be confirmed clinically in patients.

Comparison of acquisition and iterative reconstruction parameters in abdominal computed tomography-guided procedures: a phantom study.

BACKGROUND: Many computed tomography (CT) navigation systems have been developed to help radiologists improve the accuracy and safety of the procedure. We evaluated the accuracy of one CT computer-assisted guided procedure with different reduction dose protocols. METHODS: A total of 128 punctures were randomly made by two operators on two different anthropomorphic phantoms. The tube voltage was fixed to 100 kVp. Tube currents (mAs) were defined to obtain 4 dose levels: 180 mAs (D1.00), 90 mAs (D0.50), 45 mAs (D0.25) and 15 mAs (D0.10) with respective volume CT dose index (CTDIvol) of 7.02, 3.52, 1.75 and 0.59 mGy. The raw data were reconstructed using level 2 of advanced model-based iterative reconstruction (ADMIRE) (A2) for D1.00, A3 for D0.50, A4 for D0.25 and A5 for D0.10. Two 12-mm targets per phantom were selected. The mean Euclidean distance (EuD) between the tip of the needle and the isocenter of the target was measured for each puncture. The different measures were compared by paired Student's t-tests. RESULTS: The mean EuD was 7.0±3.1 mm for the 128 punctures performed. Regardless of which phantom was considered, no significant difference in accuracy occurred between the 4 dose levels, which were 7.1±3.5 mm for D1.00; 7.1±3.1 mm for D0.50; 7.2±3.0 mm for D0.25 and 6.6±2.6 mm for D0.10. CONCLUSIONS: Abdominal CT-guided procedures, using computer-assisted navigation and iterative reconstruction algorithms, allow precise punctures on anthropomorphic phantoms with a dose reduction of -92% compared to a standard protocol.

Comparison of two deep learning image reconstruction algorithms in chest CT images: A task-based image quality assessment on phantom data.

PURPOSE: The purpose of this study was to compare the effect of two deep learning image reconstruction (DLR) algorithms in chest computed tomography (CT) with different clinical indications. MATERIAL AND METHODS: Acquisitions on image quality and anthropomorphic phantoms were performed at six dose levels (CTDIvol: 10/7.5/5/2.5/1/0.5mGy) on two CT scanners equipped with two different DLR algorithms (TrueFidelityTM and AiCE). Raw data were reconstructed using the filtered back-projection (FBP) and the lowest/intermediate/highest DLR levels (L-DLR/M-DLR/H-DLR) of each algorithm. Noise power spectrum, task-based transfer function (TTF) and detectability index (d') were computed: d' modelled detection of a soft tissue mediastinal nodule, ground-glass opacity, or high-contrast pulmonary lesion. Subjective image quality of anthropomorphic phantom images was analyzed by two radiologists. RESULTS: For the L-DLR/M-DLR levels, the noise magnitude was lower with TrueFidelityTM than with AiCE from 2.5 to 10 mGy. For H-DLR, noise magnitude was lower with AiCE . For L-DLR and M-DLR, the average NPS spatial frequency (fav) values were greater for AiCE except for 0.5 mGy. For H-DLR levels, fav was greater for TrueFidelityTM than for AiCE. TTF50% values were greater with AiCE for the air insert, and lower than TrueFidelityTM for the polyethylene insert. From 2.5 to10 mGy, d' was greater for AiCE than for TrueFidelityTM for H-DLR for all lesions, but similar for L-DLR and M-DLR. Image quality was rated clinically appropriate for all levels of both algorithms, for dose from 2.5 to 10 mGy, except for L-DLR of AiCE. CONCLUSION: DLR algorithms reduce the image-noise and improve lesion detectability. Their operations and properties impacted both noise-texture and spatial resolution.

Association of Placental Mesenchymal Dysplasia With a Live Female Fetus and Complete Hydatidiform Mole: Report of a Challenging Case Confirmed by Molecular Genotyping Analysis.

Placental mesenchymal dysplasia (PMD) and complete hydatidiform mole (CHM) with a coexisting fetus are 2 rare placental abnormalities characterized by lacunar placenta and presence of an embryo on ultrasound examination. We report the case of a 34-yr-old woman referred at 32.6 weeks of gestation because of a multicystic placenta. A caesarean section was performed at 39.1 weeks of gestation giving birth to a 2905 g normal female infant. Pathological examination revealed macroscopic and microscopic morphological, and immunohistological features of PMD in the main placenta, and features of CHM in a separate placental mass. Fluorescent in situ hybridization and molecular genotyping analyses showed diandric diploidy in the CHM component and androgenetic/biparental mosaicism in the PMD component, confirming the association of PMD and CHM with a live infant. There was no progression to gestational trophoblastic neoplasia during follow-up for the mother, or any sign of Beckwith-Wiedemann syndrome or hepatic tumor in the child.

Optimization of image quality and accuracy of low iodine concentration quantification as function of kVp pairs for abdominal imaging using dual-source CT: A phantom study.

PURPOSE: To determine the suitable kVp pair for optimal image quality of the virtual monochromatic images (VMIs) and iodine quantification accuracy at low concentration, using a third generation dual-source CT (DSCT). MATERIALS AND METHODS: Multi-energy CT phantoms with and without body rings were scanned with a DSCT using four kVp pairs (tube "A"/"B" voltage): 100/Sn150, 90/Sn150, 80/Sn150 and 70/Sn150 kVp. The reference mAs was adjusted to obtain a CTDIvol close to 11 mGy. HU values accuracy (RMSDHU), noise (SD) and contrast-to-noise ratio (CNR) of iodine inserts of 0.5, 1, 2 and 5 mg/mL concentrations were assessed on VMIs at 40/50/60/70 keV. Iodine quantification accuracy was assessed using the RMSDiodine and iodine bias (IBiodine). RESULTS: The RMSDHU decreased when the tube "A" voltage increased. The mean noise value increased significantly with tube "A" voltage (p < 0.001) but decreased between 80/Sn150 and 90/Sn150 kVp for the small phantom (1.1 ± 0.1%; p = 0.047). The CNR significantly decreased with tube "A" voltage (p < 0.001), except between 80/Sn150 and 90/Sn150 kVp for all inserts and between 90/Sn150 kVp and 100/Sn150 kVp for the 1.0 and 0.5 mg/mL inserts in the large phantom. In the small phantom, no significant difference was found between 80/Sn150 kVp and 90/Sn150 kVp for all inserts and between 80/Sn150, 90/Sn150 and 100/Sn150 kVp for the 1 and 0.5 mg/mL inserts. The RMSDiodine and IBiodine decreased as the tube "A" voltage of the kVp pair increased. CONCLUSION: The kVp pair of 70/Sn150 led to better image quality in VMIs and sufficient iodine accuracy.

Comparison of two versions of a deep learning image reconstruction algorithm on CT image quality and dose reduction: A phantom study.

PURPOSE: To compare the impact on CT image quality and dose reduction of two versions of a Deep Learning Image Reconstruction algorithm. MATERIAL AND METHODS: Acquisitions on the CT ACR 464 phantom were performed at five dose levels (CTDIvol : 10/7.5/5/2.5/1 mGy) using chest or abdomen pelvis protocol parameters. Raw data were reconstructed using the filtered-back projection (FBP), the enhanced level of AIDR 3D (AIDR 3De), and the three levels of AiCE (Mild, Standard, and Strong) for the two versions (AiCE V8 vs AiCE V10). The noise power spectrum (NPS) and task-based transfer function (TTF) for bone (high-contrast insert) and acrylic (low-contrast insert) inserts were computed. To quantify the changes of noise magnitude and texture, the square root of the area under the NPS curve and the average spatial frequency (fav ) of the NPS curve were measured. The detectability index (d') was computed to model the detectability of either a large mass in the liver or lung, or a small calcification or high contrast tissue boundaries. RESULTS: The noise magnitude was lower with both AiCE versions than with AIDR 3De. The noise magnitude was lower with AiCE V10 than with AiCE V8 (-4 ± 6% for Mild, -13 ± 3% for Standard, and -48 ± 0% for Strong levels). fav and TTF50% values for both inserts shifted towards higher frequencies with AiCE than with AIDR 3De. Compared to AiCE V08, fav shifted towards higher frequencies with AiCE V10 (45 ± 4%, 36 ± 3%, and 5 ± 4% for all levels, respectively). The TTF50% values shifted towards higher frequencies with AiCE V10 as compared with AiCE V8 for both inserts, except for the Strong level for the acrylic insert. Whatever the dose and AiCE levels, d' values were higher with AiCE V10 than with AiCE V8 for the small object/calcification and for the large object/lesion. CONCLUSION: As compared to AIDR 3De, lower noise magnitude and higher spatial resolution and detectability index were found with both versions of AiCE. As compared to AiCE V8, AiCE V10 reduced noise and improved spatial resolution and detectability without changing the noise texture in a simple geometric phantom, except for the Strong level. AiCE V10 seems to have a greater potential for dose reduction than AiCE V8.

Ultra-low-dose chest CT performance for the detection of viral pneumonia patterns during the COVID-19 outbreak period: a monocentric experience.

BACKGROUND: Ultra low dose chest computed tomography (CT) acquisitions have been used for selected emergency room patients with acute dyspnea or minor thoracic trauma. The purpose of this study was to evaluate the diagnostic performance of ultra-low-dose (ULD) chest CT for detecting viral pneumonia patterns compared to standard (STD) dose chest CT. METHODS: All consecutive adult patients with two non-enhanced chest CT acquisitions, one STD and one ULD, for suspicion of viral pneumonia between March 5th and April 2nd 2020 were included. CT results were divided into two groups: non-viral pneumonia CT or compatible with viral pneumonia CT based on viral pneumonia CT patterns: ground-glass opacity (GGO), consolidation, crazy paving, air bronchogram signs and fibrous stripes. The diagnostic performance of ULD CT for suspicion of viral pneumonia was evaluated. For CTs compatible with viral pneumonia, CT pattern detection on ULD CT was assessed and STD CT was used as a reference. RESULTS: The study included 380 patients with 97 CTs (25.5%) compatible with viral pneumonia. The mean effective doses (EDs) were 1.66 (1.29; 2.18) mSv for STD and 0.20 (0.18; 0.22) mSv for ULD CT (P<0.001). The sensitivity and specificity of ULD CT for viral pneumonia detection were 98.9% and 99.0%, respectively. GGO, consolidation and fibrous stripes were equally visible in STD and ULD in 100% (n=97), 36% (n=35) and 23% (n=22) of compatible viral pneumonia-CT patients, respectively. Air bronchogram sign detection was equivalent, concerning 23% (n=22) of patients in STD and 22% (n=21) in ULD. Crazy paving was visible in 24% (n=23) of patients in STD and only 8% (n=8) in ULD (P=0.003). CONCLUSIONS: In comparison to STD dose chest CT, ULD chest CT, with a mean reduction dose of 88.0%, has comparable diagnostic performance for detecting viral pneumonia on CT.

A retrospective comparison of organ dose and effective dose in percutaneous vertebroplasty performed under CT guidance or using a fixed C-arm with a flat-panel detector.

PURPOSE: To compare the organ-dose and effective-dose (E) delivered to the patient during percutaneous vertebroplasty (PVP) of one thoracic or lumbar vertebra performed under CT guidance or using a fixed C-arm. METHODS: Consecutive adult patients undergoing PVP of one vertebra under CT-guidance, with optimized protocol and training of physicians, or using a fixed C-arm were retrospectively included from January 2016 to June 2017. Organ-doses were computed on 16 organs using CT Expo 2.4 software for the CT procedures and PCXMC 2.0 for the fixed C-arm procedures. E was also computed with both software. Dosimetric values per anatomic locations for all procedures were compared using the paired Mann-Whitney-Wilcoxon test. RESULTS: In total, 73 patients were analysed (27 men and 46 women, mean age 78 ± 10 years) among whom 35 (48%) underwent PVP under CT guidance and 38 (52%) PVP using a fixed C-arm. The median E was 11.31 [6.54; 15.82] mSv for all PVPs performed under CT guidance and 5.58 [3.33; 8.71] mSv for fixed C-arm and the differences was significant (p<0.001). For lumbar PVP, the organ doses of stomach, liver and colon were significantly higher with CT-scan than with the fixed C-arm: 97% (p=0.02); 21% (p=0.099) and 375% (p=0.002), respectively. For thoracic PVP, the lung organ dose was significantly higher with CT-scan than with the fixed C-arm (127%; p<0.001) and the oesophagus organ doses were not significantly different (p = 0.626). CONCLUSION: This study showed that the E and the organ dose on directly exposed organs were both higher for PVP performed under CT-guidance than with the fixed C-arm.

Impact of additional mattresses in emergency CT on the automated patient centering proposed by a 3D camera: a phantom study.

To assess the impact of the use of additional mattresses of different thicknesses on radiation dose and image noise based on the patient centering proposed by a 3D camera for CT. An anthropomorphic phantom was placed on mattresses of different thicknesses (from 3.5 to 13.5 cm) on the table of a CT scanner. The automated patient centering proposed by a 3D camera was analysed as a function of mattress thickness and corrected for table height. For this purpose, the impact on image noise in the lung tissues in the chest area and in the soft tissues in the abdomen-pelvis area, modulated mAs (mAsmod) by the tube current modulation system (TCM) and volume CT dose index (CTDIvol) was assessed slice-by-slice along the z-axis after CT scans. With the use of a mattress, the automated centering proposed by the 3D camera resulted in placement of the phantom above the isocentre. This incorrect positioning led to a significant increase in the mAsmod along the z-axis (p < 0.05) and in the CTDIvol. Image noise was significantly higher (p < 0.05) for automated phantom centering than with manual phantom centering. Differences of image noise between acquisitions with mattresses after automatic and manual phantom centering increased with the mattress thicknesses. The use of an additional mattress placed between the patient's back and the table-top would require correcting the vertical centering proposed by the 3D camera. This manual correction is essential to avoid increased dose delivered to the patient and higher image noise.

Impact of dose reduction and the use of an advanced model-based iterative reconstruction algorithm on spectral performance of a dual-source CT system: A task-based image quality assessment.

PURPOSE: To assess the impact of dose reduction and the use of an advanced modeled iterative reconstruction algorithm (ADMIRE) on image quality in low-energy monochromatic images from a dual-source dual energy computed tomography CT (DSCT) platform. MATERIALS AND METHODS: Acquisitions on an image-quality phantom were performed using DSCT equipment with 100/Sn150 kVp for four dose levels (CTDIvol: 20/11/8/5mGy). Raw data were reconstructed for six energy levels (40/50/60/70/80/100 keV) using filtered back projection and two levels of ADMIRE (A3/A5). Noise power spectrum (NPS) and task-based transfer function (TTF) were calculated on virtual monoenergetic images (VMIs). Detectability index (d') was computed to model the detection task of two enhanced iodine lesions as function of keV. RESULTS: Noise-magnitude was significantly reduced between 40 to 70 keV by -56±0% (SD) (range: -56%--55%) with FBP; -56±0% (SD) (-56%--56%) with A3; and -57±1% (SD) (range: -57%--56%) with A5. The average spatial frequency of the NPS peaked at 70 keV and decreased as ADMIRE level increased. TTF values at 50% were greatest at 40 keV and shifted towards lower frequencies as the keV increased. The detectability of both lesions increased with increasing dose level and ADMIRE level. For the simulated lesion with iodine at 2mg/mL, d' values peaked at 70 keV for all reconstruction types, except for A3 at 20 mGy and A5 at 11 and 20 mGy, where d' peaked at 60 keV. For the other simulated lesion, d' values were highest at 40 keV and decreased beyond. CONCLUSION: At low keV on VMIs, this study confirms that iterative reconstruction reduces the noise magnitude, improves the spatial resolution and increases the detectability of enhanced iodine lesions.

Ultra-low-dose CT versus radiographs for minor spine and pelvis trauma: a Bayesian analysis of accuracy.

OBJECTIVES: To compare diagnosis performance and effective dose of ultra-low-dose CT (ULD CT) versus radiographs in suspected spinal or pelvic ring or hip fracture for minor trauma. METHODS: ULD CT, in addition to radiography, was prospectively performed in consecutive patients admitted to the emergency department for minor traumas, during working hours over 2 months. Presence of a recent fracture was assessed by two blind radiologists independently. Sensitivities and specificities were estimated using the best valuable comparator (BVC) as a reference and using a latent class model in Bayesian inference (BLCM). Dosimetric indicators were recorded and effective doses (E) were calculated using conversion coefficient. RESULTS: Eighty areas were analyzed in 69 patients, including 22 dorsal spine, 28 lumbar spine, and 30 pelvic ring/hip. Thirty-six fractures (45%) were observed. Applying the BVC method, depending on location, ULD CT sensitivity was 80 to 100% for reader 1 and 85 to 100% for reader 2, whereas radiographic sensitivity was 60 to 85% for reader 1 and 50 to 92% for reader 2. With BLCM approach for reader 2, ULD CT sensitivity for all locations/dorsal spine/lumbar spine and pelvic ring-hip was 87.1/75.9/84.2/76.9% respectively. Corresponding radiograph sensitivity was 73.8, 54.8, 80.4, and 68.7%. Effective doses of ULD CT were similar to radiographs for dorsal and hip locations whereas for lumbar spine, ULD CT effective dose was 1.83 ± 0.59 mSv compared with 0.96 ± 0.59 mSv (p < 0.001). CONCLUSION: Sensitivity for fracture detection was higher for ULD CT compared with radiographs with an effective dose comparable to radiographs. KEY POINTS: • Ultra-low-dose spine and pelvis CT demonstrates better fracture detection when compared with radiographs. • The effective dose of ultra-low-dose spine and pelvis CT scan and radiographs is comparable. • Replacement of radiographs by ULD CT in daily practice for trauma patients is an option to consider and should be evaluated by a randomized trial.

Early Results of Unilateral Prostatic Artery Embolization as a Focal Therapy in Patients with Prostate Cancer under Active Surveillance: Cancer Prostate Embolisation, a Pilot Study.

PURPOSE: To evaluate the feasibility of prostatic artery embolization in patients with low-risk prostate cancer (PC) under active surveillance (AS). METHODS: This monocentric prospective pilot study, running from June 2018 to June 2019, included 10 patients with low-risk PC under AS, median age 72 years (range, 62-77 years), with a unilateral focal lesion visible on magnetic resonance (MR) imaging, with Prostate Imaging Reporting and Data System v2 score ≥3/5 confirmed by multiparametric MR imaging-targeted biopsy and Gleason score 6. The patients underwent unilateral prostatic artery embolization with 300-500 µm Embospheres in the affected prostatic lobe. The primary endpoint was technical feasibility (prostate and no off-target ischemia in the imaging). The secondary endpoints included safety, negative biopsies/MR imaging response/functional outcomes at 6 months, and oncologic efficacy at 1 year. RESULTS: Embolization was successfully achieved in all patients; prostate ischemia was confirmed on multiparametric MR imaging, and no off-target ischemia was reported. No major complications were reported. Four patients (40%) presented with both negative targeted and systematic biopsies at 6 months. No lesions were seen on the MR imaging in 30% of patients. The mean International Prostate Symptom Score and International Index of Erectile Function score were 7 and 19 and 5 and 20 at baseline and 6 months, respectively, with no significant difference. Nine patients (90%) were still under AS at 1 year. One patient (10%) had PC progression outside the target lesion and was switched over to curative radiotherapy. CONCLUSIONS: Prostatic artery embolization is feasible and appears safe for prostate cancer patients under AS, with no impact on erectile function or continence status. These results justify the pursuit of further studies.

Systematic review and meta-analysis on the impact of lung cancer screening by low-dose computed tomography.

INTRODUCTION: Lung cancer (LC) has the highest cancer mortality worldwide with poor prognosis. Screening with low-dose computed tomography (LDCT) in populations highly exposed to tobacco has been proposed to improve LC prognosis. Our objective was to perform a systematic review and meta-analysis to evaluate the efficacy of screening by LDCT compared with any other intervention in populations who reported tobacco consumption for more than 15 years on LC and overall mortality. METHODS: We searched randomised controlled trials (RCTs) studying screening by LDCT compared with any other intervention in a population who reported an average smoking history greater than 15 pack-years from inception until the 19th February 2018 using Medline and Cochrane Library databases. Publication selection and data extraction were made independently by two double-blind reviewers. RESULTS: Seven RCTs were included in the meta-analysis which corresponds to 84,558 participants. A significant relative reduction of LC-specific mortality of 17% (risk ratio [RR] = 0.83, 95% confidence interval [CI]: 0.76-0.91) and a relative reduction of overall mortality of 4% (RR = 0.96, 95% CI: 0.92-1.00) was observed in the screening group compared with the control group. CONCLUSION: In populations highly exposed to tobacco, screening by LDCT reduces lung cancer mortality.

Clinical evaluation of a dose management system-integrated 3D skin dose map by comparison with radiochromic films.

OBJECTIVES: To validate the performance of an automatic tool to estimate a patient's peak skin dose (PSD) and a skin dose map from data collected by a radiation dose management system (RDMS) during interventional procedures. METHODS: In total, 288 eligible consecutive patients undergoing abdominopelvic embolisation or planned coronary angioplasty using radiochromic films were screened between June 2018 and March 2019. For 98 included patients, PSD was measured using radiochromic films (PSDFilm) and computed by RDMS (PSDRDMS) using one flat and two anthropomorphic phantoms. Statistical concordance between PSDFilm and PSDRDMS was computed with Lin's concordance correlation coefficient and clinical concordance with the Bland and Altman graphic; values were compared using the paired Mann-Whitney-Wilcoxon test. RESULTS: In total, 190/288 patients were excluded and 98 patients were analysed (69 men, mean age 66 ± 14 years). The PSDFilm median (1st; 3rd quartile) was 0.59 Gy (0.40; 1.08). PSDRDMS was 0.62 Gy (0.43; 1.22) for the flat phantom and 0.62 Gy (0.42; 1.19) for anthropomorphic phantoms. The concordance between PSDFilm and PSDRDMS was good for both phantoms (flat: 0.94 [0.91; 0.95]; anthropomorphic 0.94 [0.91; 0.96]). Compared with the values of PSDFilm, the values of PSDRDMS were significantly increased by 5% (- 4%; 16%) for flat phantom (p = 0.001) and 7% (- 6%; 22%) for anthropomorphic phantoms (p = 0.002) for vascular procedures and 9% (- 4%; 26%, p = 0.01) and 6% (- 4%; 23%, p = 0.02) for cardiac procedures, respectively. Dose map representations matched for most patients. The gaps identified were due to table displacement during fluoroscopy events and the use of a wedge filter. CONCLUSIONS: The RDMS skin dose map tool allowed the computation of the PSD and skin dose distribution for all patients with fewer constraints than radiochromic films. However, the computed PSD was overestimated, increasing the number of patients requiring follow-up. KEY POINTS: • A good concordance correlation was identified between the peak skin dose (PSD) values measured with radiochromic films and estimated with the radiation dose management system (RDMS) skin dose map tool. • Differences were related to table displacement during fluoroscopy events and the use of a wedge filter, which are not accounted in the Digital Imaging and Communications in Medicine Radiation Dose Structured Reports. • For all procedures, the estimated PSDs were significantly higher than the measured PSDs by 5% (- 4%; 18%) for flat phantom (p < 0.001) and 6% (- 5%; 22%) for anthropomorphic phantoms (p < 0.001).

Image quality and dose reduction opportunity of deep learning image reconstruction algorithm for CT: a phantom study.

OBJECTIVES: To assess the impact on image quality and dose reduction of a new deep learning image reconstruction (DLIR) algorithm compared with a hybrid iterative reconstruction (IR) algorithm. METHODS: Data acquisitions were performed at seven dose levels (CTDIvol : 15/10/7.5/5/2.5/1/0.5 mGy) using a standard phantom designed for image quality assessment. Raw data were reconstructed using the filtered back projection (FBP), two levels of IR (ASiR-V50% (AV50); ASiR-V100% (AV100)), and three levels of DLIR (TrueFidelity™ low, medium, high). Noise power spectrum (NPS) and task-based transfer function (TTF) were computed. Detectability index (d') was computed to model a large mass in the liver, a small calcification, and a small subtle lesion with low contrast. RESULTS: NPS peaks were higher with AV50 than with all DLIR levels and only higher with DLIR-H than with AV100. The average NPS spatial frequencies were higher with DLIR than with IR. For all DLIR levels, TTF50% obtained with DLIR was higher than that with IR. d' was higher with DLIR than with AV50 but lower with DLIR-L and DLIR-M than with AV100. d' values were higher with DLIR-H than with AV100 for the small low-contrast lesion (10 ± 4%) and in the same range for the other simulated lesions. CONCLUSIONS: New DLIR algorithm reduced noise and improved spatial resolution and detectability without changing the noise texture. Images obtained with DLIR seem to indicate a greater potential for dose optimization than those with hybrid IR. KEY POINTS: • This study assessed the impact on image quality and radiation dose of a new deep learning image reconstruction (DLIR) algorithm as compared with hybrid iterative reconstruction (IR) algorithm. • The new DLIR algorithm reduced noise and improved spatial resolution and detectability without perceived alteration of the texture, commonly reported with IR. • As compared with IR, DLIR seems to open further possibility of dose optimization.

Value of CT to detect radiographically occult injuries of the proximal femur in elderly patients after low-energy trauma: determination of non-inferiority margins of CT in comparison with MRI.

PURPOSE: To determine the margins of non-inferiority of the sensitivity of CT and the sample size needed to test the non-inferiority of CT in comparison with MRI. MATERIALS AND METHODS: During a 2-year period, elderly patients with suspected radiographically occult post-traumatic bone injuries were investigated by CT and MRI in two institutions. Four radiologists analyzed separately the CT and MRI examinations to detect post-traumatic femoral injuries. Their sensitivities at CT (SeCT) and MRI (SeMRI) were calculated with the reference being a best valuable comparator (consensus reading of the MRI and clinical follow-up). ROC analysis followed by an exact test (Newcombe's approach) was performed to assess the 95% confidence interval (CI) for the difference SeCT-SeMRI for each reader. A sample size calculation was performed based on our observed results by using a one-sided McNemar's test. RESULTS: Twenty-nine out of 102 study participants had a post-traumatic femoral injury. SeCT ranged between 83 and 93% and SeMRI ranged between 97 and 100%. The 95% CIs for (SeCT-SeMRI) were [- 5.3%, + 0.8%], (pR1 = 0.1250), [- 4.5%; + 1.2%] (pR2 = 0.2188), [- 3.4%; + 1.1%] (pR3 = 0.2500) to [- 3.8%; + 1.6%] (pR4 = 0.3750) according to readers, with a lowest limit for 95% CIs superior to a non-inferiority margin of (- 6%) for all readers. A population of 440 patients should be analyzed to test the non-inferiority of CT in comparison with MRI. CONCLUSION: CT and MRI are sensitive for the detection of radiographically occult femoral fractures in elderly patients after low-energy trauma. The choice between both these modalities is a compromise between the most available and the most sensitive technique. KEY POINTS: • The sensitivity of four separate readers to detect radiographically occult post-traumatic femoral injuries in elderly patients after low-energy trauma ranged between 83 and 93% at CT and between 97 and 100% at MRI according to a best valuable comparator including MRI and clinical follow-up. • CT is a valuable alternative method to MRI for the detection of post-traumatic femoral injuries in elderlies after low-energy trauma if a 6% loss in sensitivity can be accepted in comparison with MRI. • The choice between CT and MRI is a compromise between the most available and the most sensitive technique.