Blinded Readers Research Articles

AI Denoising Improves Image Quality and Radiological Workflows in Pediatric Ultra-Low-Dose Thorax Computed Tomography Scans.

(1) This study evaluates the impact of an AI denoising algorithm on image quality, diagnostic accuracy, and radiological workflows in pediatric chest ultra-low-dose CT (ULDCT). (2) Methods: 100 consecutive pediatric thorax ULDCT were included and reconstructed using weighted filtered back projection (wFBP), iterative reconstruction (ADMIRE 2), and AI denoising (PixelShine). Place-consistent noise measurements were used to compare objective image quality. Eight blinded readers independently rated the subjective image quality on a Likert scale (1 = worst to 5 = best). Each reader wrote a semiquantitative report to evaluate disease severity using a severity score with six common pathologies. The time to diagnosis was measured for each reader to compare the possible workflow benefits. Properly corrected mixed-effects analysis with post-hoc subgroup tests were used. Spearman’s correlation coefficient measured inter-reader agreement for the subjective image quality analysis and the severity score sheets. (3) Results: The highest noise was measured for wFBP, followed by ADMIRE 2, and PixelShine (76.9 ± 9.62 vs. 43.4 ± 4.45 vs. 34.8 ± 3.27 HU; each p < 0.001). The highest subjective image quality was measured for PixelShine, followed by ADMIRE 2, and wFBP (4 (4–5) vs. 3 (4–5) vs. 3 (2–4), each p < 0.001) with good inter-rater agreement (r ≥ 0.790; p ≤ 0.001). In diagnostic accuracy analysis, there was a good inter-rater agreement between the severity scores (r ≥ 0.764; p < 0.001) without significant differences between severity score items per reconstruction mode (F (5.71; 566) = 0.792; p = 0.570). The shortest time to diagnosis was measured for the PixelShine datasets, followed by ADMIRE 2, and wFBP (2.28 ± 1.56 vs. 2.45 ± 1.90 vs. 2.66 ± 2.31 min; F (1.000; 99.00) = 268.1; p < 0.001). (4) Conclusions: AI denoising significantly improves image quality in pediatric thorax ULDCT without compromising the diagnostic confidence and reduces the time to diagnosis substantially.

Clinical Low Dose Photon Counting CT for the Detection of Urolithiasis: Evaluation of Image Quality and Radiation Dose.

The purpose of this study was the evaluation of image quality and radiation dose parameters of the novel photon counting CT (PCCT, Naeotom Alpha, Siemens Healthineers) using low-dose scan protocols for the detection of urolithiasis. Standard CT scans were used as a reference (S40, Somatom Sensation 40, Siemens Healthineers). Sixty-three patients, who underwent CT scans between August and December 2021, were retrospectively enrolled. Thirty-one patients were examined with the PCCT and 32 patients were examined with the S40. Radiation dose parameters, as well as quantitative and qualitative image parameters, were analyzed. The presence of urolithiasis, image quality, and diagnostic certainty were rated on a 5-point-scale by 3 blinded readers. Both patient groups (PCCT and S40) did not differ significantly in terms of body mass index. Radiation dose was significantly lower for examinations with the PCCT compared to the S40 (2.4 ± 1.0 mSv vs. 3.4 ± 1.0 mSv; p < 0.001). The SNR was significantly better on images acquired with the PCCT (13.3 ± 3.3 vs. 8.2 ± 1.9; p < 0.001). The image quality of the PCCT was rated significantly better (4.3 ± 0.7 vs. 2.8 ± 0.6; p < 0.001). The detection rate of kidney or ureter calculi was excellent with both CT scanners (PCCT 97.8% and S40 99%, p = 0.611). In high contrast imaging, such as the depiction of stones of the kidney and the ureter, PCCT allows a significant reduction of radiation dose, while maintaining excellent diagnostic confidence and image quality. Given this image quality with our current protocol, further adjustments towards ultra-low-dose CT scans appear feasible.

Improving pre-operative MRI diagnosis of peroneal tendon tears with a new objective sign and assessing the value of peroneus brevis fatty atrophy

Objectives: We aimed to compare the diagnostic performance of an objective set of magnetic resonance imaging (MRI) criteria named the cleft sign with traditional reads for pre-operative diagnosis of peroneal tendon tears. We also investigated the relationship between peroneus brevis tendon tears and muscle quality. Material and Methods: Two blinded readers retrospectively and independently evaluated pre-operative ankle MRI studies of 38 patients who had undergone peroneal tendon surgery for peroneal tendon tears, peroneus brevis muscle quality, and the cleft sign. MRI examinations from 38 control subjects were also reviewed for peroneus brevis muscle quality. The diagnostic performances of MRI for peroneal tendon tears with and without application of the cleft sign were analyzed. The correlation between peroneus brevis fatty atrophy and tendon tears was also examined. Results: In patients without prior peroneal surgery, the sensitivity and specificity of MRI for peroneus brevis tendon tears were 60%/89% and 80%/78% for readers 1 and 2, respectively. Application of the cleft sign significantly increased sensitivity in reader 1 to 95%, with a non-significant increase in accuracy in both readers. The interobserver reliability for the cleft sign was moderate for peroneus brevis (κ = 0.57). No significant difference in peroneus brevis muscle quality was present between subjects with and without peroneus brevis tendon tears and between surgical and control patients. Conclusion: In patients without prior peroneal tendon surgery, the cleft sign can significantly improve reader diagnostic sensitivity for peroneus brevis tears. The muscle quality of the peroneus brevis has limited value in MRI diagnosis of peroneal tendon tears.

Reliability of radio-ulnar and carpal alignment measurements in the wrist between radiographs and 3D imaging

ObjectiveConventional radiography is the first modality to investigate the radio-ulno-carpal joint in the event of trauma or instability. This study sought to determine the reliability of cone beam computer tomography (CBCT) and scout of view in evaluating carpal alignment compared with conventional radiographs in order to assess the influence of wrist kinematics on usual measurements. Materials and methodsWe prospectively recruited 305 patients who successively underwent plain radiography and CBCT. 51 patients with prior acute unilateral wrist trauma were eligible for entry into the study (mean age of 39 years). Three blinded readers performed the measurements separately. The axial method and bony axial lines defined previously in the literature were applied, with three categories of measurements performed, consisting of distal radio-ulnar, radiocarpal, and radio/carpometacarpal measurements. Intraclass correlation coefficients (ICCs) for paired t-test were calculated to assess inter- and intra-observer agreements. ResultsInter-observer agreement was very high (>0.94) for all modalities. Intra-observer reliability between scout view and CBCT was almost perfect for all measurements. Intra-observer reliability between radiograph and scout view/CBCT was perfect for distal radio-ulnar measurements, substantial for radio-carpal, and moderate for radio/carpometacarpal measurements. ConclusionIn the absence of a strict position control between two imaging acquisitions, only distal radio-ulnar measurements were shown perfectly reliable when using these two imaging methods, which is suggestive of a minor relevance of ulnar/radial deviation. Excepting for some angles, the radio-carpal and radio-carpometacarpal measurements were shown to differ according to wrist position, being thus more sensitive to flexion/extension of the wrist.

Predictive value of extra-prostatic disease detection by pre-operative PSMA-PET for biochemical recurrence-free survival in patients treated with radical prostatectomy: Follow-up analysis of a multicenter prospective phase 3 imaging trial.

5088 Background: To assess the predictive value of pre-operative PSMA-PET staging for biochemical recurrence (BCR) free-survival (BCR-FS) in patients treated with radical prostatectomy (RP) and pelvic lymph node dissection (PLND) with intermediate-risk (IR) to high-risk (HR) prostate cancer (PCa) included in the prospective trial used for the FDA approval of 68Ga-PSMA-11. Methods: This is a post-hoc follow-up study of the efficacy analysis cohort included in the multicenter prospective phase 3 imaging trial (n = 764; NCT03368547, NCT02611882, NCT02919111) which assessed the diagnostic accuracy of 68Ga-PSMA-11 PET for pelvic nodal metastasis detection prior to RP and PLND in patients with IR and HR PCa. Each PSMA-PET scan was read by three blinded independent readers. Readers assessed the presence of PCa (positive vs negative) by region: prostate bed (T), pelvic lymph nodes (N), extra-pelvic lymph nodes (M1a) bone (M1b) and visceral (M1c). A centralized per-region majority rule was used in case of disagreement. The surgical pathology report was used to assess the presence of pelvic lymph node metastasis by histopathology (pN0 vs pN1). The patients were followed up for biochemical progression after RP by the local investigators using electronic medical records. BCR was defined by a prostate-specific antigen (PSA) level &gt; 0.2 ng/ml after RP or an initiation of PCa specific adjuvant/salvage therapy. Pairwise comparisons using Log-Rank test was performed to evaluate BCR-FS between the pre-operative PSMA scan reads (N0M0 vs. N+ and/or M+) and the histopathology status (pN0 vs. pN1). Results: From December 2015 to December 2019, a total of 764 patients were enrolled in the trial. 277/764 (36%) underwent RP after PSMA-PET. Clinical follow-up was obtained in 240/277 (87%) patients. The median age was 67 years (interquartile range, 61-71 years). The median follow-up time from RP was 21.4 months (IQR: 8.80 - 31.53). One hundred BCR events (41%) were observed, and 98/240 patients underwent salvage therapy or other treatment (40.6%). The BCR-FS was 24.3 (IQR: 7.8 - 48.8) in the whole cohort. 160/240 (66%), 28/240 (11.6%), 39/240 (16%), 13/240 (5.4%) patients were pN0/PSMA- (N0 and M0), pN+/PSMA+ (N+ and/or M+), pN+/PSMA-, and pN0/PSMA+, respectively. BCR-FS was higher in PSMA- than in PSMA+ patients (33 vs 7.3 months; p &lt; 0.0001). BCR-FS was higher in pN0/PSMA- than in patients pN+/PSMA-, pN0/PSMA+ and pN+/PSMA+: 46 months vs 12.3, 11.7, and 3, respectively (p &lt; 0.001). BCR-FS did not significantly differ between pN0/PSMA+ and pN+/PSMA- (11.7 vs 12.3; p = 0.64). Conclusions: PSMA PET staging information is predictive of BCR-FS after RP. Patients with extra-prostatic disease detected by pre-operative PSMA-PET scan have a high risk of biochemical relapse. Clinical trial information: NCT03368547.

Ultra-High-Resolution Coronary CT Angiography With Photon-Counting Detector CT: Feasibility and Image Characterization.

The aim of this study was to evaluate the feasibility and quality of ultra-high-resolution coronary computed tomography angiography (CCTA) with dual-source photon-counting detector CT (PCD-CT) in patients with a high coronary calcium load, including an analysis of the optimal reconstruction kernel and matrix size. In this institutional review board-approved study, 20 patients (6 women; mean age, 79 ± 10 years; mean body mass index, 25.6 ± 4.3 kg/m 2 ) undergoing PCD-CCTA in the ultra-high-resolution mode were included. Ultra-high-resolution CCTA was acquired in an electrocardiography-gated dual-source spiral mode at a tube voltage of 120 kV and collimation of 120 × 0.2 mm. The field of view (FOV) and matrix sizes were adjusted to the resolution properties of the individual reconstruction kernels using a FOV of 200 × 200 mm 2 or 150 × 150 mm 2 and a matrix size of 512 × 512 pixels or 1024 × 1024 pixels, respectively. Images were reconstructed using vascular kernels of 8 sharpness levels (Bv40, Bv44, Bv56, Bv60, Bv64, Bv72, Bv80, and Bv89), using quantum iterative reconstruction (QIR) at a strength level of 4, and a slice thickness of 0.2 mm. Images with the Bv40 kernel, QIR at a strength level of 4, and a slice thickness of 0.6 mm served as the reference. Image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), vessel sharpness, and blooming artifacts were quantified. For subjective image quality, 2 blinded readers evaluated image noise and delineation of coronary artery plaques and the adjacent vessel lumen using a 5-point discrete visual scale. A phantom scan served to characterize image noise texture by calculating the noise power spectrum for every reconstruction kernel. Maximum spatial frequency (f peak ) gradually shifted to higher values for reconstructions with the Bv40 to Bv64 kernel (0.15 to 0.56 mm -1 ), but not for reconstructions with the Bv72 to Bv89 kernel. Ultra-high-resolution CCTA was feasible in all patients (median calcium score, 479). In patients, reconstructions with the Bv40 kernel and a slice thickness of 0.6 mm showed largest blooming artifacts (55.2% ± 9.8%) and lowest vessel sharpness (477.1 ± 73.6 ΔHU/mm) while achieving highest SNR (27.4 ± 5.6) and CNR (32.9 ± 6.6) and lowest noise (17.1 ± 2.2 HU). Considering reconstructions with a slice thickness of 0.2 mm, image noise, SNR, CNR, vessel sharpness, and blooming artifacts significantly differed across kernels (all P 's < 0.001). With higher kernel sharpness, SNR and CNR continuously decreased, whereas image noise and vessel sharpness increased, with highest sharpness for the Bv89 kernel (2383.4 ± 787.1 ΔHU/mm). Blooming artifacts continuously decreased for reconstructions with the Bv40 (slice thickness, 0.2 mm; 52.8% ± 9.2%) to the Bv72 kernel (39.7% ± 9.1%). Subjective noise was perceived by both readers in agreement with the objective measurements. Considering delineation of coronary artery plaques and the adjacent vessel lumen, reconstructions with the Bv64 and Bv72 kernel (for both, median score of 5) were favored by the readers providing an excellent anatomic delineation of plaque characteristics and vessel lumen. Ultra-high-resolution CCTA with PCD-CT is feasible and enables the visualization of calcified coronaries with an excellent image quality, high sharpness, and reduced blooming. Coronary plaque characterization and delineation of the adjacent vessel lumen are possible with an optimal quality using Bv64 kernel, a FOV of 200 × 200 mm 2 , and a matrix size of 512 × 512 pixels.

Implementasi Metode Iqra dalam Pemberantasan Buta Baca Alquran Pada Siswa

&#x0D; &#x0D; &#x0D; &#x0D; This study aims to examine: 1) the ability to read the Koran in grade 10 students at SMA N 13 Padang 2) the factors behind the blind reading of the Koran in grade 10 students at SMA N 13 Padang 3) the Implementation of the Iqra method in eradicating blind reading of the Koran in 10th-grade students at SMA N 13 Padang. The method used by researchers in this study is qualitative with a descriptive approach. This research was conducted at SMA Negeri 13 Padang. Data collection techniques used are observation, documentation, and interviews. The data obtained from the study were then analyzed by data reduction, data presentation, and drawing conclusions. The data validation technique used is the triangulation technique, checking the data again with a different technique so as to get valid data. The results showed that the ability to read the Koran of grade 10 students at SMA Negeri 13 Padang was still low due to the lack of interest in reading students. The background of the lack of reading the Koran at SMA Negeri 13 Padang resulted in a lack of encouragement from parents at home. The application of the Iqra method at SMA Negeri 13 Padang is increasing by using this method.&#x0D; &#x0D; &#x0D; &#x0D; &#x0D;

Reproducibility of a protocol for standardized reading of chest X-rays of children household contact of patients with tuberculosis

BackgroundThe interpretation of the chest radiograph may vary because it depends on the reader and due to the non-specificity of findings in tuberculosis (TB). We aim to assess the reproducibility of a standardized chest radiograph reading protocol in contacts of patients with pulmonary TB under the 5 years of age.MethodsDescriptive, cross-sectional study with children under the age of five, household contacts of patients with confirmed pulmonary TB from Medellín, Bello and Itagüí (Colombia) between Jan-01–2015 and May-31–2016. Standardized reading protocol: two radiologists, blinded independent reading, use of template (Dr. Andronikou design) in case of disagreement a third reading was performed. Kappa coefficient for intra and inter observer agreement, and prevalence ratio were estimated of sociodemographic characteristics, TB exposure and interpretation of chest X-ray.ResultsFrom 278 children, standardized reading found 255 (91.7%) normal X-rays, 10 (3.6%) consistent with TB, and 13 (4.7%) other alterations. Global agreement was 91.3% (Kappa = 0.51). Inter-observer agreement between readers 1–2 was 90.0% (Kappa = 0.59) and 1–3 93.2% (Kappa = 0.59). Intra-observer agreement for reader 1 was 95.5% (Kappa = 0.86), 2 84.0% (Kappa = 0.51), and 3 94.7% (Kappa = 0.68). Greater inter-observer disagreement was between readers 1–2 for soft tissue density suggestive of adenopathy (4.6%), airspace opacification (1.17%) and pleural effusion (0.58%); between readers 1–3 for soft tissue density suggestive of adenopathy (4.2%), opacification of airspace (2.5%) and cavities (0.8%).ConclusionsChest radiographs are an affordable tool that contributes to the diagnosis of TB, so having a standardized reading protocol showed good agreement and improves the reproducibility of radiograph interpretation.

Segmental strain for scar detection in acute myocardial infarcts and in follow-up exams using non-contrast CMR cine sequences

BackgroundThe purpose of the study was to investigate feasibility of infarct detection in segmental strain derived from non-contrast cardiac magnetic resonance (CMR) cine sequences in patients with acute myocardial infarction (AMI) and in follow-up (FU) exams.Methods57 patients with AMI (mean age 61 ± 12 years, CMR 2.8 ± 2 days after infarction) were retrospectively included, FU exams were available in 32 patients (35 ± 14 days after first CMR). 43 patients with normal CMR (54 ± 11 years) served as controls. Dedicated software (Segment CMR, Medviso) was used to calculate global and segmental strain derived from cine sequences. Cine short axis stacks and segmental circumferential strain calculations of every patient and control were presented to two blinded readers in random order, who were advised to identify potentially infarcted segments, blinded to LGE and clinical information.ResultsImpaired global strain was measured in AMI patients compared to controls (global peak circumferential strain [GPCS] p = 0.01; global peak longitudinal strain [GPLS] p = 0.04; global peak radial strain [GPRS] p = 0.01). In both imaging time points, mean segmental peak circumferential strain [SPCS] was impaired in infarcted tissue compared to remote segments (AMI: p = 0.03, FU: p = 0.02). SPCS values in infarcted segments were similar between AMI and FU (p = 0.8). In SPCS calculations, 141 from 189 acutely infarcted segments were accurately detected (74.6%), visual evaluation of correlating cine images detected 43.4% infarcts. In FU, 80% infarcted segments (91/114 segments) were detected in SPCS and 51.8% by visual evaluation of correlating short axis cine images (p = 0.01).ConclusionSegmental circumferential strain derived from routinely acquired native cine sequences detects nearly 75% of acute infarcts and 80% of infarcts in subacute follow-up CMR, significantly more than visual evaluation of correlating cine images alone. Acute infarcts may display only subtle impairment of wall motion and no obvious wall thinning, thus SPCS calculation might be helpful for scar detection in patients with acute infarcts, when LGE images are not available.

Extrahepatic Disease in Hepatocellular Carcinoma: Do We Always Need Whole-Body CT or Is Liver MRI Sufficient? A Subanalysis of the SORAMIC Trial.

Background: To investigate whole-body contrast-enhanced CT and hepatobiliary contrast liver MRI for the detection of extrahepatic disease (EHD) in hepatocellular carcinoma (HCC) and to quantify the impact of EHD on therapy decision. Methods: In this post-hoc analysis of the prospective phase II open-label, multicenter, randomized controlled SORAMIC trial, two blinded readers independently analyzed the whole-body contrast-enhanced CT and gadoxetic acid-enhanced liver MRI data sets of 538 HCC patients. EHD (defined as tumor manifestation outside the liver) detection rates of the two imaging modalities were compared using multiparametric statistical tests. In addition, the most appropriate treatment recommendation was determined by a truth panel. Results: EHD was detected significantly more frequently in patients with portal vein infiltration (21% vs. 10%, p < 0.001), macrovascular infiltration (22% vs. 9%, p < 0.001), and bilobar liver involvement (18% vs. 9%, p = 0.006). Further on, the maximum lesion diameter in patients with EHD was significantly higher (8.2 cm vs. 5.8 cm, p = 0.002). CT detected EHD in significantly more patients compared to MRI in both reader groups (p < 0.001). Higher detection rates of EHD in CT led to a change in management only in one patient since EHD was predominantly present in patients with locally advanced HCC, in whom palliative treatment is the standard of care. Conclusions: Whole-body contrast-enhanced CT shows significantly higher EHD detection rates compared to hepatobiliary contrast liver MRI. However, the higher detection rate did not yield a significant impact on patient management in advanced HCC.

Tantalum-specific contrast-to-noise ratio or conventional detector dose-driven exposure control in angiography: radiation dose and image quality evaluation in a porcine model

BackgroundThe aim of this animal study was to compare the fluoroscopic image quality (IQ) and radiation dose between a tantalum (Ta)-specific contrast-to-noise ratio-driven exposure control (Ta-CEC) and a detector dose-driven exposure control (DEC) in abdominal angiography.MethodsNine angiography scenarios were created in seven anaesthetised pigs using Ta-based embolisation material during percutaneous liver and kidney intervention. Fluoroscopic images were acquired using three DEC protocols with different dose levels and Ta-CEC protocols with different IQ levels, sampled in small steps. Polymethyl-methacrylate and aluminium plates were used to simulate attenuation of three water equivalent thicknesses (WET). Three blinded readers evaluated the IQ of DEC and dose equivalent Ta images and selected the Ta-IQ equivalent image corresponding to the DEC image.ResultsInterobserver agreement for the IQ assessment was 0.43 for DEC, 0.56 for Ta-CEC and for the assessment of incident air kerma at the interventional reference point (Ka,r) for the Ta-IQ equivalent image 0.73. The average IQ of the dose equivalent Ta images was superior compared to the DEC images (p < 0.001) and also for every WET (26, 31, or 36 cm) and dose level (p ≤ 0.022). The average Ka,r for the Ta-IQ equivalent images was 59 ± 16% (mean ± standard deviation) lower compared to the DEC images (p < 0.001).ConclusionsCompared to DEC, Ta-CEC significantly improved the fluoroscopic depiction of Ta, while maintaining the Ka,r. Alternatively, the Ka,r can be significantly reduced by using Ta-CEC instead of DEC, while maintaining equivalent IQ.

Magnetic resonance imaging characteristics in patients with spondyloarthritis and clinical diagnosis of heel enthesitis: post hoc analysis from the phase 3 ACHILLES trial

ObjectiveTo investigate the imaging characteristics and clinically assess heel enthesitis in spondyloarthritis (SpA) by applying in a post hoc analysis the Heel Enthesitis Magnetic Resonance Imaging Scoring system (HEMRIS) in blinded and centrally-read MRI data from the ACHILLES trial (NCT02771210).MethodsACHILLES included patients (≥18 years) with active psoriatic arthritis or axial SpA with clinical and MRI-positive heel enthesitis refractory to standard treatment. Patients were randomized to receive subcutaneous secukinumab 150/300 mg or placebo. At week 24, patients on placebo were switched to secukinumab treatment. MRI-positive heel enthesitis was confirmed in all patients by local investigators. MRIs were performed at 3 timepoints: screening and weeks 24 and 52. In the present analysis, all MRIs were re-evaluated by 2 blinded central readers in a consensus read fashion for a priori defined MRI parameters based on HEMRIS.ResultsAt screening, 171/204 (83.8%) of patients presented with entheseal inflammation and/or structural damage, considering both the Achilles tendon and plantar fascia. Pathologies were more evident in the Achilles tendon area compared to the plantar aponeurosis. The most frequent pathologies were intra-tendon hypersignal and retrocalcaneal bursitis. The mean total entheseal inflammation score at screening in the Achilles tendon area was 2.99 (N=204) and the mean change (standard deviation [SD]) from screening to weeks 24 and 52 was − 0.91 (1.99) and − 0.83 (2.12) in the secukinumab group vs − 0.48 (1.86) and − 0.80 (1.98) in the placebo-secukinumab group, respectively. The mean total structural damage score at screening was 1.36 (N=204) and the mean change (SD) from screening to weeks 24 and 52 was 0.00 (0.65) and − 0.06 (0.56) in the secukinumab group vs 0.08 (0.48) and 0.04 (0.75) in the placebo-secukinumab group, respectively.ConclusionsBased on the newly developed HEMRIS, entheseal inflammation and/or structural damage was confirmed in 83.3% of ACHILLES patients. Pathologies were more evident in the Achilles tendon area compared to plantar fascia, with the inflammatory parameters being more responsive with secukinumab treatment compared to placebo. The present analysis, with detailed information on individual MRI parameters, contributes to the scientific debate on heel enthesitis.Trial registrationClinicalTrials.gov NCT02771210.

Role of LI-RADS Indeterminate Observations in the Risk of Hepatocellular Carcinoma after HCV Eradication with Direct-Acting Antivirals.

Purpose: To assess whether HCC (LR-5) occurrence may be associated with the presence of Liver Imaging Reporting and Data System (LI-RADS) indeterminate observations in patients with hepatitis C virus infection treated with direct acting antiviral (DAA) therapy. Materials and methods: This retrospective study included patients with HCV-related cirrhosis who achieved sustained virologic response (SVR) after DAA therapy between 2015 and 2019 and submitted to CT/MRI follow-ups with a minimum interval time of six months before and after DAA. Two blinded readers reviewed CT/MRI to categorize observations according to LI-RADS version 2018. Differences in rate of LI-RADS 5 observations (i.e., LR-5) before and after SVR were assessed. Time to LR-5 occurrence and risk factors for HCC after DAAs were evaluated by using Kaplan-Meier method and Cox proportional hazard model, respectively. Results: Our final study population comprised 115 patients (median age 72 years) with a median CT/MRI follow-up of 47 months (IQR 26–77 months). Twenty-nine (25.2%) patients were diagnosed with LR-5 after DAA. The incidence of LR-5 after DAAs was 10.4% (12/115) at one year and 17.4% (20/115) at two years. LR-5 occurrence after DAA was significantly higher in patients with Child Pugh class B (log-rank p = 0.048) and with LR-3 or LR-4 observations (log-rank p = 0.024). At multivariate analysis, Child-Pugh class B (hazard ratio 2.62, p = 0.023) and presence of LR-3 or LR-4 observations (hazard ratio 2.40, p = 0.048) were independent risk factors for LR-5 occurrence after DAA therapy. Conclusions: The presence of LR-3 and LR-4 observations significantly increases HCC risk following the eradication of HCV infection.

Cerebrovascular Events in Suspected Sepsis: Retrospective Prevalence Study in Critically Ill Patients Undergoing Full-Body Computed Tomography.

PurposeThis study aimed at retrospectively evaluating full-body computed tomography (CT) examinations for the prevalence of cerebrovascular events in patients with suspected sepsis treated in the intensive care unit (ICU).MethodsAll full-body CT examinations, i.e., both cranial CT (cCT) and body CT including chest, abdomen and pelvis, for focus search in septic patients over a 12-months period were identified from three ICUs, using full-text search. From this retrospective cohort, we fully analyzed 278 cCT examinations for the occurrence of acute cerebral findings. All acute cerebrovascular events were independently reviewed by two blinded readers. Clinical and laboratory findings were extracted. The data were statistically analyzed using contingency tests.ResultsIn our population of patients with suspected sepsis, 10.8% (n = 30/278) were identified to have major cerebral events, including 7.2% (n = 20/278) major cerebrovascular events and 4.3% (n = 12/278) generalized parenchymal damage. 13.4% (n = 22/163) of patients with a severe coma as compared with non-severe coma, 4.4% (n = 3/68), showed a major cerebral event (p = 0.04). Patients referred from the cardiology/nephrology ICU ward showed major cerebral events in 16.3% (n = 22/135), as compared with 4.9% (n = 3/61) in patients from pulmonary ICU and 6.1% (n = 5/82) major cerebral events with surgical referral (p = 0.02).ConclusionOur study provides further evidence that septic patients may suffer from cerebral events with relevance to their prognosis. Severe coma and the referring ward were associated with acute cerebral conditions. Full-body CT has the advantage of both detecting of septic foci and possibly identifying ischemic or hemorrhagic stroke in this vulnerable patient population.

Deep learning–based time-of-flight (ToF) image enhancement of non-ToF PET scans

PurposeTo improve the quantitative accuracy and diagnostic confidence of PET images reconstructed without time-of-flight (ToF) using deep learning models trained for ToF image enhancement (DL-ToF).MethodsA total of 273 [18F]-FDG PET scans were used, including data from 6 centres equipped with GE Discovery MI ToF scanners. PET data were reconstructed using the block-sequential-regularised-expectation–maximisation (BSREM) algorithm with and without ToF. The images were then split into training (n = 208), validation (n = 15), and testing (n = 50) sets. Three DL-ToF models were trained to transform non-ToF BSREM images to their target ToF images with different levels of DL-ToF strength (low, medium, high). The models were objectively evaluated using the testing set based on standardised uptake value (SUV) in 139 identified lesions, and in normal regions of liver and lungs. Three radiologists subjectively rated the models using testing sets based on lesion detectability, diagnostic confidence, and image noise/quality.ResultsThe non-ToF, DL-ToF low, medium, and high methods resulted in − 28 ± 18, − 28 ± 19, − 8 ± 22, and 1.7 ± 24% differences (mean; SD) in the SUVmax for the lesions in testing set, compared to ToF-BSREM image. In background lung VOIs, the SUVmean differences were 7 ± 15, 0.6 ± 12, 1 ± 13, and 1 ± 11% respectively. In normal liver, SUVmean differences were 4 ± 5, 0.7 ± 4, 0.8 ± 4, and 0.1 ± 4%. Visual inspection showed that our DL-ToF improved feature sharpness and convergence towards ToF reconstruction. Blinded clinical readings of testing sets for diagnostic confidence (scale 0–5) showed that non-ToF, DL-ToF low, medium, and high, and ToF images scored 3.0, 3.0, 4.1, 3.8, and 3.5 respectively. For this set of images, DL-ToF medium therefore scored highest for diagnostic confidence.ConclusionDeep learning–based image enhancement models may provide converged ToF-equivalent image quality without ToF reconstruction. In clinical scoring DL-ToF-enhanced non-ToF images (medium and high) on average scored as high as, or higher than, ToF images. The model is generalisable and hence, could be applied to non-ToF images from BGO-based PET/CT scanners.

Association of golimumab trough concentrations during maintenance with clinical, biological, endoscopic and histologic remission in patients with ulcerative colitis.

Optimal golimumab concentration thresholds for important outcomes during maintenance are lacking. To investigate the association of golimumab trough concentrations during maintenance with key outcomes, including endoscopic and histologic remission, and long-term event-free persistence with golimumab, in patients with UC. This multi-centre, cross-sectional study included patients with UC on golimumab maintenance recruited either in remission or during a flare. Colonoscopy was scheduled, and study-specific rectocolonic biopsies were taken for blind central histologic reading. Samples for golimumab trough concentrations were collected close to colonoscopy. Fifty-two patients were included. Median golimumab trough concentrations (μg/ml) were significantly higher in patients who had clinical remission (2.01 vs. 0.72, p=0.047), combined clinical-biochemical remission (PMS ≤2 + faecal calprotectin <250 μg/g) (2.21 vs. 1.47, p=0.041), endoscopic healing (Mayo endoscopic subscore 0) (2.52 vs. 1.47, p=0.003), histologic remission (Geboes index ≤2.0) (2.33 vs. 1.50, p=0.02) and disease clearance (clinical remission endoscopic healing + histologic remission) (2.52 vs. 1.70, p=0.009), compared with those not meeting these criteria. Golimumab concentrations were significantly higher in patients who avoided golimumab dose escalation/discontinuation during follow-up (2.24 vs. 0.98, p=0.012). Receiver-operating characteristic analyses identified golimumab thresholds [area under the curve] of 0.85 [0.76], 1.90 [0.76], 2.29 [0.75], 1.79 [0.68], 2.29 [0.72] and 1.56 [0.71] μg/ml as associated with clinical remission, combined remission, endoscopic healing, histologic remission, disease clearance and long-term event-free persistence with golimumab, respectively. Golimumab trough concentrations during maintenance are associated with favourable treatment outcomes including endoscopic healing, histologic remission and long-term persistence on golimumab. We identified the optimal golimumab thresholds most closely associated with key outcomes.

Three-Dimensional Isotropic Versus Conventional Multisequence 2-Dimensional Magnetic Resonance Imaging of Sacroiliac Joints in Suspected Axial Spondyloarthritis.

The aims of the study were to systematically evaluate the sacroiliac joints of a consecutive series of patients with clinically suspected axial spondyloarthritis and to compare the diagnostic efficacy of 3-dimensional (3D) imaging versus conventional multisequence 2D techniques for sacroiliitis. In this cross-sectional multireader validation study, imaging studies of 104 consecutive patients with clinically suspected axial spondyloarthritis obtained with a rheumatology lumbosacral magnetic resonance imaging protocol were evaluated. Three-dimensional coronal oblique reconstructions parallel to the long axis of the sacrum were created. Two blinded readers evaluated 2D and 3D images separately for each study, and findings were compared with the reference standard for the final diagnosis and disease activity. Cohen κ and diagnostic performance measures on 2D and 3D imaging were evaluated and compared. With 2D versus 3D imaging, respectively, the sensitivity for detecting inflammatory cases was 57% versus 62% ( P = 0.1007), the sensitivity for detecting mechanical cases was 89% versus 76% ( P = 0.0312), the sensitivity for detecting active sacroiliitis was 49% versus 64% ( P = 0.0014), and the specificity for detecting active sacroiliitis was 87% versus 76% ( P = 0.0016). Interreader agreement of 2D imaging showed an overall range of κ = 0.27-0.85, and it was best for evaluation of bony ankylosis (κ = 0.85). Interreader agreement of 3D imaging was in an overall range of κ = 0.15-0.64. Single 3D isotropic magnetic resonance imaging provided adequate assessment of sacroiliac joints in this study and demonstrated significantly higher sensitivity and lower specificity for detecting active sacroiliitis. The initial results indicate that 3D imaging could be used for future works for screening sacroiliitis and abdominopelvic enthesopathy.

Uncertainty-Aware and Lesion-Specific Image Synthesis in Multiple Sclerosis Magnetic Resonance Imaging: A Multicentric Validation Study.

Generative adversarial networks (GANs) can synthesize high-contrast MRI from lower-contrast input. Targeted translation of parenchymal lesions in multiple sclerosis (MS), as well as visualization of model confidence further augment their utility, provided that the GAN generalizes reliably across different scanners. We here investigate the generalizability of a refined GAN for synthesizing high-contrast double inversion recovery (DIR) images and propose the use of uncertainty maps to further enhance its clinical utility and trustworthiness. A GAN was trained to synthesize DIR from input fluid-attenuated inversion recovery (FLAIR) and T1w of 50 MS patients (training data). In another 50 patients (test data), two blinded readers (R1 and R2) independently quantified lesions in synthetic DIR (synthDIR), acquired DIR (trueDIR) and FLAIR. Of the 50 test patients, 20 were acquired on the same scanner as training data (internal data), while 30 were scanned at different scanners with heterogeneous field strengths and protocols (external data). Lesion-to-Background ratios (LBR) for MS-lesions vs. normal appearing white matter, as well as image quality parameters were calculated. Uncertainty maps were generated to visualize model confidence. Significantly more MS-specific lesions were found in synthDIR compared to FLAIR (R1: 26.7 ± 2.6 vs. 22.5 ± 2.2 p < 0.0001; R2: 22.8 ± 2.2 vs. 19.9 ± 2.0, p = 0.0005). While trueDIR remained superior to synthDIR in R1 [28.6 ± 2.9 vs. 26.7 ± 2.6 (p = 0.0021)], both sequences showed comparable lesion conspicuity in R2 [23.3 ± 2.4 vs. 22.8 ± 2.2 (p = 0.98)]. Importantly, improvements in lesion counts were similar in internal and external data. Measurements of LBR confirmed that lesion-focused GAN training significantly improved lesion conspicuity. The use of uncertainty maps furthermore helped discriminate between MS lesions and artifacts. In conclusion, this multicentric study confirms the external validity of a lesion-focused Deep-Learning tool aimed at MS imaging. When implemented, uncertainty maps are promising to increase the trustworthiness of synthetic MRI.

Interindividual Comparison of Frequency-Selective Nonlinear Blending to Conventional CT for Detection of Focal Liver Lesions Using MRI as the Reference Standard.

BACKGROUND. Diagnosing liver lesions is challenging. CT is used for primary diagnosis, but its contrast resolution is limited. Investigating methods to improve detection of liver lesions is important. OBJECTIVE. The purpose of this study was to evaluate the effect of frequency-selective nonlinear blending on the detectability of liver lesions on CT. METHODS. A retrospective search yielded 109 patients with 356 malignant and benign liver lesions (191 principally diagnosed, 165 incidental findings) who underwent contrast-enhanced CT (CECT) in the portal venous phase and liver MRI between January 2012 and December 2017. Nonlinear blending was applied to CECT examinations, and three blinded readers independently rated the quality (5-point Likert scale) of randomly presented images. Focal lesions (n = 356) were evaluated for lesion identification and categorization to assess sensitivity. For 191 lesions (primary diagnosis), two readers evaluated CECT and nonlinear blending CT to compare lesion size and the accuracy of subjective measurements. A fourth reader performed ROI measurements for calculation of contrast-to-noise ratio (CNR), and a fifth reader reviewed MRI as the standard of reference. Statistics included interobserver agreement, quantitative comparisons of CNR, lesion size, and subjective image analyses of image quality and sensitivity for detecting liver lesions. RESULTS. Three readers rated the image quality of nonlinear blending CT (rating, 4; 10th-90th percentiles, 4-5) higher than that of CECT (rating, 2; 10th-90th percentiles, 1-3) (p < .001). CECT had good interreader agreement (interclass correlation coefficient [ICC], 0.81; 95% CI, 0.76-0.85), as did nonlinear blending CT (ICC, 0.75; 95% CI, 0.69-0.79). The median CNR of liver lesions increased with nonlinear blending (CECT, 4.18 [10th-90th percentiles, 1.67-9.06]; nonlinear blending CT, 12.49 [10th-90th percentiles, 6.18-23.39]; p < .001). Bland-Altman analysis of lesion size showed a reduction in underestimation from 2.5 (SD, 9.2) mm (95% CI, 1.2-3.9 mm) with CECT to 0.1 (SD, 3.9) mm (95% CI, -0.68 to 0.46 mm) for nonlinear blending CT (concordance correlation coefficient, 0.99). Sensitivity for detecting liver lesions increased to 86% for nonlinear blending CT. The sensitivity of CECT was 76%. CONCLUSION. Frequency-selective nonlinear blending in CECT increases image quality and CNR, increases the precision of size measurement, and increases sensitivity for detecting liver lesions. CLINICAL IMPACT. Use of nonlinear blending CT improves liver lesion detection and increases the accuracy of lesion size measurement, which is important when local ablation or liver transplant is being considered.

Relationship Between Left Ventricular Strain Assessment by Cardiac Magnetic Resonance Imaging and Response to Cardiac Resynchronization Therapy.

Although cardiac resynchronization therapy (CRT) is an established treatment for heart failure with reduced ejection fraction, 30 to 50% patients are non-responders. In this retrospective single-centre study, 19 patients underwent cardiac MRI pre-CRT, and global left ventricular (LV) strain and late gadolinium enhancement (LGE) were measured by a blinded reader. LV reverse remodeling was independently assessed using transthoracic echocardiogram before and after CRT implant. Both LV strain and extent of LGE correlated significantly with measures of reverse LV remodeling (reduction in LV volume and improvement in LV ejection fraction). These findings suggest that CMR derived strain analysis and scar evaluation may be useful preimplant predictors of response to CRT. Larger prospective multi-center studies are needed to confirm these findings and to further evaluate the role of CMR strain imaging in guiding CRT treatment decisions.