Computed tomography scan accuracy for the prediction of lobe and division of liver tumors by four board-certified radiologists.

OBJECTIVE: (1) Evaluate the accuracy of computed tomography (CT) scans for localization of liver masses. (2) Assess the agreement between radiologists on localization. (3) Determine if location influences the accuracy of localization and histopathologic diagnosis. (4) Determine what lobar vasculature radiologists found most useful for localization. STUDY DESIGN: Retrospective. ANIMALS: A total of 67 client-owned dogs with a total of 75 hepatic masses. METHODS: Records were reviewed for relevant data. Localization for each hepatic mass was performed by four radiologists (JH, EH, ML, JF) independently. RESULTS: Overall accuracy of mass localization was 217/292 (74.3%) by lobe and 264/300 (88%) by division. Accuracy for the quadrate lobe (11/27, 40.7%) was lower (p < .05) than for the caudate process of the caudate lobe (19/24, 79.2%), left medial lobe (47/64, 73.4%) and left lateral lobe (95/101, 89.6%). Accuracy for the right lateral lobe (17/35, 48.6%) was lower (p < .05) lower than for the left lateral lobe (95/101, 89.6%). Accuracy of localization was 173/192 (90.1%) for masses located in the left division, 37/48 (77.1%) in the central division, and 53/60 (88.3%) for the right division. The agreement (kappa) between radiologists was good (0.61-0.8) to excellent (0.81-1) for division and moderate (0.41-0.6) to good for lobe localization. CONCLUSION: CT localization was more accurate for division than lobe localization of canine hepatic masses. Similarly, radiologists had a better agreement for division than lobe localization. CLINICAL SIGNIFICANCE: This study supports CT as a useful modality for liver mass localization based on division. CT localization to specific lobes should be interpreted with some caution.

A case of colonic-colonic intussusception in a dog secondary to lymphoma treated with colonic resection and anastomosis.

A 2-year-old castrated male Great Dane crossbreed dog was presented with a history of diarrhea and suspected intussusception. Abdominal ultrasound revealed a colonic-colonic intussusception. The gastrointestinal tract was explored, and an approximately 5-cm intussusception was discovered mid-colon. All other gastrointestinal structures were normal in appearance. The intussusception could not be reduced manually. A colonic resection and anastomosis were performed together with a left-sided incisional colopexy. The dog recovered from surgery and histopathology revealed the intussusception to be secondary to large cell transmural lymphoma. Sections from the surgical margins revealed proliferation of fibrovascular tissue along the serosal surface segmentally, but no neoplastic cells were identified. The dog was subsequently treated with chemotherapy consisting of doxorubicin and prednisone. No evidence of disease recurrence was noted on ultrasound 9 months after surgery. Approximately 2 years after surgery, the dog is noted to be clinically normal at home with no abnormal findings on physical examination. A complete blood (cell) count and chemistry obtained at this time revealed no significant abnormalities besides mild azotemia. Additional restaging was declined by the owner.

Un cas d'intussusception colon-colon chez un chien secondaire à un lymphome traité par résection c olonique et anastomose. Un grand danois croisé mâle castré âgé de 2 ans a été présenté avec des antécédents de diarrhée et une suspicion d'intussusception. L'échographie abdominale a révélé une intussusception colon-colon. Le tractus gastro-intestinal a été exploré et une intussusception d'environ 5 cm a été découverte au milieu du côlon. Toutes les autres structures gastro-intestinales avaient un aspect normal. L'intussusception n'a pas pu être réduite manuellement. Une résection colonique et une anastomose ont été réalisées avec une colopexie incisionnelle du côté gauche. Le chien a récupéré de la chirurgie et de l'histopathologie a révélé que l'intussusception était secondaire à un lymphome transmural à grandes cellules. Des sections des marges chirurgicales ont révélé une prolifération de tissu fibrovasculaire le long de la surface séreuse de manière segmentaire, mais aucune cellule néoplasique n'a été identifiée. Le chien a ensuite été traité par une chimiothérapie composée de doxorubicine et de prednisone. Aucun signe de récidive de la maladie n'a été noté à l'échographie 9 mois après la chirurgie. Environ 2 ans après la chirurgie, le chien est cliniquement normal à la maison sans résultats anormaux à l'examen physique. Une numération sanguine (cellule) complète et l'analyse chimique obtenues à ce moment n'ont révélé aucune anomalie significative outre une légère azotémie. Une nouvelle restadification a été refusée par le propriétaire.(Traduit par Dr Serge Messier).

Validation of Second-Generation Motion-Correction Software for Computed Tomography Coronary Angiography With Novel Quantitative Approach.

INTRODUCTION: Computed tomography of the coronary arteries (CTCA) is an important diagnostic tool. However, motion degradation is sometimes a challenge to interpretation and quantification, particularly with elevated heart rates. Here, a novel quantitative method is presented as part of an evaluation of one particular motion correction algorithm. METHODS: Computed tomography of the coronary arteries scans from 49 patients, with heart rates of >70 bpm, were identified with motion artifacts in multiple coronary segments. At these foci (196), an objective measure of motion degradation, defined here by cross-section eccentricity, was determined before and after image processing with second-generation GE SnapShot Freeze software (SSF-2.0). In addition, a subjective scoring was applied by an expert cardiothoracic radiologist both before and after processing. RESULTS: An overall decrease in vessel eccentricity strongly correlated (P < 0.001) with processing of the images by motion-correction software. A concurrent overall increase in subjective vessel clarity correlated (P < 0.001) with application of the software as well. CONCLUSIONS: A novel quantitative method (and subjective analysis) for evaluation of CTCA motion has been described and applied to validation of SSF-2.0 motion-correction software. Both the technique and software demonstrate promise for robust clinical utility in CTCA evaluation.

Second-generation motion correction algorithm improves diagnostic accuracy of single-beat coronary CT angiography in patients with increased heart rate.

OBJECTIVE: To assess the effect of a second-generation motion correction algorithm on the diagnostic accuracy of coronary computed tomography angiography (CCTA) using a 256-detector row CT in patients with increased heart rates. METHODS: Eighty-one consecutive symptomatic cardiac patients with increased heart rates (≥ 75 beats per min) were enrolled. All patients underwent CCTA and invasive coronary angiography (ICA). CCTA was performed with a 256-detector row CT using prospectively ECG-triggered single-beat protocol. Images were reconstructed using standard (STD) algorithm, first-generation intra-cycle motion correction (MC1) algorithm, and second-generation intra-cycle motion correction (MC2) algorithm. The image quality of coronary artery segments was assessed by two experienced radiologists using a 4-point scale (1: non-diagnostic and 4: excellent), according to the 18-segment model. Diagnostic performance for segments with significant lumen stenosis (≥ 50%) was compared between STD, MC1, and MC2 by using ICA as the reference standard. RESULTS: The mean effective dose of CCTA was 1.0 mSv. On per-segment level, the overall image quality score and interpretability were improved to 3.56 ± 0.63 and 99.2% due to the use of MC2, as compared to 2.81 ± 0.85 and 92.5% with STD and 3.21 ± 0.79 and 97.2% with MC1. On per-segment level, compared to STD and MC1, MC2 improved the sensitivity (92.2% vs. 79.2%, 80.7%), specificity (97.8% vs. 82.1%, 90.8%), positive predictive value (89.9% vs. 48.4%, 65.1%), negative predictive value (98.3% vs. 94.9%, 95.7%), and diagnostic accuracy (96.8% vs. 81.5%, 89.0%). CONCLUSION: A second-generation intra-cycle motion correction algorithm for single-beat CCTA significantly improves image quality and diagnostic accuracy in patients with increased heart rate. KEY POINTS: • A second-generation motion correction (MC2) algorithm can further improve the image quality of all coronary arteries than a first-generation motion correction (MC1). • MC2 algorithm can significantly reduce the number of false positive segments compared to standard and MC1 algorithm.

Coronary computed tomography angiography-based SYNTAX score for comprehensive assessment of advanced coronary artery disease.

BACKGROUND: Since the initial attempt to adapt the anatomical SYNTAX score (aSS) to coronary computed tomography angiography (CCTA), CCTA imaging technology has evolved, and is currently used as a "decision-maker" for revascularization strategy in complex coronary artery disease (CAD) and has rendered necessary some updating of the aSS to the CCTA modality. OBJECTIVES: The aim is to provide updated definitions of the aSS derived from CCTA in patients with complex CAD undergoing CABG. METHODS: The modifications of CCTA-aSS are the following; (i) updated definition and detection criteria of total occlusion (TO) in CCTA based on length assessment, (ii) inclusion of scoring points for serial bifurcations located in one single coronary segment. (iii) inclusion of weighing score points for lesions located distal to a TO, not visualized on conventional coronary angiography, but visible in CCTA, (iv) removal of thrombus and bridging collateral items from the weighing score, considering the limited diagnostic capability of CCTA in detecting these specific lesion characteristics. RESULTS: the updated CCTA-aSS was tested in a first-in-man study using the sole guidance of CCTA for the planning and performance of bypass surgery in complex CAD (n â€‹= â€‹114). An interobserver analysis showed excellent reproducibility (ICC â€‹= â€‹0.96, 95 â€‹% confidence interval 0.94-0.97). CONCLUSION: The updated CCTA-aSS was implemented in a cohort of patients with complex CAD undergoing CABG with the sole guidance of CCTA and FFRCT and the Inter-reproducibility of the analysis of the updated score was found excellent. The prognostic value of the modified CCTA-aSS will be examined in future studies.

Surgery and postoperative definitive radiotherapy for management of canine soft tissue sarcoma: a multi-institutional retrospective study of 272 dogs (2010-2020).

OBJECTIVE: To report local progression and survival in dogs following surgery and postoperative definitive radiotherapy (dRT) for management of soft tissue sarcoma (STS) and to evaluate risk factors for local progression and survival. METHODS: Records were retrospectively reviewed at 9 referral hospitals for dogs managed with postoperative dRT between January 1, 2010, and January 1, 2020, following surgery for STS. Data related to presentation, surgery, dRT, systemic therapy, and outcome were abstracted. Selected variables were assessed for association with local progression and overall survival. RESULTS: 272 dogs were included. Histologic grade was reported in 249 dogs: 102 were grade 1 (40.9%), 120 were grade 2 (48.2%), and 27 were grade 3 (10.8%). Local progression was suspected or confirmed in 56 dogs. Local progression rates were similar for grade 1 (24 of 89 [26.7%]), grade 2 (23 of 111 [20.7%]), and grade 3 tumors (6 of 22 [27.3%]). Previous recurrence (P = .010) and subsequent distant metastasis (P = .014) were associated with more frequent local progression; intensity-modulated radiotherapy was associated with decreased local progression (P = .025) compared to other forms of delivery. Age (P = .049), grade (P = .009), previous recurrence (P = .009), and institution type for surgery (P = .043) were associated with overall survival. CONCLUSIONS: Outcomes for most dogs were good; however, the frequency of local progression indicates an ongoing need to critically appraise local management strategies, particularly for low-grade STS. Intensity-modulated radiotherapy was associated with lower rates of local progression and may be preferred to less precise forms of delivery. CLINICAL RELEVANCE: These data may guide clinicians when making decisions regarding dRT for management of STS.

Radiation dose reduction using deep learning-based image reconstruction for a low-dose chest computed tomography protocol: a phantom study.

Background: The aim of this study was to compare the dose reduction potential and image quality of deep learning-based image reconstruction (DLIR) with those of filtered back-projection (FBP) and iterative reconstruction (IR) and to determine the clinically usable dose of DLIR for low-dose chest computed tomography (LDCT) scans. Methods: Multi-slice computed tomography (CT) scans of a chest phantom were performed with various tube voltages and tube currents, and the images were reconstructed using seven methods to control the amount of noise reduction: FBP, three stages of IR, and three stages of DLIR. For subjective image analysis, four radiologists compared 48 image data sets with reference images and rated on a 5-point scale. For quantitative image analysis, the signal to noise ratio (SNR), contrast to noise ratio (CNR), nodule volume, and nodule diameter were measured. Results: In the subjective analysis, DLIR-Low (0.46 mGy), DLIR-Medium (0.31 mGy), and DLIR-High (0.18 mGy) images showed similar quality to the FBP (2.47 mGy) image. Under the same dose conditions, the SNR and CNR were higher with DLIR-High than with FBP and all the IR methods (all P<0.05). The nodule volume and size with DLIR-High were significantly closer to the real volume than with FBP and all the IR methods (all P<0.001). Conclusions: DLIR can improve the image quality of LDCT compared to FBP and IR. In addition, the appropriate effective dose for LDCT would be 0.24 mGy with DLIR-High.

Diagnostic concordance and discordance between angiography-based quantitative flow ratio and fractional flow reserve derived from computed tomography in complex coronary artery disease.

BACKGROUND: Both quantitative flow ratio (QFR) and fractional flow reserve derived from computed tomography (FFRCT) have shown significant correlations with invasive wire-based fractional flow reserve. However, the correlation between QFR and FFRCT is not fully investigated in patients with complex coronary artery disease (CAD). The aim of this study is to investigate the correlation and agreement between QFR and FFRCT in patients with de novo three-vessel disease and/or left main CAD. METHODS: This is a post-hoc sub-analysis of the international, multicenter, and randomized SYNTAX III REVOLUTION trial, in which both invasive coronary angiography and coronary computed tomography angiography were prospectively obtained prior to the heart team discussion. QFR was performed in an independent core laboratory and compared with FFRCT analyzed by HeartFlow™. The correlation and agreement between QFR and FFRCT were assessed per vessel. Furthermore, independent factors of diagnostic discordance between QFR and FFRCT were evaluated. RESULTS: Out of 223 patients, 40 patients were excluded from this analysis due to the unavailability of FFRCT and/or QFR, and a total of 469 vessels (183 patients) were analyzed. There was a strong correlation between QFR and FFRCT (R â€‹= â€‹0.759; p â€‹< â€‹0.001), and the Bland-Altman analysis demonstrated a mean difference of -0.005 and a standard deviation of 0.116. An independent predictor of diagnostic concordance between QFR and FFRCT was the lesion location in right coronary artery (RCA) (odds ratio 0.395; 95% confidence interval 0.174-0.894; P â€‹= â€‹0.026). CONCLUSION: In patients with complex CAD, QFR and FFRCT were strongly correlated. The location of the lesion in RCA was associated with the highest diagnostic concordance between QFR and FFRCT.

Effect of deep learning image reconstruction in the prediction of resectability of pancreatic cancer: Diagnostic performance and reader confidence.

OBJECTIVE: To assess the diagnostic performance and reader confidence in determining the resectability of pancreatic cancer at computed tomography (CT) using a new deep learning image reconstruction (DLIR) algorithm. METHODS: A retrospective review was conduct of on forty-seven patients with pathologically confirmed pancreatic cancers who underwent baseline multiphasic contrast-enhanced CT scan. Image data sets were reconstructed using filtered back projection (FBP), hybrid model-based adaptive statistical iterative reconstruction (ASiR-V) 60 %, and DLIR "TrueFidelity" at low(L), medium(M), and high strength levels(H). Four board-certified abdominal radiologists reviewed the CT images and classified cancers as resectable, borderline resectable, or unresectable. Diagnostic performance and reader confidence for categorizing the resectability of pancreatic cancer were evaluated based on the reference standards, and the interreader agreement was assessed using Fleiss k statistics. RESULTS: For prediction of margin-negative resections(ie, R0), the average area under the receiver operating characteristic curve was significantly higher with DLIR-H (0.91; 95 % confidence interval [CI]: 0.79, 0.98) than FBP (0.75; 95 % CI:0.60, 0.86) and ASiR-V (0.81; 95 % CI:0.67, 0.91) (p = 0.030 and 0.023 respectively). Reader confidence scores were significantly better using DLIR compared to FBP and ASiR-V 60 % and increased linearly with the increase of DLIR strength level (all p < 0.001). Among the image reconstructions, DLIR-H showed the highest interreader agreement in the resectability classification and lowest subject variability in the reader confidence. CONCLUSIONS: The DLIR-H algorithm may improve the diagnostic performance and reader confidence in the CT assignment of the local resectability of pancreatic cancer while reducing the interreader variability.

Comparison of Multimaterial Decomposition Fat Fraction with DECT and Proton Density Fat Fraction with IDEAL IQ MRI for Quantification of Liver Steatosis in a Population Exposed to Chemotherapy.

INTRODUCTION: Oncologic patients who develop chemotherapy-associated liver injury (CALI) secondary to chemotherapy treatment tend to have worse outcomes. Biopsy remains the gold standard for the diagnosis of hepatic steatosis. The purpose of this article is to compare 2 alternatives: Proton-Density-Fat-Fraction (PDFF) MRI and MultiMaterial-Decomposition (MMD) DECT. MATERIALS AND METHODS: 49 consecutive oncologic patients treated with Chemotherapy underwent abdominal DECT and abdominal MRI within 2 weeks of each other. Two radiologists tracked Regions of Interest independently both in the PDFF fat maps and in the MMD DECT fat maps. Non-parametric exact Wilcoxon signed rank test and Cohen's K were used to compare the 2 sequences and to evaluate the agreement. RESULTS: There was no statistically significant difference in the fat fraction measured as a continuous value between PDFF and DECT between 2 readers. Within the same imaging method (PDFF) the degree of agreement based on the k coefficient between reader 1 and reader 2 is 0.88 (p-value < 0.05). Similarly, for single-source DECT(ssDECT) the degree of agreement based on the k coefficient between reader 1 and reader 2 is 0.97 (p-value < 0.05). CONCLUSIONS: The results of this study demonstrate that the hepatic fat fraction of ssDECT with MMD are not significantly different from PDFF. This could be an advantage in an oncological population that undergoes serial CT scans for follow up of chemotherapy response.

Task-based characterization of a deep learning image reconstruction and comparison with filtered back-projection and a partial model-based iterative reconstruction in abdominal CT: A phantom study.

PURPOSE: We aimed to thoroughly characterize image quality of a novel deep learning image reconstruction (DLIR), and investigate its potential for dose reduction in abdominal CT in comparison with filtered back-projection (FBP) and a partial model-based iterative reconstruction (ASiR-V). METHODS: We scanned a phantom at three dose levels: regular (7 mGy), low (3 mGy) and ultra-low (1 mGy). Images were reconstructed using DLIR (low, medium and high levels) and ASiR-V (0% = FBP, 50% and 100%). Noise and contrast-dependent spatial resolution were characterized by computing noise power spectra and target transfer functions, respectively. Detectability indexes of simulated acute appendicitis or colonic diverticulitis (low contrast), and calcium-containing urinary stones (high contrast) (|ΔHU| = 50 and 500, respectively) were calculated using the nonprewhitening with eye filter model observer. RESULTS: At all dose levels, increasing DLIR and ASiR-V levels both markedly decreased noise magnitude compared with FBP, with DLIR low and medium maintaining noise texture overall. For both low- and high-contrast spatial resolution, DLIR not only maintained, but even slightly enhanced spatial resolution in comparison with FBP across all dose levels. Conversely, increasing ASiR-V impaired low-contrast spatial resolution compared with FBP. Overall, DLIR outperformed ASiR-V in all simulated clinical scenarios. For both low- and high-contrast diagnostic tasks, increasing DLIR substantially enhanced detectability at any dose and contrast levels for any simulated lesion size. CONCLUSIONS: Unlike ASiR-V, DLIR substantially reduces noise while maintaining noise texture and slightly enhancing spatial resolution overall. DLIR outperforms ASiR-V by enabling higher detectability of both low- and high-contrast simulated abdominal lesions across all investigated dose levels.

Safety and feasibility evaluation of planning and execution of surgical revascularisation solely based on coronary CTA and FFRCT in patients with complex coronary artery disease: study protocol of the FASTTRACK CABG study.

INTRODUCTION: The previously published SYNTAX III REVOLUTION trial demonstrated that clinical decision-making between coronary artery bypass graft (CABG) and percutaneous coronary intervention based on coronary CT angiography (CCTA) had a very high agreement with the treatment decision derived from invasive coronary angiography (ICA). The study objective of the FASTTRACK CABG is to assess the feasibility of CCTA and fractional flow reserve derived from CTA (FFRCT) to replace ICA as a surgical guidance method for planning and execution of CABG in patients with three-vessel disease with or without left main disease. METHODS AND ANALYSIS: The FASTTRACK CABG is an investigator-initiated single-arm, multicentre, prospective, proof-of-concept and first-in-man study with feasibility and safety analysis. Surgical revascularisation strategy and treatment planning will be solely based on CCTA and FFRCT without knowledge of the anatomy defined by ICA. Clinical follow-up visit including CCTA will be performed 30 days after CABG in order to assess graft patency and adequacy of the revascularisation with respect to the surgical planning based on non-invasive imaging (CCTA) with functional assessment (FFRCT) and compared with ICA. Primary feasibility endpoint is CABG planning and execution solely based on CCTA and FFRCT in 114 patients. Primary safety endpoint based on 30 day CCTA is graft assessment and topographical adequacy of the revascularisation procedure. Automatic non-invasive assessment of functional coronary anatomy complexity is also evaluated with FFRCT for functional Synergy Between percutaneous coronary intervention With Taxus and Cardiac Surgery Score assessment on CCTA. CCTA with FFRCT might provide better anatomical and functional analysis of the coronary circulation leading to appropriate anatomical and functional revascularisation, and thereby contributing to a better outcome. ETHICS AND DISSEMINATION: Each patient has to provide written informed consent as approved by the ethical committee of the respective clinical site. Results will be submitted for publication in peer-reviewed journals and will be disseminated at scientific conferences. TRIAL REGISTRATION NUMBER: NCT04142021.

Non-invasive Heart Team assessment of multivessel coronary disease with coronary computed tomography angiography based on SYNTAX score II treatment recommendations: design and rationale of the randomised SYNTAX III Revolution trial.

AIMS: The aim of this study was to investigate whether a Heart Team decision-making process regarding the choice of revascularisation strategy based on non-invasive coronary multislice computed tomography angiography (MSCT) assessment of coronary artery disease (CAD) is equivalent to the standard-of-care invasive angiography-based assessment in patients with multivessel CAD. METHODS AND RESULTS: The SYNTAX III Revolution trial is a prospective, multicentre, all-comers randomised trial that will randomise two Heart Teams to select between surgical and percutaneous treatment according to either an invasive conventional angiography or a non-invasive MSCT angiography assessment in patients with multivessel CAD. The treatment selection by each Heart Team will be guided by the SYNTAX score II calculation. The primary endpoint is the level of agreement according to kappa of the initial decision by the Heart Teams on the modality of the revascularisation based on MSCT and angiography assessments. Secondary endpoints include agreement on the number of vessels requiring treatment and the coronary segments in need of revascularisation. CONCLUSIONS: The SYNTAX III Revolution trial will provide valuable information regarding the ability of a purely non-invasive coronary anatomy assessment to select accurately the most appropriate revascularisation strategy for patients with multivessel CAD.