Nevin Manimala

Eur Radiol. 2022 Apr 14. doi: 10.1007/s00330-022-08771-x. Online ahead of print.

ABSTRACT

OBJECTIVES: Develop and evaluate the performance of deep learning and linear regression cascade algorithms for automated assessment of the image layout and position of chest radiographs.

METHODS: This retrospective study used 10 quantitative indices to capture subjective perceptions of radiologists regarding image layout and position of chest radiographs, including the chest edges, field of view (FOV), clavicles, rotation, scapulae, and symmetry. An automated assessment system was developed using a training dataset consisting of 1025 adult posterior-anterior chest radiographs. The evaluation steps included: (i) use of a CNN framework based on ResNet – 34 to obtain measurement parameters for quantitative indices and (ii) analysis of quantitative indices using a multiple linear regression model to obtain predicted scores for the layout and position of chest radiograph. In the testing dataset (n = 100), the performance of the automated system was evaluated using the intraclass correlation coefficient (ICC), Pearson correlation coefficient (r), mean absolute difference (MAD), and mean absolute percentage error (MAPE).

RESULTS: The stepwise regression showed a statistically significant relationship between the 10 quantitative indices and subjective scores (p < 0.05). The deep learning model showed high accuracy in predicting the quantitative indices (ICC = 0.82 to 0.99, r = 0.69 to 0.99, MAD = 0.01 to 2.75). The automatic system provided assessments similar to the mean opinion scores of radiologists regarding image layout (MAPE = 3.05%) and position (MAPE = 5.72%).

CONCLUSIONS: Ten quantitative indices correlated well with the subjective perceptions of radiologists regarding the image layout and position of chest radiographs. The automated system provided high performance in measuring quantitative indices and assessing image quality.

KEY POINTS: • Objective and reliable assessment for image quality of chest radiographs is important for improving image quality and diagnostic accuracy. • Deep learning can be used for automated measurements of quantitative indices from chest radiographs. • Linear regression can be used for interpretation-based quality assessment of chest radiographs.

PMID:35420306 | DOI:10.1007/s00330-022-08771-x

Eur Radiol. 2022 Apr 14. doi: 10.1007/s00330-022-08768-6. Online ahead of print.

ABSTRACT

OBJECTIVES: To assess whether systemic-pulmonary collaterals are associated with clinical severity and extent of pulmonary perfusion defects in chronic thromboembolic pulmonary hypertension (CTEPH).

METHODS: This prospective study was approved by a local ethics committee. Twenty-four patients diagnosed with inoperable CTEPH were enrolled between July 2014 and February 2017. Systemic-pulmonary collaterals were detected using pulmonary vascular enhancement on intra-aortic computed tomography (CT) angiography. The pulmonary enhancement parameters were calculated, including (1) Hounsfield unit differences (HUdiff) between pulmonary trunks and pulmonary arteries (PAs) or veins (PVs), namely HUdiff-PA and HUdiff-PV, on the segmental base; (2) the mean HUdiff-PA, mean HUdiff-PV, numbers of significantly enhanced PAs and PVs, on the patient base. Pulmonary perfusion defects were recorded and scored using the lung perfused blood volume (PBV) based on intravenous dual-energy CT (DECT) angiography. Pearson’s or Spearman’s correlation coefficients were used to evaluate correlations between the following: (1) segment-based intra-aortic CT and intravenous DECT parameters (2) patient-based intra-aortic CT parameters and clinical severity parameters or lung PBV scores. Statistical significance was set at p < 0.05.

RESULTS: Segmental HUdiff-PV was correlated with the segmental perfusion defect score (r = 0.45, p < 0.01). The mean HUdiff-PV was correlated with the mean pulmonary arterial pressure (PAP) (r = 0.52, p < 0.01), cardiac output (rho = – 0.41, p = 0.05), and lung PBV score (rho = 0.43, p = 0.04). And the number of significantly enhanced PVs was correlated with the mean PAP (r = 0.54, p < 0.01), pulmonary vascular resistance (r = 0.54, p < 0.01), and lung PBV score (rho = 0.50, p = 0.01).

CONCLUSIONS: PV enhancement measured by intra-aortic CT angiography reflects clinical severity and pulmonary perfusion defects in CTEPH.

KEY POINTS: • Intra-aortic CT angiography demonstrated heterogeneous enhancement within the pulmonary vasculature, showing collaterals from the systemic arteries to the pulmonary circulation in CTEPH. • The degree of systemic-pulmonary collateral development was significantly correlated with the clinical severity of CTEPH and may be used to evaluate disease progression. • The distribution of systemic-pulmonary collaterals is positively correlated with perfusion defects in the lung segments in CTEPH.

PMID:35420297 | DOI:10.1007/s00330-022-08768-6

Arch Endocrinol Metab. 2022 Apr 11:2359-3997000000458. doi: 10.20945/2359-3997000000458. Online ahead of print.

ABSTRACT

OBJECTIVE: Cytological analysis and Bethesda classification of thyroid nodules is the standard method of diagnosing differentiated thyroid carcinoma (DTC). However, even for nodules with a non-malignant cytological diagnosis, there is a not insignificant risk of cancer. There are doubts whether this lack of certainty would influence patient prognosis. Our aim was to compare patients with DTC, classified according to the preoperative cytological diagnosis, regarding their evolution.

METHODS: A retrospective study was carried out with 108 DTC patients submitted to total thyroidectomy (TT) between 2009 and 2015, divided into three groups according to preoperative cytological diagnosis (Bethesda classification): classes I/II, III/IV, and V/VI. Groups were compared for evolution considering response to treatment at last evaluation as well as time disease free. Statistical analysis used ANOVA, chi squared, and Kaplan-Meier curves with p<0.05 considered significant.

RESULTS: Groups differed for time between nodule puncture and TT [in months; V/VI (2.35 ± 2.48) < III/IV (7.32 ± 6.34) < I/II (13.36 ± 8.9); p < 0.0001]. There was no significant difference between groups for evolution at final evaluation (disease free status; classes I/II: 71.4%; classes III/IV: 60%; classes V/VI: 66.6%; p = 0.7433), as well as time disease free (in months; classes I/II: 34.57 ± 25.82; classes III/IV: 38.04 ± 26.66; classes V/VI: 30.84 ± 26.34; p = 0.3841).

CONCLUSION: DTC patients classified according to preoperative cytological diagnosis did not differ for evolution. Although patients with non-malignant cytological diagnoses were submitted to TT later, this did not affect the evolution of the cases.

PMID:35420266 | DOI:10.20945/2359-3997000000458

Catheter Cardiovasc Interv. 2022 Apr 14. doi: 10.1002/ccd.30176. Online ahead of print.

ABSTRACT

INTRODUCTION: The preferred approach for transcatheter aortic valve replacement (TAVR) is transfemoral. There has been widespread adoption of the Perclose Proglide^TM device for vascular closure. Typically, two devices are deployed before upsizing the access sheath in the “preclose technique.” Prior investigations have compared the use of a single device versus double device technique, but none have shown significant clinical benefit to either approach.

METHODS: Five hundred and six patients underwent transfemoral TAVR (TF-TAVR) with single or double Perclose devices for vascular closure from July 2015 to February 2020. A retrospective review was conducted, and propensity-matched analyses were used to account for differences in baseline characteristics.

RESULTS: In the matched analysis, there were 251 patients in the single Perclose group and 238 in the double. There was a statistically significant improvement in overall procedural success using the single closure device (94.6% vs. 88.5%, p = 0.009) This was defined as intraprocedural hemostatic control, lack of contrast extravasation, arterial dissection, occlusion, or stenosis >50% in the final crossover angiogram, as well as unimpaired limb perfusion without claudication throughout the index hospitalization. There was also a significant improvement in arterial dissection rates (0.6% vs. 4.6%, p = 0.004), stenosis >50% (1.3% vs. 4.4%, p = 0.028), and Valve Academic Research Consortium major vascular complications (1.8% vs. 4.9%, p = 0.038).

CONCLUSION: A single Perclose device is a safe means of vascular closure during TF-TAVR and may have important clinical benefits compared to the commonly used two-device technique.

PMID:35420254 | DOI:10.1002/ccd.30176

Vet Comp Oncol. 2022 Apr 14. doi: 10.1111/vco.12821. Online ahead of print.

ABSTRACT

OBJECTIVE: To determine the outcome of dogs with soft tissue sarcoma (STS) within the region of the ischiatic tuberosity (ITSTS) treated surgically.

STUDY DESIGN: Multi-institutional retrospective study ANIMALS: Fifty-two client-owned dogs with histologically confirmed STS in the region of the IT treated with surgical resection between March 1st, 2009, and March 1st, 2021, and a minimum follow-up time of six months.

METHODS: Data collected included signalment, preoperative diagnostics, surgical intent/method, complications, histopathology, margins, outcome, and cause of death. Statistical analyses were performed to determine significant factors in treatment and prognosis of ITSTS.

RESULTS: Fifty-two dogs with histopathologically-confirmed ITSTS included resulting in 24 grade I, 20 grade II, and seven grade III tumors. Overall survival time and disease progression were negatively associated with tumor grade while recurrence was positively associated with grade and incomplete margins. Overall survival time and progression-free survival time was not reached for tumors graded as I or II and was 255 and 268 days respectively for grade III. Median time to recurrence was not reached for tumors excised with complete margins and 398 days for incomplete margins. There was a 25% reported surgical complication rate.

CONCLUSION: Ischiatic tuberosity soft tissue sarcoma was not found to be a unique clinical entity in dogs. Treatment recommendations and prognosis were similar to STS in other locations. The outcome was influenced by histologic grade and margins.

CLINICAL SIGNIFICANCE: Ischiatic tuberosity soft tissue sarcoma of dogs does not behave more aggressively than those in other locations. Surgical complications were common but not life-threatening. Overall prognosis, including survival and disease recurrence, appears to depend on histological grade and surgical margins. This article is protected by copyright. All rights reserved.

PMID:35420253 | DOI:10.1111/vco.12821

Pediatr Pulmonol. 2022 Apr 14. doi: 10.1002/ppul.25920. Online ahead of print.

ABSTRACT

BACKGROUND: Thrombosis and embolism are possible complications in COVID-19-positive pediatric patients. Although the risk is lesser in children than it is in adults, it does exist during acute infection and multiinflammatory syndrome (MIS-C). Biomarkers such as D-dimer, Prothrombin time (PT), and Fibrinogen degradation products (FDPs) are ineffective at detecting disease severity. Homocysteine (Hcy) is a prothrombotic factor that has been reported to be higher in adult COVID-19 patients, leading to speculation that it could be used as a biomarker for disease severity.

PURPOSE: to detect the correlation between serum total homocysteine (tHcy) level and the severity of COVID-19 in pediatrics.

METHODS: a cross-sectional study was conducted on 40 children with COVID-19 and 40 healthy control subjects. Serum tHcy was measured by ELISA and correlated with the clinical, laboratory, and radiological parameters of the patients.

RESULTS: The median serum tHcy level in COVID-19 patients was 27.5 (interquartile range:23 – 31.75) μmol/L, while that in the controls was 1.8 ((interquartile range:1.6 – 1.875) μmol/L. There was a statistically significant increase in tHcy level in cases compared to controls (p<0.001). There was a statistically significant positive correlation between serum tHcy and D-dimer, ferritin, alanine transaminase (ALT), aspartate transaminase (AST), blood urea nitrogen (BUN), and a highly significant positive correlation between tHcy and CO-RADS score, PICU admission, and the disease severity classification.

CONCLUSION: Hcy could be a biomarker of importance in predicting the severity of COVID-19 in pediatrics. This article is protected by copyright. All rights reserved.

PMID:35420248 | DOI:10.1002/ppul.25920

J Magn Reson Imaging. 2022 Apr 14. doi: 10.1002/jmri.28205. Online ahead of print.

ABSTRACT

BACKGROUND: MRI guidance of arterial endovascular interventions could be beneficial as it does not require radiation exposure, allows intrinsic blood-tissue contrast, and enables three-dimensional and functional imaging, however, clinical applications are still limited.

PURPOSE: To review the current state of MRI-guided arterial endovascular interventions and to identify the most commonly reported challenges.

STUDY TYPE: Systematic review.

POPULATION: Pubmed, Embase, Web of Science, and The Cochrane Library were systematically searched to find relevant articles. The search strategy combined synonyms for vascular pathology, endovascular therapy, and real-time MRI guidance.

FIELD STRENGTH/SEQUENCE: No field strength or sequence restrictions were applied.

ASSESSMENT: Two reviewers independently identified and reviewed the original articles and extracted relevant data.

STATISTICAL TESTS: Results of the included original articles are reported.

RESULTS: A total of 24,809 studies were identified for screening. Eighty-eight studies were assessed for eligibility, after which data were extracted from 43 articles (6 phantom, 33 animal, and 4 human studies). Reported technical success rates for animal and human studies ranged between 42% to 100%, and the average complication rate was 5.8% (animal studies) and 8.8% (human studies). Main identified challenges were related to spatial and temporal resolution as well as safety, design, and scarcity of current MRI-compatible endovascular devices.

DATA CONCLUSION: MRI guidance of endovascular arterial interventions seems feasible, however, included articles included mostly small single-center case series. Several hurdles remain to be overcome before larger trials can be undertaken. Main areas of research should focus on adequate imaging protocols with integrated tracking of dedicated endovascular devices.

PMID:35420239 | DOI:10.1002/jmri.28205

J Prosthodont. 2022 Apr 14. doi: 10.1111/jopr.13518. Online ahead of print.

ABSTRACT

PURPOSE: To compare prevalence and type of complications associated with metal resin fixed complete dentures based on implant distribution.

MATERIALS AND METHODS: This retrospective study included data collected for a period of 12 years for patients treated with maxillary and mandibular implant-supported fixed complete dentures at the School of Dentistry. In total, 223 patient’s charts were reviewed which included 100 maxillary and 123 mandibular fixed complete dentures (FCDs). Implant distribution and prevalence of complications associated with each implant-supported FCD were documented. Teeth delamination, the most common complication associated with fixed complete dentures, was compared between 2 implant distribution groups in each arch. Covariates including age, sex, opposing arch, cantilever occluding units, and number of implants were evaluated to determine their association with tooth delamination. Data and hypotheses were statistically analyzed using descriptive statistics along with logistic regression model. All tests of hypotheses were considered statistically significant at an alpha level of 0.05.

RESULTS: In the maxillary arch, some effect of the prevalence of tooth delamination was seen for the group which had implants placed posterior to canine eminence but was not statistically significant. Denture tooth delamination had the highest prevalence among complications irrespective of implant distribution. Significant denture tooth delamination was seen for patients with opposing FCDs in comparison to patients with removable opposing arch prostheses.

CONCLUSIONS: Implant distribution is not a significant factor related metal resin FCDs. Opposing FCDs have a significantly higher association with DTDs. This article is protected by copyright. All rights reserved.

PMID:35420238 | DOI:10.1111/jopr.13518

J Magn Reson Imaging. 2022 Apr 14. doi: 10.1002/jmri.28203. Online ahead of print.

ABSTRACT

BACKGROUND: Early detection and accurate assessment of N-acetyl-p-aminophenol (APAP)-induced hepatotoxicity can prevent further aggravation of liver injury and reduce the incidence of liver failure.

PURPOSE: To evaluate the potential of multiple MRI parameters for assessing APAP-induced hepatotoxicity in an experimental rat model.

STUDY TYPE: Prospective.

ANIMAL MODEL: Twenty-one APAP-treated rats and 12 control rats.

FIELD STRENGTH/SEQUENCE: A 3 T, T1 mapping, Gd-EOB-DTPA-enhanced MRI, and intravoxel incoherent motion (IVIM).

ASSESSMENT: The severity of histological changes was assessed by a liver pathologist. Rat livers were pathologically classified into three groups: normal (n = 12), mild necrosis (n = 13), and moderate necrosis (n = 8). T1 relaxation time (T1) and diffusion parameters were measured. The reduction rate of T1 (ΔT1%) at different time points, the maximum value of ΔT1%, time period to the maximum value of ΔT1%, and time period from ΔT1max (%) to 2/3 value of ΔT1max (%) (ΔT1-T2/3) were calculated. Transporters activities like organic anion-transporting polypeptide 1 (oatp1) and multidrug resistance-associated protein 2 (mrp2) were compared among different necrotic groups.

STATISTICAL TESTS: ANOVA/Kruskal-Wallis. Pearson/Spearman correlation. P < 0.05 was considered statistical significance.

RESULTS: T1 Precontrast and ΔT1-T2/3 were strongly correlated with the severity of necrosis (r = 0.9094; r = 0.7978, respectively) and showed significant differences between the two groups. The apparent diffusion coefficient (ADC) and tissue diffusivity (D) values were significantly lower in the moderate necrosis group than in the normal and mild necrosis groups. The oatp1 activity of the necrosis groups was significantly reduced compared to that of the normal group, but the differences between normal and mild (P = 0.21), normal and moderate group (P = 0.56) were not significant. Meanwhile, enlargement of bile canaliculi and sparse microvilli was observed in the necrotic groups.

CONCLUSION: MRI parameters such as precontrast T1 and ΔT1-T2/3 had promising potential in assessing the severity of early-stage hepatotoxicity in an APAP overdose rat model.

EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 1.

PMID:35420237 | DOI:10.1002/jmri.28203

J Magn Reson Imaging. 2022 Apr 14. doi: 10.1002/jmri.28196. Online ahead of print.

ABSTRACT

BACKGROUND: Hyperpolarized ¹³ C MRI quantitatively measures enzyme-catalyzed metabolism in cancer and metabolic diseases. Whole-abdomen imaging will permit dynamic metabolic imaging of several abdominal organs simultaneously in healthy and diseased subjects.

PURPOSE: Image hyperpolarized [1-¹³ C]pyruvate and products in the abdomens of healthy volunteers, overcoming challenges of motion, magnetic field variations, and spatial coverage. Compare hyperpolarized [1-¹³ C]pyruvate metabolism across abdominal organs of healthy volunteers.

STUDY TYPE: Prospective technical development.

SUBJECTS: A total of 13 healthy volunteers (8 male), 21-64 years (median 36).

FIELD STRENGTH/SEQUENCE: A 3 T. Proton: T₁ -weighted spoiled gradient echo, T₂ -weighted single-shot fast spin echo, multiecho fat/water imaging. Carbon-13: echo-planar spectroscopic imaging, metabolite-specific echo-planar imaging.

ASSESSMENT: Transmit magnetic field was measured. Variations in main magnetic field (ΔB₀ ) determined using multiecho proton acquisitions were compared to carbon-13 acquisitions. Changes in ΔB₀ were measured after localized shimming. Improvements in metabolite signal-to-noise ratio were calculated. Whole-organ regions of interests were drawn over the liver, spleen, pancreas, and kidneys by a single investigator. Metabolite signals, time-to-peak, decay times, and mean first-order rate constants for pyruvate-to-lactate (k_PL ) and alanine (k_PA ) conversion were measured in each organ.

STATISTICAL TESTS: Linear regression, one-sample Kolmogorov-Smirnov tests, paired t-tests, one-way ANOVA, Tukey’s multiple comparisons tests. P ≤ 0.05 considered statistically significant.

RESULTS: Proton ΔB₀ maps correlated with carbon-13 ΔB₀ maps (slope = 0.93, y-intercept = -2.88, R² = 0.73). Localized shimming resulted in mean frequency offset within ±25 Hz for all organs. Metabolite SNR significantly increased after denoising. Mean k_PL and k_PA were highest in liver, followed by pancreas, spleen, and kidneys (all comparisons with liver were significant).

DATA CONCLUSION: Whole-abdomen coverage with hyperpolarized carbon-13 MRI was feasible despite technical challenges. Multiecho gradient echo ¹ H acquisitions accurately predicted chemical shifts observed using carbon-13 spectroscopy. Carbon-13 acquisitions benefited from local shimming. Metabolite energetics in the abdomen compiled for healthy volunteers can be used to design larger clinical trials in patients with metabolic diseases.

EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 1.

PMID:35420227 | DOI:10.1002/jmri.28196