Accuracy and Reproducibility of a Software Prototype for Semi-Automated Computer-Aided Volumetry of the solid and subsolid Components of part-solid Pulmonary Nodules

Purpose To test the accuracy and reproducibility of a software prototype for semi-automated computer-aided volumetry (CAV) of part-solid pulmonary nodules (PSN) with separate segmentation of the solid part. Materials and Methods 66 PSNs were retrospectively identified in 34 thin-slice unenhanced chest CTs of 19 patients. CAV was performed by two medical students. Manual volumetry (MV) was carried out by two radiology residents. The reference standard was determined by an experienced radiologist in consensus with one of the residents. Visual assessment of CAV accuracy was performed. Measurement variability between CAV/MV and the reference standard as a measure of accuracy, CAV inter- and intra-rater variability as well as CAV intrascan variability between two recontruction kernels was determined via the Bland-Altman method and intraclass correlation coefficients (ICC). Results Subjectively assessed accuracy of CAV/MV was 77 %/79 %–80 % for the solid part and 67 %/73 %–76 % for the entire nodule. Measurement variability between CAV and the reference standard ranged from –151–117 % for the solid part and –106–54 % for the entire nodule. Interrater variability was –16–16 % for the solid part (ICC 0.998) and –102–65 % for the entire nodule (ICC 0.880). Intra-rater variability was –70–49 % for the solid part (ICC 0.992) and –111–31 % for the entire nodule (ICC 0.929). Intrascan variability between the smooth and the sharp reconstruction kernel was –45–39 % for the solid part and –21–46 % for the entire nodule. Conclusion Although the software prototype delivered satisfactory results when segmentation is evaluated subjectively, quantitative statistical analysis revealed room for improvement especially regarding the segmentation accuracy of the solid part and the reproducibility of measurements of the nodule’s subsolid margins. Key points:

A New Perspective on Fluorapatite Dissolution in Hydrochloric Acid: Thermodynamic Calculations and Experimental Study

Apatite (Ap) dissolution in diluted acids is well described in the literature, but in technological processes which use more concentrated acids, the reaction is fast, and it is complicated to follow the process kinetics. The relationship between pH change and the apatite dissolution rate depending on HCl concentration was studied by thermodynamic calculations and experiments with synthetic fluorapatite (FAp). On the basis of experimental pH measurements, the kinetics of dissolution was analyzed. The solution composition (P, Ca, F) was determined by wet chemical methods and the solid part was characterized by XRD and FTIR. It was shown that the amount of HCl needed for FAp dissolution depends on acid concentration. FAp dissolution rate cannot be deduced from solubility data of P, Ca or F as the secondary reactions of CaF2 and CaHPO4 formation take place simultaneously. It was found that the Ap dissolution rate can be followed by pH change.

Optimal Surgical Margin to Avoid Locoregional Recurrence for Non-small Cell Lung Cancer Larger than 2.0 cm: A Retrospective Study

Background. A parenchymal surgical margin of“the clinical tumor size or more” or “2.0 cm or more” has been widely recognized as the optimal margin distance to avoid locoregional recurrence after sublobar resection for non-small cell lung cancer (NSCLC) of 2.0 cm or less. However, the safe margin distance to avoid locoregional recurrence for NSCLC larger than 2.0 cm remains unclear. Patients and Methods. Among 1,338 patients with resected primary lung cancers at two institutions between 2007 and 2016, 85 clinical N0M0 patients with NSCLCs larger than 2.0 cm who underwent sublobar resection were extracted. We classified these 85 NSCLCs as ground glass opacity (GGO)-dominant type or solid-dominant type according to computed tomography (CT) findings. Clinicopathological characteristics and the association between locoregional recurrence and margin distance were evaluated. Results. The median clinical tumor size was 2.5 (2.1-4.9) cm. Based on CT findings, 14 tumors (16%) were considered GGO-dominant type and 71 (84%) were solid-dominant type. No lymph node metastasis, lymphatic permeation or vascular invasion was pathologically confirmed in GGO-dominant type. All GGO-dominant tumors were resected with a margin distance the size of the solid part on CT or more, resulting in no local recurrence, whereas, solid-dominant tumors recurred locally even if they were resected with a margin distance of “the clinical tumor size or more”. Conclusions. The optimal surgical margin for NSCLC larger than 2.0 cm was “the size of the solid part on CT or more” for GGO-dominant type, but undefinable for solid-dominant type.

THE ETHNOSOCIAL STRUCTURE OF THE CHUVASH POPULATION IN BASHKORTOSTAN (1979–2019)

Based on the data of the All-Union and All-Russian population censuses, as well as statistical data, the article makes an attempt to reveal the ethno-social structure of the Chuvash population in Bashkortostan in 1979–2010. One of the main indicators of high social status and positive social well-being is the educational level of the population. The indicators reflecting the educational level of the Chuvash population in Bashkortostan are lower than the average ones in the Republic. Despite this, the Chuvash were represented in various spheres of the republic’s economy. A significant proportion of the Chuvash were represented in the field of industry (21.2%), a certain part worked in the field of natural sciences and healthcare, a solid part was made up of highly qualified specialists – 9.3%, as well as in the field of education – 4.5%. Among the Chuvash, the highest share among the ethnic groups of the republic was the share with several sources of livelihood: two sources – 39.0% and three sources – 2.1%, when the national average was 29.4% and 1.7%, respectively. One of the main income sources for the Chuvash was private subsidiary farming, which accounted for a little more than one third (29.6%), significantly outstripping the indicators of other ethnic groups in this area and significantly exceeding the national average (18.9%). Noting rather high indicators of the Chuvash in some areas of the republican economy, it should be emphasized that according to many other indicators, the social and professional status of the Chuvash population in Bashkortostan is still inferior to that of representatives of other ethnic groups.

CT-Detected Subsolid Nodules: A Predictor of Lung Cancer Development at Another Location?

The purpose of this case–cohort study was to investigate whether the frequency and computed tomography (CT) features of pulmonary nodules posed a risk for the future development of lung cancer (LC) at a different location. Patients scanned between 2004 and 2012 at two Dutch academic hospitals were cross-linked with the Dutch Cancer Registry. All patients who were diagnosed with LC by 2014 and a random selection of LC-free patients were considered. LC patients who were determined to be LC-free at the time of the scan and all LC-free patients with an adequate scan were included. The nodule count and types (solid, part-solid, ground-glass, and perifissural) were recorded per scan. Age, sex, and other CT measures were included to control for confounding factors. The cohort included 163 LC patients and 1178 LC-free patients. Cox regression revealed that the number of ground-glass nodules and part-solid nodules present were positively correlated to future LC risk. The area under the receiver operating curve of parsimonious models with and without nodule type information were 0.827 and 0.802, respectively. The presence of subsolid nodules in a clinical setting may be a risk factor for future LC development in another pulmonary location in a dose-dependent manner. Replication of the results in screening cohorts is required for maximum utility of these findings.

CT and pathological features in renal parenchymal malakoplakia: a case report and review of the literature

Renal malakoplakia is a rare form of chronic inflammatory granulomatous disease in the kidney. It occurs in adult patients with immunocompromised status or debilitating disease. In the present study, we reported a case of a 50-year-old woman with no underlying disease. This report describes the CT and pathological features of renal malakoplakia in a 50-year-old woman. Plain CT scan showed a large soft tissue mass at the middle and upper pole of the left kidney. Enhanced CT scan showed delayed enhancement in the solid part of the mass. Our results might provide some useful information for the diagnosis of renal parenchymal malakoplakia.

Arterial Spin Labeling MRI for Predicting Microvascular Invasion of T1 Staging Renal Clear Cell Carcinoma Preoperatively

BackgroundMicrovascular invasion (MVI) is a valuable factor for T1 staging renal clear cell carcinoma (ccRCC) operation strategy decision, which is confirmed histopathologically post-operation. This study aimed to prospectively evaluate the performance of arterial spin labeling (ASL) MRI for predicting MVI of T1 staging ccRCC preoperatively.Methods16 volunteers and 39 consecutive patients were enrolled. MRI examinations consisted of ASL (three post label delays separately) of the kidney, followed by T1 and T2-weighted imaging. Two sessions of ASL were used to evaluate the reproducibility on volunteers. Renal blood flow of renal cortex, medulla, the entire and solid part of the tumor were measured on ASL images. Conventional imaging features were extracted. MVI and WHO/ISUP classification were evaluated histopathologically. A paired t‐test was used to compare the renal cortex and medulla between ASL 1 and ASL 2. The reproducibility was assessed using the intraclass correlation. Differences in mean perfusion between the entire and the solid parts of tumors with or without MVI were assessed separately using Student’s t test. The diagnostic performance was assessed. Logistic regression analysis was used to indicate the independent prediction index for MVI.ResultsThe two sessions of ASL showed no significant difference between the mean cortex values of RBF. The cortical RBF measurements demonstrated good agreement. 12 ccRCCs presented with MVI histopathologically. Mean perfusion of the solid part of tumors with MVI were 536.4 ± 154.8 ml/min/100 g (PLD1), 2912.5 ± 939.3 ml/min/100 g (PLD2), 3280.3 ± 901.2 ml/min/100 g (PLD3). Mean perfusion of the solid part of tumors without MVI were 453.5 ± 87.2 ml/min/100 g (PLD1), 1043.6 ± 695.8 ml/min/100 g (PLD2), 1577.6 ± 1085.8 ml/min/100 g (PLD3). These two groups have significant difference at all the PLDs (p < 0.05). The RBF of PLD1 of the solid part of tumor perfusion showed well diagnostic performance for predicting MVI: sensitivity 75%, specificity 100%, positive predictive value 66.7%, and negative predictive value 95.7%. The maximum diameter of the tumor, ill-defined margin, and the solid part of tumor perfusion were the independent prediction index for MVI.ConclusionASL MR imaging has good reproducibility for renal cortex, and good diagnostic performance for predicting MVI for ccRCC.

A Multiparametric MRI-Based Radiomics Analysis to Efficiently Classify Tumor Subregions of Glioblastoma: A Pilot Study in Machine Learning

Glioblastoma multiforme (GBM) carries a poor prognosis and usually presents with heterogenous regions of a necrotic core, solid part, peritumoral tissue, and peritumoral edema. Accurate demarcation on magnetic resonance imaging (MRI) between the active tumor region and perifocal edematous extension is essential for planning stereotactic biopsy, GBM resection, and radiotherapy. We established a set of radiomics features to efficiently classify patients with GBM and retrieved cerebral multiparametric MRI, including contrast-enhanced T1-weighted (T1-CE), T2-weighted, T2-weighted fluid-attenuated inversion recovery, and apparent diffusion coefficient images from local patients with GBM. A total of 1316 features on the raw MR images were selected for each annotated area. A leave-one-out cross-validation was performed on the whole dataset, the different machine learning and deep learning techniques tested; random forest achieved the best performance (average accuracy: 93.6% necrosis, 90.4% solid part, 95.8% peritumoral tissue, and 90.4% peritumoral edema). The features from the enhancing tumor and the tumor shape elongation of peritumoral edema region for high-risk groups from T1-CE. The multiparametric MRI-based radiomics model showed the efficient classification of tumor subregions of GBM and suggests that prognostic radiomic features from a routine MRI exam may also be significantly associated with key biological processes that affect the response to chemotherapy in GBM.

Imaging diagnosis of basal ganglia germ cell tumors: subtype features subtype imaging features of GCTs

Objectives: To evaluate the subtype imaging features of basal ganglia germ cell tumors (GCTs). Methods: Clinical and imaging data of 33 basal ganglia GCTs were retrospectively analyzed, including 17 germinomas and 16 mixed germ cell tumors (MGCTs). Results: The cyst/mass ratio of germinomas (0.53 ± 0.32) was higher than that of MGCTs (0.28 ± 0.19, p = 0.030). CT density of the solid part of germinomas (41.47 ± 5.22 Hu) was significantly higher than that of MGCTs (33.64 ± 3.75 Hu, p < 0.001), while apparent diffusion coefficients (ADC, ×10-3 mm2/s) value of the solid part was significantly lower in geminomas (0.86 ± 0.27 ×10-3 mm2/s) than in MGCTs (1.42 ± 0.39 ×10-3 mm2/s, p < 0.001). MGCTs were more common with intratumoral hemorrhage (68.75% vs 11.76%, p = 0.01), T1 hyperintense foci (68.75% vs 5.88%, p < 0.001) and calcification (64.29% vs 20.00%, p = 0.025) than germinomas. There was no significant difference in internal capsule involvement between the two subtypes (p = 0.303), but Wallerian degeneration was more common in germinomas than in MGCTs (70.59% vs 25.00%, p = 0.015). Conclusion: The subtypes of GCT have different imaging features. Tumoral cystic-solidity, heterogeneity, ADC value, CT density, and Wallerian degeneration are helpful to differentiate germinomas and MGCTs in basal ganglia. Advances in knowledge: The subtypes of GCT have different histological characteristics, leading to various imaging findings. The imaging features of GCT subtypes in basal ganglia may aid clinical diagnosis and treatment.

Imaging, clinical, and pathologic findings of Sertoli-leydig cell tumors

To explore the clinical features, imaging findings, and pathological manifestations of ovarian Sertoli-Leydig cell tumors (SLCTs). The clinical and pathological manifestations, tumor location, size, morphology, vascularity, computed tomography (CT) density, magnetic resonance imaging (MRI) signal intensity, and contrast enhancement patterns in five cases with SLCTs were retrospectively reviewed. SLCTs most commonly occurred in young women. Virilization was observed in three cases (60%). All five tumors were unilateral and oval or round, with a clear boundary. The solid part of the tumor was isoattenuated on the conventional CT scan, and showed isoattenuation or slight hypoattenuation relative to adjacent myometrium on T1 weighted imaging (T1WI) and T2 weighted imaging (T2WI). On contrast-enhanced images, three tumors showed marked enhancement. DICER1 hotspot mutations were commonly seen in SLCTs. A highly vascularized mass with low signal intensity (SI) of the solid part on T2WI and androgen overproduction symptoms may suggest an SLCT.