Growth Rate Of Nodules Research Articles

Screening for Early Lung Cancer, Chronic Obstructive Pulmonary Disease, and Cardiovascular Disease (the Big-3) Using Low-dose Chest Computed Tomography: Current Evidence and Technical Considerations.

Lung cancer, chronic obstructive pulmonary disease, and cardiovascular disease are highly prevalent in the general population and expected to cause most deaths by 2050. For these "Big-3," treatment might cure, delay, or stop the progression of disease at a very early stage. Lung nodule growth rate (a biomarker for lung cancer), emphysema/air trapping (a biomarker for chronic obstructive pulmonary disease), and coronary artery calcification (a biomarker for cardiovascular disease) are imaging biomarkers of early stages of the Big-3 that can be acquired with low-dose computed tomography (CT). We hypothesize that a (combined) low-dose CT examination for detection of all 3 diseases may significantly improve the cost-effectiveness of screening in the future. We review the current evidence of the imaging biomarkers for the detection of the Big-3 diseases and present the potential health economic potential of Big-3 screening. Furthermore, we review the low-dose CT protocols to acquire these biomarkers and describe the technical considerations when combining the CT protocols for the different biomarkers.

Differences in Growth Rate on CT of Adrenal Adenomas and Malignant Adrenal Nodules

OBJECTIVE. The purpose of this study is to determine the differences in growth rate of adrenal adenomas and malignant adrenal nodules. MATERIALS AND METHODS. This was a retrospective review of adults with an adrenal nodule seen at two different abdominal or chest CT examinations or PET/CT examinations. Patients in the adenoma group were included if they had a CT, MRI, or pathologic diagnosis of an adrenal adenoma. Patients in the malignant group were included if they had a pathologically proven malignant adrenal nodule. Nodule growth was defined as a change in the largest axial diameter greater than or equal to 3 mm. Growth rate was calculated by dividing the change in the longest axial diameter by the time between the first and last imaging examination. RESULTS. There were 105 adenomas and 26 malignant nodules. Of the 105 adenomas, 34 (32.4%; 95% CI, 23.6-42.2%) grew, three (2.9%; 95% CI, 0.6-8.1%) became smaller, and 68 (64.8%; 95% CI, 54.8-73.8%), were unchanged in size. All 26 (100%; 95% CI, 89.1-100%) malignant nodules grew. The mean (± SD) growth rate of adenomas was 1.0 ± 0.67 mm/year (range, 0.3-2.8 mm/year), compared with 58.4 ± 78.5 mm/year (range, 5.8-395.4 mm/year) for malignant nodules (p < 0.001). A growth rate of 3 mm/year distinguished adenomas from malignant nodules with a sensitivity of 100% (95% CI, 86.8-100%) and a specificity of 100% (95% CI, 96.6-100%). CONCLUSION. Approximately one-third of radiologically proven adrenal adenomas grew, all of which grew at a rate less than 3 mm/year. All malignant adrenal nodules grew, and all at a rate greater than 5 mm/year.

Tumor Growth Rate Does Not Predict Malignancy in Surgically Resected Thyroid Nodules Classified as Bethesda Category III with Architectural Atypia.

It is unknown whether the growth of thyroid nodules with a Bethesda category III cytology (atypia of undetermined significance [AUS]) is predictive of malignancy, especially in cases with architectural atypia (AUS-A). This study evaluated whether tumor growth rates can help distinguish malignant from benign nodules in the AUS-A subcategory. This retrospective, single-center cohort study included 172 patients who underwent diagnostic thyroid surgery because of a nodule with a cytological diagnosis of AUS-A. The growth kinetics of nodules was assessed by serial preoperative neck ultrasonography over a median follow-up of 52.6 months (range 12.7-198.3 months). Pathologic examinations showed that 112 (65%) and 60 (35%) patients had benign and malignant nodules, respectively. The largest diameter and volume of both benign and malignant nodules increased gradually (p < 0.001). However, there was no significant difference in the growth rates of benign and malignant nodules based on the largest diameter (p = 0.132) and volume (p = 0.200). The time to tumor growth curves and estimated median time to significant tumor growth from baseline were not significantly different in malignant nodules compared to benign nodules (p = 0.458 and p = 0.568, respectively). The relative risk (RR) of malignancy of growing and stable nodules did not differ significantly based on the largest diameter (RR = 0.5; p = 0.064) and volume (RR = 0.9; p = 0.748). The size of thyroid nodules classified as AUS-A increased linearly, regardless whether these nodules were benign or malignant. These results suggest that growth kinetics on serial preoperative neck ultrasonography cannot predict malignancy in the AUS-A subcategory.

Rare earth elements in Fe-Mn nodules from southern Baltic Sea – a preliminary study

Between 1976–1990, the Polish Geological Institute performed geological works in the Polish Maritime Areas. During these works, 260 occurrences of concretions were recorded from 7,500 sampled sites. In 1980, the threshold that separates the Bornholm Basin from the Słupsk Furrow was mapped. Numerous Fe-Mn nodules on the seabed were found in that area. The results of detailed analyses of nodule samples collected from four sites are presented in this paper. Analyzed nodules represent discoidal D, irregular I, and transitional D-I types. The nodules are characterized by varied chemical composition of main oxides (Fe, Mn). The maximum Fe2O3 content is 26.63% and MnO 23.18%. Total average amount of REE + Y in the samples is approximately 165.11 ppm, ΣLREE 145.72 ppm and ΣHREE 19.39 ppm. The LREE content is enriched in comparison to HREE. The majority of nodules consist of Fe-Mn oxy-hydroxide minerals with very low crystallinity (practically amorphous phases). The main confirmed Mn-phases are birnessite and todorokite. Other main components of the nodules are: detrital quartz, albite, microcline, glauconite and muscovite, clinochlore, and clay minerals: illite and chlorite. The rate of growth of Fe-Mn nodules has been estimated using a cobalt chronometer. The nodule growth rate ranges from 0.006 to 0.134 mm/yr –1. Based on the Fe, Mn and (Cu + Co + Ni) contents, the origin of studied nodules is determined as hydrogenetic, while using REE (Cesn/Cesn · vs. Nd) – as diagenetic.

Analysis of Local Conditions on Graphite Growth and Shape During Solidification of Ductile Cast Iron

3D X-ray tomography recordings have been used to study graphite growth during solidification of ductile cast iron. Using data from such recordings, it is shown how local growth conditions influence growth rate and morphology of nodules during solidification. Experiments show that it is common for nodules to gradually change shape during solidification so that sphericity decreases. It is also found that different shaped nodules can evolve in direct contact with liquid iron and also after they are encapsulated in austenite. It is observed that a significant proportion of originally complete spherical nodules become less spherical via formation of protrusions on the surface; these new surfaces are observed to grow relatively faster. It is shown that encapsulation of the graphite nodule by austenite may be incomplete and that at the end of solidification, partial encapsulation and the effect of the number of nearest graphite nodules play a crucial role in determining the final graphite morphology.

Synchrotron quantification of graphite nodule evolution during the solidification of cast iron

In cast iron, graphite develops in conjunction with the metallic matrix during solidification. The morphology and distribution of the embedded graphite is pivotal for mechanical properties from yield strength to fatigue. A novel high temperature environmental cell was developed and combined with in situ synchrotron tomography to investigate and quantify microstructural evolution, including graphite nodule nucleation and growth rates in ductile cast iron. The mechanisms of degenerate graphite nodule formation were also revealed. The formation of a coherent primary gamma phase dendritic network before the graphite nucleation is demonstrated. The graphite nodule nucleation rate, mobility and growth rates are compared to classical models, highlighting the limitations in these models. The results provide unique insights to tune the temperature pathways during cast iron solidification to achieve desired uniform rounded graphite morphologies and size distributions.

Early detection of lung cancer using ultra-low-dose computed tomography in coronary CT angiography scans among patients with suspected coronary heart disease

ObjectivesTo assess whether an additional chest ultra-low-dose CT scan to the coronary CT angiography protocol can be used for lung cancer screening among patients with suspected coronary artery disease. Methods175 patients underwent coronary CT angiography for assessment of coronary artery disease, additionally undergoing ultra-low-dose CT screening to early diagnosis of lung cancer in the same scanner (80kVp and 15mAs). Patients presenting pulmonary nodules were followed-up for two years, repeating low-dose CTs in intervals of 3, 6, or 12 months based on nodule size and growth rate in accordance with National Comprehensive Cancer Network guidelines. ResultsUltra-low-dose CT identified 71 patients with solitary pulmonary nodules (41%), with a mean diameter of 5.50±4.00mm. Twenty-eight were >6mm, and in 79% (n=22) of these cases they were false positive findings, further confirmed by follow-up (n=20), resection (n=1), or biopsy (n=1). Lung cancer was detected in six patients due to CT screening (diagnostic yield: 3%). Among these, four cases could not be detected in the cardiac field of view. Most patients were in early stages of the disease. Two patients diagnosed at advanced stages died due to cancer complications. The addition of the ultra-low-dose CT scan represented a radiation dose increment of 1.22±0.53% (effective dose, 0.11±0.03mSv). ConclusionsLung cancer might be detected using additional ultra-low-dose protocols in coronary CT angiography scans among patients with suspected coronary artery disease.

Trade-off between benefits, harms and economic efficiency of low-dose CT lung cancer screening: a microsimulation analysis of nodule management strategies in a population-based setting

BackgroundIn lung cancer screening, a nodule management protocol describes nodule assessment and thresholds for nodule size and growth rate to identify patients who require immediate diagnostic evaluation or additional imaging exams. The Netherlands-Leuvens Screening Trial and the National Lung Screening Trial used different selection criteria and nodule management protocols. Several modelling studies have reported variations in screening outcomes and cost-effectiveness across selection criteria and screening intervals; however, the effect of variations in the nodule management protocol remains uncertain. This study evaluated the effects of the eligibility criteria and nodule management protocols on the benefits, harms and cost-effectiveness of lung screening scenarios in a population-based setting in Germany.MethodsWe developed a modular microsimulation model: a biological module simulated individual histories of lung cancer development from carcinogenesis onset to death; a screening module simulated patient selection, screening-detection, nodule management protocols, diagnostic evaluation and screening outcomes. Benefits included mortality reduction, life years gained and averted lung cancer deaths. Harms were costs, false positives and overdiagnosis. The comparator was no screening. The evaluated 76 screening scenarios included variations in selection criteria and thresholds for nodule size and growth rate.ResultsFive years of annual screening resulted in a 9.7–12.8% lung cancer mortality reduction in the screened population. The efficient scenarios included volumetric assessment of nodule size, a threshold for a volume of 300 mm3 and a threshold for a volume doubling time of 400 days. Assessment of volume doubling time is essential for reducing overdiagnosis and false positives. Incremental cost-effectiveness ratios of the efficient scenarios were 16,754–23,847 euro per life year gained and 155,287–285,630 euro per averted lung cancer death.ConclusionsLung cancer screening can be cost-effective in Germany. Along with the eligibility criteria, the nodule management protocol influences screening performance and cost-effectiveness. Definition of the thresholds for nodule size and nodule growth in the nodule management protocol should be considered in detail when defining optimal screening strategies.

P1.03-042 Nodule Size is Poorly Represented by Nodule Diameter in Low-Dose CT Lung Cancer Screening

In lung cancer screening, at least one pulmonary nodule is found in over 50% of participants, of which 99% is benign. As lung cancer probability in low-dose computed tomography (CT) lung cancer screening usually is based on nodule size and growth rate, accurate nodule size determination is of major importance to decrease false positive screen results. Previous studies showed that nodule size measurements based on semi-automated volume are preferred over diameter measurements. Aim of this study was to determine the correlation between nodule diameter and nodule size of nodules found in low-dose CT lung cancer screening, and to directly compare it with semi-automated volume measurements. We investigated baseline data of 2,240 solid nodules of intermediate size (volume 50-500mm3) in 1,500 lung cancer screening participants. Nodule volume, x, y, and z diameter and minimum / maximum diameter in any direction were generated by semi-automated software (LungCARE, Siemens). Range in maximum axial and mean nodule diameter per nodule volume category (50-100mm3, 100-200mm3, 200-300mm3, 300-400mm3, 400-500mm3) was determined. Semi-automated nodule volume represented nodule size. Intra-nodule diameter variation was defined as maximum minus minimum nodule diameter. Median participant age was 59 years, 14.1% were women. Median nodule volume was 82.4 mm3 (interquartile range [IQR], 62.9–125.4 mm3). Median nodule diameter was 6.1 mm (IQR, 5.4–7.2 mm) for mean diameter, and 6.6 mm (IQR, 5.9–7.7 mm) for maximum axial diameter. Range in mean nodule diameter per volume category varied from 8.55 mm (3.0 – 11.5 mm) for nodules with volume of 50-100 mm3 to 6.1 mm (7.2 – 13.3 mm) for nodules with volume of 200-300 mm3; range in maximum axial diameter varied from 11.2 mm (7.3 – 18.5 mm) for nodules with volume of 200-300 mm3, to 7.0 mm (9.1 – 16.1 mm) for nodules with volume of 400-500 mm3. Intra-nodule diameters varied by a median of 2.8 mm (IQR, 2.2-3.7 mm). Intra-nodule diameter variation for smaller intermediate-sized nodules (50-200 mm3) was 2.8 mm (IQR 2.2-3.5 mm), and was smaller than intra-nodule diameter variation for larger intermediate-sized nodules (200-500 mm3; median 3.6 mm [IQR 2.5-5.1 mm], P<0.01). Nodule size is poorly represented by diameter, as a nodule has an infinite number of diameters, but only one volume. Therefore, use of nodule diameter measurements may lead to misclassification of lung cancer probability. Median intra-nodule diameter variation was found to be higher as the 1.5mm LungRADS cutoff for nodule growth.

Rapid thyroid nodule growth is not a marker for well-differentiated thyroid cancer.

BackgroundRapid growth of thyroid nodules is described as being associated with thyroid cancer. The objective of the study was to determine how the growth rate of thyroid nodules during follow-up is associated with the risk of thyroid cancer.MethodsRetrospective analysis of patients undergoing thyroid surgery for nodular disease and a repetitive preoperative ultrasound work-up of at least 6 months was done. Nodule growth was considered relevant when a volume increase >49 % was detected. Growth patterns were described as rapid for a volume increase present over 6 to 24 months.ResultsOf the 297 analysed patients, 226 (76 %) displayed relevant nodule growth and 71 (24 %) no relevant growth. A rapid growth pattern was seen in 73 patients (32 %). Well-differentiated thyroid cancer was diagnosed in 33 patients (11 %; 27 papillary, 6 follicular) with a relevant nodule growth in 2 and no relevant growth in 31 patients. No rapid growth pattern was observed in any case of well-differentiated thyroid cancer. A rapid growth pattern occurred only in benign nodules (70 patients) and in 1 patient each with a lymphoma, a metastasis of a renal cell cancer and a metastasis of a gastric adenocarcinoma. Therapy with levothyroxine and/or iodine was administered to 129 patients (43 %) and was significantly inversely correlated with nodule growth (odds ratio 0.27; CI 95 % 0.14–0.53, p < 0.001).ConclusionsThyroid nodule growth alone and especially a rapid growth pattern during follow-up for thyroid nodular disease is not a marker for well-differentiated thyroid cancer and should not be used as a stand-alone argument for thyroid surgery.

Reproducibility of Volumetric Computed Tomography of Stable Small Pulmonary Nodules with Implications on Estimated Growth Rate and Optimal Scan Interval.

PurposeTo use clinically measured reproducibility of volumetric CT (vCT) of lung nodules to estimate error in nodule growth rate in order to determine optimal scan interval for patient follow-up.MethodsWe performed quantitative vCT on 89 stable non-calcified nodules and 49 calcified nodules measuring 3–13 mm diameter in 71 patients who underwent 3–9 repeat vCT studies for clinical evaluation of pulmonary nodules. Calculated volume standard deviation as a function of mean nodule volume was used to compute error in estimated growth rate. This error was then used to determine the optimal patient follow-up scan interval while fixing the false positive rate at 5%.ResultsLinear regression of nodule volume standard deviation versus the mean nodule volume for stable non-calcified nodules yielded a slope of 0.057±0.002 (r2 = 0.79, p<0.001). For calcified stable nodules, the regression slope was 0.052±0.005 (r2 = 0.65, p = 0.03). Using this with the error propagation formula, the optimal patient follow-up scan interval was calculated to be 81 days, independent of initial nodule volume.ConclusionsReproducibility of vCT is excellent, and the standard error is proportional to the mean calculated nodule volume for the range of nodules examined. This relationship constrains statistical certainty of vCT calculated doubling times and results in an optimal scan interval that is independent of the initial nodule volume.

Patterns of relapse and growth kinetics of surgery- and radiation-refractory meningiomas.

Patients with surgery- and radiation-refractory meningiomas have a poor outcome. Due to our lack of knowledge concerning multi-recurrent meningioma natural history, their clinical course is poorly defined. This retrospective study aims at defining patterns of relapse in order to help in the definition of response criteria in future clinical trials. We performed a retrospective review of surgery- and radiotherapy-refractory meningioma cases with interpretable radiological follow-up treated in our department. Tumor volumes were measured on 3D T1 Gadolinium volumetric sequences using a semi-automated algorithm for tumor segmentation. Twenty nine patients with multi-treated meningioma (11 WHO Grade II, 5 de novo WHO Grade III and 13 transformed WHO Grade III), were evaluated. Median PFS was 16 months for patients with Grade II meningiomas. In patients with Grade III meningiomas, the de novo subgroup had a median PFS of 4 months compared with 7 months in patients with malignant transformation. Volumetric analysis of tumor growth concerned 95 tumor nodules in 50 relapses. The mean growth rate of tumor nodules was 10.4 cm(3)/year (95% CI 7.3-14.8 cm(3)/year). Three patterns of tumor growth were described: "classical" for 9 (31%) patients, "local multi-nodular" for 6 (21%) patients and "multi-nodular metastatic" for the last 14 (48%) patients. Considering all tumor nodules, median time to tumor progression (TTP) was 3.7 months. Progressing tumors represent the most frequent histological subgroup of surgery and radiation-refractory meningiomas while tumors with multi-nodular metastatic dissemination are the prominent radiological pattern of progression.

Ultrasound surveillance for thyroid malignancies in survivors of childhood cancer following radiotherapy: a single institutional experience.

Survivors of childhood cancer (SCC) who have received radiotherapy to the head, neck, and upper thorax are at higher risk of developing subsequent thyroid malignancies. As part of the post treatment long-term follow-up protocol, the current Children's Oncology Group guideline recommends surveillance by annual palpation; however, thyroid nodules are difficult to detect by physical examinations alone, and potentially malignancy-harboring nodules may be undetected. Since thyroid ultrasound is a sensitive and noninvasive procedure, it was incorporated in our institutional follow-up protocol. The aim of this study was to examine the outcome of ultrasound screening in this high-risk population. The following describes our experience from 2007 to 2013. A retrospective chart review was conducted on survivors enrolled in our follow-up program. SCC who have received direct or scattered radiation to the thyroid gland, and who were ≥10 years from the diagnosis of primary childhood cancer were considered to be at-risk. Seventy-eight survivors met the inclusion criteria and were screened. Thyroid ultrasound detected thyroid nodule(s) in 46 patients (59%), 17 of which had nodule(s) between 5 and 10 mm (22%), and 15 patients had nodules ≥10 mm (19%). Fourteen patients (18%) underwent fine-needle aspiration biopsy. Six patients (8%) underwent surgery, and 5 (6%) had confirmed papillary carcinoma. At the time of the first ultrasound, thyroid nodules of various sizes were found. However, over time, these nodules demonstrated slow growth rates. Incorporation of thyroid ultrasound into routine follow-up of high-risk SCC may aid in the detection of thyroid malignancies that are not clinically apparent. The use of ultrasound allows detailed characterization of the thyroid nodule and reliable monitoring of nodule progression. In SCC without suspicious nodule(s), it may be reasonable to perform screening ultrasounds less frequently due to the slow growth rate of thyroid nodules. However, in those with suspicious features, surgical work-up resulted in the removal of a high number of malignancies, with few unnecessary surgeries and complications.

Lung cancer probability in patients with CT-detected pulmonary nodules: a prespecified analysis of data from the NELSON trial of low-dose CT screening

The main challenge in CT screening for lung cancer is the high prevalence of pulmonary nodules and the relatively low incidence of lung cancer. Management protocols use thresholds for nodule size and growth rate to determine which nodules require additional diagnostic procedures, but these should be based on individuals' probabilities of developing lung cancer. In this prespecified analysis, using data from the NELSON CT screening trial, we aimed to quantify how nodule diameter, volume, and volume doubling time affect the probability of developing lung cancer within 2 years of a CT scan, and to propose and evaluate thresholds for management protocols. Eligible participants in the NELSON trial were those aged 50-75 years, who have smoked 15 cigarettes or more per day for more than 25 years, or ten cigarettes or more for more than 30 years and were still smoking, or had stopped smoking less than 10 years ago. Participants were randomly assigned to low-dose CT screening at increasing intervals, or no screening. We included all participants assigned to the screening group who had attended at least one round of screening, and whose results were available from the national cancer registry database. We calculated lung cancer probabilities, stratified by nodule diameter, volume, and volume doubling time and did logistic regression analysis using diameter, volume, volume doubling time, and multinodularity as potential predictor variables. We assessed management strategies based on nodule threshold characteristics for specificity and sensitivity, and compared them to the American College of Chest Physicians (ACCP) guidelines. The NELSON trial is registered at www.trialregister.nl, number ISRCTN63545820. Volume, volume doubling time, and volumetry-based diameter of 9681 non-calcified nodules detected by CT screening in 7155 participants in the screening group of NELSON were used to quantify lung cancer probability. Lung cancer probability was low in participants with a nodule volume of 100 mm(3) or smaller (0·6% [95% CI 0·4-0·8]) or maximum transverse diameter smaller than 5 mm (0·4% [0·2-0·7]), and not significantly different from participants without nodules (0·4% [0·3-0·6], p=0·17 and p=1·00, respectively). Lung cancer probability was intermediate (requiring follow-up CT) if nodules had a volume of 100-300 mm(3) (2·4% [95% CI 1·7-3·5]) or a diameter 5-10 mm (1·3% [1·0-1·8]). Volume doubling time further stratified the probabilities: 0·8% (95% CI 0·4-1·7) for volume doubling times 600 days or more, 4·0% (1·8-8·3) for volume doubling times 400-600 days, and 9·9% (6·9-14·1) for volume doubling times of 400 days or fewer. Lung cancer probability was high for participants with nodule volumes 300 mm(3) or bigger (16·9% [95% CI 14·1-20·0]) or diameters 10 mm or bigger (15·2% [12·7-18·1]). The simulated ACCP management protocol yielded a sensitivity and specificity of 90·9% (95% CI 81·2-96·1), and 87·2% (86·4-87·9), respectively. A diameter-based protocol with volumetry-based nodule diameter yielded a higher sensitivity (92·4% [95% CI 83·1-97·1]), and a higher specificity (90·0% [89·3-90·7). A volume-based protocol (with thresholds based on lung cancer probability) yielded the same sensitivity as the ACCP protocol (90·9% [95% CI 81·2-96·1]), and a higher specificity (94·9% [94·4-95·4]). Small nodules (those with a volume <100 mm(3) or diameter <5 mm) are not predictive for lung cancer. Immediate diagnostic evaluation is necessary for large nodules (≥300 mm(3) or ≥10 mm). Volume doubling time assessment is advocated only for intermediate-sized nodules (with a volume ranging between 100-300 mm(3) or diameter of 5-10 mm). Nodule management protocols based on these thresholds performed better than the simulated ACCP nodule protocol. Zorgonderzoek Nederland Medische Wetenschappen and Koningin Wilhelmina Fonds.

Prognosis of small hepatocellular nodules detected only at the hepatobiliary phase of Gd-EOB-DTPA-enhanced MR imaging as hypointensity in cirrhosis or chronic hepatitis.

To evaluate the prognosis of "strict" high-risk nodules (small hepatocellular nodules detected only in the hepatobiliary phase of initial Gd-EOB-DTPA-enhanced MR examination) in patients with cirrhosis or chronic hepatitis. The study included thirty-three patients with 60 "strict" high-risk nodules showing hypointensity at the hepatobiliary phase that was undetectable at the vascular phase and other conventional sequences of initial Gd-EOB-DTPA-enhanced MR imaging. These nodules were observed on follow-up MR examinations until hypervascularity was detected. The potential predictive factors for hypervascular transformation were compared between two groups (group A showing hypervascular transformation, group B not showing hypervascularization). Ten (16.7%) of 60 "strict" high-risk nodules showed hypervascular transformation during follow-up periods (group A). The growth rates of the nodules in group A (6.3 ± 4.5mm/year) were significantly higher than those in group B (3.4 ± 7.2mm/year) (p = 0.003). Additionally, the median observation period in group A (177.5 ± 189.5day) was significantly shorter than in group B (419 ± 372.2day) (p = 0.045). The other predictive factors were not significantly correlated with hypervascularization. Subsets of "strict" high-risk nodules showed hypervascular transformation during follow-up periods in association with increased growth rates, indicating that nodule growth rate is an important predictive factor for hypervascularization. • "Strict" high-risk nodules are defined as hepatocellular nodules detected only in the hepatobiliary-phase. • Subsets of "strict" high-risk nodules showed hypervascular transformation during follow-up periods. • Increased growth rate is an important predictive factor for hypervascular transformation. • Management of patients with "strict" high-risk nodules becomes more appropriate.

Effect of Nitrate on Nodule and Root Growth of Soybean (Glycine max (L.) Merr.)

The application of combined nitrogen, especially nitrate, to soybean plants is known to strongly inhibit nodule formation, growth and nitrogen fixation. In the present study, we measured the effects of supplying 5 mM nitrate on the growth of nodules, primary root, and lateral roots under light at 28 °C or dark at 18 °C conditions. Photographs of the nodulated roots were periodically taken by a digital camera at 1-h intervals, and the size of the nodules was measured with newly developed computer software. Nodule growth was depressed approximately 7 h after the addition of nitrate under light conditions. The nodule growth rate under dark conditions was almost half that under light conditions, and nodule growth was further suppressed by the addition of 5 mM nitrate. Similar results were observed for the extending growth rate of the primary root as those for nodule growth supplied with 5 mM nitrate under light/dark conditions. In contrast, the growth of lateral roots was promoted by the addition of 5 mM nitrate. The 2D-PAGE profiles of nodule protein showed similar patterns between the 0 and 5 mM nitrate treatments, which suggested that metabolic integrity may be maintained with the 5 mM nitrate treatment. Further studies are required to confirm whether light or temperature condition may give the primary effect on the growth of nodules and roots.

Effects of high magnetic field on isothermal pearlite transformation and microstructure in a hypereutectoid steel

A high magnetic field was applied during the isothermal pearlite transformation of a hypereutectoid carbon steel at three different temperatures. It was found that the magnetic field applied can increase the transformation rate and the pearlite nodule growth rate, decrease the interlamellar spacing of pearlite and the amount of low angle boundary in ferrite lamella. The magnetic field effects are more obvious at high temperature. The mechanism of field-effect was discussed by analyzing the influences of high magnetic field on the eutectoid temperature, diffusion activation energy in austenite, Gibbs free energy of ferrite and dislocation mobility.

Juxta-vascular nodule segmentation based on flow entropy and geodesic distance.

Computed aided diagnosis of lung CT data is a new quantitative analysis technique to distinguish malignant nodules from benign ones. Nodule growth rate is a key indicator to discriminate between benign and malignant nodules. Accurate nodule segmentation is the essential for calculating the nodule growth rate. However, it is difficult to segment juxta-vascular nodules, due to the similar gray levels in nodule and attached blood vessels. To distinguish the nodule region from the adjacent vessel region, a flowing direction feature, referred to as the direction of the normal vector for a pixel, is introduced. Since blood is flowing in one single direction through a vessel, the normal vectors of pixels in the vessel region typically point in similar orientations while the directions of those in the nodule region can be viewed as disorganized. The entropy value of the flowing direction features in a neighboring region for a vessel pixel is smaller than that for a nodule pixel. Moreover, vessel pixels typically have a larger geodesic distance to the nodule center than nodule pixels. Based on k -means clustering method, the flow entropy, combined with the geodesic distance, is used to segment vessel attached nodules. The validation of the proposed segmentation algorithm was carried out on juxta-vascular nodules, identified in the Chinalung-CT screening trial and on Lung Image Database Consortium (LIDC) dataset. In fully automated mode, accuracies of 92.9% (26/28), 87.5%(7/8), and 94.9% (149/157) are reached for the outlining of juxta-vascular nodules in the Chinalung-CT, and the first and second datasets of LIDC, respectively. Furthermore, it is demonstrated that the proposed method has low time complexity and high accuracies.

基于流向特征熵和测地线距离的粘连血管型肺结节聚类分割

Computed aided diagnosis (CAD) of lung CT is a new quantitative analysis imaging technique to distinguish malignant nodules from benign ones. Nodule growth rate is a key indicator for judgment of benign or malignant nodule. Accurate nodule segmentation is the premise condition of calculating nodule growth rate. However, it is difficult to segment Juxta-vascular nodules, due to similar gray levels between nodule and vessel. To distinguish the nodule region from the adjacent vessel region, a flowing direction feature, referred to as the direction of normal vector for a pixel, is introduced. Since all blood has the same flowing direction through a vessel, the normal vectors of pixels in the vessel region typically point to similar orientations while the directions of those in the nodule region can be viewed as disorganized. So the entropy value of flowing direction features in a neighbor region for a vessel pixel is bigger than that for a nodule pixel. And vessel pixels typically have a larger geodesic distance to the nodule center than nodule pixels. Based on k-Means clustering method, the flowing entropy feature, combined with geodesic distance feature, is proposed to solve the segmentation problem of the vessel attachment nodule. The validation of the proposed segmentation algorithm was carried out on Juxta-vascular nodules (104 solid nodule and 28 Juxta-vascular nodule), identified in the Chinalung-CT screening trail and on the lung image database consortium (LIDC) dataset. Among them, there are 12 nodules in the first LIDC database (4 solid nodules and 8 Juxta-vascular nodules) and 182 nodules in the second LIDC database (25 solid nodules and 157 Juxta-vascular nodules). Comparison is done between the gold standard and experimental results. The correct segmentations on solid nodule are 100/104(96.2%), 4/4(100%) and 24/25(96.0%), respectively, while the correct segmentations on Juxta-vascular nodule are 26/28(92.9%),7/8(87.5%) and 149/157(94.9%), respectively, showing that the proposed method has low time complexity and high accurate rate.

Overview and Strategic Management of Subsolid Pulmonary Nodules

A new classification of lung adenocarcinoma has been proposed recently-the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification. Abundant information from recent lung cancer computed tomography (CT) screening programs has increased our understanding of the strong, although imperfect, correlation between histologic findings of lung adenocarcinoma and subsolid pulmonary nodules on CT, including both "pure" ground-glass nodules (GGNs) and "part-solid" GGNs. Moreover, serial CT imaging has demonstrated stepwise progression of these nodules in a subset of patients, characterized by increase in size and density of GGNs and development of a solid component. Given the higher incidence of malignancy and the considerably lower growth rate of subsolid nodules, dedicated standardized guidelines for management of these nodules have been proposed, including long-term (≥3 y) CT follow-up using a low-dose technique. Radiologists should be familiar with the new terminology of lung adenocarcinomas and strategic management of subsolid pulmonary nodules.