Application of Multislice Spiral CT Imaging Technology in the Diagnosis of Patients with Chest Sarcoidosis

Objective. To study the qualitative value of multislice spiral CT (MSCT) dynamic enhancement scanning for solitary nodules (SPN) of the chest. Methods. In this paper, 40 cases of chest nodules (including 25 cases of malignant nodules, 8 cases of inflammatory nodules, and 7 cases of benign nodules) were first scanned to determine the scope of nodules. At the two rates of 5 ml/s and 3 ml/s, CT dynamic enhancement scans were performed at the center of the nodule, and the CT values, peak enhancement (PH) and peak time (PT) before and after SPN enhancement, were recorded. It is mainly strengthened, with 80% (20/25) of net added value between 20 and 60 Hu, and 20% (5/25) >60 Hu or <20 Hu. The enhancement peak and peak time are (31.31 ± 10.62) Hu and 45 s, respectively. The time-density curve (T-DC) showed a slowly rising type; the inflammatory nodules were mainly severely strengthened, with a net increase of >40 Hu. The enhancement peak value is (49.25 ± 12.44) Hu, and the peak time is 80 s and 140 s. There is a characteristic of rising and falling and then rising in the curve. Conclusion. Multislice spiral CT dynamic enhancement scan reflects the dynamic characteristics of chest nodular blood flow, which can be used to noninvasively evaluate and diagnose SPN.

The Value of MRI Dynamic Enhancement Quantitative Parameters In Distinguishing UIP And NSIP

Background Interstitial pneumonia is a lung disease characterized by pulmonary interstitial inflammation and progressive pulmonary fibrosis. There are many causes of it, which lead to different types with different prognosis. Moreover, the mixture of different classifications will make the diagnosis difficult for radiologists, and it will also make treatment difficult for clinicians. Therefore, patients and clinicians urgently need new imaging methods to solve this problem. Currently, the most common types of interstitial pneumonia are usual interstitial pneumonia (UIP) and non-specific interstitial pneumonia (NSIP).The purpose of this article is to introduce the value of MRI dynamic enhancement quantitative parameters in the identification of UIP and NSIP.Methods All patients with interstitial pneumonia whose images on HRCT were consistent with UIP and patients with NSIP were further examined by dynamic enhanced MRI. Follow-up was continued. Patients with UIP confirmed by pathology or ineffective after treatment and with imaging characteristics consistent with UIP were classified as UIP group (n=9). In addition, NSIP was confirmed pathologically, or the treatment was effective and the imaging characteristics were consistent with NSIP, which was classified as another group (n=18). All patients underwent high-resolution CT plain scan and MRI plain scan + dynamic enhancement scan. Different types of interstitial pneumonia were compared to obtain the dynamic enhancement quantitative parameter values at the pathological site or the most severe level was selected for the region of interest after clinical diagnosis. (Region of interest, ROI) delineate the obtained quantitative parameter values, and then compare the quantitative parameter values of MRI dynamic enhancement in each group. Results The differences in dynamic enhancement quantitative parameters between the UIP and NSIP groups were statistically significant. Correspondingly, the pseudo-colour images formed by the lesions in these two groups were different. ktrans and iAUC values were lower in the UIP group than in the NSIP group, with p-values of 0.000 and 0.043 respectively; Kep and Ve values were not statistically different between the two groups. On the pseudo-colour map, the lesions in UIP were mainly blue - colourless, while the NSIP lesions were mainly light yellow - light blue.Conclusions The quantitative parameters of MRI dynamic enhancement examinations are considered to be valuable in identifying UIP and NSIP.

Hepatic sclerosed hemangioma and sclerosing cavernous hemangioma: a radiological study

Purpose To investigate and compare the CT and MRI features of hepatic sclerosed hemangioma (HSH) and sclerosing cavernous hemangioma (SCH). Materials and methods Twelve HSH cases and 36 SCH cases were included, the imaging findings on CT (9 HSH and 34 SCH) and MRI (8 HSH and 10 SCH) were analyzed. Qualitative image analysis included the location, size, shape, capsular retraction, density, calcification, signal intensity on T1-weighted image (T1WI) and T2-weighted image (T2WI), presence of diffusion restriction, apparent diffusion coefficient (ADC) map, transient hepatic attenuation difference around the lesion, and the dynamic enhancement patterns. Results The presence of liver cirrhosis in patients with HSH (3/12) was higher than SCH (1/36) (P = 0.043). The morphology appearance before enhancement showed no significant difference between HSH and SCH. Moreover, SCH had a stronger trend of centripetal enhancement patterns of cavernous hemangiomas (83.3%) compared to HSH (25%) (P < 0.001). Due to more frequent atypical enhancement features, containing rim-like enhancement, no enhancement, and peripheral heterogeneous enhancement, the misdiagnosis rate of HSH (75%) was significantly higher than that of SCH (16.7%) (P < 0.001). Furthermore, the ADC values of HSH and SCH were both higher than that of the surrounding liver parenchyma (P = 0.009, P = 0.002); however, there was no significant difference in ADC values between themselves (P = 0.613). Conclusion SCH showed the same trend of centripetal enhancement characteristics as typical hemangioma, while HSH exhibited atypical enhancement features due to complete sclerosis. Higher ADC values might contribute to the identification of atypical HSH and SCH from malignancies.

Pattern recognition of breast tumor based on image dynamic enhancement technique

At present, the diagnosis of breast tumors is affected by many factors, which leads to certain errors in the diagnosis results. Therefore, it is necessary to improve the diagnosis in combination with the actual situation. This study used the whole tumor ADC histogram to identify the heterogeneous features of benign and malignant breast lesions and used the diffusion characteristics of the whole tumor to construct a diagnostic model suitable for breast tumor image feature recognition. Simultaneously, this study combined the actual situation to construct a system framework of image enhancement algorithm based on Retinex theory, and combined image processing algorithms to improve the model. In addition, this study converted the pixel data type of the grayscale image of each color channel into a double type and converted each color channel image into a logarithmic domain. Finally, in order to study the performance of the algorithm, this study designed a comparative test for performance analysis. The research shows that the algorithm has certain clinical effects and can provide theoretical reference for subsequent related research.

Characteristics of hepatic solitary necrotic nodules on contrast-enhanced ultrasonography

Background To summarize the characteristics of solitary necrotic nodules (SNN) in the liver observed under contrast-enhanced ultrasonography (CEUS). Methods Conventional ultrasonography (US) and CEUS were performed in 24 patients who were confirmed to have SNN by pathological assessment. The US data and dynamic enhancement patterns of CEUS were recorded and retrospectively analyzed. Results Ten of 24 patients underwent surgical resection, while the other 14 patients underwent a puncture biopsy to be confirmed as SNN. Among the 24 patients, 13 patients had a single lesion and 11 patients had multiple lesions. The largest lesion was selected for CEUS examination for patients with multiple lesions. Eleven patients presented no enhancement in all three phases, while the other 13 patients presented with a peripheral thin rim-like enhancement in the arterial phase, an iso-enhancement in the portal phase and delayed phase. However, no enhancement in the interior of the lesions was detected during three phases of CEUS. Conclusions SNN has characteristic findings on the CEUS, which play an important role in the differential diagnoses of liver focal lesions.

The Bond-Slip Relationship at FRP-to-Brick Interfaces under Dynamic Loading

Interface debonding between fiber reinforced polymers (FPR) and substrates is the principal failure mode for FRP-reinforced structure. To understand the bond–slip relationship at FRP-to-brick interfaces under dynamic loading, the influences of the dynamic enhancement of material performance on the bond–slip curve were studied. Single-lap shear tests under two different loading rates were performed, and the slip distribution curves at different loading stages were fitted to derive the bond–slip relationship. Then a numerical model considering the strain rate effects on materials was built and verified with test results. Further, the influences of brick strength, FRP stiffness and slip rate on the bond–slip relationship were investigated numerically. The research results show that FRP stiffness mainly influences the shape of the bond–slip curve, while brick strength mainly influences the amplitude of the bond–slip curve. The variations of the bond–slip relationship under dynamic loading, i.e., under different slip rates, are mainly caused by the dynamic enhancement of brick strength, and also by the dynamic enhancement of FRP stiffness, especially within a specific slip rate range. The proposed empirical formula considering dynamic FRP stiffness and dynamic brick strength can be used to predict the bond–slip relationship at the FRP-to-brick interface under dynamic loading.

Characteristics of hepatic solitary necrotic nodules on contrast-enhanced ultrasonography

Background:To summarize the characteristics of solitary necrotic nodules (SNN) in the liver observed under contrast-enhanced ultrasonography (CEUS).Methods:Conventional ultrasonography (US) and CEUS were performed in 24 patients who were confirmed to have SNN by pathological assessment. The US data and dynamic enhancement patterns of CEUS were recorded and retrospectively analyzed.Results:Ten of 24 patients underwent surgical resection, while the other 14 patients underwent a puncture biopsy to be confirmed as SNN. Among the 24 patients, 13 patients had a single lesion and 11 patients had multiple lesions. The largest lesion was selected for CEUS examination for patients with multiple lesions. Eleven patients presented no enhancement in all three phases, while the other 13 patients presented with a peripheral thin rim-like enhancement in the arterial phase, an iso-enhancement in the portal phase and delayed phase. However, no enhancement in the interior of the lesions was detected during three phases of CEUS.Conclusions:SNN has characteristic findings on the CEUS, which play an important role in the differential diagnoses of liver focal lesions.

The contrasting effects of thermodynamic and dynamic processes on East Asian summer monsoon precipitation during the Last Glacial Maximum: a data-model comparison

The Last Glacial Maximum (LGM; 21 ka BP) was the most recent glacial period when the global ice sheet volume was at a maximum. Therefore, the LGM can be used to investigate atmospheric dynamics under a climate that differed significantly from the present. This study quantitatively compares pollen records of boreal summer (June–July–August) precipitation with the PMIP3 LGM simulations. The data-model comparison shows an overall agreement on a drier than pre-industrial East Asian summer monsoon (EASM) climate. Nevertheless, 17 out of 55 records show a regional precipitation increase that is also simulated over the additional land mass area due to sea level drop. The thermodynamic and dynamic responses are analyzed to explain a drier LGM EASM as a combination of these two antagonistic mechanisms. Relatively low atmospheric moisture content was the main thermodynamic control on the lower LGM (relative to pre-industrial levels) EASM precipitation amounts in both the reconstructions and the models. In contrast, two dynamic processes in relation to stationary eddy activity act to increase EASM precipitation regionally in records and simulations, respectively. Precipitation increase in records is explained by dynamic enhancement of the horizontal moisture transport, while dynamic enhancement of the vertical moisture transport leads to simulated precipitation increase over the specific region where landmass was exposed during LGM along continental coastlines of China due to significant drop in sea level (relative to pre-industrial levels). Overall, the opposing effects of thermodynamic and dynamic processes on precipitation during the LGM provide a means to reconcile the spatial heterogeneity of recorded precipitation changes in sign, although data-model comparison suggests that the simulated dynamic wetting mechanism is too weak relative to the thermodynamic drying mechanism over data-model disagreement regions.

Dynamic Enhancement Pattern on CT for Predicting Pancreatic Neuroendocrine Neoplasms with Low PAX6 Expression: A Retrospective Observational Study

Paired box 6 (PAX6) is a transcription factor that plays a critical role in tumor suppression, implying that the downregulation of PAX6 promotes tumor growth and invasiveness. This study aimed to examine dynamic computed tomography (CT) features for predicting pancreatic neuroendocrine neoplasms (Pan-NENs) with low PAX6 expression. We retrospectively evaluated 51 patients with Pan-NENs without synchronous liver metastasis to assess the pathological expression of PAX6. Two radiologists analyzed preoperative dynamic CT images to determine morphological features and enhancement patterns. We compared the CT findings between low and high PAX6 expression groups. Pathological analysis identified 11 and 40 patients with low and high PAX6 expression, respectively. Iso- or hypoenhancement types in the arterial and portal phases were significantly associated with low PAX6 expression (p = 0.009; p = 0.001, respectively). Low PAX6 Pan-NENs showed a lower portal enhancement ratio than high PAX6 Pan-NENs (p = 0.044). The combination based on enhancement types (iso- or hypoenhancement during arterial and portal phases) and portal enhancement ratio (≤1.22) had 54.5% sensitivity, 92.5% specificity, and 84.3% accuracy in identifying low PAX6 Pan-NENs. Dynamic CT features, including iso- or hypoenhancement types in the arterial and portal phases and lower portal enhancement ratio may help predict Pan-NENs with low PAX6 expression.