Correlation study between flash dual source CT perfusion imaging and regional lymph node metastasis of non-small cell lung cancer.

BACKGROUND: To explore the correlation of flash dual source computed tomography perfusion imaging (CTPI) and regional lymph node metastasis of non-small cell lung cancer (NSCLC), and to evaluate the value of CT perfusion parameters in predicting regional lymph node metastasis of NSCLC. METHODS: 120 consecutive patients with NSCLC confirmed by postoperative histopathology were underwent flash dual source CT perfusion imaging in pre-operation. The CT perfusion parameters of NSCLC, such as blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability (PMB) were obtained by the image post-processing. Then microvessel density (MVD), luminal vascular number (LVN), luminal vascular area (LVA) and luminal vascular perimeter (LVP) of NSCLC were counted by immunohistochemistry. These cases were divided into group A (patients with lymph node metastasis, 58 cases) and group B (patients without lymph node metastasis, 62 cases) according to their pathological results. The CT perfusion parameters and the microvessel parameters were contrastively analysed between the two groups. Receiver operating characteristic (ROC) curve was used to assess the diagnostic efficiency of CT perfusion parameters in predicting regional lymph node metastasis of NSCLC in pre-operation. RESULTS: Group A presented significantly lower LVA, BF and higher MTT, PMB than Group B (P < 0.05), while BV, LVN, LVP and MVD were no significant difference (P > 0.05). Correlation analysis showed that BF was correlated with LVA and LVP (P < 0.05), while BV, MTT and PMB were not correlated with LVN, LVA and LVP (P > 0.05). All the perfusion parameters were not correlated with MVD. According to the ROC curve analysis, when BF < 85.16 ml/100 ml/min as a cutoff point to predict regional lymph node metastasis of NSCLC, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 60.8, 81.7, 71.5, 75.6 and 69.5% respectively. CONCLUSION: Flash dual source CT perfusion imaging can non-invasively indicate the luminal vascular structure of tumor and BF can be used as one of the important indexes in predicting regional lymph node metastasis of NSCLC in pre-operation.

Correlation study between dual source CT perfusion imaging and the microvascular composition of solitary pulmonary nodules.

OBJECTIVE: To explore the correlation between dual source computed tomography perfusion imaging (CTPI) and microvascular parameters, and evaluate the value of CTPI in the differential diagnosis of solitary pulmonary nodule (SPN). METHODS: 65 consecutive patients with SPN who successfully underwent pre-operative CT perfusion imaging with dual source CT and received a final diagnosis by postoperative pathology. The cases were divided into malignant, benign and inflammatory groups according to the pathological results. CT perfusion parameters, such as blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface (PMB) were obtained by performing CTPI of SPNs. The postoperative specimens of SPNs were immunohistochemically stained for CD34 and SMA to detect microvessel density (MVD) and luminal vascular parameters, such as luminal vascular number (LVN), luminal vascular area (LVA) and luminal vascular perimeter (LVP). The receiver operating characteristic (ROC) curve was used to assess the diagnostic efficiency of CT perfusion parameter in diagnosing malignant SPNs. RESULTS: In these 65 cases, malignant, benign and inflammatory SPNs were respectively 39, 14 and 12 cases. Significant difference was observed in LVN/MVD, LVA and LVP among the three groups (P < 0.05). The correlation between CT perfusion parameters (BF, BV and PMB) and the luminal vascular parameters was stronger than that with MVD (P < 0.05). PMB has the strongest correlation with LVN/MVD. Using BF≥60ml/100ml/min, BV≥6.34ml/100ml and PMB≥13.35ml/100 ml/min for the diagnosis, the area under the curve (AUC) of the ROC curve was 0.760, the sensitivity was 82% and the specificity was 61%. CONCLUSIONS: The main indicators reflecting blood perfusion of SPN are the degree of lumen or maturity of microvessels (LVN, LVA and LVP), not just the number of microvessels (e.g. MVD). CT perfusion imaging can be used as an important method to non-invasively evaluate tumour angiogenesis and help to distinguish malignant SPNs from benign and inflammatory SPNs.

A new 1,3-dibutylimidazolium hexafluorophosphate ionic liquid-based dispersive liquid-liquid microextraction to determine organophosphorus pesticides in water and fruit samples by high-performance liquid chromatography.

The paper described a new ionic liquid, 1,3-dibutylimidazolium hexafluorophosphate, as extraction solvent for extraction and preconcentration of organophosphorus pesticides (fenitrothion, parathion, fenthion and phoxim) from water and fruit samples by dispersive liquid-liquid microextraction combined with high-performance liquid chromatography. The effects of experimental parameters, such as extraction solvent volume, disperser solvent and its volume, extraction and centrifugal time, sample pH, extraction temperature and salt addition, on the extraction efficiency were investigated. An extraction recovery of over 75% and enrichment factor of over 300-fold were obtained under the optimum conditions. The linearity relationship was also observed in the range of 5-1000 microgL(-1) with the correlation coefficients (r(2)) ranging from 0.9988 to 0.9999. Limits of detection were 0.01-0.05 microgL(-1) for four analytes. The relative standard deviations at spiking three different concentration levels of 20, 100 and 500 microgL(-1) varied from 1.3-2.7, 1.4-1.9 and 1.1-1.7% (n=7), respectively. Three real samples including tap water, Yellow River water and pear spiked at three concentration levels were analyzed and yielded recoveries ranging from 92.7-109.1, 95.0-108.2 and 91.2-108.1%, respectively.

Ionic liquid-based dispersive liquid-liquid microextraction followed high-performance liquid chromatography for the determination of organophosphorus pesticides in water sample.

Using 1-octyl-3-methylimidazolium hexafluorophosphate ([C(8)MIM][PF(6)]) ionic liquid as extraction solvent, organophosphorus pesticides (OPPs) (parathion, phoxim, phorate and chlorpyifos) in water were determined by dispersive liquid-liquid microextraction (DLLME) combined with high-performance liquid chromatography (HPLC). The extraction procedure was induced by the formation of cloudy solution, which was composed of fine drops of [C(8)MIM][PF(6)] dispersed entirely into sample solution with the help of disperser solvent (methanol). Parameters including extraction solvent and its volume, disperser solvent and its volume, extraction time, centrifugal time, salt addition, extraction temperature and sample pH were investigated and optimized. Under the optimized conditions, up to 200-fold enrichment factor of analytes and acceptable extraction recovery (>70%) were obtained. The calibration curves were linear in the concentration range of 10.5-1045.0 microg L(-1) for parathion, 10.2-1020.0 microg L(-1) for phoxim, 54.5-1089.0 microg L(-1) for phorate and 27.2-1089.0 microg L(-1) for chlorpyifos, respectively. The limits of detection calculated at a signal-to-noise ratio of 3 were in the range of 0.1-5.0 microg L(-1). The relative standard deviations for seven replicate experiments at 200 microg L(-1) concentration level were less than 4.7%. The proposed method was applied to the analysis of four different sources water samples (tap, well, rain and Yellow River water) and the relative recoveries of spiked water samples are 99.9-115.4%, 101.8-113.7% and 87.3-117.6% at three different concentration levels of 75, 200 and 1000 microg L(-1), respectively.