Xiang-Sheng Xiao

Role of magnetic resonance diffusion-weighted imaging in evaluating response after chemoembolization of hepatocellular carcinoma

OBJECTIVE To investigate the value of hepatocellular carcinoma pretreatment apparent diffusion coefficients (ADCs) and its ADCs changes after treatment in predicting and early monitoring the response after chemoembolization. MATERIALS AND METHODS Twenty-five responding and nine nonresponding hepatocellular carcinoma lesions were prospectively evaluated with magnetic resonance diffusion-weighted imaging in 24 h before and in 48 h after chemoembolization. Quantitative ADC maps were calculated with images with b values of 0 and 500 s/mm(2). RESULTS Nonresponding lesions had a significantly higher pretreatment mean ADC than did responding lesions (1.726+/-0.323 x 10(-3) mm(2)/s vs.1.294+/-0.18510(-3) mm(2)/s, P< or =0.001). The results of receiver operator characteristic (ROC) analysis for identification of nonresponding lesions showed that threshold ADC value of 1.618 x 10(-3) mm(2)/s had 96.0% sensitivity and 77.8% specificity. After transarterial chemoembolization, responding lesions had a significant increase in %ADC values than did nonresponding lesions (32.63% vs. 5.24%, P=0.025). The results of ROC analysis for identification of responding lesions showed that threshold %ADC value of 16.21% had 72% sensitivity and 100% specificity. No significant change was observed in normal liver parenchyma (P=0.862) and spleen (P=0.052). CONCLUSION High pretreatment mean ADC value of hepatocellular carcinoma was predictive of poor response to chemoembolization. A significant increase in %ADC value was observed in lesions that responded to chemoembolization.

Relationship of apparent diffusion coefficient to survival for patients with unresectable primary hepatocellular carcinoma after chemoembolization

OBJECTIVES to evaluate the prognostic value of apparent diffusion coefficient (ADC) values from MR diffusion-weighted imaging of unresectable hepatocellular carcinoma after chemoembolization. METHODS our study was proved by our institute and informed consent was obtained from all patients before commencement of the study. Twenty-three patients with unresectable hepatocellular carcinoma were scanned immediately before and after chemoembolization within 24h using conventional anatomical MR imaging and diffusion-weighted imaging, from which ADC values in the lesions were measured. The changes in ADC values after chemoembolization were calculated. The relationship between the lesion ADC and the survival time was analyzed by correlation analysis. The overall cumulative survival was analyzed by the Kaplan-Meier method, and survival curves were compared by the log-rank test. RESULTS the mean overall survival period was (25.0±8.7) months. The pre-chemoembolization lesion ADC value was (1.36±0.249)×10(-3) mm2/s; the change in ADC values post-chemoembolization was (0.377±0.332)×10(-3) mm2/s. There were significant linear regression relation between the survival time and pre-chemoembolization lesion ADC values (r=-0.698, P<0.001) or the changes in ADC value post-chemoembolization (r=0.702, P<0.001). And Log-rank test showed that pre-chemoembolization ADC values (χ2=7.339, P=0.007) or the changes in ADC value post-chemoembolization (χ2=9.820, P=0.002) significantly influenced the overall cumulative survival. CONCLUSION Pre-treatment ADC values as well as changes in ADC values after treatment may provide useful information for predicting survival for patients with unresectable hepatocellular carcinoma.

Aortoesophageal Fistula and Aortic Pseudoaneurysm Induced by Swallowed Fish Bone: A Report of Two Cases

Esophageal perforation caused by accidental swallowing of fish bones can lead to rare complications, such as aortoesophageal fistula accompanied by aortic pseudoaneurysm, which can be fatal if not properly handled. We report two rare cases of aortoesophageal fistula and aortic pseudoaneurysm caused by esophagus perforation after accidental swallow of fish bone; the patients also had purulent mediastinitis and esophagitis. The treatment of aortic pseudoaneurysm was successful in both cases, with one patient undergoing surgical resection and aortic neoplasty and the other patient undergoing endovascular stent graft placement. Long-term antibiotic treatment was administered to both patients after surgery. There were no postsurgical complications, and the patients recovered without incident.

Empirical description of bronchial and nonbronchial arteries with MDCT

PURPOSE We aimed to retrospectively evaluate bronchial and nonbronchial systemic arteries using multi-detector row helical computed tomographic (MDCT) angiography in patients with pulmonary disorders. MATERIALS AND METHODS Thirty-nine patients (24 men, 15 women; mean age, 63.4 years; range, 20-82 years) with congenital and acquired pulmonary disorders of the bronchial and nonbronchial systemic arteries underwent multi-detector row helical computed tomographic angiography of the thorax using a 16-detector row scanner. Each of these patients had experienced an episode of hemoptysis. Computed tomographic angiogram data, which included maximum intensity projections, multiplanar reconstruction, and three-dimensional volume-rendered images, were used to retrospectively analyse the characteristics of the bronchial and nonbronchial systemic arteries. RESULTS We identified a total of 128 bronchial arteries (76 on the right side and 52 on the left) in 39 patients. We detected 42 nonbronchial systemic artery branches, including 19 internal mammary artery branches, 8 subclavian artery branches, 8 inferior phrenic artery branches, 5 intercostal artery branches, 1 thyrocervical trunk branch, and 1 celiac trunk branch. Thirty-five dilated and tortuous nonbronchial systemic arteries entered into the lung parenchyma and extended down to the lesions. Every case, except the one case of sequestration, was associated with pleural thickening where the vascular structures passed through the extrapleural fat. CONCLUSIONS The variations in both the bronchial artery anatomy and the location and type of the nonbronchial arteries were great. Nonbronchial arteries may be a significant source of hemoptysis. MDCT angiography can be used to detect detailed anatomical information about the origins and courses of bronchial and nonbronchial systemic arteries and their pathophysiologic features.

Clinical data and CT findings of pulmonary infection caused by different pathogens after kidney transplantation

PURPOSE The overall objective was to review clinical data and CT findings of pulmonary infection caused by different pathogens after kidney transplantation in an attempt to help early clinical qualitative diagnosis. MATERIALS AND METHODS 446 cases of clinically confirmed pulmonary infection after kidney transplantation in recent 10 years were evaluated with respect to the time of occurrence and 89 cases with complete CT data and pathogenic diagnosis were further analyzed for pathogen types and CT manifestations. Statistical analysis was performed using Fishers exact test. RESULTS Pulmonary infection reached the peak in 3 months after transplantation. Bacterial infection and mixed infection were predominant between 1 and 6 months. And most tuberculosis occurred after one year. Bacterial (38.2%) and mixed infections (38.2%) were the common types. The next was fungal infection, tuberculosis and viral infection (10.1%, 7.9% and 5.6%, respectively). CT manifestations of pulmonary infections after kidney transplantation were diverse and complex, lacking characteristic signs. CONCLUSION More than 3/4 of pulmonary infections after kidney transplantation can be attributed to bacteria and mixed pathogens. The combination of time course, clinical data and CT manifestations plays an important role in the early clinical qualitative diagnosis.

Demonstration of pulmonary perfusion heterogeneity induced by gravity and lung inflation using arterial spin labeling

OBJECTIVE To evaluate the effect of gravity and lung inflation on pulmonary perfusion heterogeneity in human lung using an arterial spin labeling (ASL) sequence called flow sensitive alternating inversion recovery (FAIR). MATERIALS AND METHODS Magnetic resonance imaging of lung perfusion using arterial spin labeling sequence was performed in supine position in ten healthy volunteers on a 1.5T whole body scanner (GE Healthcare). Five coronal slices at an interval of 3cm from dorsal to ventral (labeled as P3, P6, P9, P12, P15, sequently) were obtained when the volunteers performed breath holding on end expiration and the relative pulmonary blood flow (rPBF) was measured. Then, another coronal perfusion-weighted image of P3 slice was obtained on end inspiration. Tagging efficiency of pulmonary parenchyma with IR (DeltaSI), rPBF and area of the P3 slice were analyzed. RESULTS (1) Along the direction of gravity, a gradient was visually perceived as a vertical increase in rPBF. There were significant statistic differences in rPBF between any two coronal planes except that between P12 and P15. In supine position, regression coefficients of right and left lung were -4.98 and -5.16, respectively. This means that rPBF decreased 4.98 (right) and 5.16 (left) for each centimeter above the dorsal. No statistical difference was seen between ROIs placed along iso-gravitational plane. (2) For a same slice, there were significant statistic differences in DeltaSI, rPBF and area at different respiratory phases (P<0.05). Greater DeltaSI and more perfusion were observed on end expiration than on end inspiration. The area was larger on end inspiration than on end expiration. CONCLUSION Both gravity and respiratory phase are important determinants of pulmonary perfusion heterogeneity. FAIR is sensitive to demonstrate gravity- and respiratory phase-dependent differences in lung perfusion. Positioning the patient so that the area of interest is down-gravity and asking patient to hold breath on end expiration may help in detection of perfusion defects.

Diagnosis of arterial sequestration using multidetector CT angiography

BACKGROUND Arterial sequestration is a rare congenital disorder. The diagnostic evaluation of this condition using multidetector computerized tomography (MDCT) has not been described previously. The purpose of this study was to describe the characteristic features of this disorder and to assess the use of MDCT in visualizing the characteristic anatomic features. METHODS We retrospectively reviewed the records of seven patients with anomalous systemic blood supply to left lower lobe of the lung. All the patients had undergone MDCT angiography. To evaluate the lung parenchyma, bronchial branching pattern, and vascular anatomy, four series of images were systematically reconstructed as follows: contiguous transverse CT scans viewed at mediastinal and pulmonary window settings, oblique coronal and sagittal maximum intensity projections (MIP), multiplanar reconstruction (MPR), and three-dimensional volume-rendered images (VR) of airway and thoracic vascular structures. RESULTS All 7 cases had isolated and tortuous arterial anatomy from the descending thoracic aorta to the basal segment of the left lower lobe; however, variable distribution of branches was observed. Characteristic findings of anomalous systemic arterial (ASA) supply were distinct from those seen in other pulmonary sequestration syndromes and were well visualized by the use of noninvasive MDCT. CONCLUSION Complex CT findings allow clear imaging of arterial sequestration and the ASA blood supply; MDCT angiography has demonstrated its value and accuracy in diagnosing this condition, obviating the use of digital subtraction angiography and magnetic resonance angiography for the diagnosis of arterial sequestration.

Comparison of lung lesion biopsies between low-dose CT-guided and conventional CT-guided techniques

Background The low-dose computed tomography (CT) technique has been widely used because it decreases the potential risk of radiation exposure, as well as enabling low-dose CT-guided lung lesion biopsy. However, uncertainties remain regarding diagnostic accuracy, radiation dose, complication rate, and image quality. Purpose To compare the diagnostic accuracy, radiation dose, complication rate, and image quality of lung lesion biopsy between conventional CT-guided and low-dose CT-guided techniques. Material and Methods A total of 90 patients were prospectively enrolled and randomized into two groups (group A: 120 kv; 200 mA; thickness, 2.0 mm; pitch, 16 mm/rot; n = 44; group B: 120 kv;10 mA; thickness, 2.0 mm; pitch, 23 mm/rot; n = 46). Sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), radiation dose, image quality, and complication rate were compared. All variables between the two groups were analyzed using chi-square and Students t tests. A P value of < 0.05 was considered statistically significant. Results The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) for diagnosing lung lesions were 96.88%, 100%, 97.5%, 100%, and 88.89% in group A, respectively. In group B, the values were 96.67%, 100%, 97.5%, 100%, and 90.91%, respectively (P > 0.05). The mean weighted CT dose index (CTDIw) and dose-length product (DLP) were 29.29 ± 3.93 mGy and 211.74 ± 37.89 mGy*cm in group A and 1.55 ± 0.15 mGy and 10.98 ± 1.56 mGy*cm in group B (P < 0.001). Image quality satisfied the need for a coaxial biopsy. Complications in group A and group B were observed in 27.28% and 23.91% of the patients, respectively (P > 0.05). Conclusion Compared to conventional CT-guided biopsies, lung lesion biopsies guided by the low-dose CT biopsy protocol showed dramatically lower CTDIw and DLP levels. In contrast, the diagnostic yield of the procedures did not differ significantly, which is a recommended technique in certain populations.

Prognostic Value of Tissue Inhibitor of Metalloproteinase-2 Expression in Patients with Non–Small Cell Lung Cancer: A Systematic Review and Meta-Analysis

Background and Objectives Tissue inhibitor of metalloproteinase-2 (TIMP-2) is a small secretory glycoprotein with anti–matrix metalloproteinase activity. Data on the value of TIMP-2 as a prognostic factor in non–small cell lung cancer (NSCLC) are discordant and remain controversial. A systematic review and meta-analysis was performed to explore this issue. Methods We identified the relevant literature by searching the PubMed, EMBASE, Web of Science, China National Knowledge Infrastructure, SinoMed, and Wanfang Data databases (search terms: “non-small cell lung cancer” or “NSCLC” or “Lung Carcinoma, Non-Small-Cell”, “Tissue Inhibitor of Metalloproteinase-2” or “TIMP-2”, and “prognosis” or “prognostic” or “survive”) for updates prior to March 1, 2014. The pooled hazard ratio (HR) of overall survival with a 95% confidence interval (95% CI) was used to evaluate the strength of the association between positive TIMP-2 expression and survival in patients with NSCLC. Results We included 12 studies in our systematic review; five studies involving 399 patients with NSCLC were meta-analyzed. The pooled HR of all included patients was 0.57 (95% CI: 0.43–0.77), and the HRs of subgroup analysis according to stage (I–IV), testing method (immunohistochemistry) and high TIMP-2 expression percentage (<50%) were 0.63 (95% CI: 0.43–0.92), 0.55 (95% CI: 0.41–0.74), and 0.50 (95% CI: 0.28–0.88), respectively. These data suggested that high TIMP-2 expression is associated with favorable prognosis in NSCLC. The meta-analysis did not reveal heterogeneity or publication bias. Conclusions TIMP-2 expression indicates favorable prognosis in patients with NSCLC; as a protective factor, it could help predict outcome and may guide clinical therapy in the future.

Evaluation of early imaging response after chemoembolization of hepatocellular carcinoma by phosphorus-31 magnetic resonance spectroscopy-initial experience.

PURPOSE To evaluate the value of phosphorus-31 ((31)P) magnetic resonance (MR) spectroscopy in early monitoring and predicting the response of hepatocellular carcinoma (HCC) after chemoembolization. MATERIALS AND METHODS The authors evaluated 17 HCC target tumors with (31)P MR spectroscopy before and after chemoembolization. Alterations of phosphorus metabolism were analyzed by the MR spectroscopy analysis package (SAGE 7.0; GE Medical Systems, Milwaukee, Wisconsin). Ratios of the peak areas of phosphomonoesters (PME), phosphodiesters (PDE), and inorganic phosphate (Pi) to the peak area of nucleoside triphosphates (NTP) or the total phosphorus content (TPC) were measured. The changes in these ratios after chemoembolization were calculated from baseline (before chemoembolization). The therapy effect was assessed by computed tomography (CT) or MR imaging 4 weeks after chemoembolization. The ability of phosphorus metabolism in monitoring therapy effect was evaluated by using receiver operating characteristic analysis. RESULTS Decreases in the PDE/NTP ratio (Wilcoxon signed rank test, P = .024) and the PDE/TPC ratio (Wilcoxon signed rank test, P = .011) that occurred after treatment were the most remarkable changes secondary to chemoembolization. Of the 17 lesions evaluated quantitatively, at the follow-up examination done 4 weeks after chemoembolization, 12 lesions were responsive to chemoembolization, whereas 5 were not. In the responsive group, the PDE/TPC ratio (median 24.15% vs 13.15%; P = .008) was significantly decreased after chemoembolization, whereas the NTP/TPC ratio (median 37.35% vs 49.9%; P = .024) was significantly increased. In the nonresponsive group, phosphorus metabolism had no significant changes after treatment. Results from the receiver operating curve analysis showed that the threshold percentage change of the PDE/NTP (%PDE/NTP) value was -1.25% with 91.7% sensitivity and 100% specificity for identifying tumor response to chemoembolization, and the threshold percentage change of the NTP/TPC (%NTP/NTP) value was 15.3% with 75% sensitivity and 100% specificity. CONCLUSIONS Phosphorus-31 MR spectroscopy is a promising technique for the noninvasive assessment of HCC response to chemoembolization. Future studies are necessary to confirm these preliminary results.