Zilai Pan

Value of multidetector-row computed tomography in the preoperative T and N staging of gastric carcinoma: A large-scale Chinese study

To investigate the value of multidetector‐row computed tomography (MDCT) in the preoperative T and N staging of gastric carcinoma and to further investigate the clinicopathological factors affecting the diagnostic accuracy.

Gastric Cancer Staging with Dual Energy Spectral CT Imaging

Purpose To evaluate the clinical utility of dual energy spectral CT (DEsCT) in staging and characterizing gastric cancers. Materials and Methods 96 patients suspected of gastric cancers underwent dual-phasic scans (arterial phase (AP) and portal venous phase (PP)) with DEsCT mode. Three types of images were reconstructed for analysis: conventional polychromatic images, material-decomposition images, and monochromatic image sets with photon energies from 40 to 140 keV. The polychromatic and monochromatic images were compared in TNM staging. The iodine concentrations in the lesions and lymph nodes were measured on the iodine-based material-decomposition images. These values were further normalized against that in aorta and the normalized iodine concentration (nIC) values were statistically compared. Results were correlated with pathological findings. Results The overall accuracies for T, N and M staging were (81.2%, 80.0%, and 98.9%) and (73.9%, 75.0%, and 98.9%) determined with the monochromatic images and the conventional kVp images, respectively. The improvement of the accuracy in N-staging using the keV images was statistically significant (p<0.05). The nIC values between the differentiated and undifferentiated carcinoma and between metastatic and non-metastatic lymph nodes were significantly different both in AP (p = 0.02, respectively) and PP (p = 0.01, respectively). Among metastatic lymph nodes, nIC of the signet-ring cell carcinoma were significantly different from the adenocarcinoma (p = 0.02) and mucinous adenocarcinoma (p = 0.01) in PP. Conclusion The monochromatic images obtained with DEsCT may be used to improve the N-staging accuracy. Quantitative iodine concentration measurements may be helpful for differentiating between differentiated and undifferentiated gastric carcinoma, and between metastatic and non-metastatic lymph nodes.

Rectal cancer: 3D dynamic contrast-enhanced MRI; correlation with microvascular density and clinicopathological features

PurposeThe primary aim of this prospective study was to evaluate the relationship between three-dimensional dynamic contrast-enhanced magnetic resonance (3D-DCE-MR) imaging parameters and clinicopathological features of rectal cancer and assess their potential as new radiological prognostic predictors.Materials and methodsThree-dimensional DCE-MR was performed on 26 cases of pathologically proved rectal adenocarcinoma 1 week prior to operation. Data were analysed to calculate transfer constant (Ktrans), leakage space (Ve) and rate constant (Kep) of both tumour and normal rectal wall. Microvessel density (MVD) was evaluated by immunohistochemical staining of surgical specimens. All findings were analysed prospectively and correlated with tumour/node/metastasis (TNM) staging, Dukes staging, histological grading, presence of lymph node metastasis, serosal involvement and MVD.ResultsMean Ktrans, Ve and Kep for tumours were as follows: Ktrans 7.123±3.850/min, Ve 14.2±3.0%, Kep 49.446±20.404/min, revealing the significant difference between the tumour and normal rectal wall (p=0.001). There was a significant difference for Ktrans not only between patients with and without lymphatic involvement (p=0.000), but also among Dukes staging (p=0.04) and pTNM staging (p=0.03). Kep showed moderate correlation with TNM stages (r=0.479, p=0.02). Ve and MVD revealed no significant correlation with the clinicopathological findings described above (p>0.05).ConclusionOwing to the moderate and strong relationship between Ktrans and clinicopathological elements, Ktrans might be the prognostic indicator of rectal cancer. Threedimensional DCE high-resolution MR imaging provides a competing opportunity to assess contrast kinetics.RiassuntoObiettivoL’obiettivo principale dello studio è valutare la correlazione tra i parametri ottenuti mediante studio dinamico post-contrasto in risonanza magnetica tridimensionale (3D-DCE-MRI) te le caratteristiche clinico-patologiche del carcinoma rettale e definire le potenzialità di tali parametri di imaging come nuovi fattori prognostici.Materiali e metodiVentisei pazienti affetti da adenocarcinoma del retto, confermato istologicamente, sono stati sottoposti a 3D-DCE-MRI una settimana prima dell’intervento chirurgico. A livello del tessuto tumorale e della parete rettale indenne sono stati calcolati i seguenti parametri: costante di transito (Ktrans), la percentuale dello spazio di distribuzione extravascolare extracellulare — leakage space — (Ve) te la rate constant (Kep). La densità microvascolare è stata stimata mediante analisi immunoistochimica su sezioni del pezzo operatorio. Le analisi sono state condotte in modo prospettico ed i risultati ottenuti correlati alle seguenti caratteristiche clinico-patologiche: stadio di malattia secondo i sistemi TNM e Dukes, grading istologico, presenza di linfonodi metastatici, coinvolgimento della tunica sierosa e densità microvascolare.RisultatiDall’analisi del tessuto tumorale sono stati ottenuti i seguenti valori medi di Ktrans, Ve e Kep: Ktrans 7,123±3,850/min, Ve 14,2±3,0 %, Kep 49,446±20,404/min con differenza statisticamente significativa (p=0,001) rispetto ai valori relativi alla parete rettale indenne. Il valore della costante di transito (Ktrans) è risultato significativamente diverso in caso di presenza o meno di coinvolgimento linfonodale di malattia (p=0,000) e nei diversi stadi sia secondo la classificazione di Dukes (p=0.04) che secondo il pTNM (p=0,03). Moderata correlazione è stata dimostrata tra il parametro Kep e gli stadi TNM (r=0,479, p=0,02). Nessuna correlazione statisticamente significativa è stata stabilita per i parametri Ve e MVD (p>0,05).ConclusioniLa stretta correlazione dimostrata tra i valori di Ktrans e le caratteristiche clinico-patologiche prese in esame rende tale parametro un utile indice prognostico per l’adenocarcinoma del retto. Lo studio dinamico mediante risonanza magnetica 3D rappresenta un valido strumento diagnostico per la valutazione della vascolarizzazione tumorale.

Evaluation of dual energy spectral CT in differentiating metastatic from non-metastatic lymph nodes in rectal cancer: Initial experience.

OBJECTIVES To investigate the value of dual energy spectral CT (DEsCT) imaging in differentiating metastatic from non-metastatic lymph nodes in rectal cancer. METHODS Fifty-five patients with rectal cancer underwent the arterial phase (AP) and portal venous phase (PP) contrast-enhanced DEsCT imaging. The virtual monochromatic images and iodine-based material decomposition images derived from DEsCT imaging were interpreted for lymph nodes (LNs) measurement. The short axis diameter and the normalized iodine concentration (nIC) of metastatic and non-metastatic LNs were measured. The two-sample t test was used to compare the short axis diameters and nIC values of metastatic and non-metastatic LNs. ROC analysis was performed to assess the diagnostic performance. RESULTS One hundred and fifty two LNs including 92 non-metastatic LNs and 60 metastatic LNs were matched using the radiological-pathological correlation. The mean short axis diameter of metastatic LNs was significantly larger than that of the non-metastatic LNs (7.28±2.28mm vs. 4.90±1.64mm, P<0.001). The mean nIC value for metastatic LNs was significantly lower than that of non-metastatic LNs (0.24±0.08 vs. 0.34±0.21, P=0.001 in AP; 0.47±0.18 vs. 0.64±0.17, P<0.001 in PP). Combining nIC (PP) with the short axis diameter, the overall accuracy could be improved to 82.9%. CONCLUSIONS With the combination of nIC value in PP and conventional size criterion, dual energy spectral imaging may be used to differentiate metastatic from non-metastatic lymph nodes in rectal cancer.

Diffusion Kurtosis Imaging Study of Rectal Adenocarcinoma Associated with Histopathologic Prognostic Factors: Preliminary Findings

Purpose To determine the correlation between diffusion kurtosis imaging (DKI)-derived parameters and prognostic factors for rectal adenocarcinoma. Materials and Methods This study was approved by the local institute review board, and written informed consent was obtained from each patient. Data from 56 patients (median age, 59.5 years; age range, 31-86 years) with rectal adenocarcinoma between April 2014 and September 2015 were involved in this prospective study. DKI (b = 0, 700, 1400, and 2100 sec/mm2) and conventional diffusion-weighted imaging (b = 0, 1000 sec/mm2) were performed. Kurtosis and diffusivity from DKI and apparent diffusion coefficients (ADCs) from diffusion-weighted imaging were measured by two radiologists. Student t test, receiver operating characteristic curves, and Spearman correlation were used for statistical analysis. Results Kurtosis was significantly higher in high-grade than in low-grade rectal adenocarcinomas on the basis of both the number of poorly differentiated clusters (PDCs) (1.136 ± 0.086 vs 0.988 ± 0.060, P < .05) and World Health Organization (WHO) grades (1.103 ± 0.086 [standard deviation] vs 1.034 ± 0.103, P < .05). In PDC grading, the diffusivity and ADC were significantly lower in high-grade tumors than in low-grade tumors (1.187 ± 0.150 vs 1.306 ± 0.129 and 1.020 ± 0.113 vs 1.108 ± 0.097, respectively; P < .05) and showed similar correlations with histologic grades (r = -0.486 and r = -0.406, respectively; P > .05). Compared with both diffusivity and ADC, kurtosis showed significantly higher sensitivity (83.3% [20 of 24] vs 70.8% [17 of 24] and 70.8% [17 of 24], respectively) and specificity (96.8% [31 of 32] vs 84.4% [24 of 32] and 81.3% [26 of 32], respectively). Kurtosis showed a better correlation with PDC grades than with WHO grades (r = 0.797 vs r = 0.293, P < .05). Kurtosis was significantly higher in pN1-2 than in pN0 tumors (1.086 ± 0.103 vs 1.009 ± 0.086, P < .05). Conclusion Kurtosis derived from DKI demonstrated a higher correlation with histologic grades compared with diffusivity and ADC. It also showed better performance in differentiating between high- and low-grade rectal adenocarcinomas and between pN1-2 and pN0 tumors.

Evaluation of coronary artery in-stent restenosis with prospectively ECG-triggered axial CT angiography versus retrospective technique: a phantom study

PurposeThis study compared the performance of prospectively electrocardiographically (ECG)-triggered axial computed tomography (CT) angiography with retrospective technique in evaluating coronary artery stent restenosis by 64-slice CT.Materials and methodsA pulsing cardiac phantom with artificial coronary artery in-stent restenosis was examined by CT angiography with different types of scan modes. The visibility of in-stent restenosis was evaluated with a three-point score. Artificial lumen narrowing [(inner stent diameter-measured lumen diameter)/inner stent diameter], lumen attenuation increase ratio [(in-stent attenuation-coronary artery lumen attenuation)/coronary artery lumen attenuation], measurement error of restenosis percent [(known restenosis percent-measured restenosis percent)/known restenosis percent] and imaging noise were analysed.ResultsProspective acquisition showed better visibility than retrospective acquisition (p<0.05): 61% of in-stent restenoses had good visibility on the prospective acquisition compared with 17% on the retrospective acquisition. Furthermore, the effective dose was 6.2±0.3 mSv for the prospective technique compared with 18.8±1.1 mSv for the retrospective technique. Artificial lumen narrowing (mean 40%), lumen attenuation increase ratio (mean 33%) and measurement error of restenosis percent were not different between types of CT acquisitions.ConclusionsCompared with the traditional retrospective technique, prospective coronary CT angiography offers improved image quality and reduces effective radiation dose in evaluating in-stent restenosis.RiassuntoObiettivoQuesto studio ha confrontato la performance dell’angio TC 64 strati ECG-sincronizzata prospettica assiale con la tecnica retrospettica nella valutazione della restenosi intrastent delle arterie coronarie.Materiali e metodiE’ stato esaminato mediante angio-TC un prototipo di fantoccio cardiaco con stenosi intrastent delle arterie coronarie artificiali con differenti tipi di scansione. Il riconoscimento della restenosi intrastent è stato valutato con un punteggio a tre valori. Sono stati analizzati il lume artificiale stenotico, [(diametro interno dello stent — diametro del lume misurato)/ diametro interno dello stent], l’incremento percentuale di attenuazione del lume [(attenuazione intrastent — attenuazione del lume dell’arterie coronarie)/ attenuazione del lume dell’arterie coronarie], l’errore di misura della percentuale di restenosi [(percentuale di restenosi nota — percentuale di restenosi misurata)/ percentuale di restenosi nota] e il rumore dell’immagine.RisultatiL’acquisizione prospettiva ha dimostrato una migliore identificazione rispetto all’acquisizione retrospettiva (p<0,05): il 61% delle restenosi intrastent ha dimostrato una buona identificazione nelle acquisizioni prospettiche a fronte del 17% ottenuto con le acquisizioni retrospettiche. Inoltre, la dose effettiva è risultata 6,2±0,3 mSv per la tecnica prospettiva a confronto con 18,8±1,1 mSv per la tecnica retrospettiva. Il lume artificiale stenotico (media del 40%), il rapporto di incremento di attenuazione del lume (media del 33%), e l’errore di misura di restenosi in percentuale non erano differenti tra i diversi tipi di acquisizioni TC.ConclusioniA confronto con la tecnica retrospettiva tradizionale, l’angio TC conorarica prospettiva offre una migliore qualità delle immagini e riduce la dose di radiazioni effettiva nella valutazione della restenosi intrastent.

Gastric Cancer: Preoperative TNM Staging With Individually Adjusted Computed Tomography Scanning Phase.

Objective The aim of this study was to evaluate test bolus scan technology on preoperative diagnostic performance, vascular enhancement, and artery visualization for gastric cancer. Methods The institutional review board approved this study. Fifty-four patients in protocol 1 were resigned to a fixed delay time scan method, and their images were obtained in the late arterial phase (AP) and portal venous phase (PP), with start delays of 40 and 70 seconds, respectively. Fifty-six patients in protocol 2 had undergone the test bolus method first and received the time to peak enhancement of the aorta. Their images were obtained in the AP and PP with start delays in the time to peak enhancement and 20 seconds after the AP, respectively. Two radiologists performed consensus interpretation of the preoperative TNM staging, vascular enhancement, tumor contrast-to-noise ratio (CNR) and artery visualization between the 2 protocols. Results There is no significant difference in the T, N, and M staging diagnostic accuracy between the protocols (P = 0.41, P > 0.99, and P = 0.34, respectively). For serosa-negative (T1, T2, and T3) tumors, the diagnostic accuracy obtained with protocol 2 was superior to that obtained with protocol 1 (P = 0.04). Protocol 2 was superior for perigastric vessel enhancement (left gastric artery, right gastroepiploic artery, and splenic artery; P < 0.001, P < 0.001, and P = 0.001, respectively). The stomach-to-tumor CNR during the PP of protocol 2 was significantly higher than that during either the AP or PP of protocol 1 (P = 0.004 and P = 0.001, respectively). The mean rankings of the artery visualization were significantly higher with protocol 2 than with protocol 1 (P < 0.001). Conclusions The dual-phase scan with test bolus technology could improve the tumor CNR and had high staging accuracy for serosa-negative tumors as well as high perigastric artery enhancement, yielding satisfactory artery visualization for diagnosis.

Stomach Virtual Non-Enhanced CT with Second-Generation, Dual-Energy CT: A Preliminary Study

Objectives To compare the true non-enhanced (TNE) and virtual non-enhanced (VNE) data sets in patients who underwent gastric preoperative dual-energy CT (DECT) and to evaluate potential radiation dose reduction by omitting a TNE scan. Methods A total of 74 patients underwent gastric DECT. The mean CT values, length, image quality and effective radiation doses for VNE and TNE images were compared. Results There was no statistical difference in maximal thickness of gastric tumors and maximal diameter of enlarged lymph nodes among the TNE and VNE images (P>0.05). The mean CT value differences between TNE and VNE were statistically significant for all tissue types, except for aorta attenuation measurements (P<0.05), but the absolute differences were under 10 HU. Lower noise was found for VNE images than TNE images (P<0.01). Image quality of VNE was diagnostic but lower than that of TNE (P<0.01). The dose reduction achieved by omitting the TNE acquisition was 21.40±4.44%. Conclusion VNE scan may potentially replace TNE as part of a multi-phase gastric preoperative staging imaging protocol with consequent saving in radiation dose.

Evaluation of Effects of TGF-β1 Inhibition on Gastric Cancer in Nude Mice by Diffusion Kurtosis Imaging and In-Line X-ray Phase Contrast Imaging With Sequential Histology: Shi et al.: TGF-β1 Inhibition by DKI and ILXPCI

Accurate and complete response evaluation after treatment is important to implement individualized therapy for gastric cancer.