Assessment of pancreatic adenocarcinoma: Use of low-dose whole pancreatic CT perfusion and individualized dual-energy CT scanning.

INTRODUCTION: The objective of this study was to investigate the value of low-dose whole pancreatic computed tomography (CT) perfusion integrated with individualized dual-energy CT (DECT) scanning in the diagnosis of pancreatic adenocarcinoma. METHODS: Twenty patients with pancreatic adenocarcinoma underwent pancreatic CT perfusion as well as individualized dual-phase DECT pancreatic scans. Perfusion characteristics of non-tumourous pancreatic parenchyma and pancreatic adenocarcinoma were analysed. Weighted-average 120 kVp images and the optimal monoenergetic images in dual phase were reconstructed and the contrast noise ratio (CNR) of pancreas-to-tumour were compared. RESULTS: There were significant difference on blood flow as well as blood volume between pancreatic adenocarcinoma and the non-tumourous pancreatic parenchyma (P < 0.05), whereas no difference on permeability (P > 0.05). CNRs of pancreas-to-tumour in individualized pancreatic phase were significantly higher than those in venous phase (P < 0.05), and CNRs of optimal monoenergetic images were higher than those on weighted-average 120 kVp images (P < 0.05) in both phase. Total effective radiation dose of CT examination was around 9.32-13.75 mSv. CONCLUSIONS: Low-dose whole pancreatic CT perfusion can provide functional information, and the individualized pancreatic phase DECT scan is the optimal method for detecting pancreatic adenocarcinomas. The integration of the two techniques has great value in clinical application.

Diagnostic Value of Prospective Electrocardiogram-triggered Dual-source Computed Tomography Angiography for Infants and Children with Interrupted Aortic Arch.

BACKGROUND: Accurate assessment of intra- as well as extra-cardiac malformations and radiation dosage concerns are especially crucial to infants and children with interrupted aortic arch (IAA). The purpose of this study is to investigate the value of prospective electrocardiogram (ECG)-triggered dual-source computed tomography (DSCT) angiography with low-dosage techniques in the diagnosis of IAA. METHODS: Thirteen patients with suspected IAA underwent prospective ECG-triggered DSCT scan and transthoracic echocardiography (TTE). Surgery was performed on all the patients. A five-point scale was used to assess image quality. The diagnostic accuracy of DSCT angiography and TTE was compared with the surgical findings as the reference standard. A nonparametric Chi-square test was used for comparative analysis. P <0.05 was considered as a significant difference. The mean effective radiation dose (ED) was calculated. RESULTS: Diagnostic DSCT images were obtained for all the patients. Thirteen IAA cases with 60 separate cardiovascular anomalies were confirmed by surgical findings. The diagnostic accuracy of TTE and DSCT for total cardiovascular malformations was 93.7% and 97.9% (P > 0.05), and that for extra-cardiac vascular malformations was 92.3% and 99.0% (P < 0.05), respectively. The mean score of image quality was 3.77 ± 0.83. The mean ED was 0.30 ± 0.04 mSv (range from 0.23 mSv to 0.39 mSv). CONCLUSIONS: In infants and children with IAA, prospective ECG-triggered DSCT with low radiation exposure and high diagnostic efficiency has higher accuracy compared to TTE in detection of extra-cardiac vascular anomalies.

Low-dose whole organ CT perfusion of the pancreas: preliminary study.

OBJECTIVES: To investigate the feasibility of low-dose whole pancreas CT perfusion in the clinical practice. METHODS: Sixty-one patients suspected pancreatic disease underwent low-dose whole pancreas CT perfusion scan (by body weight, group A: 70 kV, 120 mAs; group B: 80 kV, 100 mAs) and the individualized pancreas scan. Forty-six patients were enrolled. Perfusion characteristics, such as, blood flow, blood volume and permeability, were analyzed. The effective radiation dose of the whole pancreas CT perfusion and the total CT scan protocol were recorded. CT findings were histologically confirmed by surgical intervention or diagnostic puncture. RESULTS: Of the 46 cases, 33 were pancreatic adenocarcinoma, 5 were solid-pseudo-papillary tumors of pancreas, 8 cases of pancreatic endocrine tumors on the perfusion study. There was significant interobserver agreement on the measurement of normal pancreatic CT perfusion parameters of group A (n = 28)and group B (n = 18), respectively (p > 0.05). For the normal pancreas, there was no significant difference on CT perfusion parameters between group A and group B (p > 0.05). There were significant differences on blood flow as well as blood volume between the pancreatic adenocarcinomas and the normal pancreas (p < 0.001), whereas no difference on the permeability (p > 0.05). The time to peak of the normal pancreas is 28.94 ± 4.37 s (range from 24 to 38 s). Different pancreatic tumors had different types of time attenuation curve (TAC). TACs were different between pancreatic adenocarcinomas and normal pancreas. The effective radiation dose of the whole pancreas CT perfusion of Group A and Group B were 3.60 and 4.88 mSv (DLP 246 and 325 mGy cm), respectively, and the total radiation dose was around 8.01-16.22 mSv. CONCLUSIONS: Low-dose whole pancreatic CT perfusion can effectively reduce radiation dose, and provide the best phase for the individualized pancreas scan, which has great value in the clinical practice.

MDCT angiography to evaluate the therapeutic effect of PTVE for esophageal varices.

AIM: To evaluate the role of multi-detector row computed tomography (MDCT) angiography for assessing the therapeutic effects of percutaneous transhepatic variceal embolization (PTVE) for esophageal varices (EVs). METHODS: The subjects of this prospective study were 156 patients who underwent PTVE with cyanoacrylate for EVs. Patients were divided into three groups according to the filling range of cyanoacrylate in EVs and their feeding vessels: (1) group A, complete obliteration, with at least 3 cm of the lower EVs and peri-/EVs, as well as the adventitial plexus of the gastric cardia and fundus filled with cyanoacrylate; (2) group B, partial obliteration of varices surrounding the gastric cardia and fundus, with their feeding vessels being obliterated with cyanoacrylate, but without reaching lower EVs; and (3) group C, trunk obliteration, with the main branch of the left gastric vein being filled with cyanoacrylate, but without reaching varices surrounding the gastric cardia or fundus. We performed chart reviews and a prospective follow-up using MDCT images, angiography, and gastrointestinal endoscopy. RESULTS: The median follow-up period was 34 mo. The rate of eradication of varices for all patients was 56.4% (88/156) and the rate of relapse was 31.3% (41/131). The rates of variceal eradication at 1, 3, and 5 years after PTVE were 90.2%, 84.1% and 81.7%, respectively, for the complete group; 61.2%, 49% and 42.9%, respectively, for the partial group; with no varices disappearing in the trunk group. The relapse-free rates at 1, 3 and 5 years after PTVE were 91.5%, 86.6% and 81.7%, respectively, for the complete group; 71.1%, 55.6% and 51.1%, respectively, for the partial group; and all EVs recurred in the trunk group. Kaplan-Meier analysis showed P values of 0.000 and 0.000, and odds ratios of 3.824 and 3.603 for the rates of variceal eradication and relapse free rates, respectively. Cyanoacrylate in EVs disappeared with time, but those in the EVs and other feeding vessels remained permanently in the vessels without a decrease with time, which is important for the continued obliteration of the feeding vessels and prevention of EV relapse. CONCLUSION: MDCT provides excellent visualization of cyanoacrylate obliteration in EV and their feeding veins after PTVE. It confirms that PTVE is effective for treating EVs.

A new classification of duplex kidney based on kidney morphology and management.

BACKGROUND: The initial classic classification of duplex kidney into complete (two ureters) and incomplete ("Y" shaped ureter) types are based on the ureter status. At the meantime, the features of the upper and lower moieties of duplex kidney were very crucial for appropriate procedure of hemi-nephrectomy, which was most commonly used for addressing the issues caused by a duplex kidney; and recently more applications of laparoscopy were used. In this study, we aimed prudently to propose a new classification based on the features of the upper and lower moieties of duplex kidney. METHODS: Sixty-five children with 83 duplex kidneys were reviewed retrospectively. Based on kidney morphology found in CT urography and surgical findings, duplex kidney was classified into five types. RESULTS: The first was the appendant type (36/83) and its feature was that the mini upper moiety was located on top of the lower one, with a visualized shallow groove between them. The ureter was dilated with an ectopic orifice or ureterocele. The second was the embedded type (13/83), the feature of which was that mini upper moiety located in the interior top of the lower one within the same capsule. The upper ureter was dilated with an ectopic orifice or ureterocele. The third was the hydronephrosis type (12/83). The severe hydronephrotic upper moiety was almost as big as the lower moiety. The upper ureter was severely dilated and circuitous with an ectopic orifice. The forth was the dual-poor type (2/83). The two moieties were all very small with "Y" shaped ureters and ectopic orifices. The last was the dual-well type (20/83). The upper moiety was almost the same size as the lower one, without apparent dilation of "Y" shaped or double ureters. CONCLUSION: Based on kidney morphology, duplex kidney can be mainly classified into five types which can be depicted by CT urography prior to management and can provide an aid in selecting a successful course of surgical correction.

Intravenous leiomyomatosis: CT findings.

Intravenous leiomyomatosis (IVL) is a rare smooth muscle tumor. Although IVL is histologically benign, it might be aggressive in its behavior and can grow into pelvic veins and the inferior vena cava (IVC) extending into the heart chambers and pulmonary vasculature. Occasionally, it was found to have lung metastasis. We describe four cases of IVL in the IVC with a history of hysterectomy for uterine leiomyoma, one extending into the left renal vein and three growing into the right heart chamber. We report the computed tomography (CT) findings in the four cases and briefly discuss the CT features of IVL in order to help making accurately preoperative diagnosis and improve the rate of surgical resection and survival.