CT depiction of small arteries in the pancreatic head: assessment using coronal reformatted images with 16-channel multislice CT

Progress in the application of dual-energy CT in pancreatic diseases

Pancreatic diseases are difficult to diagnose due to their insidious onset and complex pathophysiological developmental characteristics. In recent years, dual-energy computed tomography (DECT) imaging technology has rapidly advanced. DECT can quantitatively extract and analyze medical imaging features and establish a correlation between these features and clinical results. This feature enables the adoption of more modern and accurate clinical diagnosis and treatment strategies for patients with pancreatic diseases so as to achieve the goal of non-invasive, low-cost, and personalized treatment. The purpose of this review is to elaborate on the application of DECT for the diagnosis, biological characterization, and prediction of the survival of patients with pancreatic diseases (including pancreatitis, pancreatic cancer, pancreatic cystic tumor, pancreatic neuroendocrine tumor, and pancreatic injury) and to summarize its current limitations and future research prospects.

The dorsal pancreatic artery: A meta-analysis with clinical correlations

BACKGROUND/OBJECTIVES

The dorsal pancreatic artery is the main artery of the body and tail of the pancreas. Its origin and branching is highly variable. The aim of this study was to perform a meta-analysis to generate pooled prevalence data on the presence and origin of the dorsal pancreatic artery. Clinically important aspects of the dorsal pancreatic artery were summarised during the literature review.

METHODS

Major medical databases were searched. Data on the presence and point of origin of the dorsal pancreatic artery were extracted and quantitatively synthesised. The obtained data of anatomical based studies and computed tomography based studies were statistically analysed.

RESULTS

In total, 30 studies, comprising 2322 anatomical and computed tomography based cases were included. The dorsal pancreatic artery was present in 95.8% of cases. It originated from the splenic artery in 37.6% of cases, common hepatic artery in 18.3% of cases, coeliac trunk in 11.9% of cases and the superior mesenteric artery in 23.9% of cases. Other rare origins were present in 2.77% of cases. Multiple dorsal pancreatic arteries were found in 1,7% of cases. There was no significant difference in the presence or origin of the dorsal pancreatic artery between anatomical and computed tomography based studies.

CONCLUSION

The dorsal pancreatic artery is present in the vast majority of cases. Its origin and branching are highly variable. Multiplicity of the dorsal pancreatic artery is infrequent.

Dual-energy CT with virtual monoenergetic images to improve the visualization of pancreatic supplying arteries: the normal anatomy and variations

Background

Pancreatic ductal adenocarcinoma (PDAC) remains a malignancy with poor prognosis, appropriate surgical resection and neoadjuvant therapy depend on the accurate identification of pancreatic supplying arteries. We aim to evaluate the ability of monoenergetic images (MEI [+]) of dual-energy CT (DECT) to improve the visualization of pancreatic supplying arteries compared to conventional polyenergetic images (PEI) and investigate the implications of vascular variation in pancreatic surgery and transarterial interventions.

Results

One hundred patients without pancreatic diseases underwent DECT examinations were retrospectively enrolled in this study. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) at 40-keV MEI (+) were significantly higher than those of PEI (p < 0.05). All subjective MEI (+) scores were significantly higher than those of PEI (p < 0.05). The visualization rates were significantly higher for posterior superior pancreaticoduodenal artery (PSPDA), anterior and posterior inferior pancreaticoduodenal artery (AIPDA, PIPDA), anterior and posterior pancreaticoduodenal arcade (APAC, PPAC), transverse and caudal pancreatic artery (TPA, PCA) at 40-keV MEI (+) than those of PEI (p < 0.05). However, there were no significant differences for visualizing anterior superior pancreaticoduodenal artery (ASPDA), inferior pancreaticoduodenal artery (IPDA), dorsal and magnificent pancreatic artery (DPA, MPA) between 40-keV MEI (+) and PEI (p > 0.05). Four types of variations were observed in the origin of DPA and three to five types in the origin of PSPDA, AIPDA and PIPDA.

Conclusions

40-keV MEI (+) of DECT improves the visualization and objective and subjective image quality of pancreatic supplying arteries compared to PEI. Pancreatic supplying arteries have great variations, which has important implications for preoperative planning of technically challenging surgeries and transarterial interventions.

Feasibility of utilizing ultra-low-dose contrast medium for pancreatic artery depiction using the combination of advanced virtual monoenergetic imaging and high-concentration contrast medium: an intra-patient study

Objectives

The least amount of contrast medium (CM) should be used under the premise of adequate diagnosis. The purpose of this study is to evaluate the feasibility of utilizing ultra-low-dose (224 mgI/kg) CM for pancreatic artery depiction using the combination of advanced virtual monoenergetic imaging (VMI+) and high-concentration (400 mgI/mL) CM.

Materials and methods

41 patients who underwent both normal dose CM (ND-CM, 320 mgI/kg) and low dose CM (LD-CM, 224 mgI/kg) thoracoabdominal enhanced CT for tumor follow-up were prospectively included. The VMI+ at the energy level of 40-kev for LD-CM images was reconstructed. CT attenuation, signal-to-noise ratios (SNRs), and contrast-to-noise ratios (CNRs) of the abdominal artery, celiac artery, and superior mesenteric artery (SMA) and qualitative scores of pancreatic arteries depiction were recorded and compared among the three groups (ND-CM, LD-CM, and VMI+ LD-CM images). ANOVA and Friedman tests were used for statistical analysis.

Results

All quantitative and qualitative parameters on LD-CM images were lower than that on ND-CM images (all p < 0.01). There were no significant differences of all arteries’ qualitative scores between ND-CM and VMI+ LD-CM images (all p > 0.05). VMI+ LD-CM images had the highest mean CT and CNR values of all arteries (all p < 0.0001). The CM volume was 52.6 ± 9.4 mL for the ND-CM group and 37.0 ± 6.7 mL for the LD-CM group.

Conclusion

Ultra-low-dose CM (224 mgI/kg) was feasible for depicting pancreatic arteries. Inferior angiographic image quality could be successfully compensated by VMI+ and high-concentration CM.

Dorsal Pancreatic Artery—a Study of Its Detailed Anatomy for Safe Pancreaticoduodenectomy

Early division of the dorsal pancreatic artery (DPA) or its branches to the uncinate process during pancreaticoduodenectomy (PD) in addition to early division of the gastroduodenal artery and inferior pancreaticoduodenal artery should be performed to reduce blood loss by completely avoiding venous congestion. However, the significance of early division of DPA or its branches to the uncinate process has not been reported. The aim of this study was to investigate the anatomy of DPA and its branches to the uncinate process using the currently available high-resolution dynamic computed tomography (CT) as the first step to investigate the significance of DPA in the artery-first approach during PD. Preoperative dynamic thin-slice CT data of 160 consecutive patients who underwent hepato–pancreato–biliary surgery were examined focusing on the anatomy of DPA and its branches to the uncinate process. DPA was recognized in 103 patients (64%); it originated from the celiac axis or its branches in 70 patients and from the superior mesenteric artery or its branches in 34 patients. The branches to the uncinate process were visualized in 82 patients (80% of those with DPA), with diameters of 0.5–1.5 mm in approximately 80% of the 82 patients irrespective of DPA origin. DPA branches to the uncinate process were recognized using high-resolution CT in approximately half of the patients.

Surgical Anatomy of the Superior Mesenteric Vessels Related to Pancreaticoduodenectomy: a Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

Mesopancreas dissection with central vascular ligation and the superior mesenteric artery (SMA)-first approach represent the cornerstone of current principles for radical resection for pancreatic head cancer. The surgeon dissecting around the SMV and SMA should be aware regarding the anatomical variants in this area. The aims of this systematic review and meta-analysis are to detail the surgical anatomy of the superior mesenteric vessels and to propose a standardized terminology with impact in pancreatic cancer surgery.

METHODS

We conducted a systematic search to identify all published studies in PubMed/MEDLINE and Google Scholar databases from their inception up to March 2017.

RESULTS

Seventy-eight studies, involving a total of 18,369 specimens, were included. The prevalence of the mesenteric-celiac trunk, replaced/accessory right hepatic artery (RRHA), common hepatic artery, and SMV inversion was 2.8, 13.2, 2.6, and 4.1%, respectively. The inferior pancreaticoduodenal artery has its origin into the first jejunal artery, SMA, and RRHA, in 58.7, 35.8, and 1.2% of cases, respectively. The SMV lacks a common trunk in 7.5% of cases. The first jejunal vein has a trajectory posterior to the SMA in 71.8% of cases. The left gastric vein drains into the portal vein in 58%, in splenic vein (SV) in 35.6%, and into the SV-PV confluence in 5.8% of cases.

CONCLUSIONS

Complex pancreaticoduodenal resections require detailed knowledge of the superior mesenteric artery and vein, which is significantly different from the one presented in the classical textbooks of surgery. We are proposing the concept of the first jejunopancreatic vein which impacts the current oncological principles of pancreatic head cancer resection.

Anatomo-radiological patterns of pancreatic vascularization, with surgical implications: Clinical and anatomical study

The pancreas receives multiple arterial sources that should be considered in patients undergoing pancreatic surgery. The aim of this study is to describe pancreatic vascularization and to explore the anatomical basis of postoperative complications. Ten specimens from unembalmed cadavers, including the retroperitoneal vessels and organs and spleen, were injected with acrylic resins to obtain vascular casts. Thirty computed tomography angiographies (CTA) of subjects with no pancreatic pathology (mean age 70.9 years) were also analyzed. A paucivascular area at the neck of the pancreas was apparent in all vascular casts. At CTA: (1) the transverse pancreatic artery, the only artery running from the cervicocephalic to the somatocaudal segment, was visible in 76.9% of cases; (2) the splenic artery was suprapancreatic in 66.7% and intrapancreatic with a tortuous course in 33.3%; (3) the posterior superior pancreaticoduodenal artery was visible in 100% of cases, the anterior superior pancreatico-duodenal artery in 92.6%, the anterior inferior pancreaticoduodenal artery in 73.1%, the posterior inferior pancreaticoduodenal artery in 86.4%, the dorsal pancreatic artery in 65.4%, the great pancreatic artery in 73.1%, and the pancreatic arteries to the body and caudal pancreatic arteries in 96.2%. Our study demonstrated great individual variability of the pancreatic vasculature, which can be explored by CTA and could be relevant to surgical procedures. Clin. Anat. 30:614-624, 2017. © 2017 Wiley Periodicals, Inc.

Extrahepatic Arteries Originating from Hepatic Arteries: Analysis Using CT During Hepatic Arteriography and Visualization on Digital Subtraction Angiography

PURPOSE

To investigate the prevalence and site of origin of extrahepatic arteries originating from hepatic arteries on early phase CT during hepatic arteriography (CTHA) was accessed. Visualization of these elements on digital subtraction hepatic angiography (DSHA) was assessed using CTHA images as a gold standard.

MATERIALS AND METHODS

A total of 943 patients (mean age 66.9 ± 10.3 years; male/female, 619/324) underwent CTHA and DSHA. The prevalence and site of origin of extrahepatic arteries were accessed using CTHA and visualized using DSHA.

RESULTS

In 924 (98.0%) patients, a total of 1555 extrahepatic branches, representing eight types, were found to originate from hepatic arteries on CTHA. CTHA indicated the following extrahepatic branch prevalence rates: right gastric artery, 890 (94.4%); falciform artery, 386 (40.9%); accessory left gastric artery, 161 (17.1%); left inferior phrenic artery (IPA), 43 (4.6%); posterior superior pancreaticoduodenal artery, 33 (3.5%); dorsal pancreatic artery, 26 (2.8%); duodenal artery, 12 (1.3%); and right IPA, 4 (0.4%). In addition, 383 patients (40.6%) had at least one undetectable branch on DSHA. The sensitivity, specificity, and accuracy of visualization on DSHA were as follows: RGA, 80.0, 86.8, and 80.4%; falciform artery, 53.9, 97.7, and 80.0%; accessory LGA, 64.6, 98.6, and 92.3%; left IPA, 76.7, 99.8, and 98.7%; PSPDA, 100, 99.7, and 99.9%; dorsal pancreatic artery, 57.7, 100, and 98.8%; duodenal artery, 8.3, 99.9, and 98.7%; and right IPA, 0, 100, and 99.6%, respectively.

CONCLUSION

Extrahepatic arteries originating from hepatic arteries were frequently identified on CTHA images. These arteries were frequently overlooked on DSHA.

Spectral CT in the Demonstration of the Pancreatic Arteries and Their Branches: A Comparison With Conventional CT

The aim of this study was to investigate the performance of monochromatic images of spectral computed tomographic (CT) in the visualization of the pancreatic arteries compared with polychromatic CT images. We conducted a case-control study in a group of 26 consecutive patients with monochromatic CT and contrasted the results against a control group of 26 consecutive patients with polychromatic CT. The CNR (contrast-to-noise ratio), SIR (signal intensity ratio), SNR (signal to noise ratio), and image noise were measured. A 5-score classification system was used to evaluate the branch order of pancreatic arteries. The course of pancreatic arteries was compared. Compared with polychromatic images, the CNR, SIR, and SNR obtained by monochromatic images were increased by 64.74%, 23.99%, and 39.50%. Branch visualization of PSPDA (posterior superior pancreaticoduodenal artery), ASPDA (anterior superior pancreaticoduodenal artery), and DPA (dorsal pancreatic artery) was better at monochromatic images than at polychromatic images. The display rate was significantly better in monochromatic images for the second and third segments of PSPDA, total course of ASPDA, and artery of uncinate process. Compared with polychromatic images, monochromatic images can improve the visualization of pancreatic arteries.

Demonstration of the dorsal pancreatic artery by CTA to facilitate superselective arterial infusion of stem cells into the pancreas

PURPOSE

To investigate the diagnostic performance of 64-section CTA in the detection of dorsal pancreatic artery before interventional therapy for patients with diabetes.

MATERIALS AND METHODS

The study was approved by the institutional ethics committee; written informed consent was obtained. Forty-two consecutive patients with diabetes received an experimental treatment of autologous bone marrow-derived stem cell transplantation by means of infusion into the dorsal pancreatic artery. All cases underwent abdominal CTA before angiography of pancreatic arteries in order to locate the origin and course of dorsal pancreatic artery. Angiography of coeliac artery, splenic artery, common hepatic artery and superior mesenteric artery were performed both in CTA and DSA. Superselective catheterization of dorsal pancreatic artery was carried out for the infusion of stem cell. Sensitivity, specificity and accuracy for the detection of dorsal pancreatic artery with CTA were calculated using DSA images as the reference standard.

RESULTS

Thirty-five and thirty-six dorsal pancreatic arteries were detected by CTA and DSA respectively. Dorsal pancreatic artery was not visualized in either CTA or DSA in 5 patients. The sensitivity, specificity and accuracy for CTA were 94.4%, 83.3% and 92.9%.

CONCLUSION

64-section CTA is accurate for the detection of dorsal pancreatic artery. It may be useful for the facilitation of superselective arterial infusion of stem cells to pancreas.

Stenosis of the third portion of the duodenum due to bleeding from the anterior pancreaticoduodenal artery: assessment by multiphase contrast-enhanced examination with multislice CT

BACKGROUND

This study was undertaken to analyze the CT findings for the rare pathological process that stenosis of the third portion of the duodenum was presumed to be caused by bleeding from the anterior pancreaticoduodenal artery.

METHODS

Four consecutive patients presenting with frequent vomiting, who did not have well-known underlying disorders causing duodenal stenosis, were retrospectively recruited. Multiphase contrast-enhanced CT examinations were performed with 0.5- or 1-mm collimation. Two radiologists evaluated 2-mm axial and multiplanar reformatted images.

RESULTS

In all patients, endoscopy demonstrated severe edematous stenosis of the third portion of the duodenum not associated with ulcer, bleeding, or neoplasm. The following CT findings were observed in all patients: homogenous swelling of the third portion of the duodenum associated with luminal stenosis in un-enhanced images, a band-like area of lower contrast-enhancement surrounding the walls of the third portion of the duodenum in pancreatic-phase images, and stenosis of the celiac axis. In three patients, aneurysms of the anterior pancreaticoduodenal artery in arterial-phase images were depicted. In the remaining patient, the diameter of the artery was irregular.

CONCLUSIONS

Multiphase contrast-enhanced CT examination using a multislice CT scanner helps to establish the diagnosis of this pathological process.