Usefulness of helical computed tomography for diagnosis of cystic lesions of the pancreas

Using helical computed tomography (CT), we evaluated cystic pancreatic lesions in 11 patients and compared the imaging and the histopathologic findings. Helical CT allowed us to assess the tumor vasculature. Contrastenhanced images showed satisfactory details of the cysts, cyst walls, and intracystic structures. Helical CT is extremely useful for the evaluation of cystic pancreatic lesions.     

Combined use of endoscopic retrograde cholangiopancreatography and computed tomography for identifying pancreatic abscesses

A 40-year-old male showed intermittent spike fever 2 1/2 months after receiving conservative medical treatment for acute pancreatitis. Endoscopic retrograde cholangiopancreatography (ERCP) revealed leakage of the contrast media from the main pancreatic duct into the pancreatic parenchyma. Immediately following ERCP, computed tomography (CT) scans revealed separate poolings of this contrast media in the pancreatic head and tail. Surgical debridement of the pancreatic head and tail was therefore performed, after which drains were placed at both sites. The patient recovered successfully. To own knowledge, this is the first reported case in which pancreatic abscesses, a late complication of acute pancreatitis, were clearly identified by the use of ERCP followed by CT.     

Spiral computed tomography assessment of resectability of pancreatic ductal adenocarcinoma: analysis of results

BACKGROUND: Despite more recent technical advances, single detector spiral computed tomography is still the most widely used imaging technique for the detection and staging of pancreatic adenocarcinoma. Many reports have recently focused on single detector spiral computed tomography imaging findings indicative of unresectability AIM: To evaluate the ability of single detector spiral computed tomography in the pre-operative staging of ductal adenocarcinoma of the pancreas in selecting surgically resectable versus unresectable cases, considering different parameters (vascular and local infiltration, liver metastases, lymphadenopathy, and peritoneal carcinomatosis). PATIENTS AND METHODS: A total of 100 patients diagnosed with ductal adenocarcinoma of the pancreas, pathologically verified, and examined with single detector spiral computed tomography were considered. Of these, 63 underwent surgery; 37 were excluded (imaging evidence of unresectability in biopsy-proven adenocarcinomas). Single detector spiral computed tomography studies, performed at the time of surgery, were retrospectively reviewed by two radiologists. The final results were reached by consensus, without being aware of the operation. All prospective clinical readings were also considered, and tabulated. RESULTS: In the patients undergoing surgery, 44 proved to be unresectable and 19 resectable. Considering the above-mentioned parameters, the prospective assessment of resectability demonstrated a rather low sensitivity (68%), with high specificity (95%). Accordingly, a high positive predictive value (97%) was achieved, while the negative predictive value was 56%. After the retrospective evaluation, the value of sensitivity increased (84%) to the expense of the specificity (84%). Moreover, a positive predictive value of 92.5%, and a negative predictive value of 69.5% were obtained. CONCLUSIONS: The demonstration of many signs of unresectability of pancreatic ductal adenocarcinoma reported in the literature yields a better sensitivity in the diagnosis, but unfortunately, is associated with an inevitable reduction in specificity.     

Role of positron emission tomography in decisions on treatment strategies for pancreatic cancer

Background/Purpose

The purpose of this study was to estimate the usefulness of positron emission tomography (PET) in deciding on strategies for the treatment of pancreatic cancer. The following two parameters were evaluated: the ability of PET to provide an estimation of the progression of pancreatic cancer, and the ability of PET to predict survival and the effect of chemoradiotherapy.

Methods

Forty-two patients underwent PET as part of the procedure for making a diagnosis of pancreatic tumors. The maximum standardized uptake value (SUVmax) levels were compared with clinicopathological factors and analyzed.

Results

PET provided a sensitivity of 87%, a specificity of 67%, and an overall accuracy of 85% for the diagnosis of pancreatic malignancy. Tumors with distant metastases showed significantly higher SUV levels than tumors without metastasis. In the patients who received chemoradiotherapy, the overall survival of the group in which SUVmax was less than 7.0 was better than that of the group in which SUVmax was more than 7.0.

Conclusions

We conclude that PET is a useful tool for determining pathological status and distant metastasis in pancreatic cancer, and for predicting the prognosis of patients receiving chemoradiotherapy.     

Differentiation of autoimmune pancreatitis from suspected pancreatic cancer by fluorine-18 fluorodeoxyglucose positron emission tomography

Background Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) has been widely used for the diagnosis of pancreatic cancer. Because autoimmune pancreatitis is easily misdiagnosed as pancreatic cancer and can be tested for by FDG-PET analysis based on the presence of suspected pancreatic cancer, we attempted to clarify the differences in FDG-PET findings between the two conditions. Methods We compared FDG-PET findings between 15 patients with autoimmune pancreatitis and 26 patients with pancreatic cancer. The findings were evaluated visually or semiquantitatively using the maximum standardized uptake value and the accumulation pattern of FDG. Results FDG uptake was found in all 15 patients with autoimmune pancreatitis, whereas it was found in 19 of 26 patients (73.1%) with pancreatic cancer. An accumulation pattern characterized by nodular shapes was significantly more frequent in pancreatic cancer, whereas a longitudinal shape indicated autoimmune pancreatitis. Heterogeneous accumulation was found in almost all cases of autoimmune pancreatitis, whereas homogeneous accumulation was found in pancreatic cancer. Significantly more cases of pancreatic cancer showed solitary localization, whereas multiple localization in the pancreas favored the presence of autoimmune pancreatitis. FDG uptake by the hilar lymph node was significantly more frequent in autoimmune pancreatitis than in pancreatic cancer, and uptake by the lachrymal gland, salivary gland, biliary duct, retroperitoneal space, and prostate were seen only in autoimmune pancreatitis. Conclusions FDG-PET is a useful tool for differentiating autoimmune pancreatitis from suspected pancreatic cancer, if the accumulation pattern and extrapancreatic involvement are considered. IgG4 measurement and other current image tests can further confirm the diagnosis.     

Normal pancreatic volume assessment using abdominal computed tomography volumetry

To determine the normal range of pancreatic volume (PV) in Chinese adults using computed tomography (CT) volumetry. To assess the relationships of PV with patient demographics and clinical parameters. To analyze the degree of correlation between PV values determined by manual segmentation and those calculated by formulas.A total of 240 adults (120 women, 120 men) between the ages of 18 and 79 years were reviewed. There were 6 groups of patients, with 40 patients in each decade regarding age. PV was segmented manually on computed tomography images slice by slice for each patient, and 2 formulas were used to calculate PV^∗ and PV^#.The mean PV was 77.44 ± 19.11 cm³ (range from 28.55–138.15 cm³). PV was significantly correlated with height (r = 0.427, P < .001), weight (r = 0.525, P < .001), body mass index (r = 0.377, P < .001), the width of the first lumbar vertebral body (r = 0.166, P = .01), the transverse abdominal diameter (r = 0.455, P < .001), and the sagittal abdominal diameter (r = 0.456, P < .001). There was a negative correlation between PV and age (r = –0.209, P = .001). The correlation coefficients between PV and PV^∗ and PV^# were 0.676 and 0.376, respectively, with both P < .001.PV associated with patient demographics and clinical parameters. A more accurate and simpler formula should be used in the future to calculate and monitor changes in PV.     

Multislice spiral computed tomography in diagnosis and staging of pancreatic carcinoma: preliminary experience

BACKGROUND: Computed tomography has become the modality of choice for preoperative evaluation of patients with suspected pancreatic carcinoma, although some limitations are well known. AIMS: To evaluate use of multislice spiral computed tomography in preoperative assessment of patients with suspected pancreatic carcinoma using volume-rendering as image reconstruction algorithm. PATIENTS: A total of 27 patients with suspected pancreatic carcinoma underwent multislice spiral computed tomography examination. METHODS: All studies were performed on a multislice computed tomography scanner with the following parameters: slice collimation, 1 mm; slice thickness, 1.25 mm; reconstruction interval, 1 mm; scan time, 22-25 sec; mAs, 165. Scans were acquired with a biphasic technique with a 30-sec (pancreatic phase) and a 70-sec (portal venous phase) delay time after start of contrast material injection. Diagnostic confirmation was obtained with surgical exploration, percutaneous biopsy, or with a combination of follow-up imaging studies. RESULTS: Multislice spiral computed tomography yielded correct diagnosis of pancreatic carcinoma in 20 cases (sensitivity, 95%; specificity, 100%). Positive predictive values for resectability and unresectability were 80% and 93.3%, respectively. Three-dimensional volume-rendered images improved diagnostic confidence in the depiction of major vascular structures. Two cases of anomalous origin of hepatic artery were also identified with volume-rendered images. CONCLUSIONS: Multislice technology improves accuracy of spiral computed tomography for diagnosis and staging of pancreatic carcinoma.     

Value of contrast-enhanced 18F-fluorodeoxyglucose positron emission tomography/computed tomography in detection and presurgical assessment of pancreatic cancer: a prospective study

Background and Aim: Positron Emission Tomography (PET) using ¹⁸F‐fluorodeoxyglucose (FDG) associated with computed tomography (CT) is increasingly used for the detection and the staging of pancreatic cancer, but data regarding its clinical added value in pre‐surgical planning is still lacking. The aim of this study is to investigate the performance of FDG PET associated with contrast‐enhanced CT in detection of pancreatic cancer. Methods: We prospectively evaluated FDG PET/CT studies obtained in patients with suspicion of operable pancreatic cancer between May 2006 and January 2008. Staging was conducted according to a standardized protocol, and findings were confirmed in all patients by surgical resection or biopsy examination. Results: Forty‐five patients with a median age of 69 (range 22–82) were included in this study. Thirty‐six had malignant tumors and nine had benign lesions (20%). The sensitivity of enhanced versus unenhanced PET/CT in the detection of pancreatic cancer was 96% versus 72% (P = 0.076), the specificity 66.6% versus 33.3% (P = 0.52), the positive predictive value 92.3% versus 80% (P = 0.3), the negative predictive value 80% versus 25% (P = 0.2), and the accuracy 90.3% versus 64% (P = 0.085). Conclusions: Our preliminary data obtained in a limited number of patients shows that contrast‐enhanced FDG PET/CT offers good sensitivity in the detection and assessment of pancreatic cancer, but at the price of a relatively low specificity. Enhanced PET/CT seems to be superior to unenhanced PET/CT. Further larger prospective studies are needed to establish its value for pre‐surgical diagnosis and staging in pancreatic cancer.     

Chest computed tomography in the staging of pancreatic and periampullary carcinoma

Background: Staging of the tumours in the pancreas and periampullary region usually consists of abdominal computed tomography (CT). Laparoscopy is also advocated. Little attention has been paid to extra‐abdominal staging. In addition to peritoneal, lymphatic and hepatic metastases, lung metastases are frequently found. The chest CT scan has been demonstrated as better than the plain chest roentgenogram or conventional tomography in demonstrating lung tumours. This study was done to evaluate whether the chest CT scan gives information additional to the plain chest roentgenogram in the staging of pancreatic and periampullary tumours. Methods: Fifty‐three patients with a pancreatic or periampullary tumour underwent helical CT scan of the chest in addition to the abdominal CT scan. The CT scans and the chest roentgenograms were read separately without the result of the other being known; the results were compared with each other and with the clinical and operative findings. Results: In the chest CT scan, 7 out of 53 (13%) patients had nodules in the lungs. The chest pathologies were not seen in the chest roentgenogram except for pneumonia in one patient and lung tumours in another (sensitivity of the chest roentgenogram 2/7?=?29%). Liver metastasis, local invasion of the tumour or poor general condition of the patient made lung biopsy or bronchoscopy unnecessary or impossible. Conclusion: Lung metastases seldom appear in patients with pancreatic or periampullary carcinoma without other contraindications for resection, which is why the chest CT scan cannot be recommended in the staging of these tumours for operation.     

Small carcinoma of the pancreas is curable: new computed tomography finding, pathological study and postoperative results from a single institute

BACKGROUND: It is well known that pancreatic cancer is rarely cured and is usually fatal. The clinicopathological features of small (greatest dimension < or = 2 cm by histologic measurement) carcinoma of the pancreas (s-PC), were reviewed, paying special attention to new computed tomography (CT) finding that suggests the presence of s-PC. METHODOLOGY: Sixteen patients with s-PC have undergone curative surgery at Aichi Cancer Center Hospital during the past 11 years. Their preoperative diagnostic findings, pathological findings and postoperative prognoses were analyzed. RESULTS: The most useful diagnostic clue was dilatation of the main pancreatic duct (MPD). It was difficult to identify the tumor in four patients because of pancreatitis accompanying the MPD obstruction. In three of these four cases, early phase-enhanced CT revealed a contrasting effect between the proximal and distal sides of the pancreatic parenchyma at the site of the MPD obstruction (black & white sign). The longest diameters of the tumors ranged from 0.9 to 2 cm (average 1.3 cm). Positive rates of capsular invasion, retroperitoneal invasion, and lymph node metastasis were 6.3% (1/16), 31.3% (5/16), and 18.8% (3/16), respectively. Six patients (37.5%) were classed at stage I, six (37.5%) stage II, three (18.8%) stage III, and one (6.2%) at stage IV according to pathological TNM classification. One patient died of the disease, and the cumulative 3- and 5-year survival rates were 88.9% and 59.3%, respectively. CONCLUSIONS: The presence of s-PC qualifies as early PC and has a good prognosis. The CT black + white sign will be useful in the diagnosis of s-PC accompanying pancreatitis.     

Computed tomography in diagnosing vascular invasion in pancreatic and periampullary cancers: a systematic review and meta-analysis

BACKGROUND: Preoperative diagnosis of local vascular invasion is very important to the selection of therapeutic protocols and prediction of the prognosis of pancreatic and periampullary cancers. This meta-analysis was designed to evaluate the accuracy of computed tomography (CT) in diagnosing vascular invasion in patients with pancreatic and periampullary cancers. DATA SOURCES: English-language articles reporting diagnostic accuracy of CT for vascular invasion in pancreatic and periampullary cancers were se...     

Diagnostic value of diffusion-weighted magnetic resonance imaging compared with fluorodeoxyglucose positron emission tomography/computed tomography for pancreatic malignancy: a meta-analysis using a hierarchical regression model

Background and Aim: To obtain diagnostic performance of diffusion‐weighted magnetic resonance imaging (DWI) and fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the detection of pancreatic malignancy. Methods: We performed a meta‐analysis of all available studies of the diagnostic performance of DWI and PET/CT for pancreatic malignancy. MEDLINE, EMBASE, Cochrane library and some other databases were searched for initial studies. We determined sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR+ and LR?), and constructed summary receiver operating characteristic curves (SROC) using hierarchical regression models. Results: Across 16 studies with 804 patients, PET/CT sensitivity was 0.87 (95% confidence interval [CI], 0.82, 0.81) and specificity was 0.83 (95% CI, 0.71, 0.91). Overall, LR+ was 5.84 (95% CI, 4.59, 7.42) and LR? was 0.24 (95% CI, 0.17, 0.33). DWI sensitivity was 0.85 (95% CI, 0.74, 0.92) and specificity was 0.91 (95% CI, 0.71, 0.98). LR+ was 9.53 (95% CI, 2.41, 37.65) and LR? was 0.17 (95% CI, 0.09, 0.32). In subgroup analysis, the sensitivity of enhanced versus unenhanced PET/CT in the detection of pancreatic cancer was 0.91 (95% CI, 0.86, 0.96) versus 0.84 (95% CI, 0.78, 0.90) (P > 0.05), the specificity 0.88 (95% CI, 0.73, 1.00) versus 0.81 (95% CI, 0.69, 0.94) (P > 0.05). Conclusion: Positron emission tomography/computed tomography (PET/CT) was highly sensitive and DWI was a highly specific modality in diagnosing patients with pancreatic malignancy. PET/CT and DWI could play different roles in diagnosing pancreatic carcinoma. Enhanced PET/CT seems to be superior to unenhanced PET/CT. Further larger prospective studies are needed to establish its value for diagnosis in pancreatic cancer.     

Recent advances in 3D computed tomography techniques for simulation and navigation in hepatobiliary pancreatic surgery

A few years ago it could take several hours to complete a 3D image using a 3D workstation. Thanks to advances in computer science, obtaining results of interest now requires only a few minutes. Many recent 3D workstations or multimedia computers are equipped with onboard 3D virtual patient modeling software, which enables patient‐specific preoperative assessment and virtual planning, navigation, and tool positioning. Although medical 3D imaging can now be conducted using various modalities, including computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and ultrasonography (US) among others, the highest quality images are obtained using CT data, and CT images are now the most commonly used source of data for 3D simulation and navigation image. If the 2D source image is bad, no amount of 3D image manipulation in software will provide a quality 3D image. In this exhibition, the recent advances in CT imaging technique and 3D visualization of the hepatobiliary and pancreatic abnormalities are featured, including scan and image reconstruction technique, contrast‐enhanced techniques, new application of advanced CT scan techniques, and new virtual reality simulation and navigation imaging.     

Imaging pancreatobiliary ductal system with optical coherence tomography: A review

An accurate, noninvasive and cost-effective method of in situ tissue evaluation during endoscopy would be highly advantageous for the detection of dysplasia or early cancer and for identifying different disease stages. Optical coherence tomography (OCT) is a noninvasive, high-resolution (1-10 μm) emerging optical imaging method with potential for identifying microscopic subsurface features in the pancreatic and biliary ductal system. Tissue microstructure of pancreaticobiliary ductal system has been successfully imaged by inserting an OCT probe through a standard endoscope operative channel. High-resolution OCT images and the technique’s endoscopic compatibility have allowed for the microstructural diagnostic of the pancreatobiliary diseases. In this review, we discussed currently available pancreaticobiliary ductal imaging systems to assess the pancreatobiliary tissue microstructure and to evaluate varieties of pancreaticobiliary disorders and diseases. Results show that OCT can improve the quality of images of pancreatobiliary system during endoscopic retrograde cholangiopancheatography procedure, which may be important in distinguishing between the neoplastic and non-neoplastic lesions.     

Use of pancreatic schilling test to determine efficiency of pancreatic enzyme delivery in pancreatic insufficiency

The pancreatic Schilling test (PST), a noninvasive, sensitive pancreatic function test, was studied to determine its ability to detect pancreatic proteolytic enzyme replacement in patients with pancreatic insufficiency. Seven subjects with welldocumented pancreatic insufficiency and an abnormal PST consistent with pancreatic insufficiency were studied with three enzyme regimens: (1) Viokase (four tablets), (2) Pancrease (three capsules), and (3) Pancrease (10 capsules). The effect of cimetidine on the results of the PST with high-dose Pancrease was also determined in two subjects with pancreatic insufficiency and in two normal volunteers. The results of the investigation demonstrate that the PST is a sensitive noninvasive test for the presence of orally administered proteolytic enzymes in subjects with pancreatic insufficiency and in normals. Furthermore, the studies illustrate that the administration of enzymes in a form of entericcoated microspheres does not enhance the delivery of proteolytic enzymes to the small intestine when compared to conventional highdose enzyme replacement. Cimetidine appears to decrease the inactivation of the proteolytic enzymes in entericcoated microspheres, suggesting that a low pH in the small intestine and stomach are responsible for the poor delivery of the enzymes into the small intestine.     

胰腺囊性肿瘤的诊治体会

胰腺囊性肿瘤（pancreatic cystic neoplasms）,也称为囊性胰腺肿瘤（cystic pancreatic neoplasms）,约占胰腺肿瘤的5％。随着对其认识的提高和影像学检查发现的增多,在过去的十年里,受到了前所未有的关注。胰腺囊性肿瘤在病变性质上可分为良性、交界性和恶性。1996年WHO根据肿瘤形态以及上皮细胞的特征,将胰腺囊性肿瘤分为三类,     

Therapeutic intervention and surgery of acute pancreatitis

The clinical course of acute pancreatitis varies from mild to severe. Assessment of severity and etiology of acute pancreatitis is important to determine the strategy of management for acute pancreatitis. Acute pancreatitis is classified according to its morphology into edematous pancreatitis and necrotizing pancreatitis. Edematous pancreatitis accounts for 80–90% of acute pancreatitis and remission can be achieved in most of the patients without receiving any special treatment. Necrotizing pancreatitis occupies 10–20% of acute pancreatitis and the mortality rate is reported to be 14–25%. The mortality rate is particularly high (34–40%) for infected pancreatic necrosis that is accompanied by bacterial infection in the necrotic tissue of the pancreas (Widdison and Karanjia in Br J Surg 80:148–154, 1993; Ogawa et al. in Research of the actual situations of acute pancreatitis. Research Group for Specific Retractable Diseases, Specific Disease Measure Research Work Sponsored by Ministry of Health, Labour, and Welfare. Heisei 12 Research Report, pp 17–33, 2001). On the other hand, the mortality rate is reported to be 0–11% for sterile pancreatic necrosis which is not accompanied by bacterial infection (Ogawa et al. 2001; Bradely and Allen in Am J Surg 161:19–24, 1991; Rattner et al. in Am J Surg 163:105–109, 1992). The Japanese (JPN) Guidelines were designed to provide recommendations regarding the management of acute pancreatitis in patients having a variety of clinical characteristics. This article describes the guidelines for the surgical management and interventional therapy of acute pancreatitis by incorporating the latest evidence for the management of acute pancreatitis in the Japanese-language version of JPN guidelines 2010. Eleven clinical questions (CQ) are proposed: (1) worsening clinical manifestations and hematological data, positive blood bacteria culture test, positive blood endotoxin test, and the presence of gas bubbles in and around the pancreas on CT scan are indirect findings of infected pancreatic necrosis; (2) bacteriological examination by fine needle aspiration is useful for making a definitive diagnosis of infected pancreatic necrosis; (3) conservative treatment should be performed in sterile pancreatic necrosis; (4) infected pancreatic necrosis is an indication for interventional therapy. However, conservative treatment by antibiotic administration is also available in patients who are in stable general condition; (5) early surgery for necrotizing pancreatitis is not recommended, and it should be delayed as long as possible; (6) necrosectomy is recommended as a surgical procedure for infected necrosis; (7) after necrosectomy, a long-term follow-up paying attention to pancreatic function and complications including the stricture of the bile duct and the pancreatic duct is necessary; (8) drainage including percutaneous, endoscopic and surgical procedure should be performed for pancreatic abscess; (9) if the clinical findings of pancreatic abscess are not improved by percutaneous or endoscopic drainage, surgical drainage should be performed; (10) interventional treatment should be performed for pancreatic pseudocysts that give rise to symptoms, accompany complications or increase the diameter of cysts and (11) percutaneous drainage, endoscopic drainage or surgical procedures are selected in accordance with the conditions of individual cases.