Comparison of three-dimensional negative-contrast CT cholangiopancreatography with three-dimensional MR cholangiopancreatography for the diagnosis of obstructive biliary diseases

Purpose

The purpose of our study was to compare three-dimensional (3D) negative-contrast CT cholangiopancreatography (3D-nCTCP) with 3D MR cholangiopancreatography (3D-MRCP) for the diagnosis of obstructive biliary diseases.

Materials and methods

3D-nCTCP and 3D-MRCP were performed on seventy clinically documented obstructive biliary diseases patients. The accuracy of each technique in determining the location and cause of biliary obstruction was evaluated compared with the final clinical diagnoses.

Results

Both methods achieved 100% of accuracy in the diagnosis of the presence and location of biliary obstruction, and had a similar sensitivity, specificity, accuracy in differentiating benign from malignant biliary obstruction or calculous from noncalculous biliary obstruction (p > 0.05). At 3D-nCTCP, six patients with stones were misinterpreted as cholangitis (N = 2), papillitis (N = 3), or bile duct adenocarcinoma (N = 1); two metastases were mistaken as acute pancreatitis or pancreatic head carcinomas, and one intrahepatic cholangiocarcinoma was misled as bile duct adenoma. At 3D-MRCP, one small stone, one ampullary adenoma, and one intrahepatic cholangiocarcinoma were mistaken as cholangitis, ampullary stone, and intrahepatic bile duct stone, respectively, and three gallbladder carcinomas and another intrahepatic cholangiocarcinoma were misdiagnosed as hilar cholangiocarcinoma (N = 3) or common hepatic duct stone (N = 1); four metastases were mistaken as pancreatic head carcinomas (N = 3) or distal cholangiocarcinoma (N = 1). The overall accuracy in making specific diagnosis of the cause of biliary obstruction was 87.1% for 3D-nCTCP and 84.3% for 3D-MRCP, respectively, (p > 0.05).

Conclusion

3D-nCTCP has the similar effects as 3D-MRCP for the diagnosis of biliary obstruction and, the location and the cause of biliary obstruction. In view of selected cases contraindications for MRI, 3D-nCTCP is a potential substitute.     

Intraductal papillary mucinous neoplasm of the pancreas: differentiate from chronic pancreatits by MR imaging

Purpose

To evaluate the differentiating factors for intraductal papillary mucinous neoplasm of the pancreas and chronic pancreatitis as determined by MR imaging.

Materials and methods

During a three-year period, we performed MR imaging on 33, consecutive patients with IPMN and on 41 patients with chronic pancreatitis. All IPMNs were confirmed by surgery. Two radiologists retrospectively analyzed the ductal change, the cyst shape, CBD dilatation, lymphadenopathy, and parenchymal change. The sensitivity and specificity were calculated for each MRI findings using the Chi square test. Statistically significant MR findings were further analyzed using multivariate logistic regression analysis. The diagnostic performance was evaluated according to the area under the receiver operating characteristic curve (A_z) using specific MRI findings. Simple κ statistics were used to evaluate the inter-observer reliability.

Results

Statistically specific findings for IPMN compared with those for chronic pancreatitis, were duct dilatation without stricture (specificity = 95.1%, sensitivity = 75.8%, p < 0.0001), bulging ampulla (specificity = 97.6%, sensitivity = 30.3%, p < 0.0001), nodule in a duct (specificity = 100%, sensitivity = 15.2%, p < 0.0004), grape-like cyst shape (specificity = 97.6%, sensitivity = 78.8%, p < 0.0001), and nodule in a cyst (specificity = 100%, sensitivity = 24.2%, p < 0.0001). Statistically specific findings for chronic pancreatitis compared with those for IPMN, were duct dilatation with strictures (specificity = 93.9%, sensitivity = 95.1%, p < 0.0001), the presence of a stone (specificity = 97.0%, sensitivity = 56.1%, p < 0.0001), and a unilocular cyst shape (specificity = 93.9%, sensitivity = 34.1%, p < 0.0004). Duct dilatation without stricture and a grape-like cyst shape were independently associated with the IPMN. Duct dilatation with strictures was independently associated with the chronic pancreatitis. Interobserver agreement was good to excellent for each finding (κ = 0.762–1.000).

Conclusion

Highly specific findings for IPMN include duct dilatation without stricture, bulging ampulla, nodule in a duct, grape-like cyst shape, and nodule in a cyst. MRI is very useful for differentiating IPMN from chronic pancreatitis using these specific findings.     

Diagnostic performance of MRI and EUS in the differentiation of benign from malignant pancreatic cyst and cyst communication with the main duct

Purpose

To assess the diagnostic ability of MRI and EUS for differentiating benign from malignant pancreatic cyst focusing on cyst communication with pancreatic duct.

Materials and methods

During 44 months, we performed MRI on 65 pancreatic cysts. Among them, 36 patients had confirmed cyst communication with duct by ERCP or surgery and 39 patients underwent EUS. Fifty-one had proven by surgery or aspiration. Among them, 36 had confirmed malignant cysts. Two radiologists independently graded cyst communication with duct and the likelihood of malignancy. When the readers’ interpretations differed, third opinion was obtained. They also measured the size of cyst and main duct. The diagnostic performance was analyzed using the ROC curve. The Mann–Whitney U test and κ statistics were used to determine interobserver agreement.

Results

The Az of MRI and EUS for determining diagnostic performance regarding the cyst communication with duct, were 0.931 and 0.930, without statistically difference (p = 0.6). Interobserver agreement was excellent (κ = 0.81) on MRI and substantial (κ = 0.69) on EUS. The Az of MRI and EUS for assessing diagnostic performance to differentiate malignant from benign cyst, was 0.902 and 0.923, without statistically difference (p = 0.587). Interobserver agreement was excellent (κ = 0.81) on MRI and moderate (κ = 0.47) on EUS. The mean cyst size (3.98 cm + 2.74: 3.17 cm + 1.26, p = 0.327) and the duct size (5.20 mm + 3.22: 4.39 mm + 4.12, p = 0.227) showed no statistically difference between malignant and benign cysts.

Conclusion

MRI and EUS can accurately assess pancreatic cyst communication with duct and are very useful for obtaining a differential diagnosis of malignant cyst versus benign pancreatic cyst.     

Multidetector row computed tomography of acute pancreatitis: Utility of single portal phase CT scan in short-term follow up

Objective

The purpose of this study is to evaluate the question of whether nonenhanced CT or contrast enhanced portal phase CT can replace multiphasic pancreas protocol CT in short term monitoring in patients with acute pancreatitis.

Materials and methods

This retrospective study was approved by the Institutional Review Board. From April 2006 to May 2010, a total of 52 patients having acute pancreatitis who underwent initial dual phase multidetector row CT (unenhanced, arterial, and portal phase) at admission and a short term (within 30 days) follow up dual phase CT (mean interval 10.3 days, range 3–28 days) were included. Two abdominal radiologists performed an independent review of three sets of follow up CT images (nonenhanced scan, single portal phase scan, and dual phase scan). Interpretation of each image set was done with at least 2-week interval. Radiologists evaluated severity of acute pancreatitis with regard to pancreatic inflammation, pancreatic necrosis, and extrapancreatic complication, based on the modified CT severity index. Scores of each image set were compared using a paired t-test and interobserver agreement was evaluated using intraclass correlation coefficient statistics.

Results

Mean scores of sum of CT severity index on nonenhanced scan, portal phase scan, and dual phase scan were 5.7, 6.6, and 6.5 for radiologist 1, and 5.0, 5.6, and 5.8 for radiologist 2, respectively. In both radiologists, contrast enhanced scan (portal phase scan and dual phase scan) showed significantly higher severity score compared with that of unenhanced scan (P < 0.05), while portal phase and dual phase scan showed no significant difference each other. The trend was similar regarding pancreatic inflammation and extrapancreatic complications, in which contrast enhanced scans showed significantly higher score compared with those of unenhanced scan, while no significant difference was observed between portal phase scan and dual phase scan. In pancreatic necrosis analysis, there was no significant difference between the three image sets for both radiologists. However, when only the patients having pancreatic necrosis (n = 13) was separately analyzed, significant differences were observed between the unenhanced and portal phase scan (P = 0.04, for radiologist 1), or unenhanced and dual phase scan (P = 0.013, for radiologist 2).

Conclusion

For short-term follow up imaging in assessment of patients with acute pancreatitis, single portal phase CT images without adding unenhanced or arterial phase images provide sufficient information, and thereby reduce radiation exposure.     

Evaluation of pancreatic cancer by multiple breath-hold dynamic contrast-enhanced magnetic resonance imaging at 3.0T

Objective

To investigate the microcirculation in pancreatic cancer by pharmacokinetic analysis of multiple breath-hold dynamic contrast-enhanced magnetic resonance imaging at 3.0 T.

Materials and methods

Multiple breath-hold dynamic contrast-enhanced magnetic resonance imaging was performed in 40 healthy volunteers and 40 patients with pancreatic cancer proven by histopathology using an axial three-dimensions fat-saturated T1-weighted spoiled-gradient echo sequence at 3.0 T. A two compartment model with T1 correction was used to quantify the transfer constant, the rate constant of backflux from the extravascular extracellular space to the plasma and the extravascular extracellular space fractional volume in pancreatic cancer, obstructive pancreatitis distal to the malignant tumor, adjacent pancreatic tissue proximal to the tumor and normal pancreas. All parameters were statistically analyzed.

Results

Statistical differences were noticed in both the transfer constant (p = 0.000075) and the rate constant of backflux (p = 0.006) among different tissues. Both the transfer constant and the rate constant of backflux in pancreatic cancer were statistically lower than those in normal pancreas and adjacent pancreatic tissue (p < 0.05). Both the transfer constant and the rate constant of backflux in obstructive pancreatitis were statistically lower than those in normal pancreas and adjacent pancreatic tissue (p < 0.05). The extravascular extracellular space fractional volume in pancreatic cancer was statistically lager than that in normal pancreas (p = 0.002).

Conclusion

Multiple breath-hold dynamic contrast-enhanced magnetic resonance imaging offers a useful technique to evaluate the microenvironment in pancreatic cancer at 3.0 T. Compared to normal pancreas, pancreatic cancer has lower transfer constant, rate constant of backflux and larger extravascular extracellular space fractional volume.     

Age-related changes in normal adult pancreas: MR imaging evaluation

Objective

To investigate age-related changes in normal adult pancreas as identified by magnetic resonance imaging (MRI).

Materials and methods

We examined 115 patients without pancreatic diseases (21–90 years) who underwent upper abdominal MRI to evaluate the normal pancreatic MRI findings related to aging. The parameters examined were the pancreatic anteroposterior (AP) diameter, pancreatic lobulation, pancreatic signal intensity (SI), depiction of the main pancreatic duct (MPD), grade of the visual SI decrease on the opposed-phase T1-weighted images compared with in-phase images, and enhancement effect of the pancreas in the arterial phase of dynamic imaging.

Results

The pancreatic AP diameter significantly reduced (head, p = 0.0172; body, p = 0.0007; tail, p < 0.0001), and lobulation (p < 0.0001) and parenchymal fatty change (p < 0.0001) became more evident with aging. No significant correlation was observed between aging and pancreatic SI, however the SI on the in-phase T1-weighted images tended to decrease with aging. No significant correlation was observed between aging and the depiction of the MPD as well as aging and contrast enhancement.

Conclusion

MRI findings of pancreatic atrophy, lobulation, and fatty degeneration are characteristic changes related to aging, and it is necessary to recognize these changes in the interpretation of abdominal MRI in patients with and without pancreatic disease.     

The application value of contrast-enhanced ultrasound in the differential diagnosis of pancreatic solid-cystic lesions

Objective

To retrospectively determine the accuracy of baseline ultrasound (BUS) and of contrast-enhanced ultrasound (CEUS) in the differential diagnosis of pancreatic solid-cystic lesions.

Methods

Fifty-four pancreatic solid-cystic lesions in 52 patients were examined with BUS and CEUS, two different seniority radiologists read the images independently, Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic value of BUS and CEUS in the diagnosis of benign or malignant pancreatic solid-cystic lesions, the diagnostic consistency between different seniority radiologists was evaluated by Kappa statistics.

Results

Among the 54 lesions, there were pancreatic cyst five cases, pancreatic pseudocyst twenty cases, pancreatic cystadenoma eight cases, pancreatic cystadenocarcinoma seven cases, intraductal papillary mucinous neoplasm of pancreas (IPMN) three cases, pancreatic carcinoma combined liquefied six cases, solid-pseudopallary tumor of pancreas (SPTP) three cases, pancreatic myopericytoma one case, pancreatic lymphangioma one case. After ROC analysis, the areas under the ROC curve (Az) were 0.752 by BUS, 0.928 by CEUS to resident radiologist, and 0.896 by BUS, 0.954 by CEUS to staff radiologist. The correct diagnosis rate of specific disease was 42.6% by BUS, 64.8% by CEUS to staff radiologist (P < 0.05), and 33.3% by BUS, 53.7% by CEUS to resident radiologist (P < 0.05). The interobserver agreement in CEUS is higher than that in BUS, the Kappa value was 0.889 ± 0.062 and 0.428 ± 0.126 respectively.

Conclusion

Compared with BUS, CEUS can significantly enhance the diagnostic rate of pancreatic solid-cystic lesions.     

MR imaging of acute pancreatitis: Correlation of abdominal wall edema with severity scores

Objective

To study MRI findings of abdominal wall edema (AWE) in acute pancreatitis as well as correlations between AWE and the severity of acute pancreatitis according to the MR severity index (MRSI) and the Acute Physiology And Chronic Healthy Evaluation III (APACHE III) scoring system.

Materials and methods

A total of 160 patients with AP admitted to our institution between December 2009 and March 2011 were included in this study. MRI was performed within 48 h after admission. MRI findings of acute pancreatitis were noted, including AWE on the MRI. The abdominal wall area was divided into quarters, and each area involved was recorded as 1 point to score the severity of AWE. The severity of acute pancreatitis was studied using both the MRSI and the APACHE III scoring system. Spearman correlation of AWE with the MRSI and the APACHE III scoring system was analyzed.

Results

In 160 patients with acute pancreatitis, 53.8% had AWE on MRI. The average AWE score was 1.2 ± 1.4 points. The prevalence of AWE was 30.5%, 64.5% and 100% in mild, moderate and severe AP, respectively, according to MRSI. AWE on MRI was correlated with MRSI scores (r = 0.441, p = 0.000). According to APACHE III scores, the averages were 2.0 ± 1.1 and 2.6 ± 1.1 points in mild AP and severe AP, respectively (P = 0.016). AWE was slightly correlated with the APACHE III scores (r = 0.222, p = 0.005).

Conclusion

AWE on MRI in acute pancreatitis is common, which may be a supplementary indicator in determining the severity of AP.     

Clinical usefulness of free-breathing navigator-triggered 3D MRCP in non-cooperative patients: comparison with conventional breath-hold 2D MRCP

Purpose

To assess the clinical usefulness of free-breathing 3D MRCP in non-cooperative patients compared conventional breath-hold 2D MRCP.

Materials and methods

We performed FB navigator-triggered 3D MRCP using prospective acquisition correction and BH 2D MRCP in 48 consecutive, non-cooperative patients among 772 patients. Thirteen patients had malignant obstruction. Two radiologists independently graded the likelihood of a malignant obstruction, the overall image quality, and the visibility of ten, individual anatomic segments of both the biliary and pancreatic duct in each sequence. The area under the ROC curve and the repeated measures analyses of variance with multiple comparisons were used for the comparison. The κ statistics were used for interobserver agreement.

Result

The diagnostic performance for detecting malignancy was significantly higher on FB MRCP (A_z = 0.962) than on either BH SS-RARE (A_z = 0.820, P < 0.0185) or MS-HASTE MRCP (A_z = 0.816, P < 0.0067). Interobserver agreement was excellent for FB MRCP (κ = 0.889) and fair for both BH SS-RARE (κ = 0.578) and MS-HASTE MRCP (κ = 0.49). FB MRCP had a significantly higher technical quality than BH MRCP (P < 0.001). FB MRCP was seen to have statistically better visibility of peripheral IHD, right main IHD, CHD, cystic duct, and CBD than BH MRCP (P < 0.001). FB MRCP and BH SS-RARE MRCP had statistically better visibility of both the left main IHD and pancreatic duct than did BH MS-HASTE MRCP (P < 0.001).

Conclusion

FB 3D MRCP is useful for non-cooperative patients in whom conventional BH 2D methods cannot be used successfully.     

Cell apoptosis and proliferation inhibition of pancreatic cancer induced by sub-threshold focused ultrasound (FUS)

Objective

To evaluate the effects of sub-threshold focused ultrasound (FUS) sonication on the pancreatic cancer cell.

Materials and methods

The human pancreatic carcinoma cell line PaTu 8988t suspension and pancreatic carcinoma xenograft in nude mice were sonicated by FUS using sub-threshold doses. The temperature at the focus was controlled at below 60 °C. The cell apoptosis in vitro was tested by flow cytometer at 3, 6, 12, 24 and 48 h after FUS sonication. Colony formation was used to evaluate the cell growth inhibition of FUS in vitro. The tumor volume of the xenograft was measured before and after FUS sonication. Then the slides of the tumor were under hematoxylin–eosin (H&;E) staining and TdT-mediated dUTP nick end labeling (TUNEL) to evaluate the effect of FUS on pancreatic carcinoma xenograft in vivo.

Results

The maximum cell suspension temperature of the FUS sonication group was 55.8 ± 2.17 °C. The cell apoptosis rate peaked at 24 h after FUS sonication, the differences between the FUS sonication group and control group were statistically significant (P < 0.05). Colony formation rates were 50.40 ± 3.81% for the control group and 26.82 ± 2.88% for FUS sonication group (P < 0.05). For the xenografts in nude mice, the mean tumor volumes of the control group and the FUS sonication group 15 days after sonication were 1746.58 ± 312.77 mm³ and 1085.23 ± 217.13 mm³ (P < 0.05). H&;E staining and TUNEL assay showed both necrotic and apoptotic cells.

Conclusion

Sub-threshold FUS sonication could induce cell apoptosis and inhibit the proliferation of pancreatic cancer cells.     

Pancreatic multicenter ultrasound study (PAMUS)

Aim

To describe the typical CEUS pattern of pancreatic lesions and to evaluate the diagnostic accuracy of Contrast-enhanced ultrasound (CEUS) in their characterization.

Materials and methods

All US and CEUS examinations of focal pancreatic masses performed in six centers during a period of five years were reviewed. Inclusion criteria were: focal pancreatic mass pathologically proved, visible at ultrasound (US) and studied with CEUS. All lesions were then evaluated for size, aspect and enhancement pattern. Sensitivity, specificity, positive and negative predictive values with 95% CIs were calculated to define diagnostic accuracy of CEUS in respect to pathology. Diagnostic confidence of US and CEUS, discerning between benign and malignant lesions, were represented by using ROC (receiver operating characteristics) curves. Agreement was evaluated by means of k statistics.

Results

1439 pancreatic lesions were included. At CEUS the lesions were divided into solid (89%) and cystic (12%) masses and classified into six and eight categories, respectively. Among the solid lesions, adenocarcinomas were characterized with an accuracy of 87.8%. Among the cystic lesions, cystic tumors were diagnosed with an accuracy of 97.1%. ROC curve area increased from 0.637 for US to 0.877 for CEUS (p < 0.0001). Inter-observer agreement was slightly higher for solid (k = 0.78) than cystic (k = 0.62) lesions. In none of the centers side effects were reported.

Conclusion

CEUS is accurate in the characterization of pancreatic lesions. CEUS should be considered as a complementary imaging method for pancreatic lesions characterization.     

Dynamic MDCT of the pancreas: Is time–density curve morphology useful for the differential diagnosis of solid lesions? A preliminary report

Purpose

CT perfusion has been proposed for pancreatic lesion characterization. However, scan and analysis protocols influence numerical data. To overcome this, the purpose of our study is to evaluate the use of time–density curves obtained from MDCT perfusion of the pancreas for the characterization of normal parenchyma, adenocarcinoma, chronic pancreatitis and endocrine tumors.

Methods

31 patients with solid pancreatic lesions and 21 patients with renal cell carcinoma underwent 64-row MDCT perfusion of the pancreas after injection of 50 cc of a 370 mg I/ml solution at 5 cc/s. 63 time–density curves were obtained from normal parenchyma (21 patients), adenocarcinoma (25), endocrine tumors (4) and atrophic parenchyma (13). Two readers independently categorized the 63 time–density curves into 4 different morphologies: normal wash-in and wash-out (A), low wash-in followed by plateau (B), low wash-in followed by faint wash-out (C) and high wash-in and wash-out (D). Interobserver agreement was calculated with kappa statistics. Fisher test was used to calculate sensitivity, specificity, positive (PPV) and negative (NPV) predictive values for each type of curve.

Results

Interobserver agreement was very good (Kappa = 0.849). Curve A had 94.4% sensitivity, 91.1% specificity, 80.95% PPV, 97.6% NPV for ‘normal parenchyma’. Curve B had 74.19% sensitivity, 93.75% specificity, 92% PPV, 78.95% NPV in diagnosing ‘adenocarcinoma’. Curve C had 45.45% sensitivity, 84.62% specificity, 38.46% PPV, 88% NPV for ‘chronic pancreatitis’. Curve D had 100% sensitivity, 98.33% specificity, 75% PPV, 100% NPV for ‘endocrine tumor’.

Conclusions

The morphology of MDCT perfusion time–density curves appears to be useful in characterizing pancreatic lesions, and might help overcome the differences in scan and postprocessing techniques.     

Pancreatic iron stores assessed by magnetic resonance imaging (MRI) in beta thalassemic patients

Purpose

To assess the correlation between MRI findings of the pancreas with those of the heart and liver in patients with beta thalassemia; to compare the pancreas T2* MRI results with glucose and ferritin levels and labile plasma iron (LPI).

Materials and methods

We retrospectively evaluated chronically transfused patients, testing glucose with enzymatic tests, serum ferritin with chemiluminescence, LPI with cellular fluorescence, and T2* MRI to assess iron content in the heart, liver, and pancreas. MRI results were compared with one another and with serum glucose, ferritin, and LPI. Liver iron concentration (LIC) was determined in 11 patients’ liver biopsies by atomic absorption spectrometry.

Results

289 MRI studies were available from 115 patients during the period studied. 9.4% of patients had overt diabetes and an additional 16% of patients had impaired fasting glucose. Both pancreatic and cardiac R2* had predictive power (p < 0.0001) for identifying diabetes. Cardiac and pancreatic R2* were modestly correlated with one another (r² = 0.20, p < 0.0001). Both were weakly correlated with LIC (r² = 0.09, p < 0.0001 for both) and serum ferritin (r² = 0.14, p < 0.0001 and r² = 0.03, p < 0.02, respectively). None of the three served as a screening tool for single observations. There is a strong log–log, or power-law, relationship between ratio of signal intensity (SIR) values and pancreas R2* with an r² of 0.91.

Conclusions

Pancreatic iron overload can be assessed by MRI, but siderosis in other organs did not correlate significantly with pancreatic hemosiderosis.     

Distinction between upper and lower gastrointestinal perforation: usefulness of the periportal free air sign on computed tomography

Purpose

To evaluate the usefulness of the periportal free air (PPFA) sign on computed tomography (CT) to distinguish upper from lower gastrointestinal (GI) tract perforation.

Materials and methods

During a 30-month period, we retrospectively analyzed abdominal CT images of 53 consecutive patients with surgically proven GI tract perforation. We divided the patients into two groups, i.e. upper and lower GI tract perforation groups. According to the distribution of free air, we divided the peritoneal cavity into supramesocolic compartment and inframesocolic compartment. We observed the presence or absence of free air in each compartment in each group. When there was free air in the periportal area, it was defined as periportal free air (PPFA) and the sign was positive. To evaluate the usefulness of the PPFA sign, we compared the PPFA sign with the falciform ligament sign and the ligamentum teres sign, both of which are well-known CT signs of pneumoperitoneum. Statistical analyses were performed with univariate and multivariate analyses using SPSS version 11.5 for significant findings among the CT signs.

Results

Free air was seen in supramesocolic compartment in 29 of 30 (97%) patients in the upper GI perforation group and in 17 of 23 (74%) in the lower GI perforation group. Free air in inframesocolic compartment did not show significant difference in either group (p = .16). The PPFA sign was seen in 28 of 30 (93%) patients with upper GI tract perforation, but in only 8 of 23 (35%) patients with lower GI tract perforation (p < .0001). The falciform ligament sign was seen in 24 of 30 (80%) patients with upper GI tract perforation and in 10 of 23 (43%) patients with lower GI tract perforation (p = .020). The ligamentum teres sign was seen in 16 of 30 (53%) patients with upper GI tract perforation and in 2 of 23 (8%) patients with lower GI tract perforation (p = .008). Multivariate logistic regression analysis showed that the PPFA sign was the only variable, which adjusted odds ratio of 15.5 (p = .002).

Conclusion

The PPFA sign is a useful finding which can help to distinguish upper from lower GI tract perforation. When this sign is present, upper GI tract perforation is strongly suggested.     

Dual-energy CT-cholangiography in potential donors for living-related liver transplantation: improved biliary visualization by intravenous morphine co-medication

Purpose

To prospectively evaluate whether intravenous morphine co-medication improves bile duct visualization of dual-energy CT-cholangiography.

Materials and methods

Forty potential donors for living-related liver transplantation underwent CT-cholangiography with infusion of a hepatobiliary contrast agent over 40 min. Twenty minutes after the beginning of the contrast agent infusion, either normal saline (n = 20 patients; control group [CG]) or morphine sulfate (n = 20 patients; morphine group [MG]) was injected. Forty-five minutes after initiation of the contrast agent, a dual-energy CT acquisition of the liver was performed. Applying dual-energy post-processing, pure iodine images were generated. Primary study goals were determination of bile duct diameters and visualization scores (on a scale of 0 to 3: 0—not visualized; 3—excellent visualization).

Results

Bile duct visualization scores for second-order and third-order branch ducts were significantly higher in the MG compared to the CG (2.9 ± 0.1 versus 2.6 ± 0.2 [P < 0.001] and 2.7 ± 0.3 versus 2.1 ± 0.6 [P < 0.01], respectively). Bile duct diameters for the common duct and main ducts were significantly higher in the MG compared to the CG (5.9 ± 1.3 mm versus 4.9 ± 1.3 mm [P < 0.05] and 3.7 ± 1.3 mm versus 2.6 ± 0.5 mm [P < 0.01], respectively).

Conclusion

Intravenous morphine co-medication significantly improved biliary visualization on dual-energy CT-cholangiography in potential donors for living-related liver transplantation.     

Hepatic arterial perfusion increases in the early stage of severe acute pancreatitis patients: evaluation by perfusion computed tomography

Purpose

Although hepatic perfusion abnormalities have been reported in patients with acute pancreatitis, hepatic perfusion with severe acute pancreatitis (SAP) has not been quantitatively evaluated in humans. Therefore, we investigated hepatic perfusion in patients with SAP using perfusion CT.

Materials and methods

Hepatic perfusion CT was performed in 67 patients with SAP within 3 days after symptom onset. The patients were diagnosed as having SAP according to the Atlanta criteria. Fifteen cases were established as a control group. Perfusion CT was obtained for 54 s beginning with a bolus injection of 40 ml of contrast agent (600–630 mgI/kg) at a flow rate of 4 ml/s. Perfusion data were analyzed by the dual-input maximum slope method to obtain hepatic arterial perfusion (HAP) and hepatic portal perfusion (HPP). Finally, we compared HAP and HPP in SAP patients with those in the control group, respectively.

Results

Average HAP was significantly higher in SAP patients than in the control group (75.1 ± 38.0 vs. 38.2 ± 9.0 ml/min/100 ml; p < 0.001). There was no significant difference in average HPP between SAP patients and the control group (206.7 ± 54.9 vs. 204.4 ± 38.5 ml/min/100 ml; p = 0.92).

Conclusion

Using quantitative analysis on perfusion CT, we first demonstrated an increase of HAP in the right hepatic lobe in SAP patients.     

Diagnostic value of the delayed phase image for iso-attenuating pancreatic carcinomas in the pancreatic parenchymal phase on multidetector computed tomography

Purpose

To assess the value of the delayed phase (DP) in pancreatic carcinomas which appear iso-attenuating in the pancreatic parenchymal phase (PPP).

Materials and methods

Fifty-seven preoperative MDCT studies of pancreatic carcinomas were retrospectively reviewed. The size of the tumors, and the Hounsfield unit (HU) of the tumors and pancreatic parenchyma were measured. The tumor-to-pancreas contrast (TPC: |HU [tumor] − HU [normal pancreas]|) was calculated.

Results

Eight cases (14.0%) showed iso-attenuation and 49 showed hypo-attenuation in the PPP. The DP images revealed seven of eight (87.5%) iso-attenuating tumors to be hyper-attenuating. The size of iso-attenuating tumors was smaller than that of hypo-attenuating tumors (mean ± S.D.: 12.4 ± 4.8 mm vs. 30.3 ± 9.0 mm, p < 0.0001). In hypo-attenuating tumors, TPC in the PPP (60.2 ± 24.6 HU) was higher than those in the portal venous phase (PVP, 40.5 ± 23.0 HU, p < 0.0001) and DP (18.3 ± 11.8 HU, p < 0.0001). In contrast, in iso-attenuating tumors, TPC in the DP (26.0 ± 4.9 HU) was higher than those in the PPP (9.2 ± 3.7 HU, p = 0.0003) and PVP (7.1 ± 4.7 HU, p = 0.001) phases.

Conclusion

The DP image is helpful in depicting small iso-attenuating pancreatic carcinomas as slightly hyper-attenuating tumors.     

Predictive factors for complete excision and underestimation of one-pass en bloc excision of non-palpable breast lesions with the Intact(®) breast lesion excision system

Objective

Image-guided percutaneous biopsy is the recommended initial diagnostic procedure for suspicious mammographic lesions. This study was conducted to determine the accuracy of the Intact^® breast lesion excision system (BLES) and to identify predictive factors for complete excision and underestimation.

Material and methods

A prospective study was conducted between January 28, 2008 and April 30, 2009 on 166 biopsy procedures using Intact^® biopsy device. Diagnoses obtained from biopsy specimen were compared with to final diagnosis on surgical excision specimen.

Results

Of the 166 patients, 15 (9%) displayed lesions with cell atypia, 28 (17%) had an intra ductal carcinoma (IDC) and 9 (5%) had an invasive carcinoma. Eight of 15 patients with cell atypia had open surgical excision, and none showed underestimation. All patients with IDC underwent surgical excision: we found an invasive carcinoma in 6 cases (21.4% underestimation) and a complete removal of the lesion by the Intact^® BLES in 11 cases (39%). All 9 patients with invasive carcinoma had a surgical excision, with 1 complete removal of the lesion by Intact^® BLES. Multivariate analyses did not identify predictive factors for underestimation; clear margins ≥1 mm on biopsy specimen was the only independent predictive factor of complete excision (OR = 8.51, p = 0.02).

Conclusions

Intact^® BLES provides a safe alternative to vacuum assisted core needle biopsy (VACNB) with an underestimation rate comparable to those previously reported for VACNB. The high rate of complete removal of the lesions, particularly ISC, offers an interesting perspective of avoiding subsequent excisional surgery for small lesions and thus requires further confirmational study.     

Using low tube voltage (80kVp) quadruple phase liver CT for the detection of hepatocellular carcinoma: two-year experience and comparison with Gd-EOB-DTPA enhanced liver MRI

Purpose

To validate the diagnostic performance of quadruple phase low tube voltage liver CT through the comparison with Gd-EOB-DTPA enhanced liver MRI for the detection of HCC.

Materials and methods

Non-obese patients (38 men, eight women) with 68 HCCs underwent quadruple-phase CT at 16 MDCT (using low tube voltage, 80 kVp; moderately high tube current, 280 mAs) and Gd-EOB-DTPA-enhanced 3 T MRI. Three observers independently and randomly reviewed the CT and MR images on a tumor-by-tumor basis. The diagnostic accuracy of these techniques for detecting HCC was assessed using alternative free-response receiver operating characteristic analysis. Sensitivity and positive predictive values were evaluated. The mean effective doses for the low dose CT were also evaluated.

Results

The areas under the ROC curves were 0.963, 0.959, and 0.941 for low dose CT and 0.981, 0.982, and 0.976 for MRI. Differences in Az of the two techniques for each observer were not statistically significant (P > .05). Differences in sensitivity and positive predictive values between the two techniques for each observer were not also statistically significant: sensitivity (86.8%, 82.4%, 85.3% for CT and 95.6%, 94.1%, 91.2% for MRI) and positive predictive values (92.2%, 90.3%, 89.2% for CT and 92.9%, 92.8%, 92.5% for MRI). Six HCCs (8.8%) in five patients were observed only on hepatobiliary phase of MRI, and all were smaller than 1.5 cm. The mean effective dose for CT was approximately 10.2 mSv.

Conclusions

Quadruple-phase low-dose liver CT (80 kVp, 280 mAs) had relatively good diagnostic performance for detecting HCC in non-obese patients. Because no significant difference was observed between low-dose CT and MRI, the use of low-dose liver CT can be justified based on its reduced radiation effects.     

Clinical usefulness of the visibility of the transcerebral veins at 3T on T2*-weighted sequence in acute stroke patients

Objectives

The objective of this work was to investigate the clinical usefulness of the visibility of the transcerebral veins (VTV) in acute ischemic stroke patients at 3 T.

Methods

Sixty consecutive carotid artery territory stroke patients were included retrospectively. Two readers categorized the VTV on T2*-weighted sequence at 3 T for each hemisphere, and asymmetry of this sign was assessed between each hemisphere by an asymmetry index (AI) using a three-item scale. The VTV and AI were correlated with clinical and radiological covariates. Particular interest was focused on patients for whom initial diffusion-weighted imaging alone was inconclusive.

Results

VTV were detected in the stroke hemisphere in 58.3% (n = 35) and in the contralateral side in 10% (n = 6, p < 0.0001). Asymmetry of the VTV between ischemic and contralateral hemispheres was present in 53.3% (n = 32). Intracranial artery occlusion, final infarct volume and symptomatic hemorrhagic transformation were correlated with a higher AI at baseline (ρ = 0.563, ρ = 0.291, and ρ = 0.285, p < 0.05, respectively). Three hyperacute stroke patients with subtle DWI high signal intensity at admission demonstrated VTV.

Conclusions

The pathological value of the VTV seems to reside in its asymmetry between hemispheres, as it was correlated with important clinical parameters. This study also suggests that the VTV could be a supportive finding in stroke diagnosis, especially when DWI is unreliable.