Sequential variation in brain functional magnetic resonance imaging after peripheral nerve injury: A rat study.

Although treatment protocols are available, patients experience both acute neuropathic pain and chronic neuropathic pain, hyperalgesia, and allodynia after peripheral nerve injury. The purpose of this study was to identify the brain regions activated after peripheral nerve injury using functional magnetic resonance imaging (fMRI) sequentially and assess the relevance of the imaging results using histological findings. To model peripheral nerve injury in male Sprague-Dawley rats, the right sciatic nerve was crushed using an aneurysm clip, under general anesthesia. We used a 7.04T MRI system. T2* weighted image, coronal slice, repetition time, 7 ms; echo time, 3.3 ms; field of view, 30 mm × 30 mm; pixel matrix, 64 × 64 by zero-filling; slice thickness, 2 mm; numbers of slices, 9; numbers of average, 2; and flip angle, 8°. fMR images were acquired during electrical stimulation to the rat's foot sole; after 90 min, c-Fos immunohistochemical staining of the brain was performed in rats with induced peripheral nerve injury for 3, 6, and 9 weeks. Data were pre-processed by realignment in the Statistical Parametric Mapping 8 software. A General Linear Model first level analysis was used to obtain T-values. One week after the injury, significant changes were detected in the cingulate cortex, insular cortex, amygdala, and basal ganglia; at 6 weeks, the brain regions with significant changes in signal density were contracted; at 9 weeks, the amygdala and hippocampus showed activation. Histological findings of the rat brain supported the fMRI findings. We detected sequential activation in the rat brain using fMRI after sciatic nerve injury. Many brain regions were activated during the acute stage of peripheral nerve injury. Conversely, during the chronic stage, activation of the amygdala and hippocampus may be related to chronic-stage hyperalgesia, allodynia, and chronic neuropathic pain.

Pancreaticobiliary Juice Reflux in Patients With a Morphologically Normal Ductal System: Assessment Using Unenhanced MRI With Spin Labeling.

OBJECTIVE: The purpose of this article is to evaluate pancreaticobiliary reflux and to assess its correlation with clinical findings in patients without morphologic pancreaticobiliary maljunction by using a new MRI technique. MATERIALS AND METHODS: A total of 320 consecutive patients with suspected pancreaticobiliary diseases underwent MRCP and flow analysis by MRI. MRI flow analysis, clinical, and laboratory findings of each patient were retrospectively reviewed. The visible pancreaticobiliary reflux was graded on a 5-point confidence scale. RESULTS: Among all 320 patients with pancreatic juice reflux, 14.1% had reflux scored as grades 4 and 5 combined, and 5.0% had reflux scored as grade 5. By univariate analysis and multivariate analysis, a relatively long common channel was found to be the only significant causal factor for pancreatic juice reflux. Of patients with pancreatic juice reflux of grade 4 or 5, 11.1% (5/45) also had biliary malignancies; 18.8% (3/16) of those with pancreatic juice reflux of grade 5 had biliary malignancies. Conversely, pancreatic juice reflux of grade 4 or 5 occurred in 35.7% (5/14) of patients with biliary malignancies, and reflux of grade 5 occurred in 21.4% (3/14) of those patients. CONCLUSION: It was possible to evaluate pancreaticobiliary reflux using an MRI technique that may be suitable as a screening tool. Our results revealed that pancreaticobiliary reflux is relatively frequent in individuals without pancreaticobiliary maljunction.

Direct visualization of pancreatic juice flow using unenhanced MRI with spin labeling can be aid in diagnosing chronic pancreatitis.

OBJECTIVE: The purpose of this study is to prospectively assess whether direct visualization of pancreatic juice flow using an unenhanced MRI technique with spin labeling can aid in the diagnosis of chronic pancreatitis. SUBJECTS AND METHODS: Ten healthy volunteers and 50 patients who were categorized as having no chronic pancreatitis (n = 11), early chronic pancreatitis (n = 7), or established chronic pancreatitis (n = 32) underwent MRI, including direct pancreatic juice visualization using a flow-out technique with a time-spatial labeling inversion pulse, comprising a nonselective inversion recovery pulse immediately followed by a spatially selective inversion labeling pulse. The mean velocities and volumes of pancreatic juice excretion were also obtained. Variance tests were used to evaluate the clinical groups with respect to the appearance rate and mean velocity; the Kruskal-Wallis test was used for volume. RESULTS: There were no significant differences between healthy volunteers and patients with no chronic pancreatitis. The appearance rate, mean velocity, and volume of pancreatic juice excretion tended to decrease with the degree of chronic pancreatitis. Although the difference in these values was statistically significant between the healthy group and the established chronic pancreatitis group, the values of the early group and other groups were not statistically significant. There was a significant correlation between the appearance rate of pancreatic juice and the clinical groups (τ = -0.4376, p = 0.0015). CONCLUSION: The measurement of directly visualized pancreatic juice flow may aid in establishing the diagnosis of chronic pancreatitis.

High b-value diffusion-weighted MRI for detecting gallbladder carcinoma: preliminary study and results.

The aim of this preliminary study was to retrospectively evaluate the usefulness of high b-value diffusion-weighted MR imaging (DWI) in the detection of gallbladder carcinoma. Fifteen patients with gallbladder carcinoma and 14 other patients were included in this study. All patients and subjects underwent DWI, and images were evaluated by two radiologists. The area under the receiver operating characteristic curve (AUC), apparent diffusion coefficient (ADC) measurement, sensitivity and specificity were calculated. An AUC yielded 0.980 (95% CI, 0.850-0.999) and 0.941 (95% CI, 0.791-0.990) for the two radiologists. The mean sensitivity and specificity were 83.3% and 100%, respectively. The mean ADC value of gallbladder carcinoma was (1.28 +/- 0.41)x10(-3) mm(2)/s and that of control gallbladder lesions was (1.92 +/- 0.21)x10(-3) mm(2)/s (P < 0.01). According to the results of our preliminary study, high b-value DWI might be a useful tool for detecting gallbladder carcinoma by measuring the ADC value and direct visual assessment.

Cystic artery and cystic duct assessment with 64-detector row CT before laparoscopic cholecystectomy.

PURPOSE: To retrospectively assess 64-detector row computed tomography (CT) in the preoperative depiction of the cystic duct and cystic arteries in and around the Calot triangle. MATERIALS AND METHODS: Institutional review board approval was obtained, with waiver of informed consent. A total of 245 consecutive patients (133 men, 112 women), including 48 patients who subsequently underwent cholecystectomy, were examined. Two independent observers evaluated the CT data set on the basis of axial sections, coronal and sagittal multiplanar reformations, and three-dimensional volume rendering. The relationship between the cystic arteries and the Calot triangle--which is bordered by the undersurface of the liver, common hepatic duct, and cystic duct--was also evaluated, and each patient was classified on the basis of the origin of the cystic arteries and the course to the Calot triangle. Statistical analysis was performed, and percentages and confidence intervals were calculated. RESULTS: The cystic arteries were delineated in 234 of the 245 patients. Both the Calot triangle and the cystic arteries were delineated in 223 patients. One cystic artery was seen in the Calot triangle in 173 patients, and two cystic arteries were seen in the Calot triangle in 12. One artery in the Calot triangle with accessory arteries from different origins outside the Calot triangle was seen in 18 patients, and no cystic artery was identified in 20. Cystic arteries were seen in 42 (92%; 95% confidence interval: 87%, 98%) of the 48 patients who subsequently underwent cholecystectomy. The relationship between the cystic arteries and the Calot triangle was in agreement with the surgical records for all patients. CONCLUSION: The configuration of the cystic duct and cystic arteries can be depicted preoperatively with 64-detector row CT in patients scheduled to undergo cholecystectomy.

Pd(OAc)2-catalyzed carbonylation of amines.

A phosphine-free catalytic system [Pd(OAc)2-Cu(OAc)2-air] induced a substrate-specific carbonylation of amines in boiling toluene under CO gas (1 atm). Symmetrical N,N'-dialkylureas were obtained by the carbonylation of primary amines. N,N,N'-Trialkylureas were selectively formed by addition of a secondary amine to the above reaction vessel. Secondary amines did not give tetraalkylureas. However, dialkylamines with a phenyl group on their alkyl chains, such as N-monoalkylated benzylic amine or phenethylamine derivatives, underwent a direct aromatic carbonylation to afford five- or six-membered benzolactams. In the carbonylation, the chelation effect or steric repulsion between Pd(II) and the meta-substituent in the ortho-palladation and the ring sizes of cyclopalladation products that were formed prior to carbonylation were found to generate good site selectivity and increase the reaction rate. In contrast, carbonylation of omega-arylalkylamines with a hydroxyl group gave neither ureas nor benzolactams but instead produced 1,3-oxazolidinones smoothly. Hydrochlorides of amines also underwent carbonylation to afford the corresponding amides under the conditions used. This procedure made it possible to prepare ureas of amino acid esters and N-alkylcarbamates in practical yields.

[Phase III additional clinical study of 111In-pentetreotide (MP-1727): diagnosis of gastrointestinal hormone producing tumors based on the presence of somatostatin receptors].

Additional phase III multicenter clinical study was performed to investigate the efficacy, safety, and usefulness of somatostatin receptor scintigraphy using 111In-pentetreotide (MP-1727), which binds to somatostatin receptors. Forty patients were included in the study; Group A: 18 patients, gastrointestinal hormone producing tumors had been detected with conventional imaging modalities, Group B: 22 patients, no tumors had been detected with conventional imaging modalities in spite of high serum hormone levels. By comparing the results of the octreotide suppression test, 12/16 cases (75.0%) of Group A and 11/19 cases (57.9%) of Group B were assessed as "effective." By comparing the results of immunohistological examination, 5/9 cases (55.6%) of Group A and 2/4 cases (50.0%) of Group B were assessed as "effective." Severe adverse events were not observed in any of the evaluable 35 cases. MP-1727 was judged as clinically useful in 11/16 cases (68.8%) of Group A and 5/19 cases (26.3%) of group B. These results suggest that MP-1727 scintigraphy is very useful for the diagnosis and decision of the therapeutic strategy of gastrointestinal hormone producing tumors.

Evaluation of 18F-FDG PET in patients with advanced, metastatic, or recurrent gastric cancer.

UNLABELLED: PET with 18F-FDG has been widely used in oncology, but its application for stomach neoplasms has been limited. The aim of this study was to evaluate the visual diagnostic accuracy of (18)F-FDG PET for advanced, metastatic, or recurrent gastric cancer and to generate semiquantitative values for lesions. METHODS: 18F-FDG PET scans were obtained on 42 patients (29 men, 13 women; age, 27-78 y; median age, 63 y): 20 patients with a PT931/04 scanner and 22 patients with a SET2400W scanner. The PT931/04 has a spatial resolution of 6.0 mm at full width at half maximum (FWHM) and covers 15 cm above and below the targeted lesion, and the SET2400W has a spatial resolution of 3.9 mm at FWHM and images the entire body. All PET images were interpreted visually, and tracer uptakes were quantitated as standardized uptake values (SUVs) on SET2400W images. RESULTS: The sensitivity, specificity, and accuracy as a whole were as follows: 71%, 74%, and 73%, respectively, with the SET2400W scanner and 47%, 79%, and 62%, respectively, with the PT931/04 scanner. Values were high for primary lesions, liver, lymph node, and lung metastases, but were low for bone metastases, ascites, peritonitis, and pleuritis carcinomatoses. SUVs were 8.9 +/- 4.2 (primary lesions, 19 patients/19 lesions), 6.5 +/- 2.2 (liver, 9/55), 6.1 +/- 2.5 (lymph nodes, 14/38), 6.5 +/- 1.8 (abdominal wall, 4/7), 3.9 +/- 2.0 (bone, 3/27), and 4.7 +/- 2.6 (lung, 2/3). Comparing SUVs and histologic findings for 17 untreated patients, values for well-differentiated and moderately differentiated adenocarcinomas versus poorly differentiated adenocarcinomas and signet ring cell carcinomas were 13.2 +/- 6.3 (4/4) versus 7.7 +/- 2.6 (13/13) (P < 0.05) for the primary lesions, 7.0 +/- 2.4 (5/39) versus 5.6 +/- 2.8 (2/2) for the liver, and 5.5 +/- 1.9 (9/28) versus 8.8 +/- 3.3 (3/8) (P < 0.05) for the lymph nodes. CONCLUSION: Our results indicate that 18F-FDG PET is a useful diagnostic modality for advanced, metastatic, or recurrent gastric cancer but not for detecting bone metastases, peritonitis, or pleuritis carcinomatoses. 18F-FDG uptake by gastric cancers is relatively high but does not parallel histopathologic features of malignancy.

Regional differences in distribution volume of I-123 IMP in the human brain: effect on CBF calculated by ARG method.

OBJECTIVE: Two methods of quantitating cerebral blood flow (CBF) with iodine-123-labeled N-isopropyl-p-iodoamphetamine (I-123 IMP) and a two-compartment model had been proposed; one is the table look-up (TLU) method and the other is the autoradiographic (ARG) method. The TLU method provides values of the cerebral blood flow (CBF) values and distribution volume of I-123 IMP (Vd) independently. In the ARG method, a fixed Vd is applied for the entire brain to calculate CBF. Our purpose was to evaluate regional differences in Vd in the human brain, or possible effects of regional differences in Vd on CBF calculated by the ARG method. METHODS: In the present study, two SPECT scans were acquired from each of eight normal subjects (aged 44.0 +/- 16.7) at 40 min and 180 min of mid-scan-time after intravenous 1 min infusion of 111 MBq IMP. A single arterial blood sampling was performed 10 min after the IMP infusion. All images were anatomically normalized and analyzed with SPM99 and Matlab. We generated CBF and Vd images for each subject by the TLU method and evaluated differences in Vd among brain structures. We subsequently generated another set of CBF images by the ARG method and examined differences between CBF calculated by the TLU method and that by the ARG method. RESULTS: Significant main effects of subject and brain structure in Vd were observed (two-way ANOVA). Vd values were higher in the deep gray matter than in the cerebral cortical regions. Among the cerebral cortical regions, no significant difference in Vd was observed. In spite of the significant differences in Vd among the brain structures, the voxel-by-voxel analyses as well as the ROI analyses revealed no statistically significant difference between CBF calculated by the TLU method and that by the ARG method. CONCLUSIONS: Although regional differences in Vd were observed, the present results support the assumption that a fixed Vd does not cause significant error in the calculation of CBF by the ARG method.

Lymphatic mapping and gamma probe guided laparoscopic biopsy of sentinel lymph node in patients with clinical stage I testicular tumor.

PURPOSE: We attempted to detect lymphatic drainage and sentinel lymph node with radioactive tracer in patients with testicular tumor. We then tried to determine if sentinel lymph node biopsy with gamma probe guided laparoscopic procedure was feasible as a staging tool for patients with clinical stage I testicular tumor. MATERIALS AND METHODS: Technetium-labeled phytate was injected around the tumor in 15 consecutive patients with clinical stage I testicular tumor. Lymphatic drainage and sentinel lymph nodes were imaged by a gamma camera. Localization of the sentinel lymph node was confirmed with a handheld gamma probe. After we confirmed that sentinel lymph nodes were detected in the initial 10 patients, gamma probe guided laparoscopic sentinel lymph node biopsy was performed after routine orchiectomy in the next 4. To confirm whether the radioactive node was really a sentinel lymph node the final patient in this series underwent laparoscopic retroperitoneal lymph node dissection with a unilateral template. RESULTS: Sentinel lymph nodes were detected in all patients by lymphoscintigraphy and handheld gamma probe, and each node varied. Right tumors in sentinel lymph node were detected at the inter-aortocaval, paracaval or common iliac region. Para-aortic lymph nodes were detected as sentinel lymph node in cases of left tumor. In the 4 patients who underwent gamma probe navigated laparoscopic procedure sentinel lymph nodes were easily detected and safely removed for pathological examination. In the last patient who underwent laparoscopic lymph node dissection micrometastasis was found only at the sentinel lymph node. CONCLUSIONS: Sentinel lymph node can be detected by lymphoscintigraphy and handheld gamma probe. Gamma probe guided laparoscopic biopsy of sentinel lymph node is technically possible. These techniques may have a role in the management of clinical stage I testicular tumor but further trials are required for establishment of the concept of sentinel lymph node in testicular tumor.

[Performance evaluation of dual-head coincidence gamma camera for positron imaging].

AIM AND METHODS: We assessed the performance evaluation of a dual-head coincidence gamma camera (Millennium VG, General Electric, Milwaukee, USA) as a positron emission tomography (PET) scanner based on the measurement indicator for performance evaluation of PET device. RESULTS: The axial spatial resolution was 4.98 mm FWHM at the center of the field of view. The true high count-rate characteristic curve was relatively straight within the range 0-0.2 microCi/ml. The relative recovery coefficient was 0.1 with a diameter of 10 mm and 0.39 with a diameter of 20 mm. CONCLUSION: In this study, we had to make a some change in the protocols described in the measurement indicator for performance evaluation of PET devices.