Selection of peripheral intravenous catheters with 24-gauge side-holes versus those with 22-gauge end-hole for MDCT: A prospective randomized study.

PURPOSE: To compare the 24-gauge side-holes catheter and conventional 22-gauge end-hole catheter in terms of safety, injection pressure, and contrast enhancement on multi-detector computed tomography (MDCT). MATERIALS & METHODS: In a randomized single-center study, 180 patients were randomized to either the 24-gauge side-holes catheter or the 22-gauge end-hole catheter groups. The primary endpoint was safety during intravenous administration of contrast material for MDCT, using a non-inferiority analysis (lower limit 95% CI greater than -10% non-inferiority margin for the group difference). The secondary endpoints were injection pressure and contrast enhancement. RESULTS: A total of 174 patients were analyzed for safety during intravenous contrast material administration for MDCT. The overall extravasation rate was 1.1% (2/174 patients); 1 (1.2%) minor episode occurred in the 24-gauge side-holes catheter group and 1 (1.1%) in the 22-gauge end-hole catheter group (difference: 0.1%, 95% CI: -3.17% to 3.28%, non-inferiority P=1). The mean maximum pressure was higher with the 24-gauge side-holes catheter than with the 22-gauge end-hole catheter (8.16±0.95kg/cm2 vs. 4.79±0.63kg/cm2, P<0.001). The mean contrast enhancement of the abdominal aorta, celiac artery, superior mesenteric artery, and pancreatic parenchyma in the two groups were not significantly different. CONCLUSION: In conclusion, our study showed that the 24-gauge side-holes catheter is safe and suitable for delivering iodine with a concentration of 300mg/mL at a flow-rate of 3mL/s, and it may contribute to the care of some patients, such as patients who have fragile and small veins. (Trial registration: UMIN000023727).

MRI and 11C-methyl-L-methionine PET Differentiate Bevacizumab True Responders After Initiating Therapy for Recurrent Glioblastoma.

PURPOSE: Normalization of tumor vasculature after administering bevacizumab (BEV) makes assessment of therapeutic response using MRI difficult. The aim of this study was to clarify whether PET with C-methyl-L-methionine (MET-PET) would supplement MRI assessing of response after initiating BEV in glioblastoma. METHODS: Twenty patients with recurrent glioblastoma were treated with biweekly BEV plus temozolomide. Both MRI and MET-PET were performed before treatment (baseline) and at 4 and 8 weeks after starting treatment. Results on MRI (response or nonresponse) were compared with those on MET-PET, with response defined as a tumor-to-normal brain ratio of SUV (SUVT/N) of less than 1.6. Progression-free survival (PFS) was compared between responders and nonresponders on MRI alone and MET-PET alone. Progression-free survival was also compared between patients showing response on both MRI and MET-PET and patients showing response on MRI but nonresponse on MET-PET at each time point. RESULTS: PFS was significantly longer in responders than nonresponders on both MRI at 4 and 8 weeks and MET-PET at 8 weeks, whereas MET-PET at 4 weeks provided no information regarding outcomes. Combined assessment with MRI and MET-PET at 4 weeks was not provide predictive of PFS, whereas patients showing response on both modalities (true responders) at 8 weeks exhibited significantly longer PFS than did patients showing response on MRI but nonresponse on MET-PET (pseudoresponders). CONCLUSIONS: Combined assessment with MRI and MET-PET at 8 weeks can differentiate true responders who are predicted to show more favorable prognosis from pseudoresponders.

Clinical evaluation of (18)F-fludeoxyglucose positron emission tomography/CT using point spread function reconstruction for nodal staging of colorectal cancer.

OBJECTIVE: For patients with colorectal cancer, lymph node metastasis is a very important factor for prognostic and treatment determinations. Fluorine-18 fludeoxyglucose positron emission tomography/CT ((18)F-FDG-PET/CT) is among the useful tools for detecting lymph node metastasis. Recently, a new (18)F-FDG-PET/CT reconstruction technique for improving spatial resolution and signal-to-noise ratios, point spread function (PSF), has become available. We assessed the effect of PSF reconstruction on standardized uptake values and its diagnostic accuracy for lymph node staging in patients with colorectal cancer. METHODS: We retrospectively analysed records from patients with colorectal cancer who underwent (18)F-FDG-PET/CT for pre-operative staging. All positron emission tomography CT (PET/CT) examinations were reconstructed using ordered subset expectation maximization (OSEM) and OSEM + PSF. We compared sensitivities, specificities, positive-predictive values (PPVs), negative-predictive values (NPVs) and accuracies of conventional PET/CT (reconstructed with OSEM) and PSF-PET/CT (reconstructed with OSEM + PSF) for identifying lymph node metastases. We also analysed the diagnostic confidence level on a 5-point scale. RESULTS: With conventional PET/CT, the sensitivity, specificity, PPV, NPV and accuracy were 53.1%, 99.1%, 94.4%, 88.3% and 89.1%, respectively. With PSF PET/CT, the corresponding values were 65.6%, 99.1%, 95.4%, 91.2% and 91.8%, respectively. Conventional PET/CT and PSF PET/CT did not differ significantly in terms of N-stage definition (p = 0.125). However, the diagnostic confidence level of PSF PET/CT was significantly higher than that of conventional PET/CT (p < 0.01). CONCLUSION: PSF reconstruction might slightly increase sensitivity without impairing specificity. Moreover, this technique is expected to facilitate more confident radiological decisions when compared with conventional PET/CT. Advance in knowledge: This study demonstrates the clinical effectiveness of PSF PET/CT for lymph node staging in colorectal cancer.

[Failure to Remove Long-Term Indwelling Central Venous Catheters in Two Patients].

The use ofa central venous(CV)port system has become common for the treatment of patients with tumors. We report on the failure to remove CV catheters in 2 patients. The first patient was a 50 years woman with acute myeloid leukemia. She underwent CV port implantation via the left brachial approach 11 years previously. The second patient was an 80 years man with a lower gingival carcinoma. He underwent CV port implantation via the left brachial approach 6 years previously. CV catheter removal was attempted in both patients, but was unsuccessful because of strong adhesion to the vessel wall. Based on our experience, if catheter removal is impossible, its retention is more suitable.

Analyses of sexual dimorphism of reconstructed pelvic computed tomography images of contemporary Japanese using curvature of the greater sciatic notch, pubic arch and greater pelvis.

Three-dimensional pelvic images were reconstructed from multi-slice CT data of contemporary Japanese (males: 124; females: 104, 25-92 years old), and curvature analysis to examine sexual dimorphism was carried out in the great sciatic notch (GSN), the pubic arch and the greater pelvis in the images. Reconstructed pelvic CT images were visualized fairly well and anatomical landmarks were easily recognizable. When calculating the radii (curvature radii) of the best-fit circles for the spline curve lines set along the edges of the GSNs and of the pubic arches, sexes from these regions were correctly identified in 89.1% (males: 93.8%; females: 83.7%) and 94.7% (males: 97.3%; females: 91.8%) of cases, respectively, by setting an appropriate cut-off value. Furthermore, sexing was possible even in deeper regions of the GSN which are relatively resistant to postmortem damage. Curvature radii of the best-fit spheres of greater pelves showed no significant difference between sexes. However, curvature of the best-fit sphere for the left iliac fossa was significantly larger than that of the right one (p<10(-24)) in males, and the ratios were >1.0 in 88% of all male specimens analyzed. Meanwhile, no significant difference was observed among female samples. Although some left-sided dominancy has been reported in 2-dimensional measurements of the human pelvis, this 3-dimensional laterality in males was much more significant, and is a potential index of sex difference.

Interobserver agreement on the diagnosis of bowel ischemia: assessment using dynamic computed tomography of small bowel obstruction.

PURPOSE: The aim of this study was to evaluate the accuracy and interobserver variability of dynamic computed tomography (CT) for diagnosis of small bowel obstruction. METHOD AND MATERIALS: A total of 115 patients with a CT diagnosis of small bowel obstruction were included. Two radiologists and two residents performed blinded, independent, retrospective reviews of CT studies. Attention was focused on the presence of reduced early enhancement of the bowel wall and closed loop obstruction. Results were correlated with surgical findings in 15 cases and clinical follow-up in 100 cases. Sensitivity and specificity were calculated, and kappa statistics were used to analyze interobserver agreement. RESULTS: In all, 13 cases were surgically confirmed small bowel ischemia. Sensitivity, specificity, positive predictive value, and negative predictive value for the diagnosis of ischemia were 85%, 96%-97%, 73%-79%, and 97%-98%, respectively, for radiologists and 69%-93%, 93%-95%, 63%-64%, and 96%-99%, respectively, for residents. For agreement in the interpretations of reduced early enhancement of bowel wall, closed loop obstruction, and presence of bowel ischemia, the values were 0.62, 0.71, and 0.80, respectively, between radiologists and 0.57-0.70, 0.63-0.74, and 0.56-0.68, respectively, between radiologists and residents. CONCLUSION: There was moderate or substantial agreement for the diagnosis of small bowel ischemia between radiologists and residents. However, there was substantial agreement for the presence of closed loop obstruction.

Porous gelatin particles for uterine artery embolization: an experimental study of intra-arterial distribution, uterine necrosis, and inflammation in a porcine model.

PURPOSE: We evaluated the location of porous gelatin particles (GP; Gelpart; Nippon Kayaku/Astellas, Tokyo, Japan) within the arterial vasculature and their acute effects on uterine necrosis and inflammation after uterine artery embolization (UAE) in swine. MATERIALS AND METHODS: Adult nonpregnant pigs (n = 6) were allocated to either 1- (n = 3) or 2-mm GP (n = 3). Superselective and bilateral embolization of the uterine arteries was performed. All animals were killed 1 week after UAE. Macroscopic and microscopic findings, including the level of arterial occlusion and their effect on uterine necrosis and inflammation, were analyzed. RESULTS: All UAE procedures were completed without severe complications. The macroscopic necrosis was seen in two animals in the 2-mm group with an extent of <50%. The location of the occluded arteries did not differ significantly between groups. The median diameters of the occluded arteries were 449 microm (95% confidence interval [CI] 417-538 microm) in the 1-mm GP group and 484 microm (95% CI 370-560 microm) in the 2-mm GP group. As for microscopic necrosis, no statistically significant difference was observed. The qualitative inflammatory reaction was significantly greater in the 2-mm GP group than in the 1-mm group (p < 0.001). CONCLUSIONS: Both 1- and 2-mm GP occluded the arteries relevant to the target diameter for UAE in porcine uterus, presumably due to the plastic deformity. Both sizes of GP were associated with limited areas of necrosis; however, evaluation of inflammatory reaction was preliminary. Further study with adequate evaluation of inflammatory reactions is suggested.

Analyses of sexual dimorphism of contemporary Japanese using reconstructed three-dimensional CT images--curvature of the best-fit circle of the greater sciatic notch.

We examined various expression methods of sexual dimorphism of the greater sciatic notch (GSN) of the pelvis in contemporary Japanese residents by analyzing the three-dimensional (3D) images reconstructed by multi-slice computed tomography (CT) data, using image-processing and measurement software. Mean error of anthropological measurement values between two skeletonized pelves and their reconstructed 3D-CT images was 1.4%. A spline curve was set along the edge of the GSN of reconstructed pelvic 3D-CT images. Then a best-fit circle for subsets of the spline curve, 5-60mm in length and passing through the deepest point (inflection point) of the GSN, was created, and the radius of the circle (curvature radius) and its ratio to the maximum pelvic height (curvature quotient) were computed. In analysis of images reconstructed from CT data of 180 individuals (male: 91, female: 89), sexes were correctly identified in with 89.4% of specimens, with a spline curve length of 60mm. Because sexing was possible even in deeper regions of the GSN, which are relatively resistant to postmortem damage, the present method may be useful for practical forensic investigation.

Cerebral air embolism treated with hyperbaric oxygen therapy following percutaneous transthoracic computed tomography-guided needle biopsy of the lung.

A 71-year-old man presented with cough and sputum for 12 months. Chest radiography showed a homogeneous opacity in the right lower lobe. Computed tomography (CT) showed a nodular opacity, 2 cm in diameter, in the posterior segment of the right lower lobe. Mild emphysematous changes were also seen. With the patient in a prone position, a 19-gauge 7.8-cm introducer was placed in the lesion during a single inspiratory breath-hold. A coaxial 20-gauge automated needle was inserted through the introducer using a biopsy gun. Although the patient did not complain of any symptoms, postbiopsy CT showed air in the left ventricle and ascending aorta. After 5 h of bed rest, we found weakness in his left lower extremity. He was transferred to a hyperbaric oxygen chamber and recovered the next day. Air embolism is a rare, potentially fatal complication of percutaneous lung biopsy. Although the true effect of hyperbaric oxygen therapy is controversial, knowledge regarding the prompt management of such cases may help radiologists who perform this procedure.

Impact of multislice CT angiography on planning of radiological catheter placement for hepatic arterial infusion chemotherapy.

The objective of this study was to assess prospectively the role of multislice CT angiography (MSCTA) on planning of radiological catheter placement for hepatic arterial infusion chemotherapy (HAIC). Forty-six patients with malignant liver tumors planned for HAIC were included. In each patient, both MSCTA and intra-arterial digital subtraction angiography (DSA) were performed, except one patient who did not undergo DSA. Comparison of MSCTA and DSA images was performed for the remaining 45 patients. Detectability of anatomical variants of the hepatic artery, course of the celiac trunk, visualization scores of arterial branches and interobserver agreement, presence of arterial stenosis, and technical outcome were evaluated. Anatomical variations of the hepatic artery were detected in 19 of 45 patients (42%) on both modalities. The course of the celiac trunk was different in 12 patients. The visualization scores of celiac arterial branches on MSCTA/DSA were 3.0 +/- 0/2.9 +/- 0.2 in the celiac trunk, 3.0 +/- 0/2.9 +/- 0.3 in the common hepatic artery, 2.9 +/- 0.2/2.9 +/- 0.3 in the proper hepatic artery, 2.9 +/- 0.3/2.9 +/- 0.4 in the right hepatic artery, 2.8 +/- 0.4/2.9 +/- 0.4 in the left hepatic artery, 2.9 +/- 0.2/2.9 +/- 0.3 in the gastroduodenal artery, 2.1 +/- 0.8/2.2 +/- 0.9 in the right gastric artery, and 2.7 +/- 0.8/2.6 +/- 0.8 in the left gastric artery. No statistically significant differences exist between the two modalities. Interobserver agreement for MSCTA was equivalent to that for DSA. Two patients showed stenosis of the celiac trunk on both modalities. Based on these imaging findings, technical success was accomplished in all patients. In conclusion, MSCTA is accurate in assessing arterial anatomy and abnormalities. MSCTA can provide adequate information for planning of radiological catheter placement for HAIC.