Assessment of a New Elbow Joint Positioning Method Using Area Detector Computed Tomography.

We propose a sitting position that achieves both high image quality and a reduced radiation dose in elbow joint imaging by area detector computed tomography (ADCT), and we compared it with the 'superman' and supine positions. The volumetric CT dose index (CTDIvol) for the sitting, superman, and supine positions were 2.7, 8.0, and 20.0 mGy and the dose length products (DLPs) were 43.4, 204.7, and 584.8 mGy • cm, respectively. In the task-based transfer function (TTF), the highest value was obtained for the sitting position in both bone and soft tissue images. The noise power spectrum (NPS) of bone images showed that the superman position had the lowest value up to approx. 1.1 cycles/mm or lower, whereas the sitting position had the lowest value when the NPS was greater than approx. 1.1 cycles/mm. The overall image quality in an observer study resulted in the following median Likert scores for Readers 1 and 2: 5.0 and 5.0 for the sitting position, 4.0 and 3.5 for the superman position, and 4.0 and 2.0 for the supine position. These results indicate that our proposed sitting position with ADCT of the elbow joint can provide superior image quality and allow lower radiation doses compared to the superman and supine positions.

Risk factors for unsuccessful removal of central venous access ports implanted in the forearm of adult oncologic patients.

PURPOSE: To evaluate the risk factors for unsuccessful removal of a central venous access port (CV port) implanted in the forearm of adult oncologic patients. MATERIALS AND METHODS: This study included 97 adult oncologic patients (51 males, 46 females; age range, 30-88 years; mean age, 63.7 years) in whom removal of a CV port implanted in the forearm was attempted at our hospital between January 2015 and May 2021. Gender, age at removal, body mass index, and diagnosis were examined as patient characteristics; and indwelling period, indwelling side, and indication for removal were examined as factors associated with removal of a CV port. These variables were compared between successful and unsuccessful cases using univariate analysis. Then, multivariate analysis was performed to identify independent risk factors for unsuccessful removal of a CV port using variables with a significant difference in the univariate analysis. A receiver-operating characteristics (ROC) curve was drawn for significant risk factors in the multivariate analysis and the Youden index was used to determine the optimum cut-off value for predicting unsuccessful removal of a CV port. RESULTS: Removal of CV ports was successful in 79 cases (81.4%), but unsuccessful in 18 cases (18.6%) due to fixation of the catheter to the vessel wall. Multivariate logistic regression analysis showed that the indwelling period (odds ratio 1.048; 95% confidence interval 1.026-1.070; P < 0.0001) was a significant independent risk factor for unsuccessful removal of a CV port. ROC analysis showed that the cut-off value for successful removal was 41 months, and 54% of cases with an indwelling period > 60 months had unsuccessful removal. CONCLUSION: The indwelling period is an independent risk factor for unsuccessful removal of a CV port implanted in the forearm of adult oncologic patients, with a cut-off of 41 months.

Ultraselective transcatheter arterial embolization with small-sized microcoils for acute lower gastrointestinal bleeding.

PURPOSE: To evaluate the clinical outcome of ultraselective transcatheter arterial embolization (TAE) with small-sized microcoils for acute lower gastrointestinal bleeding (LGIB). MATERIALS AND METHODS: The subjects were 17 consecutive patients (mean age, 69 years) with LGIB who were treated with ultraselective TAE using small-sized microcoils between December 2013 and December 2019. Ultraselective TAE was defined as embolization of one or both of the long or short branches of the vasa recta. The etiologies of bleeding were colonic diverticulosis in 16 patients (94%) and malignancy in one patient (6%). The bleeding foci were in the ascending colon in 11 patients (65%), transverse colon in 2 patients (12%), and sigmoid colon in 4 patients (23%). A total of 18 branches (diameter: range 0.5-1.5 mm, mean 1.1 mm) of the vasa recta in 17 patients were embolized with small-sized microcoils (size range 1-3 mm, mean combined lengths of all microcoils 7.6 cm). The mean follow-up period was 19 months (range 1-80 months). The technical and clinical success rate, recurrent bleeding rate, major complications and long-term clinical outcomes were retrospectively evaluated. RESULTS: Technical and clinical success was achieved in all patients (17/17). The rates of early recurrent bleeding (within 30 days of TAE) and major complications were 0% (0/17). Recurrent bleeding occurred in one patient at 2 months after TAE, but was stopped with conservative treatment. There were no other bleeding episodes or complications in the follow-up period. CONCLUSION: Ultraselective TAE with small-sized microcoils is a highly effective and safe treatment modality for LGIB.

Utility of the Virtual Liver Parenchymal Perfusion Area Using a Commercially Available Workstation in Transarterial Chemoembolization for Hepatocellular Carcinoma.

PURPOSE: To evaluate the accuracy of the virtual liver parenchymal perfusion area using a commercially available workstation and liver analysis software in conventional transarterial chemoembolization (cTACE) for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This method was retrospectively applied to 29 treated HCCs in 23 patients. The virtual embolic area (VEA) was estimated based on cone beam computed tomography during hepatic arteriography using a commercially available workstation and liver analysis software by two observer groups (group A: experts; group B: semi-experts). The real embolic area (REA) was defined as the area where iodized oil accumulated on computed tomography at 1 week after cTACE. The REA was estimated by each of the two groups, and the mean REA between the groups (mREA) was used as a standard reference. Agreement of volume and cross-sectional area in three orthogonal planes between the VEA and mREA were analyzed using intraclass correlation coefficients (ICCs) and Bland-Altman plots. RESULTS: The ICCs for volume between VEA and mREA were 0.97 and 0.88 for groups A and B, respectively, and those for cross-sectional area were 0.94 and 0.88 for the axial plane, 0.95 and 0.83 for the coronal plane, and 0.87 and 0.74 for the sagittal plane, respectively. Thus, the overall agreement was excellent, except for the sagittal imaging plane in group B. CONCLUSION: This method using a commercially available workstation and liver analysis software can be useful for estimating the embolic area in cTACE.

Percutaneous drainage of psoas and iliopsoas muscle abscesses with a one-step technique under real-time computed tomography fluoroscopic guidance.

PURPOSE: To evaluate the utility and safety of drainage catheter installation for psoas/iliopsoas muscle abscesses using a one-step technique under the guidance of real-time computed tomography (CT) fluoroscopy. MATERIALS AND METHODS: Ten psoas or iliopsoas muscle abscesses in 7 patients that were treated with percutaneous drainage were included in this study. All drainage procedures were carried out using a one-step technique under real-time CT fluoroscopic guidance. RESULTS: The drainage catheter insertion was performed successfully with the one-step technique in all lesions. Improvements in the patients' symptoms and blood test results were seen after the drainage procedure in all cases. In addition, postoperative CT scans demonstrated that the abscesses had reduced in size or disappeared in all but one patient, who was transferred to another institution while the drainage catheter was still in place. No major complications were seen in any case. CONCLUSION: The one-step procedure is simple to perform. The percutaneous drainage of psoas or iliopsoas muscle abscesses with the one-step technique under real-time CT fluoroscopic guidance is accurate and safe. Moreover, compared with the two-step technique the one-step procedure results in a shorter drainage procedure and exposes the patient and operator to lower amounts of radiation. J. Med. Invest. 63: 323-327, August, 2016.

Three-dimensional CT for preoperative detection of the left gastric artery and left gastric vein in laparoscopy-assisted distal gastrectomy.

INTRODUCTION: We evaluated 3-D CT imaging for preoperative classification of the left gastric artery and vein in patients with early gastric cancer and estimated its clinical benefit. METHODS: Between April 2009 and March 2014, 279 patients underwent preoperative 3-D CT using a 64-row multi-detector CT scanner, followed by laparoscopy-assisted distal gastrectomy. The 3-D CT images of the arterial and portal phases were reconstructed and fused. The operative outcomes were compared between patients who had not undergone 3-D CT (2007-2008) and who had undergone 3-D CT (2009-2011). RESULTS: According to Adachi's classification, the numbers of type I, II, III, IV, V, and VI arterial patterns were 253, 15, 1, 3, 3, and 1, respectively. Three cases could not be classified. According to the Douglass classification, the left gastric vein flowed into the portal vein, splenic vein, junction of the portal vein and splenic vein, and left branch of the portal vein in 119, 111, 36, and 5 patients, respectively. The left gastric vein could not be visualized in six patients, and two patients could not be classified. In addition, the relation was absent for an Adachi type I vein and one of the "other" types of veins. The total operative time was significantly shorter with 3-D CT than without it (P = 0.01), and the degree of lymph-node dissection was significantly higher (P = 0.01). Inflammatory parameters and operative morbidity tended to decrease with 3-D CT. CONCLUSION: Three-dimensional CT is a useful modality to visualize the vessel anatomy around the stomach, and it improves clinical effectiveness and reduces the invasiveness of surgery.