Kim C, et al. Korean J Radiol. 2020 Jul;21(7):838-850. https://doi.org/10.3348/kjr.2019.0711

This study quantified the impact of respiratory motion on liver stiffness measurements according to different shear wave elastography (SWE) techniques and region of interest (ROI) methods, using liver fibrosis phantoms. Three operators measured stiffness values in four phantoms with different stiffness on a moving platform with two SWE techniques (point-SWE [pSWE] and 2-dimensional SWE [2D-SWE]), three types of motion (static mode and moving mode at low and high speeds), and four ROI methods in 2D-SWE (circle, point, box, and multiple). The circular ROI method was used to compare the two SWE techniques. The occurrence of technical failure and unreliable measurements, stiffness values, and measurement time were evaluated. Technical failure was observed only in moving mode for pSWE and 2D-SWE (n=1 for both). Unreliable measurements were also only observed in moving mode and were significantly less common in 2D-SWE (n=1) than in pSWE (n=12) (P<0.001). No statistically significant differences in the technical failure rate or stiffness values were noted between the static and moving modes for both SWE techniques. The technical failure and unreliable measurement rates were not significantly different among the ROI methods for 2D-SWE. Stiffness values did not differ significantly according to the ROI method used in any moving mode. However, the multiple ROI method had significantly shorter measurement times than the circular ROI method for all moving modes. 2D-SWE may be preferable for evaluating liver fibrosis in patients with poor breath-hold. Furthermore, 2D-SWE with multiple ROIs enables rapid measurements, without affecting liver stiffness values.

We aimed to evaluate the feasibility and safety of long-term balloon indwelling technique for the treatment of single benign biliary stricture. Five patients with single benign biliary stricture were included from December 2014 to November 2016. The patients were three men and two women with a mean age of 50 years (range, 30-65 years). A balloon catheter was inserted into the drainage catheter and emerged through the side hole of the catheter so that the balloon and drainage catheters could be placed together at the stricture site. Follow-up fluoroscopic examination was performed at least once every 2 weeks to evaluate the adequacy of expansion and location of the balloon. The balloon was reinflated at each session, and then removed after an approximately two-month indwelling period. The catheters used were 10-16 French and the diameter of indwelling balloons were 4-8 mm. The primary technical and clinical success rates were 100%. Maintenance of the balloon location was achieved in 25 of 26 follow-up fluoroscopic examinations (mean, 5.2 times per patient) with a rate of 96.1%. The mean follow-up period after successful removal of the balloon was 542.2 days (range, 93-1042 days), and there were no recurrences in the five cases. The long-term balloon indwelling technique is a good way to induce maximal dilatation at the stricture site without large diameter skin and subcutaneous tract dilatation and can be successfully used for single benign biliary stricture.

This study aimed to validate the accuracy of the peripherally inserted central catheter (PICC) length prediction formula using only anteroposterior chest radiographs (AP-CXR) and the technical feasibility of bedside ultrasound-guided PICC placement. This study included 156 Asian adult patients who underwent bedside PICC placement at three hospitals from September 2021 to March 2022. The shortest straight-line distance from the cubital crease to the puncture point (CP) was measured first. Using the formula of a previous study, the CP + estimated PICC length (eCL) was calculated with the parameters measured on AP-CXR. The formula was as follows: 19.409 + 0.424 × (MHTD, maximal horizontal thoracic diameter) + 0.287 × (CL, clavicle length) + 0.203 × (DTV, distance of thoracic vertebrae) + (2VBUs, two vertebral body units below the carina inferior border) (if from the left, 3.063cm was added; if female, 0.997cm was subtracted). Catheters were pretrimmed according to calculated eCL prior to the procedure. Technical success was evaluated, and the validation success of catheter length prediction was classified according to the catheter tip position as follows: optimal position or suboptimal position. Technical success was achieved in 153 cases (98.1%). Evaluation of validation success revealed that the position was “optimal” in 108 cases (70.6%) and “suboptimal” in 45 cases (29.4%). There was no validation failure. There was no case where the catheter was inserted too deep as to wedge into the right atrial wall. In conclusion, the PICC could be positioned accurately using the formula based on only AP-CXR. Furthermore, this bedside procedure was technically feasible.

To investigate the effectiveness of intraprocedural dual-phase cone-beam computed tomography (CBCT) in detecting hepatocellular carcinoma (HCC) during conventional transcatheter arterial chemoembolization (TACE) and its effect on improving treatment outcomes. Between November 2018 and November 2019, data from 111 patients with unresectable HCCs (N = 263 lesions) were reviewed retrospectively. All patients had undergone baseline magnetic resonance imaging (MRI) scans within one month prior to the procedure. Both arterial-phase (AP) and delayed-phase CBCT images were acquired during all conventional TACEs. Each HCC detection rate when read by AP-CBCT and when read by dual-phase (DP) CBCT including both AP and delayed phase was compared with that of MRI, and the diagnosis of HCC was based on MRI. Additionally, the follow-up results concerning lipiodol uptake status and tumor response of the lesions detected only by AP-/DP-CBCT were analyzed and compared with MRI-only detected lesions. The overall sensitivity of DP-CBCT (94.7%) was significantly higher than that of AP-CBCT (89.0%) (p = 0.003). In particular, the rate of subcentimeter HCC detection by DP-CBCT was pronounced (91.5% vs. 80.3%) (p = 0.01). Lesions found only by DP-CBCT exhibited positive lipiodol uptake (n = 31/31; 100%) and showed complete or partial responses (n = 24/31; 77.4%) on follow-up CT imaging, while MRI-only detected lesions had less lipiodol uptake (n = 6/14, 42.9%) and complete or partial responses (n = 4/14; 28.6%) (p ≤ 0.001). DP-CBCT imaging during TACE enabled better detection of HCCs than when using AP-CBCT alone, and AP- and DP-CBCT is superior to MRI in detecting chemoembolization-sensitive lesions. This resulted in increased detectability of HCCs and the achievement of better treatment outcomes.

Purpose: To develop formulas that predict the optimal length of a peripherally inserted central catheter (PICC) from variables measured on anteroposterior (AP) chest radiography (CXR). Materials and methods: A total of 134 patients who underwent PICC insertion at the angiography suites were included. Clinical information such as patient height, weight, sex, age, cubital crease to inferior carina border length (CCL), and approach side were recorded. The following variables via measurement on AP-CXR were also collected: (1) distance from the T1 to T12 vertebra (DTV), (2) maximal horizontal thoracic diameter (MHTD), and (3) clavicle length (CL). Results: Significant correlations between CCL and the following variables were identified in linear regression analyses: approach side, height, weight, sex, DTV, MHTD, and CL. Multiple regression results motivated the following two formulas: (1) with height data, estimated CCL (cm) = 12.429 + 0.113 × Height + 0.377 × MHTD (if left side, add 2.933 cm, if female, subtract 0.723 cm); (2) without height data, estimated CCL = 19.409 + 0.424 × MHTD + 0.287 × CL + 0.203 × DTV (if left side, add 3.063 cm, if female, subtract 0.997 cm). Estimated final PICC length can be calculated as (Estimated CCL, cm) + 4.0 (distance from inferior carina border to about 2.0 vertebra body unit, cm) − (distance from set cubital crease to designated puncture point, cm). Conclusion: This study suggests new formulas to predict the appropriate PICC length for bedside insertion using previous AP-CXRs. With this formula, ideal positioning of the catheter’s tip can be achieved in the clinical practice, avoiding or minimalizing the exposed catheter out of skin. These formulas may be helpful for patients who cannot undergo intra-hospital transport due to hemodynamic instability or who are concerned about isolation precautions due to any infectious-related contamination.