Mechanical Properties of a 3 Dimensional-Printed Transparent Flexible Resin Used for Vascular Model Simulation Compared with Those of Porcine Arteries.

PURPOSE: To develop a vascular intervention simulation model that replicates the characteristics of a human patient and to compare the mechanical properties of a 3-dimensional (3D)-printed transparent flexible resin with those of porcine arteries using the elastic modulus (E) and kinetic friction coefficient (µk). MATERIALS AND METHODS: Resin plates were created from a transparent flexible resin using a 3D printer. Porcine artery plates were prepared by excising the aorta. E values and the adhesive strengths of the resin and arterial surfaces toward a polyethylene plate, were measured with a tensile-compressive mechanical tester. Resin transparency was measured using an ultraviolet-visible light spectrometer. The µk value of the resin plate surface after applying silicone spray for 1-5 seconds and that of the artery were measured using a translational friction tester. RESULTS: E values differed significantly between the arteries and resin plates at each curing time (0.20 MPa ± 0.04 vs 8.53 MPa ± 2.37 for a curing time of 1 minute; P < .05). The resin was stiffer than the arteries, regardless of the curing times. The visible light transmittance and adhesive strength of the resin decreased as the curing time increased. The adhesive strength of the artery was the lowest. The µk value of the silicone-coated resin surface created by applying silicone for 2-3 seconds (thickness of the silicone layer, 1.6-2.0 µm) was comparable with that of the artery, indicating that the coating imparted a similar slippage to the resin as to the living artery. CONCLUSIONS: A transparent flexible resin is useful for creating a transparent and slippery vascular model for vascular intervention simulation.

Imaging of 17O-labeled Water Using Fast T2 Mapping with T2-preparation: A Phantom Study.

17O-labeled water is a T2-shortening contrast agent used in proton MRI and is a promising method for visualizing cerebrospinal fluid (CSF) dynamics because it provides long-term tracking of water molecules. However, various external factors reduce the accuracy of 17O-concentration measurements using conventional signal-intensity-based methods. In addition, T2 mapping, which is expected to provide a stable assessment, is generally limited to temporal-spatial resolution. We developed the T2-prepared based on T2 mapping used in cardiac imaging to adapt to long T2 values and tested whether it could accurately measure 17O-concentration in the CSF using a phantom. The results showed that 17O-concentration in a fluid mimicking CSF could be evaluated with an accuracy comparable to conventional T2-mapping (Carr-Purcell-Meiboom-Gill multi-echo spin-echo method). This method allows 17O-imaging with a high temporal resolution and stability in proton MRI. This imaging technique may be promising for visualizing CSF dynamics using 17O-labeled water.

Magnetic Resonance Water Tracer Imaging Using 17 O-Labeled Water.

ABSTRACT: Magnetic resonance imaging (MRI) is a crucial imaging technique for visualizing water in living organisms. Besides proton MRI, which is widely available and enables direct visualization of intrinsic water distribution and dynamics in various environments, MR-WTI (MR water tracer imaging) using 17 O-labeled water has been developed, benefiting from the many advancements in MRI software and hardware that have substantially improved the signal-to-noise ratio and made possible faster imaging. This cutting-edge technique allows the generation of novel and valuable images for clinical use. This review elucidates the studies related to MRI water tracer techniques centered around 17 O-labeled water, explaining the fundamental principles of imaging and providing clinical application examples. Anticipating continued progress in studies involving isotope-labeled water, this review is expected to contribute to elucidating the pathophysiology of various diseases related to water dynamics abnormalities and establishing novel imaging diagnostic methods for associated diseases.

Blockage of CSF Outflow in Rats after Deep Cervical Lymph Node Ligation Observed Using Gd-based MR Imaging.

PURPOSE: To investigate whether deep cervical lymph node (DCLN) ligation alters intracranial cerebrospinal fluid (CSF) tracer dynamics and outflow using a rat model with intrathecal dynamic contrast-enhanced (DCE) MRI. METHODS: Six bilateral DCLN-ligated and six sham-operated rats were subjected to DCE MRI with Gd-BTDO3A, and dynamic T1-weighted images were acquired. ROIs were collected from the CSF at the C1 level (CSF_C1), CSF between the olfactory bulbs (CSF_OB), CSF at the pituitary recess (CSF_PitR), and CSF at the pineal recess (CSF_PinR), upper nasal turbinate (UNT), olfactory bulbs, cerebrum, and the jugular region. Time-intensity curves were evaluated, and the maximum slope, peak timing, peak signal ratio, and elimination half-life for the four CSF ROIs and UNT were calculated and compared. RESULTS: Delayed tracer arrival in the rostral CSF space and the nasal cavity with tracer retention in the ventral CSF space were observed in the ligation group. The maximum slopes were smaller in the ligation group at UNT (sham: 0.075 ± 0.0061, ligation: 0.044 ± 0.0086/min, P = 0.011). A significant difference was not detected in peak timings. The peak signal ratio values were lower in the ligation group at UNT (sham: 2.12 ± 0.19, ligation: 1.72 ± 0.11, P = 0.011). The elimination half-life was delayed in the ligation group at CSF_C1 (sham: 30.5 ± 2.70, ligation: 44.4 ± 12.6 min, P = 0.043), CSF_OB (sham: 30.2 ± 2.67, ligation: 44.8 ± 7.47 min, P = 0.021), and CSF_PitR (sham: 30.2 ± 2.49, ligation: 41.3 ± 7.57 min, P = 0.021). CONCLUSION: The DCLN ligation in rats blocked CSF outflow into the nasal cavity and caused CSF retention.

Combination Therapy by Transarterial Injection of Miriplatin-Iodized Oil Suspension with Microwave Ablation for Medium-Sized Hepatocellular Carcinoma: the Preliminary Experience.

Purpose: To evaluate the feasibility and safety of transarterial injection of a miriplatin-iodized oil suspension combined with Emprint miriplatin-iodized oil suspension-microwave ablation in patients with medium-sized (3-5 cm) hepatocellular carcinomas. Materials and Methods: This retrospective study included a total of 11 patients with 12 hepatocellular carcinomas (mean size, 3.6 ± 0.6 cm) underwent miriplatin-iodized oil suspension-microwave ablation. Microwave ablation was performed under the guidance of computed tomography fluoroscopy following transarterial miriplatin-iodized oil suspension injection on the same day. Technical success, complications, and local tumor progression were assessed. Results: The primary and secondary technical success rates were 75.0% and 100%, respectively. The number of treatment sessions per nodule was 1.25 ± 0.45. A total 15 sessions were required to achieve technical success (one session in nine lesions, two sessions in three lesions). Two major complications (pneumothorax [n = 1] and hemorrhage [n = 1]) occurred (2/15, 13.3%). No local tumor progression was observed during the follow-up period (mean 12.0 ± 2.0 months, range 2.7-23.9 months). Conclusions: Miriplatin-iodized oil suspension-microwave ablation for medium-sized hepatocellular carcinomas can be safely performed with good local control.

Usefulness of preoperative simulation with patient-specific hollow vascular models for high-flow renal arteriovenous fistula embolization using a preloading coil-in-plug technique.

The development of three-dimensional printers has facilitated the creation of patient-specific hollow vessel models. Preoperative simulations using these types of models have improved our ability to select appropriate devices and embolic materials before performing complex endovascular procedures. This report describes 2 cases of high-flow renal arteriovenous fistulas (r-AVFs) that were successfully treated via short-segment embolization using the preloading coil-in-plug (p-CIP) technique. To our knowledge, this is the first report of r-AVF being treated using the p-CIP technique. Our findings demonstrate that preoperative simulation has the potential to improve the safety and reliability of complex vascular embolization procedures.

Lymphangiography as a Treatment for Refractory Congenital Chylothorax Due to RASopathies: A Report of Two Cases.

In this study, we report two cases in which intranodal lymphangiography helped improve congenital chylothorax due to RASopathies. We performed lymphangiography after conservative treatments failed to improve chylothorax in an 8-year-old girl with cardiofaciocutaneous syndrome and a 2-month-old boy with Noonan syndrome. Inguinal lymph nodes were punctured with 25-gauge needles under ultrasonographic guidance, and 4 and 1 mL of iodized oil were injected, respectively, showing a backflow of iodized oil into the lungs. Chylothorax had improved in both patients after nodal lymphangiography. However, the second child experienced worsening of disease-associated extremity edema and died of sepsis 4 months later.

Use of Microballoon Catheter in Transarterial Ethanol Embolization of Renal Angiomyolipoma: A Retrospective Comparative Study with Historical Control?

Purpose: To clarify the utility of microballoon catheter in renal arterial ethanol embolization of renal angiomyolipoma (AML). Material and Methods: A total of 20 patients (15 women, 5 men) with median age of 45 years (39-60 years) underwent embolization to treat 22 AMLs. A mixture of ethanol and iodized oil was injected into the feeding arteries of 13 tumors using balloon occlusion (the balloon embolization group) with a microballoon catheter and 9 tumors without using balloon occlusion (the non-balloon embolization group). Changes in the maximum tumor diameter, tumor volume, and adverse events were evaluated. Result: The median baseline maximum tumor diameters and volumes were 6.3 cm and 61.4 cm3 in the balloon embolization group, and 4.6 cm and 40.1 cm3 in the non-balloon embolization group, respectively. Tumor enhancement disappeared on postembolization angiography in all cases. All tumors shrunk after embolization. There were no statistically significant differences in the percent decrease in the maximum tumor diameter and volume at 10-12 month between balloon occlusion group (31.5% and 67.9%) and control group (34.8% and 62.6%). Fever was significantly more frequent when balloon occlusion was used: 38% vs. 0% (p = 0.03). No major complication was observed in either patient group. Conclusions: Balloon occlusion may not affect tumor shrinkage when embolizing AMLs with a mixture of ethanol and lipiodol.

Clinical Experience of Percutaneous Radiofrequency Ablation Using an arfa RF ABLATION SYSTEMⓇ in Various Organs.

Purpose: To evaluate the feasibility, safety, and efficacy of radiofrequency (RF) ablation using an ablation system (arfa RF ABLATION SYSTEMⓇ; Japan Lifeline Co. Ltd.) for treating solid tumors in various organs. Material and Methods: Between October 2019 and August 2021, 80 patients (29 women, 51 men; median age, 70.0 yr) underwent 107 RF ablation sessions using the ablation system to treat 151 tumors in the liver (n = 86), lung (n = 51), adrenal gland (n = 4), pleura (n = 4), bone (n = 3), lymph node (n = 2), and kidney (n = 1). The maximum tumor diameter was 2-40 mm (median, 11 mm). This study evaluated technical success (defined as the completion of planned RF ablation), technique efficacy (defined as the complete tumor ablation on follow-up images), and adverse events. Local tumor progression in 146 curatively treated malignant tumors was evaluated. Results: The technical success rate was 100% (107/107). Ablation zones in two tumors were insufficient. Therefore, the primary technique efficacy rate was 98.1% (105/107). Grade 3 hepatic infarction (1.6%, 1/64) and grade 4 pleuritis (3.4%, 1/29) occurred respectively after liver and lung RF ablation. During the median follow-up period of 10.2 months (Interquartile range, 4.2 and 16.4 months), local tumor progression developed in two tumors (1.4%, 2/146). Conclusions: The arfa RF ABLATION SYSTEMⓇ is a feasible, safe, and effective RF ablation device for managing solid tumors in various organs.

Combination therapy by transarterial injection of miriplatin-iodized oil suspension with radiofrequency ablation (RFA) versus microwave ablation (MWA) for small hepatocellular carcinoma: a comparison of therapeutic efficacy.

PURPOSE: To compare the technical efficacy and complications of the transarterial injection of a miriplatin-iodized oil suspension combined with radiofrequency ablation (RFA) or microwave ablation (MWA) in the treatment of small hepatocellular carcinomas (HCCs). MATERIALS AND METHODS: This retrospective study included 123 HCCs in 101 patients treated with the transarterial injection of a miriplatin-iodized oil suspension and RFA (MPT-RFA) (maximum diameter: 1.5 [Formula: see text] 0.5 cm, range: 0.6-3.0 cm) and 68 HCCs in 49 patients treated with the transarterial injection of a miriplatin-iodized oil suspension and MWA (MPT-MWA) (maximum diameter: 1.6 [Formula: see text] 0.7 cm, range: 0.5-3.0 cm). Technical success was defined as the achievement of an ablative margin of at least 5 mm for each tumor. Technical success, complications, and local tumor progression were compared between the two groups. RESULTS: The initial technical success rate was significantly higher with MPT-MWA (94.1%) than with MPT-RFA (76.4%; P = 0.003). The number of treatment sessions per nodule was significantly lower with MPT-MWA (1.1) than with MPT-RFA (1.3) (P = 0.004). The major complication rates were similar with MPT-RFA (5.8%) and MPT-MWA (2.7%) (P = 0.391). The one-year local tumor progression rate was similar between MPT-RFA (0%) and MPT-MWA (0%) (P = 0.73). CONCLUSION: MPT-MWA may have improved therapeutic efficiency in the treatment of small HCCs.

Successful transvenous embbolization for type II uterine arteriovenous malformation: A case report.

A 40-year-old female (gravida 3 para 1) presented with menstrual, urinary, and anal pain. Computed tomography revealed type II acquired uterine arteriovenous malformation, a common dilated venous sac with bilateral uterine arteries, and multiple branches of iliac arteries draining to the bilateral ovarian veins. Venous sac transvenous embolization via the left ovarian vein of dominant outflow was planned, since complete arteriovenous malformation occlusion was difficult with super-selective transarterial embolization of multiple feeders. Therefore, transarterial embolization of the minor feeder was performed before completing transvenous embolization using coils and 50% glue under left iliac artery flow control. Immediately thereafter, angiography confirmed the complete disappearance of the uterine arteriovenous malformation, and all pain symptoms remitted. In conclusion, transvenous embolization combined with adjunctive transarterial embolization can be an effective and radical treatment for type II uterine arteriovenous malformations.

Successful Embolization of Collaterals from the Round Ligament Artery during Uterine Artery Embolization for Traumatic Uterine Leiomyoma Rupture: A Case Report.

We describe the case of a 48-year-old woman who presented with traumatic rupture of a giant leiomyoma and massive hemoperitoneum caused by slipping and falling in the bathroom. She was in shock on arrival, and resuscitation was performed. Contrast-enhanced computed tomography showed massive intra-abdominal hematoma and extravasation from the subserous leiomyoma. Uterine artery embolization was performed, but she went into shock again after 6 h. The second contrast-enhanced computed tomography revealed persistence of extravasation. During 2nd UAE, an angiogram revealed extravasation originating from left round ligament artery. After the embolization of the left round ligament and bilateral uterine arteries, the patient recovered from shock. Total abdominal hysterectomy was performed on day 2 of admission to prevent re-bleeding and infection, then she discharged on day 19 of admission.