The additional utility of apparent diffusion coefficient values of clear-cell renal cell carcinoma for predicting metastasis during clinical staging

Background The apparent diffusion coefficient (ADC) value is known to be an indicator of tumor activity. The ADC value of high-grade clear-cell renal cell carcinoma (RCC) is significantly lower than that of low-grade clear-cell RCC. Purpose To investigate the utility of ADC values of clear-cell RCC by comparing ADC values between groups with T1a RCC (tumor size ≤ 4 cm) without metastasis and the group with metastasis. Material and Methods A retrospective review was performed on 51 patients with 51 RCCs who underwent 1.5 T magnetic resonance imaging (MRI) for evaluating a renal mass confirmed pathologically to be clear-cell RCC between January 2010 and August 2014. We compared ADC values between group A (T1a RCC without metastasis, T1aN0M0) and group B (RCC with metastasis) using the Mann–Whitney U test. Results The patients were divided into group A (n = 30; tumor size: median, 24.5 mm; range, 8–40 mm; ADC value [×10−3 mm2/s]: median, 1.71; range, 1.23–2.24) and group B (n = 21; tumor size: median, 87.5 mm; range, 18–150 mm; ADC value [×10−3 mm2/s]: median, 1.35; range, 0.91–1.94). The ADC value differed significantly between the two groups. The area under the receiver operating characteristic curve was 0.869. Using the optimum cutoff value (1.552 × 10−3 mm2/s), ADC had a sensitivity of 80.0% and specificity of 81.0%. Conclusion There was a statistically significant difference in the ADC between group A (T1a clear-cell RCC without distant metastasis) and group B (advanced clear-cell RCC with lymph node metastasis or distant metastasis)

Acute abdomen by red degeneration of a parasitic leiomyoma: A case report and literature review

A 43-year-old woman, with a history of uterine fibroids and multiple myomectomy, presented with acute lower abdominal pain. Computed tomography revealed multiple tumors, including a high-density mass in the left lower abdomen indicative of a parasitic leiomyoma undergoing red degeneration. This uncommon condition is due to acute occlusion, often caused by peripheral venous thrombosis at the fibroid edge. The diagnosis was corroborated by distinctive findings on magnetic resonance imaging and computed tomography. Notably, high signal intensity on T1-weighted images (T1WI) suggested methemoglobin presence due to hemorrhagic infarction, whereas low signal intensity on T2-weighted images (T2WI) indicated deoxyhemoglobin. Symptom improvement followed treatment with analgesics. This case underscores the significance of considering parasitic myomas in the differential diagnosis of intraperitoneal tumors after myomectomy and proposes that vascular torsion from mechanical stress on the mobile mesentery may contribute to red degeneration in such tumors. In this report, we detail the imaging characteristics and clinical progression of red degeneration in a parasitic leiomyoma, emphasizing the importance of this diagnosis in patients with a history of uterine surgery

Steerable-wire technique using high-flow steerable microcatheter and 0.025-inch guidewire

A high-flow steerable microcatheter has been reported to be useful as a triaxial system. Moreover, the benefits of steerable microcatheters in acute-angle bifurcation vessel insertions and a compact coil-packing technique using intentional folding with a bendable catheter tip have been reported. However, research on the usefulness of a high-flow steerable catheter and 0.025-inch guidewire combination (steerable-wire) technique is lacking. Herein, we report a case of balloon-occluded retrograde transvenous obliteration (BRTO) via the femoral venous approach to illustrate the usefulness of the steerable-wire technique. The steerable-wire technique facilitates the selection of the wire into the target vessel. The steerable-wire can be used instead of the 0.035-inch guidewire, which is versatile as other devices can follow the steerable wire

Three-dimensional velocity vector image obtained via 4-dimensional flow magnetic resonance imaging for in-stent flow visualization in the superficial femoral artery

The assessment of stent lumen patency via non–contrast-enhanced 2-dimensional time-of-flight magnetic resonance angiography (2D TOF MRA) is complex due to stent-related artifacts. However, an imaging technique using the phase-contrast method, which can reduce susceptibility to artifact, is available. Herein, we report the use of 3-dimensional velocity vector image obtained via 4-dimensional flow magnetic resonance imaging (4D flow MRI) for in-stent flow visualization after stent development in the right superficial femoral artery. Hence, instead of 2D TOF MRA, 4D flow MRI using the phase-contrast method can be performed to assess stent lumen patency as it reduces stent-related artifacts

Simulation on Toroidal Field Power Supply of HL-2A Tokamak: Application of Dual DQ0 Transformation for Six-Phase Synchronous Generator Model

The toroidal field power supply of HL-2A Tokamak operated in pulse mode is fed by two sets of motor generators with corresponding diode rectifiers. Each six-phase generator has two star stator windings with a phase difference of 30o between them. In this paper, the model of six-phase generator with rectifier load is built and toroidal field discharge operated in pulse mode is simulated based on dual DQ0 transformation

Matrix Converter in Power Electronics as a Power Supply for Plasma Control : A Short Review and a Foresight

In recent years, with the state advancement of R&D strategies in matrix converter and the increasing demand of high efficient power supply in power electronics, matrix converter has raised wide attention among the research scientists. In order to cope with these demands, various converters with different rate of power are being developed and related research is realized to accomplish the new matrix converters. Thus, matrix converter as a power supply for plasma control is an important case in this paper. Survey of matrix converter topologies with low cost, small volume and high efficiency are discussed as a power supply for the plasma control. And a short review and a foresight of milestones, significant research and development of a matrix converter from 1950 till present are appended in this paper. In addition, the major contributions which review includes primary, secondary and significant historical research milestones in matrix converters with thematical and chronological order respectively are demonstrated