Maximum Area Ratio Research Articles

Assessment of renal congestion in a rat model with congestive heart failure using superb microvascular imaging.

Renal congestion is a therapeutic target in congestive heart failure. However, its detailed evaluation in a clinical setting is challenging. This study sought to assess renal congestion impairment using superb microvascular imaging (SMI), a simple and accessible method. Dahl salt-sensitive rats, used as a model for congestive heart failure, underwent central venous pressure (CVP) measurements. Renal congestion was evaluated through measurements of renal medullary pressure (RMP) and assessment of renal perfusion using contrast-enhanced ultrasonography at both the early (control group) and heart failure phases (HF group). All rats were assessed with SMI. The region of interest (ROI) was set in interlobular vessels, interlobar vessels, and a combination of these areas. The area ratio was calculated from the color pixel count in the ROI divided by the total pixel count in the ROI. Intrarenal perfusion index (IRPI) was defined as (maximum area ratio-minimum area ratio) / maximum area ratio. There were no significant differences in renal function and left ventricular ejection fraction between the two groups. CVP, time-to-peak (TTP) in the medulla, and RMP were higher in the HF group than in the control group. In the HF group, IRPI, evaluated in the interlobular vessels, was significantly higher than in the control group. IRPI was positively correlated with TTP in the medulla (p = 0.028, R = 0.60) and RMP (p < 0.001, R = 0.84), indicating that IRPI reflected renal congestion. IRPI is a useful tool for assessing renal congestion in rats with congestive heart failure.

オーステナイト系ステンレス鋼SUS310S溶接金属の微細粒組織形成とワイヤ送給条件

The aim of this study was to investigate the influence of wire feeding conditions such as wire feeding position and power supply distance on the fine grain formation in weld metal of type 310S stainless steel. When the wire feeding position was far from electrode of GTAW, area ratio of fine grain in weld metal increased. The maximum area ratio was obtained when the filler wire was fed to the back of weld pool and the wire melting depended on the joule heating. When the power supply distance was short, the wire wasn't fed to the back of weld pool. On the other hands, when the power supply distance was long, the wire wasn't also fed to the back of weld pool. Because, this phenomenon was related to the local melting region in the wire corresponding to the temperature gradient of wire. Therefore, the adequate feeding conditions was required to form the fine grain by hot-wire GTAW process.

A prospective follow up of age related changes in the subchondral bone density of the talus of healthy Labrador Retrievers.

BackgroundDuring growth, the skeletal structures adapt to the increased loading conditions and mature to a fully-grown skeleton. Subchondral bone density reflects the effect of long-term joint loading and it is expected to change over time. The aim of this study was to describe the long-term changes in the density distribution of the subchondral bone of the talus of healthy Labrador Retrievers in a prospective study.ResultsThe subchondral bone density distribution was evaluated using computed tomographic osteoabsorptiometry (CTOAM). Visually, all joints showed very similar density distribution patterns. No significant differences in the topography of the density maxima were found between t1 and t2. The mean density, maximum density, and maximum area ratio (MAR) were significantly increased with increasing age.ConclusionsThe subchondral bone density of the talus of healthy Labrador Retrievers increases with increasing age. It is likely an adaptive response of the subchondral bone due to increased joint loading during growth.

Abstract P2-01-32: Comparison between positive and false-negative sentinel lymph nodes in breast cancer patients

Abstract Background: Intra-operative sentinel node biopsy (SNB) is performed for clinically node negative invasive carcinoma (IC). Despite a negative result for metastasis from rapid frozen section (FS) diagnosis of intra-operative SNB, some cases may be diagnosed positive when permanent sections (PS) are analyzed (i.e., false negative). In order to reduce the false-negative rate, it is necessary to determine why macrometastases measuring greater than 2 mm cannot be accurately diagnosed using frozen specimens. The aim of this study was to compare the pathological characteristics of false-negative and positive cases of macrometastasis using FSs. We also reviewed whether there were differences in postoperative prognoses between positive and false-negative cases. Methods: We retrospectively reviewed 1632 intra-operative SNBs collected from 2008 to 2011 at St. Luke’s International Hospital, Tokyo, JAPAN. Of these, 980 patients had undergone surgery for the treatment of IC without neoadjuvant chemotherapy. Lymph nodes were sectioned every 2 mm and examined. For FSs, we performed hematoxylin and eosin (HE) staining, and for PSs, we used HE and cytokeratin (AE1/AE3) staining. Image J (NIH Image, Bethesda, MD, USA) was used for assessment of the metastatic area of lymph nodes. Micro- and macrometastases were defined as metastatic lesions measuring between 0.2 and 2 mm or measuring 2 mm or more, according to TMN classification. Results: Using FSs, we identified 104 patients (10.6%) who were positive for macrometastasis, 16 patients (1.6%) who were positive for micrometastasis, and 860 patients (87.8%) who were negative for metastasis. Of the negative cases, the result was changed to micrometastasis in 37 cases (4.3%) and to macrometastasis (false-negative cases) in 14 cases (1.6%). Ten of the 14 patients did not have additional axillary lymph nodes dissection. The mean age of the patients was 55.1 ± 3.1 years for false-negative cases and 52.3 ± 1.2 years for positive cases. In terms of histological features, there were statistically significant differences between false-negative and positive cases for invasive ductal carcinoma (IDC), invasive lobular carcinoma (ILC), and IDC plus ILC (p &amp;lt; 0.05). There were no statistically significant differences between false-negative and positive cases in terms of the total number of slices for lymph nodes (8.4 ± 1.6 vs. 9.7 ± 0.6, respectively; p = 0.41) but tendency in the number of slices for metastases (2.4 ± 1.2 vs. 4.8 ± 0.5, respectively; p = 0.07). The maximum area ratio of metastasis was significantly lower in false-negative cases than in positive cases (3.0% ± 0.1% vs. 20.0% ± 0.2%, respectively; p &amp;lt; 0.05). There was no significant difference in disease-free survival between false-negative and positive cases (p = 0.43). Conclusions: Although it is necessary to reduce false-negative cases, no difference in prognosis was detected in our study. False-negative cases had lower metastasis area ratios than positive cases diagnosed using rapid diagnosis of intra-operative SNBs, and ILC is known to be high in histological features. Therefore, using AE1/AE3 stain together with rapid diagnosis of intra-operative SNBs may lower the false-negative rate when a diagnosis includes ILC in pre-operation analysis. Citation Format: Eriko Abe, Naoki Hayashi, Toshinao Onoda, Yang Yang, Mieko Uno, Hideko Yamauchi, Sachiko Ohde, Koyu Suzuki. Comparison between positive and false-negative sentinel lymph nodes in breast cancer patients [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-01-32.

Usefulness of Three-Dimensional Computerized Tomographic Volumetry for Determining Split Renal Function in Donors for Living-Related Kidney Transplantation

BackgroundIn living-related kidney transplantation, it is important to spare the superior kidney for the donor if there is a significant difference in split renal function. We have been using renal scintigraphy to decide which kidney to be donated. Recently, we used data regarding kidney volume and maximum area in the frontal plane of the 3-dimensional computerized tomography (3DCT) image of the kidney. We evaluated the validity of these parameters for estimating split renal function. MethodsWe calculated the ratio of right kidney volume (VOL-ratio) and maximum area in the frontal plane of the kidney (AREA-ratio) with the use of 3DCT and examined the correlation between these 2 parameters and the ratio of right kidney estimated renal plasma flow (ERPF-ratio) calculated with the use of technetium-99m mercaptoacetyltriglycine (99mTc-MAG3) renal scintigraphy. Forty-six donors for living-related kidney transplantation were evaluated. Their mean age was 53 years; there were 14 male and 32 female donors. ResultsCorrelation coefficients between VOL-ratio and ERPF-ratio and between AREA-ratio and ERPF-ratio were 0.441 and 0.471, respectively (P = .002; P = .001). Bland-Altman analysis confirmed that the majority of difference scores between VOL-ratio–ERPF-ratio and AREA-ratio–ERPF-ratio were within the 95% confidence interval of the differences. The differences between VOL-ratio–ERPF-ratio and AREA-ratio–ERPF-ratio were (mean ± 1.96SD) 1.17 ± 6.04% and −0.82 ± 6.09%, respectively. It seemed that the distribution of AREA-ratio–ERPF-ratio was less biased than that of VOL-ratio–ERPF-ratio. ConclusionsThe discrepancy between the ratio of kidney volume and the maximum area in the frontal plane of the kidney may have been due to the rotation of the kidney. The ratio of ERPF obtained with the use of renal scintigraphy approximates not only the ratio of kidney volume but also the ratio of maximum area in the frontal plane of the kidney. Thus, our findings suggest that the use of 99mTc-MAG3 renal scintigraphy alone may underestimate the function of a rotated kidney.

An approach to segmenting speech into vowel-and nonvowel-like intervals

A speaker-independent algorithm is given for segmenting continuous speech in English into vowel-like (V) and nonvowel-like (NV) intervals. The algorithm has three stages: measurements (parameter extraction), phonetic feature detection, and V/NV decision. In measurements, the broad-band rms energy, the back-to-total cavity volume ratio (BTR), the signed front-to-back maximum area ratio (SFBR), and the normalized high-to low frequency energy ratio (HLR) are computed. The BTR and SFBR are new parameters derived from linear prediction area functions and are interpreted in terms of the speech spectrum. The BTR is useful for distinguishing nasal segments from V segments, while the SFBR is effective for detecting the bursts of voiced plosives. In phonetic feature detection, three independent types of intervals are detected on the basis of the parameters: silence, preliminary V/NV, and turbulence noise. The V/NV decision stage accomplishes the final V/NV interval decision. Interspeaker differences are handled by normalizing the frequency scale on the basis of an estimated average vocal-tract length. Ten sentences spoken by each of two males and two females resulted in 93.3 percent correct V/NV segment-detection decisions (92.9 percent for design speakers, and 93.7 percent for test speakers).