Defect Contrast Research Articles

術前に確定診断困難であった感染性肝嚢胞穿孔による汎発性腹膜炎の1例(A case of generalized peritonitis caused by infected liver cyst perforation which was difficult to definitive diagnose before surgery)

感染性肝嚢胞はしばしば症例報告され経皮的ドレナージの対象となるが，感染性肝嚢胞穿孔は極めて稀な疾患である。今回我々は，術前に診断困難であった感染性肝嚢胞穿孔により汎発性腹膜炎を来した1例を経験したため報告する。症例は86歳の男性。既往に肝S2に嚢胞の指摘あり。胆嚢炎，胆管炎で1か月の入院歴があり，内視鏡的乳頭切開術および抗菌薬治療で改善し退院となっていたが，退院当日夜間より39℃の発熱があり，改善に乏しいため再入院となった。CTで胆嚢腫大，壁肥厚があることと胆管炎を否定できないことから，内視鏡的胆嚢・胆管ドレナージを施行し抗菌薬投与を開始した。既知の肝嚢胞は壁の造影効果に乏しく感染は否定的であった。解熱傾向にあったが，入院4日目に40℃の発熱と腹膜刺激徴候を認め緊急手術を行った。手術所見として，既知の肝嚢胞に穿孔を来し膿汁流出を認め，嚢胞開窓ドレナージ術および胆嚢摘出術を施行した。術中よりショック状態であり集中治療管理を要するも，術後経過は良好であり術後37日目に自宅退院した。胆道系感染からの逆行性感染により既知の肝嚢胞に感染を来し穿孔したものと考えられたが，術前診断は困難であった。しばしば診断確定困難な急性腹症が散見され低侵襲治療が試みられるが，腹部所見を手がかりにして手術のタイミングを逃してはならない。 Infected liver cysts are often reported in cases and are treated by percutaneous drainage. However, infected liver cyst perforation occurs very rarely. Herein, we report a case of peritonitis caused by perforation of an infected liver cyst that was difficult to diagnose before surgery. The patient was an 86–year–old man with a cyst in liver S2. He had a history of hospitalization for 1 month with cholecystitis and cholangitis. Although he was discharged from hospital, he had a fever of 39℃ on the night of discharge. Therefore, he was re–hospitalized. Endoscopic gall bladder/bile duct drainage was performed and antibiotic drug administration was initiated. While there was a tendency towards fever, he ultimately developed a fever of 40℃ and signs of peritoneal irritation on the fourth day of hospitalization, which required an emergency operation. Perforation and pus were observed in the known liver cyst, and cyst open fenestration drainage and cholecystectomy were performed. The postoperative course was good and the patient was discharged from hospital on the 37th postoperative day. Often acute abdominal disease, which is hard to diagnose, is only found incidentally. However, we should not miss the clues from abdominal findings that lead to surgery. 肝嚢胞はcomputed tomography（以下CT），腹部超音波検査で発見されるありふれた病変であり，ときに感染を併発し治療を要するが感染性肝嚢胞穿孔は極めて稀な疾患である。我々は，肝嚢胞感染から穿孔および汎発性腹膜炎を呈し緊急手術を要した稀な1例を経験したため報告する。 なお，本研究はHelsinki人権宣言に基づいており，所属施設の倫理委員会の承認を得ている。また個人情報保護に基づき匿名化をしている。 患 者：86歳の男性 主 訴：全身倦怠感，食欲不振 現病歴：7日前からの発熱，全身倦怠感が改善せず，食事摂取困難となり当院受診。 既往歴：発作性心房細動，慢性腎不全，肝嚢胞（S2），急性胆管炎 来院時現症：意識清明。血圧71/52mmHg，脈拍80bpm，呼吸数16/分，SpO2 98%（room air），体温38.9℃であった。身体診察では腹部を含め有意な異常所見を認めなかった。 血液検査では，WBC 15,400/μL，CRP 20.86mg/dLと炎症値の上昇，BUN 53.0mg/dL，Cre 2.19mg/dLと腎機能の増悪，T–Bil 2.9mg/dLと上昇を認めるもその他の肝胆道系酵素の上昇は認めなかった。尿培養は陰性，血液培養は1/4本でEscherichia coliが陽性であった。胸腹部CT，magnetic resonance cholangiopancreatography（以下MRCP）で胆嚢腫大およびび漫性の総胆管拡張を認めたため，endoscopic retrograde cholangiopancreatography（以下ERCP）を施行したが造影欠損は認めず，傍乳頭憩室による生理的変化と判断した（Fig. 1a, b）。乳頭炎の可能性は否定できず悪性腫瘍の関与も懸念されたことから，endoscopic sphincterotomy（EST）および生検を施行したが悪性所見は認めなかった。絶食，meropenem（以下MEPM）による抗菌薬治療で速やかに解熱，炎症値の低下が得られ，経過中出血性十二指腸潰瘍合併などがあり入院が長期化したものの第37病日に独歩退院となった。しかし，退院当日夜間より39℃の発熱を認め改善に乏しく退院後4日目に当院再受診した。 (a) MRCP recognized diffuse biliary dilatation. (b) ERCP recognized diffuse biliary dilatation but did not recognize image of contrast defect. (c) Pneumobillia considered to be a change after EST is admitted. (d) Accepted gallbladder swelling and surrounding fluid accumulation. (e) No contrast effect of liver cyst wall was recognized. (f) Endoscopic gallbladder biliary duct drainage was performed. 来院時血圧83/54mmHg，脈拍130bpmで心房細動，呼吸数18/分，SpO2 98%（room air），体温37.5℃であった。身体診察では心窩部に軽度圧痛を認めるのみであった。 血液検査では，WBC 13,900/μL，CRP 16.43mg/dLと炎症値の上昇，BUN 39.0mg/dL，Cre 1.21g/dLと腎機能の増悪，肝胆道系酵素はT–Bil 1.4mg/dL，ALP 411IU/Lと上昇を認める以外は正常であった。 CTではEST後の変化と思われるpneumobilliaおよび胆嚢腫大を認めた（Fig. 1c, d）が，肝嚢胞壁の造影効果は認めなかった（Fig. 1e）。胆道系感染と判断したが腹部所見に乏しく，手術などより低侵襲であるERCPによる胆嚢・胆管内瘻化ドレナージを行った（Fig. 1f）。胆汁培養ではEscherichia coli，Enterococcus faeciumが検出された。絶食，MEPM投与で熱型，炎症値ともに改善傾向にあったが，第4病日に再度39.8℃まで発熱し，心窩部痛の増悪と腹壁全体の緊張を伴う腹膜刺激徴候を呈した。頻呼吸および発熱からやや不穏，SIRSを呈しqSOFA スコアは2点，SOFAスコアは1点であった。血液検査ではWBC 11,300/μL，CRP 10.83mg/dLと炎症値の増悪は認めなかったが，日本止血血栓止血学会DIC診断基準2017年版感染症型で5点とDICを呈していた（Table 1）。CT上多量の腹水の出現および既知の肝嚢胞に壁の造影効果を認めた（Fig. 2a, b）。感染性肝嚢胞が疑われたが，汎発性腹膜炎を呈していたため緊急手術を行ったところ，腹腔内に大量の混濁した腹水を認めた。胆嚢は肉眼的な炎症所見には乏しかったが，胆汁培養から細菌検出があり摘出，また肝S2の嚢胞にpin hole上の穿孔所見と膿汁流出を認め（Fig. 2c），嚢胞開窓術，洗浄ドレナージ術を施行した。手術時間は3時間42分，出血量は140mL，腹水および膿汁培養からは細菌検出は認めなかったものの膿汁中白血球は強陽性であった。術中より平均動脈圧65mmHgの維持にノルアドレナリン0.06γ，ドーパミン5γ投与を要するショック状態であったが，lactateは2mmol/Lを超えることなく推移し敗血症よりも循環血液量減少性ショックの要素が強かった。術後人工呼吸器管理，昇圧薬投与，アンチトロンビンIII製剤，トロンボモジュリン製剤の使用，ヒドロコルチゾン200mg/日使用など集中治療を要した（Fig. 3）が第37病日に独歩退院となった。 (a) Contrast effect of liver cyst wall was recognized. (b) A large amount of ascites appeared. (c) Liver cyst was infected and perforated. (d) Contrast agent reflux from the duodenum to the common bile duct. Clinical course of the patient. NAD: noradrenalin, AT III: antithrombin III, rTM: recombinant thrombomodulin, MEPM: meropenem, VCM: vancomycin, LVFX: levofloxacin, MBP: mean blood pressure 退院後経過は良好も，上部消化管造影で十二指腸から総胆管への逆流所見を認め（Fig. 2d）乳頭機能不全もしくはESTにより逆流を招いた可能性が示唆された。 肝嚢胞は日常診療においてよく遭遇する病変であるが治療を必要とする頻度は高くない 1。嚢胞の巨大化による圧迫症状や，嚢胞の細菌感染や出血を合併すれば治療対象となるが，感染性肝嚢胞の本邦報告例は100例に満たず 2, 3比較的稀な病態である。感染性肝嚢胞の臨床像として，肝膿瘍が左葉に生じることが稀であるのに対し，比較的均等に右葉，左葉に認めることおよび感染例の多くが5cm以上の嚢胞であることが報告されている 4。治療として経皮的ドレナージ術が試みられる報告が多く 5手術加療を要する例は少ないものの，経皮的ドレナージ術困難，ドレナージ後の再燃，感染コントロール不良を理由に手術施行となった報告が散見される 6, 7, 8。また細菌性肝膿瘍が穿孔し手術を要した報告も認める 9が，本症例のように感染性肝嚢胞が穿孔し手術となった例は検索し得る限り報告がなく，極めて稀な例であるといえる。細菌性肝膿瘍での穿孔頻度は7.1～15.1% 10，肝膿瘍全体での腹腔内への穿孔頻度は1.8% 11と報告されており，感染性肝嚢胞穿孔となるとそれ以下の頻度であると考えられる。 肝嚢胞への感染経路として胆道系が多いと言われており 12，本症例も再入院時胆汁培養から細菌が検出され，先行する胆道系感染から逆行性に嚢胞内感染を来したものと考えられた。嚢胞内感染では超音波検査で嚢胞内容物のエコー輝度増加など画像変化が生じることは知られているが，その変化は１か月程度遅れてから認める例もあり早期診断は困難である 13。CT上の嚢胞壁造影効果についても，感染性肝嚢胞の60%程度にしか認めないという報告があり画像上の確定診断は困難である 14。本症例でも再入院時CTでは，肝嚢胞壁の造影効果は乏しくこの時点で嚢胞内感染を起こしていたかは不明であった。また，手術前CTでも後方視的に読影すれば嚢胞壁の造影効果を認めるように観察されるものの確定できるほどの所見とはいえず，少なくとも穿孔を予測することは困難であった。穿孔後の画像変化に関しては稀な例であり，有用な報告がなく，多量の膿汁流出を伴えば嚢胞サイズの縮小を認めることが考えられるが，本症例ではpin hole上の穿孔で流出膿汁も少なく嚢胞サイズの変化は明らかでなかった。感染性肝嚢胞と診断し得たとしても穿孔を来しており，経皮的ドレナージ術では治癒し得ず手術加療の選択は妥当であったと考える。 本症例では膿汁培養から白血球が強陽性であったものの細菌検出は認めなかった。感染性肝嚢胞では，嚢胞内容の培養検査に先駆けて抗菌薬が投与される例がほとんどであり，40%の例で起炎菌が陰性になることが報告されている 2。本症例においても膿汁培養提出3日前より抗菌薬投与がなされており細菌検出を認めなかったのであろう。胆道系からの逆行性感染と考えられる例であり，起炎菌は入院時胆汁培養から検出されたEscherichia coli，Enterococcus faeciumと推察される。 内視鏡的治療や経皮的ドレナージの発達に伴い肝胆道系感染に対する手術機会は著しく減少している。CTなど画像診断の発達に伴い診断確定困難な急性腹症も減少し，診断未確定で手術加療を選択することはしばしばためらわれる。しかし，本症例のように術前確定診断困難ながら手術加療を要する例は確実に存在し，手術のタイミングを逃さないためにも丁寧な腹部診察と腹部所見に基づく手術選択の決断力が腹部救急に携わる医師には求められる。 本症例は感染性肝嚢胞穿孔という稀な疾患であり術前診断は困難であった。しばしば確定診断困難な急性腹症が散見され低侵襲治療から加療が試みられるが，腹部所見を手がかりにして手術のタイミングを逃してはならない。 本論文の要旨は，第45回日本救急医学会総会・学術集会（大阪）で発表した。 本研究に対して企業・組織または団体からの資金提供はなく，著者全員に発表内容に関係する企業・組織に関して利益相反はない。

Application of scanning electron diffraction in the transmission electron microscope for the characterisation of dislocations in minerals

AbstractWe present an application of scanning electron diffraction for the characterisation of crystal defects in olivine, quartz and phase A (a high pressure hydrated phase). In this mode, which takes advantage of the ASTAR™ module from NanoMEGAS, a slightly convergent probe is scanned over the sample with a short acquisition time (a few tens of ms) and the spot patterns are acquired and stored for further post-processing. Originally, orientation maps were constructed from automatic indexing at each probe location. Here we present another application where images are reconstructed from the intensity of diffraction spots, producing either so-called ‘virtual’ bright- or dark-field images. We show that these images present all the characteristics of contrast (perfect crystal or defects) of conventional transmission electron microscopy images. Data are acquired with a very short time per probe location (a few tens of milliseconds), this technique appears very attractive for the characterisation of beam-sensitive materials. However, as the acquisition is done at a given orientation, fine tuning of the diffraction conditions at a given location for each reflection is not possible. This might present a difficulty for some precise, quantitative contrast analysis.

Electronic imaging of subcritical defect accumulation in single crystal silicon under fatigue loading

High resolution electron beam induced current (EBIC) imaging technique successfully visualized defect accumulation process in single crystal silicon under compression fatigue loading at 50 °C with the relative humidity of 75%. Dark line-like defect contrast emanating from deep-etched stress concentration notch appeared in EBIC images in a scanning electron microscope, after a certain number of fatigue cycles, but they were mostly invisible with secondary electron. This line-like defect contrast eventually extended along the direction which was expected in correspondence to one of the crystal slip systems of silicon with the largest resolved shear stress. Hence it is strongly suggested that crystal slips take place in bulk silicon under repeated loading, which presumably leads to local stress concentration and further to fatigue fracture especially in case tensile stress is applied in fatigue cycles.

Electron ptychography of 2D materials to deep sub-ångström resolution.

Aberration-corrected optics have made electron microscopy at atomic resolution a widespread and often essential tool for characterizing nanoscale structures. Image resolution has traditionally been improved by increasing the numerical aperture of the lens (α) and the beam energy, with the state-of-the-art at 300 kiloelectronvolts just entering the deep sub-ångström (that is, less than 0.5 ångström) regime. Two-dimensional (2D) materials are imaged at lower beam energies to avoid displacement damage from large momenta transfers, limiting spatial resolution to about 1 ångström. Here, by combining an electron microscope pixel-array detector with the dynamic range necessary to record the complete distribution of transmitted electrons and full-field ptychography to recover phase information from the full phase space, we increase the spatial resolution well beyond the traditional numerical-aperture-limited resolution. At a beam energy of 80 kiloelectronvolts, our ptychographic reconstruction improves the image contrast of single-atom defects in MoS2 substantially, reaching an information limit close to 5α, which corresponds to an Abbe diffraction-limited resolution of 0.39 ångström, at the electron dose and imaging conditions for which conventional imaging methods reach only 0.98 ångström.

Joint reconstruction of rest/stress myocardial perfusion SPECT

Myocardial perfusion imaging (MPI) using rest/stress single photon emission computed tomography (SPECT) allows non-invasive assessment of reversible cardiac perfusion defects. Conventionally, reversible defects are identified using a difference image, called reversible map, obtained by subtracting the stress image from the rest image after registration and normalization of the two images. The identification of reversible defects using the conventional subtraction method is however limited by noise. We propose to jointly reconstruct rest and stress projection data to directly obtain the reversible map in a single reconstruction framework to improve the detectability of reversible defects. To evaluate the performance of the proposed method, we performed phantom studies to mimic reversible defects with different levels of severity and doses. As compared to the conventional subtraction method, the joint method yielded reversible maps with much lower noise and improved defect detectability. At a normal clinical dose level, the joint method improved the signal to noise ratio (SNR) of defect contrast in reversible maps from 13.2 to 66.4, 9.7 to 35.0, 6.1 to 13.2, and 3.1 to 6.5, for defect to normal myocardium concentration ratios of 0%, 25%, 50%, and 75%, respectively. The SNRs obtained using the joint method were improved from 6.1 to 13.2, 3.9 to 9.4, 3.0 to 8.0, and 2.1 to 7.1, for 100%, 75%, 50%, and 25% of the normal clinical dose as compared to the conventional subtraction method. To access clinical feasibility, we applied the joint method to a rest/stress SPECT MPI patient study. The joint method yielded a reversible map with much lower noise, translating into a much higher defect detectability as compared to the conventional subtraction method. Our results indicate that the joint method has the potential to improve radiologists’ performance for assessing defects in rest/stress SPECT MPI. In addition, the joint method can be used to reduce dose or imaging time.

Study on the Detection of CFRP Material with Subsurface Defects Using Barker-Coded Thermal Wave Imaging (BC-TWI) as a Nondestructive Inspection (NDI) Tool

In this paper, a Barker-coded thermal wave imaging approach is reported on the detection of carbon fiber reinforced polymer (CFRP) laminate with subsurface defects, using an integrated Barker code sequence and sinusoidal carrier-modulated laser as the excitation source. Artificial flat bottom holes as subsurface defects are prepared for the experimental investigation. Cross-correlation (CC) algorithm is applied for extracting characteristics of thermal wave signal and forming the corresponding peak delay time and phase images. The effects of Barker code sequence length and carrier-modulated frequency are investigated, which are both most important factors on the detectability of BC-TWI method. The results of the experiments show 5-bit Barker code and 0.1 Hz carrier frequency are the most suitable selection for enhancing inspection capability and obtaining the highest image SNR for a given CFRP laminate material. Furthermore, a comparative experiment is carried out between BC-TWI and lock-in thermography (LIT) method by taking the defect contrast and SNR into account. The results indicate that the BC-TWI CC phase image has higher contrast and SNR than the LIT phase image.

Towards bend-contour-free dislocation imaging via diffraction contrast STEM

Dislocation imaging using transmission electron microscopy (TEM) has been an invaluable tool for characterizing crystallographic defects in metals. Compared to conventional TEM imaging, diffraction contrast imaging scanning transmission electron microscopy (DCI STEM) with appropriate setting can provide better defect contrast with almost negligible bend contour artifacts, enabling more effective analysis of dislocation structures. Here, we investigated why STEM can suppresses bend contour, and how dislocation contrast behaves along with different STEM imaging parameters. Using a body-centered cubic HT-9 ferritic/martensitic alloy as an example, a simple procedure and operational theory are described at the beginning to help set up DCI STEM experiments. Comparing with conventional TEM and the STEM strictly complying with the principle of reciprocity, we found that a pair of STEM convergence and collection semi-angles, αS and βS, a few milliradians in size is essential for bend-contour-free defect imaging. It works in concert such that the convergence STEM probe opens up the reciprocal space, and then a comparable collection region evens out the rocking-curve oscillation and alleviates bend contours from the reciprocal space. This fundamental advantage is unique in DCI STEM. Practical guidelines regarding STEM parameters and specimen orientation and thickness are then provided for DCI STEM dislocation imaging. Lastly, we show that coupling DCI STEM with spectrum images of electron energy loss spectroscopy and of energy-dispersive X-ray Spectroscopy offers a comprehensive characterization of crystallographic defects and chemical information of complex microstructures.

Suppression of thermal transients in advanced LIGO interferometers using CO2 laser preheating

In high optical power interferometric gravitational wave detectors, such as Advanced LIGO, the thermal effects due to optical absorption in the mirror coatings and the slow thermal response of fused silica substrate cause time dependent changes in the mirror profile. After locking, high optical power builds up in the arm cavities. Absorption induced heating causes optical cavity transverse mode frequencies to drift over a period of hours, relative to the fundamental mode. At high optical power this can cause time dependent transient parametric instability, which can lead to interferometer disfunction. In this paper, we model the use of CO2 laser heating designed to enable the interferometer to be maintained in a thermal condition such that transient changes in the mirrors are greatly reduced. This can minimize transient parametric instability and compensate dark port power fluctuations. Modeling results are presented for both single compensation where a CO2 laser acting on one test mass per cavity, and double compensation using one CO2 laser for each test mass. Using parameters of the LIGO Hanford Observatory X-arm as an example, single compensation allows the maximum mode frequency shift to be limited to 6% of its uncompensated value. However, single compensation causes transient degradation of the contrast defect. Double compensation minimise contrast defect degradation and reduces transients to less than 1% if the CO2 laser spot is positioned within 2 mm of the cavity beam position.

The Relationship between Dirt Levels of Inspection Surface and Defect Detection in Visual Inspection Utilizing Peripheral Vision

This study focuses on adhered dirt such as dust on a product in production process, and considers the relationship between dirt levels of inspection surface and defect detection in visual inspection utilizing peripheral vision. Specifically, images of an inspection surface in an actual factory are analyzed using image analysis for modeling dirt. Moreover, dirt levels of inspection surface, defect locations, and defect characteristics (luminance contrast, size, and bright-dark defects) are designed as experimental factors, and their effect on defect detection rate is evaluated. As a result, it is clarified that the defect detection rate suddenly reduces as the inspection surface becomes dirtier. Consequently, the defects that can be detected easily becomes harder to detect, as the inspection surface is dirtier in visual inspection utilizing peripheral vision.

GIT1 regulates synaptic structural plasticity underlying learning.

The signaling scaffold protein GIT1 is expressed widely throughout the brain, but its function in vivo remains elusive. Mice lacking GIT1 have been proposed as a model for attention deficit-hyperactivity disorder, due to alterations in basal locomotor activity as well as paradoxical locomotor suppression by the psychostimulant amphetamine. Since we had previously shown that GIT1-knockout mice have normal locomotor activity, here we examined GIT1-deficient mice for ADHD-like behavior in more detail, and find neither hyperactivity nor amphetamine-induced locomotor suppression. Instead, GIT1-deficient mice exhibit profound learning and memory defects and reduced synaptic structural plasticity, consistent with an intellectual disability phenotype. We conclude that loss of GIT1 alone is insufficient to drive a robust ADHD phenotype in distinct strains of mice. In contrast, multiple learning and memory defects have been observed here and in other studies using distinct GIT1-knockout lines, consistent with a predominant intellectual disability phenotype related to altered synaptic structural plasticity.

Abstract P4-13-12: Immediate one-stage implant-based breast reconstruction without an acellular dermal matrix in Japanese breast cancer patients

Abstract Background. In immediate one-stage implant-based breast reconstruction, acellular dermal matrix (ADM) has been usually used due to cover the outside part of the pectoralis major muscle in the world. Unfortunately, ADM is not approved in Japan yet. Therefore we have performed safety one-stage implant-based breast reconstruction without ADM according to several unique technics in our institution and obtain the excellent results. We report single institution experience using the retrospective medical data. Methods. We chose the surgical method of immediate breast reconstruction (autologous and prosthetic) according to patient's preference, breast volume and cancer condition in early breast cancer patients (pts). Two hundred fifty four early breast cancer pts underwent immediate artificial breast reconstruction from January 2014 to March 2017 in our institution. Thirty seven pts were excluded in this analysis because of preplanned the expander insertion. ALLERGAN Natrelle 410 series were used as the silicon breast implant (SBI). We performed three unique steps to determine the one-stage SBI cases as follow. ICG fluorescence imaging to confirm the blood flow state of the chest skin after mastectomy is used as standard method. If there is a defective contrast region, we remove these area. And then, serratus anterior muscle/fascial and external oblique fascial flap is elevated to completely cover the SBI together with the pectoralis major muscle so that the between mastectomy field and the SBI insertion section are isolated. We used sizer to confirm the skin tension and form of breast. After confirming these steps, we adopted cases whether SBI insertion can be safety done. We evaluated the total cosmetic finding based on three categories of inframammary fold position, balance of both breast size and form at half year after operation. If the difference between both inframammary fold positions was under 1cm, if compensatory pad is not necessary with underwear, if the protrusion of the lower pole is sufficient compared with the contralateral side, we gain the point one on each categories in each cases. The total cosmetic evaluation was classified as three categories. Good, fair and poor were defined as gained 3 points, 2 points and 0/1 points, respectively. Results. Among 217 planned immediate prosthetic breast reconstruction pts, 186 pts (85.7%) were succeed one-stage implant-based breast reconstruction. Among 186 pts, the median age was 47 years old (23-75), median body weight was 53kg (35-84), median body mass index was 21.08 kg/m2(16.20-29.41), removed breast volume was 240g (56-522) and implant volume was 220cc (90-425). Implant removed in one case because of complications and infection was occurred in five cases. The revision surgery was performed in one cases because of malposition. Among all pts, the good, fair and poor of total cosmetic evaluation is 84.3%, 13.5% and 2.2%, respectively. Conclusions. Immediate one-stage implant-based breast reconstruction without ADM may be useful and safe procedure according to our unique technics in early breast cancer patients who hope the immediate prosthetic breast reconstruction in Japan. Citation Format: Okumura S, Tatibana S, Narita C, Hyodo I, Sawaki M, Hattori M, Yoshimura A, Ishiguro J, Kotani H, Gondo N, Adati Y, Iwata H, Kamei Y. Immediate one-stage implant-based breast reconstruction without an acellular dermal matrix in Japanese breast cancer patients [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-13-12.

Identification of Left Atrial Appendage Thrombi in Patients With Persistent and Long-Standing Persistent Atrial Fibrillation Using Intra-Cardiac Echocardiography and Cardiac Computed Tomography.

Intracardiac echocardiography (ICE) and cardiac computed tomography (CCT), in addition to standard transesophageal echocardiography (TEE), have been used to identify left atrial (LA) thrombi prior to ablation for atrial fibrillation (AF). The clinical advantages of this, however, remain unclear. This study therefore investigated the advantages of additional pre-procedural LA appendage (LAA) thrombus evaluation using ICE and the clinical value of CCT in persistent and long-standing persistent AF.Methods and Results:We analyzed data from 108 consecutive patients with persistent and long-standing persistent AF who were scheduled to undergo AF ablation. TEE was performed within 24 h prior to ablation. ICE was performed for 97 patients in whom a thrombus was not detected on TEE. CCT was performed in 95 patients. Thrombus or sludge was detected on TEE in 11 patients (10.3%), for whom ablation was cancelled. Four additional patients were diagnosed with LAA thrombus on ICE. When TEE and ICE were used as the reference for thrombus detection, the sensitivity, specificity, positive predictive value, and negative predictive value of CCT for identifying contrast defects in the LAA were 100%, 81.0%, 40.7%, and 100%, respectively. ICE combined with TEE increased the detection rate of LAA thrombi in patients with persistent and long-standing persistent AF. Moreover, CCT had high sensitivity and negative predictive value for LAA thrombus detection.

Detection of Sub-Design Rule Shorts for Process Development in Advanced Technology Nodes

Electric shorts down to atomic scale have emerged as the most critical yield detractors in advanced technology process development. In this paper, we demonstrate successful detection by various charging dynamic effects which stem from the transistor level response under electron beam exposure. We found that charging dynamic effects coupled with photon or scan direction are exceptionally useful for critical voltage contrast defect detection. Correlation with other characterization methods on the same defective location from electron beam inspection scan shows consistent results for various shorting mechanisms.

MRI-assisted dual motion correction for myocardial perfusion defect detection in PET imaging.

Myocardial perfusion (MP) PET imaging is a powerful tool in risk assessment and stratification of patients with coronary artery disease. Involuntary organ motion degrades cardiac PET image resolution, while respiratory and/or cardiac gating to freeze the motion leads to noisier reconstructed images due to reduced counts in the gated frames. In this work, we propose an MRI-assisted dual motion correction method to compensate for respiratory and cardiac motion in MP PET data and study the impact of dual motion correction on MP defect detection using systematically designed experiments. The proposed dual motion correction method addresses the respiratory motion before correcting the cardiac motion among the respiratory motion corrected cardiac gates. The respiratory motion is estimated from the respiratory-gated only PET images and compensated within a 4D motion-incorporated image reconstruction algorithm. The cardiac motion is then corrected using the motion vector fields estimated from the corresponding cardiac-gated MR images. To evaluate the proposed method, we performed experiments using the standard XCAT phantom and two individual-specific volunteer XCAT phantoms. For each of the three phantoms, we simulated four dual-gated Rb-82 MP PET imaging datasets, one with normal perfusion and the other three with 50% nontransmural, 75% nontransmural, and transmural regionally reduced perfusion. The corresponding cardiac-gated MR images were simulated by the SIMRI simulator, with the sequence specified to be 3D T1-weighted as used in a protocol of a clinical PET/MRI scanner. We quantitatively evaluated the reconstructed images with no motion correction, only respiratory motion correction and dual motion correction, in terms of the myocardium to blood pool contrast and the trade-off between the noise and the normal to defect contrast. Using the channelized Hotelling observer, we performed receiver operating characteristic analysis for the task of detecting perfusion abnormalities with various myocardial coverages. Compared with no motion correction, the respiratory motion correction was demonstrated to improve the myocardium to blood pool contrast as well as the trade-off between the noise and the normal to defect contrast, on top of which the cardiac motion correction furthered the improvement. In the task of detecting regional perfusion defects, transmural or different levels of nontransmural, the respiratory motion correction significantly increased the defect detectability compared with no motion correction. Additionally, the respiratory and cardiac motion correction significantly improved the defect detection compared with the respiratory motion correction alone. Furthermore, the separability of the transmural and nontransmural defects was also improved by the proposed MRI assisted dual motion correction method. The proposed dual respiratory and cardiac motion correction technique improves the accuracy of PET quantification and MP defect detection and classification, which shows its promise for clinical applications especially in cardiac PET/MR imaging.

Better Contrast for Imaging Defects by ABF

Better Contrast for Imaging Defects by ABF

A predictive diagnostic model using multiparametric MRI for differentiating uterine carcinosarcoma from carcinoma of the uterine corpus.

To construct a diagnostic model for differentiating carcinosarcoma from carcinoma of the uterus. Twenty-six patients with carcinosarcomas and 26 with uterine corpus carcinomas constituted a derivation cohort. The following nine MRI features of the tumors were evaluated: inhomogeneity, predominant signal intensity, presence of hyper- and hypointense areas, conspicuity of tumor margin, cervical canal extension on T2WI, presence of hyperintense areas on T1WI, contrast defect area volume percentage, and degree of enhancement. Two predictive models-with and without contrast-were constructed using multivariate logistic regression analysis. Fifteen other patients with carcinosarcomas and 30 patients with carcinomas constituted a validation cohort. The sensitivity and specificity of each model for the validation cohort were calculated. Inhomogeneity, predominant signal intensity on T2WI, and presence of hyperintense areas on T1WI were significant predictors in the unenhanced-MRI-based model. Presence of hyperintensity on T1WI, contrast defect area volume percentage, and degree of enhancement were significant predictors in the enhanced-MRI-based model. The sensitivity/specificity of unenhanced MRI were 87/73 and 87/70% according to reviewer 1 and 2, respectively. The sensitivity/specificity of the enhanced-MRI-based model were 87/70% according to both reviewers. Our diagnostic models can differentiate carcinosarcoma from carcinoma of the uterus with high sensitivity and moderate specificity.

Evaluation of general-purpose collimators against high-resolution collimators with resolution recovery with a view to reducing radiation dose in myocardial perfusion SPECT: A preliminary phantom study

BackgroundThere is a growing focus on reducing radiation dose to patients undergoing myocardial perfusion imaging. This preliminary phantom study aims to evaluate the use of general-purpose collimators with resolution recovery (RR) to allow a reduction in patient radiation dose. MethodsImages of a cardiac torso phantom with inferior and anterior wall defects were acquired on a GE Infinia and Siemens Symbia T6 using both high-resolution and general-purpose collimators. Imaging time, a surrogate for administered activity, was reduced between 35% and 40% with general-purpose collimators to match the counts acquired with high-resolution collimators. Images were reconstructed with RR with and without attenuation correction. Two pixel sizes were also investigated. Defect contrast was measured. ResultsDefect contrast on general-purpose images was superior or comparable to the high-resolution collimators on both systems despite the reduced imaging time. Infinia general-purpose images required a smaller pixel size to be used to maintain defect contrast, while Symbia T6 general-purpose images did not require a change in pixel size to that used for standard myocardial perfusion SPECT. ConclusionThis study suggests that general-purpose collimators with RR offer a potential for substantial dose reductions while providing similar or better image quality to images acquired using high-resolution collimators.

Searching for biomarkers of CDKL5 disorder: early-onset visual impairment in CDKL5 mutant mice.

CDKL5 disorder is a neurodevelopmental disorder still without a cure. Murine models of CDKL5 disorder have been recently generated raising the possibility of preclinical testing of treatments. However, unbiased, quantitative biomarkers of high translational value to monitor brain function are still missing. Moreover, the analysis of treatment is hindered by the challenge of repeatedly and non-invasively testing neuronal function. We analyzed the development of visual responses in a mouse model of CDKL5 disorder to introduce visually evoked responses as a quantitative method to assess cortical circuit function. Cortical visual responses were assessed in CDKL5 null male mice, heterozygous females, and their respective control wild-type littermates by repeated transcranial optical imaging from P27 until P32. No difference between wild-type and mutant mice was present at P25-P26 whereas defective responses appeared from P27-P28 both in heterozygous and homozygous CDKL5 mutant mice. These results were confirmed by visually evoked potentials (VEPs) recorded from the visual cortex of a different cohort. The previously imaged mice were also analyzed at P60–80 using VEPs, revealing a persistent reduction of response amplitude, reduced visual acuity and defective contrast function. The level of adult impairment was significantly correlated with the reduction in visual responses observed during development. Support vector machine showed that multi-dimensional visual assessment can be used to automatically classify mutant and wt mice with high reliability. Thus, monitoring visual responses represents a promising biomarker for preclinical and clinical studies on CDKL5 disorder.

Development of Body Phantom for Evaluation of Appropriate Administered Radioactivities and Image Quality on 99mTc-DMSA Scintigraphy in Pediatric Nuclear Medicine

We conducted a field survey about pediatric nuclear medicine. As a result, it was suggested that 99mTc-DMSA scintigraphy was performed at many institutions, whereas various examinations such as image acquisition and processing are not carried out using the renal phantom. Therefore, we developed the body phantom for the evaluation of appropriate administered radioactivities and image quality with renal scintigraphy in pediatric nuclear medicine. We created three differently sized body phantoms (1-, 5-, and 20-year-old models). These pediatric body phantoms were filled with a 99mTc solution based on the consensus guideline of pediatric radiopharmaceutical administered radioactivity in Japan. The planar image was evaluated using acquisition count, uniformity and defect contrast. SPECT images were evaluated with a recovery coefficient (RC). The acquisition counts for pediatric body phantoms were relatively corresponded to the clinical study. The appropriate acquisition counts and the pixel size for the planar image were approximately 140 counts per pixel and 1.23-1.35 mm at 5 min acquisition times in 1- and 5-year-old pediatric body phantom studies, respectively. Although the uniformity and the cold contrast did not depend on pixel size and body size, the cold contrast was affected by body size. The RC for SPECT images depended on the performance of SPECT systems, the resolution recovery algorithm and body phantom size. The developed pediatric body phantom could allow us to establish optimal image acquisition and more evidence on renal scintigraphy in pediatric nuclear medicine.

Detection of right ventricular myocardial fibrosis using quantitative CT attenuation of the right ventricular myocardium in the late phase on 320 slice CT in subjects with pulmonary hypertension

PurposeRight ventricular myocardial (RVM) fibrosis may be a significant indicator of prognosis in pulmonary hypertension (PH). To detect the presence of RVM fibrosis in PH subjects, we employed ECG gated 320-slice CT. Methods62 confirmed PH subjects (16 males; 55±16years; 45 chronic thromboembolic PH (CTEPH) who underwent conventional non-surgical medical therapy; and 17 pulmonary arterial hypertension (PAH)) underwent ECG-gated 320-slice CT. On CT, RV fibrosis was defined as contrast defect in the early phase and conversely abnormal enhancement in the late phase. ResultsRVM fibrosis was observed in 14 subjects (23%) on CT (CTEPH 22%; PAH 29%; P=0.91). CT attenuation of RVM in the late phase was significantly greater in subjects with RVM fibrosis than in those without (P=0.025). ROC curves of CT attenuation of RVM in the early and late phase, and ratio of CT attenuation of RVM in the early phase/late phase showed AUCs of 0.55, 0.70, and 0.65, respectively. The best cutoff points of 79.5 HU (sensitivity of 50% and specificity of 69% for CT attenuation of RVM in the early phase, P=0.59), 99.5 HU (sensitivity of 50% and specificity of 88% for CT attenuation of RVM in the late phase, P=0.025), and 1.416 (sensitivity of 29% and specificity of 94% for ratio of CT attenuation of RVM in the early phase/late phase, P=0.092) were used to distinguish subjects±RVM fibrosis. ConclusionQuantitative-measurement of CT attenuation of RVM in the late phase may be able to detect presence of RVM fibrosis in PH subjects.