造影剤

関: contrast agent、contrast material、contrast media、radiocontrast

WordNet

(meat) cooked until there is just a little pink meat inside
(biology) a substance in which specimens are preserved or displayed
a liquid with which pigment is mixed by a painter
a state that is intermediate between extremes; a middle position; "a happy medium"
an intervening substance through which something is achieved; "the dissolving medium is called a solvent"
(usually plural) transmissions that are disseminated widely to the public (同)mass medium
someone who serves as an intermediary between the living and the dead; "he consulted several mediums" (同)spiritualist, sensitive
a means or instrumentality for storing or communicating information
an intervening substance through which signals can travel as a means for communication
the surrounding environment; "fish require an aqueous medium"
put in opposition to show or emphasize differences; "The middle school teacher contrasted her best students work with that of her weakest student"
the opposition or dissimilarity of things that are compared; "in contrast to", "by contrast" (同)direct contrast
the act of distinguishing by comparing differences
the range of optical density and tone on a photographic negative or print (or the extent to which adjacent areas on a television screen differ in brightness)
the perceptual effect of the juxtaposition of very different colors
to show differences when compared; be different; "the students contrast considerably in their artistic abilities" (同)counterpoint
strikingly different; tending to contrast; "contrasting (or contrastive) colors" (同)contrastive

PrepTutorEJDIC

中間(中程度)にあるもの,中庸(mean) / 媒介物,媒体 / 《複数形mediaで》=mass media / 『手段』,方法(means) / (芸術の)表現手段,手法 / (動植物がそこで生存し機能を発揮する)環境;(細菌の)培地,培養基 / 霊媒者 / 『中間の』,並みの
(違いを示すために)(二つのもの)'を'『対照させる』,対比する;(…と)…'を'対照させる《+『名』+『with』+『名』》 / (…と)『対照する』,対照的に引き立つ《+『with』+『名』》 / 〈U〉(…との)『対照』,対比《+『with』(『to』)+『名』》 / 〈C〉〈U〉(…間の)対照的な差,(特に色・明るさの)対照,コントラスト《+『between』+『名』+『and』+『名』》,(…との)著しい相違《+『to』+『名』》 / 〈C〉(…と)対照的な人(物)《+『to』+『名』》

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/01/26 00:00:19」(JST)

wiki en

[Wiki en表示]

A medical contrast medium (or contrast agent) is a substance used to enhance the contrast of structures or fluids within the body in medical imaging.^[1] It is commonly used to enhance the visibility of blood vessels and the gastrointestinal tract.

Types

Several types of contrast media are in use in medical imaging and they can roughly be classified based on the imaging modalities where they are used. Although other types exist, most common contrast agents work based on X-ray attenuation and magnetic resonance signal enhancement.

X-ray attenuation

Main article: Radiocontrast agent

Iodine and barium are the most common types of contrast medium for enhancing x-ray-based imaging methods. Various sorts of iodinated contrast media exist, with variations occurring between the osmolarity, viscosity and absolute iodine content of different media. Non-ionic dimers are favored for their low osmolarity and toxicity, but have a correspondingly higher price attached to their use.^[2]

MR signal enhancing

Main article: MRI contrast agent

This would include gadolinium for use in magnetic resonance imaging as a MRI contrast agent. In the 3+ oxidation state the metal has 7 unpaired f electrons. This causes water around the contrast agent to relax quickly, enhancing the quality of the MRI scan.

Ultrasound scattering and frequency shift

Main article: Contrast-enhanced ultrasound

Microbubble contrast agents are used to aid the sonographic examination, specifically echocardiograms, for the detection of a cardiac shunt. These bubbles are composed of agitated saline solution, most of which are too large to pass through the lung capillaries. Therefore, the only ones that reach the left side of the heart pass through an abnormal connection between the two sides of the heart, a so-called right-to-left shunt. In addition, pharmaceutically prepared microbubbles are composed of tiny amounts of nitrogen or perfluorocarbons strengthened and supported by a protein, lipid, or polymer shell. These are small enough to pass through the capillaries and are used to increase the contrast in the left ventricle, improving the visualization of its walls. The drop in density on the interface between the gas in the bubble and the surrounding liquid strongly scatters and reflects the ultrasound back to the probe. This process of backscattering gives the liquid with these bubbles a high signal, which can be seen in the resulting image.

Adverse effects

While modern contrast media are generally safe to use,^[2] medical conditions can be caused by the administration of various contrast media. Reactions can range from minor to severe, sometimes resulting in death^[3] with death being about 0.9 per 100,000 cases. To better understand the reactions and to efficiently manage patients at risk, it is useful to classify them.^[4] Risk factors for developing severe reactions include strong allergies, bronchial asthma, cardiac disease and beta-blocker use.^[5]^[6]

A common misconception that even exists among healthcare professionals is that an allergy to contrast media is related to an allergy to seafood (usually shellfish) because both share iodine in common, implicating iodine as a source.^[7]^[8] Numerous studies have shown that although iodine is common in contrast media, iodine is not the cause of allergic reactions to contrast media and instead the more likely culprit are the inert ingredients and the patient's past history of having other strong allergic reactions.^[9] One important distinction is that allergic effects are by definition immunoglobulin E related histamine storms and studies have shown that contrast media cause no such reaction in vivo ^[10] thereby refuting the possibility that contrast media or the iodine in it is likely to be an allergen. Although it may seem contradictory, the few rare cases of contrast medium mediated IgE are exceedingly rare compared to all adverse reactions and when they happen, are often because the patient already has multiple risk factors that suggest the patient has other allergy related problems.^[5]

Historically, contrast media was sometimes highly dangerous but these dangers were not well-understood during the development of the early types of contrast media, such as Thorotrast.

References

^ "contrast agent" at Dorland's Medical Dictionary
^ ^a ^b Thomson, K; Varma, D (2010). "Safe use of radiographic contrast media". Australian Prescriber, 33:19-22. Available at http://www.australianprescriber.com/magazine/33/1/19/22/
^ Caro, J. Jaime; Evelinda Trindade, Maurice McGregor (1991). "The Risks of Death and of Severe Nonfatal Reactions with High- vs Low Osmolarity Contrast Media: A Meta-analysis". American Journal of Roentgenology (American Roentgen Ray Society) 156 (4): 825–832. PMID 1825900. http://www.ajronline.org/cgi/content/abstract/156/4/825.
^ Böhm I, Heverhagen JT, Klose KJ. Classification of acute and deleayed contrast media-induced reactions: proposal of a three-step system. Contrast Media & Molecular Imaging 2012;7(6):537-41 url=http://onlinelibrary.wiley.com/doi/10.1002/cmmi.1475/pdf
^ ^a ^b Brockow, K.; et al. (11 Jan 2005). "Management of hypersensitivity reactions to iodinated contrast media". Allergy (European Journal of Allergy & Clinical Immunology) 60 (2): 150–158. doi:10.1111/j.1398-9995.2005.00745.x. PMID 15647034. http://www3.interscience.wiley.com/journal/118649563/abstract.
^ Boehm I. Contrast media and patients at risk: asthma. Acta Radiologica 2009; 50(3): 348
^ Coakley, Fergus; David M. Panicek (October 1997). "Iodine Allergy: An Oyster Without a Pearl?". American Journal of Roentology (AJR) 169 (4): 951–952. http://www.scopus.com/record/display.url?eid=2-s2.0-0031253782&view=basic&origin=inward&txGid=sahILGe6CUTnUXnL0epp4EJ%3a9.
^ http://www.wdxcyber.com/ngen22.htm
^ Boehm, Ingrid (August 2008). "Seafood Allergy and Radiocontrast Media: Are Physicians Propagating a Myth?". The American Journal of Medicine (Elsevier) 121 (8): e19. doi:10.1016/j.amjmed.2008.03.035. PMID 18691465. http://linkinghub.elsevier.com/retrieve/pii/S0002934308003537.
^ Carr, Denis H.; Archi C. Walker (1984). "Contrast Media Reactions: experimental evidence against the allergy theory". British Journal of Radiology (British Institute of Radiology) 57 (678): 469–473. doi:10.1259/0007-1285-57-678-46. PMID 6722447. http://bjr.birjournals.org/cgi/content/abstract/57/678/469.

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 造影剤誘発性腎症の予防 prevention of contrast induced nephropathy
2. コントラスト心エコー検査：造影剤、安全性、およびイメージング技術 contrast echocardiography contrast agents safety and imaging technique
3. 腹部大動脈瘤ステントグラフト留置術に対する麻酔 anesthesia for endovascular aortic repair
4. Rapid sequence induction and intubation (RSII) for anesthesia
5. 内視鏡的逆行性胆道膵管造影（ERCP）の稀な合併症 rare complications of endoscopic retrograde cholangiopancreatography ercp

English Journal

A case of lateral sinus insufficiency with acute otitis media: Early surgical intervention for prevention of lateral sinus thrombosis.

Takahashi K1, Yamamoto Y2, Ogi M2, Ohshima S2, Morita Y2, Takahashi S2.
Auris, nasus, larynx.Auris Nasus Larynx.2015 Dec;42(6):492-5. doi: 10.1016/j.anl.2015.04.007. Epub 2015 May 29.
OBJECTIVE: To describe a case of lateral sinus insufficiency, presumably occurring just prior to lateral sinus thrombosis (LST), and to discuss the importance of early surgical intervention and the pathophysiology of full-blown LST.CASE REPORT: A 4-year-old boy developed headaches and vomiting after
PMID 26031937

Transport of citrate-coated silver nanoparticles in unsaturated sand.

Kumahor SK1, Hron P2, Metreveli G3, Schaumann GE4, Vogel HJ5.
The Science of the total environment.Sci Total Environ.2015 Dec 1;535:113-21. doi: 10.1016/j.scitotenv.2015.03.023. Epub 2015 Mar 29.
Chemical factors and physical constraints lead to coupled effects during particle transport in unsaturated porous media. Studies on unsaturated transport as typical for soils are currently scarce. In unsaturated porous media, particle mobility is determined by the existence of an air-water interface
PMID 25827720

Low prevalence of peripheral arterial disease in a cross-sectional study of Danish HIV-infected patients.

Knudsen A1, Malmberg CA, Kjær A, Lebech AM.
Infectious diseases (London, England).Infect Dis (Lond).2015 Nov;47(11):780-6. doi: 10.3109/23744235.2015.1061204. Epub 2015 Jun 26.
BACKGROUND: Patients infected with human immunodeficiency virus (HIV) appear to be at increased risk of cardiovascular disease (CVD). The ankle-brachial index (ABI) is a well-established screening tool for peripheral arterial disease (PAD) and future cardiovascular events in the general population.
PMID 26114988

Japanese Journal

Relationship between vessel porosity and leaf emergence pattern in ring- and diffuse-porous deciduous trees in a temperate hardwood forest

Takahashi Sayaka,Okada Naoki,Nobuchi Tadashi
Botany 93(1), 31-39, 2015-01
… More of the trees with intermediate-type formed medium-sized vessels or sparse wide vessels than trees with the flush-type leaf emergence, especially between full leaf expansion and the end of shoot elongation. … In contrast, diffuse-porous species formed vessels 0–8 weeks after full leaf expansion. …
NAID 120005526642

Stability of pixel density in cone-beam computed tomographic images

Nakashima Yukako,Yotsui Yoritaka,Shimizutani Kimishige
Journal of Osaka Dental University 48(2), 97-102, 2014-10
… The contrast medium lopamidol (lopamiron 300^[○!R]; …
NAID 110009865341

尿路造影検査で造影剤を投与したところ,血圧が低下し,患者は呼吸困難を訴えだした。 (特集泌尿器科で起きる患者の急変 : なにを考え,どのように対応するか!) -- (泌尿器科検査時に起きる急変)

中島耕一
臨床泌尿器科 = Japanese journal of clinical urology 68(9), 654-656, 2014-08
NAID 40020180342

Related Pictures

★リンクテーブル★

リンク元	「造影剤」「radiocontrast」「contrast agent」「contrast material」
関連記事	「medium」「contrasting」

「造影剤」

　　[★]

英: contrast media, contrast medium, contrast agent
関: ヨード造影剤

種類

ヨード造影剤

禁忌

ヨード造影剤の禁忌　参考(1)

絶対禁忌

ヨード造影剤に対する過敏症の既往
重症の甲状腺疾患

相対禁忌

全身状態不良
気管支喘息
重症心疾患、重症肝疾患、腎不全、急性膵炎、マクログロブリン血症、多発性骨髄腫、テタニー、褐色細胞腫

バリウムの禁忌 RNT.33

腸管穿孔、縫合不全(疑い)

副作用 RNT.33

ヨード製剤

アナフィラキシーショック、喉頭浮腫
嘔気・嘔吐、皮疹(蕁麻疹、発赤)、腎機能低下

バリウム製剤

便秘

要注意 RNT.33

ヨード製剤

高度の人気脳障害、高度の肝機能障害、多発骨髄腫(腎不全誘発)、褐色細胞腫(発作性高血圧誘発)

バリウム製剤

誤嚥の可能性

誤嚥により、呼吸困難、肺炎、肺肉芽腫の形成等を引き起こすおそれがあるので、誤嚥を起こすおそれのある患者（高齢者、嚥下困難、喘息患者等）に経口投与する際には注意すること。誤嚥した場合には、観察を十分に行い、急速に進行する呼吸困難、低酸素血症、胸部Ｘ線による両側性びまん性肺浸潤陰影が認められた場合には、呼吸管理、循環管理等の適切な処置を行うこと。(参考3)
老人など誤嚥の可能性がある患者は、肺に入った場合除去できないので使用しない。(参考4)

→食道気管支瘻の場合は使えないことになる