Contrast-enhanced and targeted ultrasound

Ultrasonic imaging is becoming the most popular medical imaging modality,owing to the low price per examination and its safety.However,blood is a poor scatterer of ultrasound waves at clinical diagnostic transmit frequencies.For perfusion imaging,markers have been designed to enhance the contrast in B-mode imaging.These so-called ultrasound contrast agents consist of microscopically small gas bubbles encapsulated in biodegradable shells.In this review,the physical principles of ultrasound contrast agent microbubble behavior and their adjustment for drug delivery including sonoporation are described.Furthermore,an outline of clinical imaging applications of contrast-enhanced ultrasound is given.It is a challenging task to quantify and predict which bubble phenomenon occurs under which acoustic condition,and how these phenomena may be utilized in ultrasonic imaging.Aided by high-speed photography,our improved understanding of encapsulated microbubble behavior will lead to more sophisticated detection and delivery techniques.More sophisticated methods use quantitative approaches to measure the amount and the time course of bolus or reperfusion curves,and have shown great promise in revealing effective tumor responses to anti-angiogenic drugs in humans before tumor shrinkage occurs.These are beginning to be accepted into clinical practice.In the long term,targeted microbubbles for molecular imaging and eventually for directed anti-tumor therapy are expected to be tested.

Ultrasonography in diagnosing chronic pancreatitis: New aspects

The course and outcome is poor for most patients with pancreatic diseases.Advances in pancreatic imaging are important in the detection of pancreatic diseases at early stages.Ultrasonography as a diagnostic tool has made,virtually speaking a technical revolution in medical imaging in the new millennium.It has not only become the preferred method for first line imaging,but also,increasingly to clarify the interpretation of other imaging modalities to obtain efficient clinical decision.We review ultrasonography modalities,focusing on advanced pancreatic imaging and its potential to substantially improve diagnosis of pancreatic diseases at earlier stages.In the first section,we describe scanning techniques and examination protocols.Their consequences for image quality and the ability to obtain complete and detailed visualization of the pancreas are discussed.In the second section we outline ultrasonographic characteristics of pancreatic diseases with emphasis on chronic pancreatitis.Finally,new developments in ultrasonography of the pancreas such as contrast enhanced ultrasound and elastography are enlightened.

Is irritable bowel syndrome an organic disorder?

Irritable bowel syndrome(IBS)is a common gastrointestinal disorder that is generally considered to be functional because there appears to be no associated anatomical defect.Stress and psychological factors are thought to play an important role in IBS.The gut neuroendocrine system(NES),which regulates all functions of the gastrointestinal tract,consists of endocrine cells that are scattered among the epithelial cells of the mucosa,and the enteric nervous system.Although it is capable of operating independently from the centra nervous system(CNS),the gut NES is connected to and modulated by the CNS.This review presents evidence for the presence of an anatomical defect in IBS patients,namely in the gastrointestinal endocrine cells.These cells have specialized microvilli that project into the lumen and function as sensors for the luminal content and respond to luminal stimuli by releasing hormones into the lamina propria,which starts a chain reaction that progresses throughout the entire NES.The changes in the gastrointestinal endocrine cells observed in IBS patients are highly consistent with the other abnormalities reported in IBS patients,such as visceral hypersensitivity,dysmotility,and abnormal secretion.

Gastric accommodation assessed by ultrasonography

胃的住所为在机能性消化不良的病理生理学的理解是重要的并且为在另外的混乱的症状产生也是相关的。术语胃的住所有至少三个不同意思：住所过程，调节反射，和住所反应。胃的住所过程是描述胃的分隔空间的尺寸怎么响应饭变化的复杂现象。电子 barostat 在估计胃的住所被认为标准答案。成像方法，包括的 MRI， SPECT，和 ultrasonography 可以也被使用，特别地在压力应答的病人，例如机能性消化不良病人，因为一个非侵略、不太导致压力的方法是赞成的。Ultrasonography 满足它不由自己弄歪的这些标准在压力应答的个人的生理的反应。

Gastrointestinal neuroendocrine peptides/amines in inflammatory bowel disease

Inflammatory bowel disease(IBD) is a chronic recurrent condition whose etiology is unknown,and it includes ulcerative colitis,Crohn's disease,and microscopic colitis. These three diseases differ in clinical manifestations,courses,and prognoses. IBD reduces the patients' quality of life and is an economic burden to both the patients and society. Interactions between the gastrointestinal(GI) neuroendocrine peptides/amines(NEPA) and the immune system are believed to play an important role in the pathophysiology of IBD. Moreover,the interaction between GI NEPA and intestinal microbiota appears to play also a pivotal role in the pathophysiology of IBD. This review summarizes the available data on GI NEPA in IBD,and speculates on their possible role in the pathophysiology and the potential use of this information when developing treatments. GI NEPA serotonin,the neuropeptide Y family,and substance P are proinflammatory,while the chromogranin/secretogranin family,vasoactive intestinal peptide,somatostatin,and ghrelin are antiinflammatory. Several innate and adaptive immune cells express these NEPA and/or have receptors to them. The GI NEPA are affected in patients with IBD and in animal models of human IBD. The GI NEPA are potentially useful for the diagnosis and follow-up of the activity of IBD,and are candidate targets for treatments of this disease.

Endocrine cells in the oxyntic mucosa of the stomach in patients with irritable bowel syndrome

AIM: To study the different endocrine cell types in the oxyntic mucosa of patients with irritable bowel syndrome(IBS).METHODS: Seventy-six patients with IBS were included in the study(62 females and 14 males; mean age 32 years, range 18-55 years), of which 40 also fulfilled the Rome Ⅲ criteria for functional dyspepsia(FDP). Of the entire IBS cohort, 26 had diarrhea as the predominant symptom(IBS-D), 21 had a mixture of diarrhea and constipation(IBS-M), and 29 had constipation as the predominant symptom(IBS-C). Fortythree age and sex-matched healthy volunteers withoutany gastrointestinal complaints served as controls. The patients were asked to complete the Birmingham IBS symptom questionnaire. Both the patients and controls underwent a standard gastroscopy, during which three biopsy samples were taken from the corpus. Sections from these biopsy samples were immunostained using the avidin-biotin complex(ABC) method, for ghrelin, serotonin, somatostatin and histamine. The densities of these cell types and immunoreactivity intensities were quantified using computerized image analysis with Olympus cellSens imaging software(version 1.7).RESULTS: The densities of the ghrelin cells in the control, IBS-total, IBS-D, IBS-M and IBS-C groups were 389(320, 771), 359(130, 966), 966(529, 1154), 358(120, 966) and 126(0, 262) cells/mm2, respectively. There was a significant difference between the tested groups(P < 0.0001). Dunn's multiple comparison test showed that the ghrelin cell density was significantly higher in IBS-D and lower in IBS-C than in the controls(P = 0.03 and 0.0008, respectively). The ghrelin cell density in patients with both IBS and FDP was 489(130, 966), and in those with IBS only 490(130, 956). There was no statistical significant difference between these 2 groups of patients(P = 0.9). The immunoreactivity intensity did not differ between any of the groups(P = 0.6). The diarrhea score of the Birmingham IBS symptom questionnaire was significantly positively correlated with ghrelin cell density(r = 0.65; P < 0.0001) and significantly inversely correlated with that of constipation(r = 90.69; P < 0.0001). The densities of the serotonin cells were 63(51, 82), 51(25, 115), 120(69, 128), 74(46, 123) and 40(0, 46) cells/mm2 in the control, IBS-total, IBS-D, IBS-M and IBS-C groups, respectively. A statistically significant difference was found between the tested groups(P < 0.0001). Posttest revealed that serotonin cell density was significantly higher in IBS-D and lower in IBS-C than in controls(P = 0.02 and 0.004, respectively), but did not differ in the IBS-total and IBS-M groups from that in controls(P = 0.5 and 0.4, respectively). The serotonin cell densityin patients with both IBS and FDP was 62(25, 115)and in those with IBS only 65(25, 123). There was no statistically significant difference between these2 groups of patients(P = 1). The immunoreactivity intensity of serotonin did not differ significantly between any of the groups(P = 0.0.9). The serotonin cell density was significantly positively correlated with the diarrhea score of the Birmingham IBS symptom questionnaire(r = 0.56; P < 0.0001) and significantly inversely correlated with that of constipation(r = 0.51;P < 0.0001). The densities of the somatostatin cells were 97(72, 126), 72(0, 206), 29(0, 80), 46(0, 103)and 206(194, 314) cells/mm2 in the control, IBS-total,IBS-D, IBS-M and IBS-C groups, respectively(Figures7 and 8). There was a statistically significant difference between the controls and the IBS subgroups(P <0.0001). The density of somatostatin cells was significantly lower in the IBS-D and IBS-M groups but higher in IBS-C patients than in the controls(P < 0.01, P =0.02, and P = 0.0008, respectively). The somatostatin cell density in patients with both IBS and FDP was 86(0-194), and in those with IBS only 110(0-206). There was no statistically significant difference between these 2 groups of patients(P = 0.6). There was no significant difference in somatostatin immunoreactivity intensity between the controls. The diarrhea score of the Birmingham IBS symptom questionnaire was inversely correlated with somatostatin cell density(r =0.38; P = 0.0007) and was positively correlated with that of constipation(r = 0.64; P < 0.0001).CONCLUSION: The finding of abnormal endocrine cells in the oxyntic mucosa shows that the endocrine cell disturbances in IBS are not restricted to the intestine. Furthermore, it appears that ghrelin, serotonin and somatostatin in the oxyntic mucosa of the stomach may play an important role in the changing stool habits in IBS through their effects on intestinal motility.

Endocrine cells in the ileum of patients with irritable bowel syndrome

AIM:To study the ileal endocrine cell types in irritable bowel syndrome(IBS)patients.METHODS:Ninety-eight patients with IBS(77 females and 21 males;mean age 35 years,range 18-66 years)were included,of which 35 patients had diarrhea(IBS-D),31 patients had a mixture of both diarrhea and constipation(IBS-M),and 32 patients had constipation(IBS-C)as the predominant symptoms.The controls were 38 subjects(26 females and 12 males;mean age 40 years,range 18-65 years)who had submitted to colonoscopy for the following reasons:gastrointestinal bleeding,where the source of bleeding was identified as hemorrhoids(n=24)or angiodysplasia(n=3),and health worries resulting from a relative being diagnosed with colon carcinoma(n=11).The patients were asked to complete the:Birmingham IBS symptom questionnaire.Ileal biopsy specimens from all subjects were immunostained using the avidinbiotin-complex method for serotonin,peptide YY(PYY),pancreatic polypeptide(PP),enteroglucagon,and somatostatin cells.The cell densities were quantified by computerized image analysis,using Olympus cellSens imaging software.RESULTS:The gender and age distributions did not differ significantly between the patients and the controls(P=0.27 and P=0.18,respectively).The total score of Birmingham IBS symptom questionnaire was21±0.8,and the three underlying dimensions:pain,diarrhea,and constipation were 7.2±0.4,6.6±0.4,and 7.2±0.4,respectively.The density of serotonin cells in the ileum was 40.6±3.6 cells/mm2in the controls,and 11.5±1.2,10.7±5.6,10.0±1.9,and13.9±1.4 cells/mm2in the all IBS patients(IBS-total),IBS-D,IBS-M,and IBS-C patients,respectively.The density in the controls differed significantly from those in the IBS-total,IBS-D,IBS-M,and IBS-C groups(P<0.0001,P=0.0001,P=0.0001,and P<0.0001,respectively).There was a significant inverse correlation between the serotonin cell density and the pain dimension of Birmingham IBS symptom questionnaire(r=-0.6,P=0.0002).The density of PYY cells was 26.7±1.6 cells/mm2in the controls,and 33.1±1.4,27.5±1.4,34.1±2.5,and 41.7±3.1 cells/mm2in the IBStotal,IBS-D,IBS-M,and IBS-C patients,respectively.This density differed significantly between patients with IBS-total and IBS-C and the controls(P=0.03 and<0.0001,respectively),but not between controls and,IBS-D,and IBS-M patients(P=0.8,and P=0.1,respectively).The density of PYY cells correlated significantly with the degree of constipation as recorded by the Birmingham IBS symptom questionnaire(r=0.6,P=0.0002).There were few PP-,enteroglucagon-,and somatostatin-immunoreactive cells in the biopsy material examined,which made it impossible to reliably quantify these cells.CONCLUSION:The decrease of ileal serotonin cells is associated with the visceral hypersensitivity seen in all IBS subtypes.The increased density of PYY cells in IBS-C might contribute to the constipation experienced by these patients.

How to perform gastrointestinal ultrasound: anatomy and normal findings

Gastrointestinal ultrasound is a practical, safe, cheap and reproducible diagnostic tool in inflammatorybowel disease gaining global prominence amongst clinicians. Understanding the embryological processes of the intestinal tract assists in the interpretation of abnormal sonographic findings. In general terms, the examination principally comprises interrogation of the colon, mesentery and small intestine using both lowfrequency and high-frequency probes. Interpretation of findings on GIUS includes assessment of bowel wall thickness, symmetry of this thickness, evidence of transmural changes, assessment of vascularity using Doppler imaging and assessment of other specific features including lymph nodes, mesentery and luminal motility. In addition to B-mode imaging, transperineal ultrasonography, elastography and contrast-enhanced ultrasonography are useful adjuncts. This supplement expands upon these features in more depth.

Morphology and motor function of the gastrointestinal tract examined with endosonography

Endosonography 是为学习胃肠道的形态学和运动机能的一个有用工具。管腔内 ultrasonography 是用被插入到官方补给的道的体内变换器的超声考试的普通命名。因此，内脏的墙和邻近的结构能详细被想象。这评论在肠胃病学描述 endosonography 的实用性，特别地关于机械的简历和胃肠道的运动机能的研究。象 3-D EUS， elastography 和种类率成像那样的新技术被讨论。

Advanced imaging and visualization in gastrointestinal disorders

Advanced medical imaging and visualization has a strong impact on research and clinical decision making in gastroenterology. The aim of this paper is to show how imaging and visualization can disclose structural and functional abnormalities of the gastrointestinal (GI) tract. Imaging methods such as ultrasonography, magnetic resonance imaging (MRI), endoscopy, endosonography, and elastography will be outlined and visualization with Virtual Reality and haptic methods. Ultrasonography is a versatile method that can be used to evaluate antral contractility, gastric emptying, transpyloric flow, gastric configuration, intragastric distribution of meals, gastric accommodation and strain measurement of the gastric wall. Advanced methods for endoscopic ultrasound, three-dimensional (3D) ultrasound, and tissue Doppler (Strain Rate Imaging) provide detailed information of the GI tract. Food hypersensitivity reactions including gastrointestinal reactions due to food allergy can be visualized by ultrasonography and MRI. Development of multi-parametric and multi-modal imaging may increase diagnostic benefits and facilitate fusion of diagnostic and therapeutic imaging in the future.