Degree Of Distension Research Articles

Comparison of routine and unprepped CT colonography augmented by low fiber diet and stool tagging: a pilot study

We performed a pilot study examining the feasibility of a new unprepped CT colonography (CTC) strategy: low fiber diet and tagging (unprepped) vs. low fiber diet, tagging and a magnesium citrate cleansing preparation (prepped). Prior reports of tagging were limited in that the residual stool was neither measured and stratified by size nor did prior reports subjectively evaluate the ease of interpretation by a reader experienced in interpreting CTC examinations. Prospective randomized to unprepped n = 14 and prepped n = 14. Colonic segments were subjectively evaluated for residual stool that would potentially interfere with interpretation. Scores were given in the following categories: percentage of residual stool that was touching or nearly touching mucosa, the largest piece of retained stool, effectiveness of tagging, height of residual fluid, degree of distention, ease of interpretation, and reading time. Ease of the CT read (scale where 4 = optimal read) averaged 1.3 for the unprepped group and 2.3 for the prepped group. The mean read time averaged 17.5 min for unprepped and 17.9 min for prepped. The degree of distention (scale where 4 = well distended) averaged 3.7 for unprepped and 3.6 for prepped. Supine and prone images combined, the unprepped group had 160 segments with stool; prepped group had 58 segments. The amount of stool covering the mucosa in all segments averaged 1.6 (33%-66% coverage) in the unprepped group and 0.35 (<33% mucosal coverage) in the prepped group. The mean size of the largest piece of stool was 33.67 mm for unprepped and 4.01 mm for prepped. Percentage of tagged stool was not significantly different between the groups (range of 94-98%). The height of residual fluid averaged 8.37 mm for unprepped and 13.4 mm for prepped. Three polyps in three patients were found during optical colonoscopy (OC) in the unprepped group (5, 6, and 10 mm), none of which were prospectively detected at CTC. Three polyps in three patients were detected during OC in the prepped group (5, 10, and 15 mm), two of which were prospectively detected at CTC. Two false-positive lesions were observed at CTC in one patient in the prepped group. There was more stool in the unprepped group and while this factor did not slow down the reading time, it made the examination subjectively harder to interpret and likely caused the three polyps in this group to be missed. We conclude that a truly unprepped strategy that leaves significant residual stool, even if well tagged, is not desirable.

Serotonin and sensory signalling from the gastrointestinal lumen

Serotonin and sensory signalling from the gastrointestinal lumen

Does endoluminal coil embolization cause distension of intracranial aneurysms?

The aim of the present study was to determine whether intracranial aneurysms are distended after coil embolization and to evaluate the distensibility of ruptured aneurysms treated with endovascular coiling. This was a prospective study of 20 consecutive patients with 22 aneurysms, who presented with a ruptured cerebral aneurysm and were treated with endovascular coiling of the aneurysm in a single institution. A diagnostic digital subtraction angiography (DSA) and a three-dimensional radiographic angiography (3DRA) were performed with bi-plane angiography equipment (Philips V5000) immediately before and after the embolization procedure to detect volume enlargement of the aneurysm after embolization, and the extent of the enlargement. A simulation study with steel spheres was carried out to study the possible error of over-estimation of the postembolization volume due to the beam-hardening artifact. There was no procedure-related rupture of the aneurysms. The percentage by volume of solid coil within the coil mass ranged from 15.78% to 82.01% in the present series. All aneurysms showed distension which ranged from 0.09% to 34.23%. The distensibility of the aneurysms was 34.23%. Error due to the beam-hardening artifact was negligible. Endoluminal packing of intracranial saccular aneurysms with embolization coils could cause a certain degree of distension in aneurysms treated with coil embolization, with the degree of distension up to 34.2%. Intracranial aneurysms were able to tolerate a certain degree of endoluminal distension without a risk of immediate rupture, even those that had ruptured recently.

Evaluation of Bowel Distention and Bowel Wall Appearance by Using Neutral Oral Contrast Agent for Multi–Detector Row CT

To prospectively evaluate the performance of an orally administered 0.1% barium suspension, Volumen, as a bowel-marking agent for multi-detector row computed tomography (CT). This HIPAA-compliant study was approved by the Institutional Review Board and conformed to the institutional standards for research funded by a commercial sponsor. A total of 60 patients (33 women, 27 men; average age, 58.2 years) who were referred for multi-detector row CT of the pancreas were randomized into two groups. Prior to examination, group 1 consumed 1200 mL of Volumen over a 30-minute period and group 2 consumed 1200 mL of a solution containing three parts water and one part methylcellulose over a 30-minute period. Results were independently reviewed by two radiologists who were unaware of the contrast agent used. The degree of distention and the visualization of mural detail were qualitatively scored on a five-point scale. Differences were evaluated by using the Mann-Whitney test at a confidence level of 95%. There was significantly better distention in the stomach (P = .013), duodenum (P = .006), jejunum (P = .029), and ileum (P = .014) [corrected] in group 1 compared with group 2. Significant distention was also evident by comparing the products of the widest cross-sectional diameters in duodenum (P = .143), jejunum (P < .001), and ileum (P < .001). Group 1 also demonstrated significantly better visualization of mural features in the duodenum (P = .003), jejunum (P = .024), and ileum (P = .01) and a trend toward better visualization of mural features in the stomach (P = .092). Oral administration of Volumen provided excellent distention and excellent visualization of mural features in the gastrointestinal tract.

Magnetic Resonance Imaging of the Rectum During Distension

A knowledge of the relationships between the rectum and its surrounding structures during distention may improve our understanding of the results of studies assessing rectal sensory-motor responses to distention. This magnetic resonance imaging study was designed to assess the shape of the rectum and the degree of distention at which the surrounding structures are compressed. Nine healthy patients underwent magnetic resonance imaging of the rectum under resting conditions and after the inflation of a plastic bag to volumes of 50, 100, 150, 200, and 250 ml. The thickness of the rectovesical space was assessed as a measure of the compression of the perirectal structures, and the perception of sensations were recorded. The shape of the rectum changed from being quasicylindrical at distention volumes of <100 ml to bean-shaped at larger volumes. The thickness of the rectovesical space at a distention volume of 50 ml was the same as when the bag was not inflated, but it progressively decreased until the difference became statistically significant at distention volumes of > or = 200 ml, corresponding to a mean +/- standard deviation rectal radius of 2.66 +/- 0.37 cm. Statistically significant compression of the rectovesical space was recorded when the sensations of gas, desire to defecate, and urgency were perceived. The shape of the rectum changes during distention; it significantly compresses the extrarectal structures in the tested range of distention that induces non-painful sensations. Magnetic resonance imaging is a useful means of assessing the morphologic changes in the rectum during distention.

Pressure/cross-sectional area relations in the proximal urethra of healthy males. Part III: the time dependent pressure response following forced dilation: standardization of a technique.

The urethral response to a sudden forced dilation was studied in ten healthy male volunteers aged from 27 to 71 years. Measurements were performed from the bladder neck and beyond the region of high pressure using a specially designed probe. The pressure response after dilation showed a characteristic course, which could be described by a double exponential function of the form: P(t) = P(equ) + P(alpha)e(-t/tau(alpha) + P(beta)e(-t/tau(beta) where P(t) is pressure at time t, P(equ) is equilibrium pressure after dilation, P(alpha) and P(beta) are pressure decay, and tau(alpha) and tau(beta) are time constants. The size and velocity of dilation, as well as the degree of distension before dilation, proved of significance for the magnitude of the pressure response. The characteristics of the pressure response are given by the properties of the periluminal structures strained during dilation, and are thus predominantly determined of elastic, collagen, muscular, and glandular components. However, a high degree of relaxation after straining, and a modest stiffness, indicates that the muscular component dominates the response. The significance of the prostatic tissues remains unclear.

The Value of Prone Imaging in CT Pneumocolon

AIM: To evaluate the value of prone imaging in computed tomography pneumocolon.MATERIALS AND METHODS: In the U.K., patients commonly undergo computed tomography (CT) pneumocolon in the supine position alone. A prospective analysis of both supine and prone CT images was performed. The degree of distension and the presence/absence of fluid/faecal residue were documented.RESULTS: Twenty-five patients were examined in total. In all cases, all five segments of the colon were well visualized on combined assessment of supine/prone images. Diagnostic distension was obtained in all five segments of the bowel in 69% of cases in the prone position, but in only 24% of patients in the supine position. The rectum and sigmoid colon were well distended in 100 and 88%, respectively, on prone CT, but in only 58 and 35% of cases, respectively, on supine CT. Problems encountered by fluid/faecal residue were eliminated on prone CT.CONCLUSION: Adjunctive prone pelvic CT should be performed in all patients undergoing CT pneumocolon unless the supine images can be fully reviewed and shown to be satisfactory before the patient leaves the CT department. If a single positional sequence is to be performed, then prone CT is the position of choice.Yong, A. A. (2000). Clinical Radiology55, 959–963.

Postadministration of oral contrast material for abdominal CT in patients with gastrectomy: modified drip ingestion method.

We introduce the modified drip ingestion method (MDIM) of administering oral contrast material for abdominal computed tomography (CT) in patients after gastrectomy. MDIM consists of the drip ingestion method, which we have recently reported, with additional ingestion of effervescent agent. MDIM in abdominal CT is a useful technique to improve the degree of distention of the gastrointestinal lumen including anastomotic sites in patients after gastrectomy.

Sonography of the normal feline gastrointestinal tract.

The normal sonographic appearance of the stomach in various degrees of distension, the duodenum, the small intestine, and the large intestine was determined in awake and sedated cats. The mean stomach rugal fold thickness was 4.38 mm, and the interrugal thickness was 2.03 mm. No significant difference in stomach wall thickness was seen when the stomach was empty, half full, or full. The duodenal wall thickness was significantly greater than other parts of the small intestine, and this difference was accentuated by sedation (awake mean 2.4 mm; sedated mean 2.71 mm). The mean small intestinal wall thickness was 2.1 mm, and the mean colonic wall thickness was 1.67 mm. The five characteristic sonographic layers similar to that seen in the gastrointestinal tract of other species were routinely identified at all regions of the feline gastrointestinal tract.

Original Article: Sonographic assessment of symphyseal joint distention intra partum

Objective. To elucidate whether there is a distention of the symphysis pubis intra partum and whether a history of pelvic pain during pregnancy is associated with increased distention during delivery. Methods. Using ultrasonography, the width of the symphysis pubis was measured on two occasions during delivery; firstly, upon engagement of the fetal head in the pelvic inlet, secondly, when the largest diameter of the fetal head was at the level of the ischiadic spines. The first measurement was conducted in 24 patients, the second measurement was obtained in 16 of these patients. Results. The average width of the symphysis pubis at onset of labor was 5.8 mm. The average distention of the symphysis during labor was 1.1 mm for those without pelvic pain and 0.2 mm for those with a history of pelvic pain during pregnancy (p = 0.02). Parity and ensuing birth weight had no statistically significant influence on degree of distention. Conclusion. The symphyseal distention during labor is minimal regardless of pari...

Effect of distension and feeding on phasic changes in human proximal gastric tone.

Proximal stomach by virtue of its property of accommodation acts as a reservoir for the ingested food, but its role in emptying and the factors modulating it remain unexplored. To assess the effects of distension and of feeding on proximal gastric tone. 14 healthy volunteers with no current or past history of any gastro-intestinal symptoms. Isobaric changes in volume of the proximal stomach were recorded both during fasting and for the first 30 minutes after a meal. For a given degree of distension, the mean (SEM) intragastric pressure was consistently lower, immediately after meal ingestion (9.8 (1.1), mm Hg) than during fasting (12.9 (0.6) mm Hg; p < 0.01). Proximal gastric tone was continuously variable with a frequency of fluctuation of 0.9-1.3/minute and an amplitude of 16.8 (2.2) ml, superimposed upon slower higher amplitude fluctuations in baseline tone. These variations in tone were unaffected by the degree of gastric distension or by food. While proximal gastric tone decreases after meal ingestions consistent with accommodation, the fluctuations in tone are not an importance factor in the modulation of nutrient emptying from the proximal stomach in the immediate postprandial period.

756 Rectal balloon for CT of rectal cancer clinical applications and methods

CT plays an important role for the pre-surgical evaluation of rectal cancer, both for staging versus RT and for planning the operation. Pelvic scans provide the surgeon with a complete, readable map of the anatomy. The aim of the study is to optimise the protocol for CT of rectal cancer. The luminal distension of visceral wall has been obtained in a clean, well tolerable way by using a balloon catheter filled with water. The catheter is positioned in the rectum at the level of the neoplastic lesion. It consists of a 20 cm long latex balloon 6 cm in diameter, assembled over 12F double-way polyethylene catheter: one to inflate the balloon, the second for a guidewire, both for giving stiffness to the system, to advance it and to make the catheter radiopaque to evaluate the correct positioning by CT Fluoroscopy or Scout View. The balloon in gently injected with water, monitoring the degree of distension on minimal discomfort complained by the patient. Optimal distension is usually obtained by injecting 100–200 ml of water. The patient decubit is determined by the position of the lesion leaving it sloping. The scans are performed by a General Electric Pro Speed. After the exam without contrast, 80 ml bolus of lopamidol 370 is injected in 60′. CT with the rectal balloon allows a precise evaluation of a series of parameters important for the pre-surgical staging: the distance between anal sphincters and tumor, extension of the tumor and the invasion of perirectal fat and surrounding structures, lymphnodes metastases. The execution of this exam is simple and clean. Rectal distension is well tolerated by patients, without complaints as when entire colon is involved. Avoiding the injection of contrast material in the colon, the CT doesn’t interfere with other exams that can be executed on the same day. The quality of images allows a high diagnostic accuracy.

Arterial distensibility and compliance in hypertension

Under normal circumstances arteries, especially the larger elastic ones, distend during systole, and hence are able to store volume energy during this phase of the cardiac cycle. In this way the increase in blood pressure during systole will be leveled off. The amount of energy that can be stored depends not only on the degree of distension (distensibility), but also on the initial diameter of the vessel—two parameters actually determining the compliance of an artery. In both established and borderline hypertension distensibility and compliance of the larger elastic arteries are reduced, as compared with normotensives, but not of the radial artery, at least in patients with established hypertension. In these patients this artery shows a pronounced increase in intima-media thickness. The elastic modulus of the radial artery is not different in hypertensive and normotensive subjects. In the present state of the art, it cannot be concluded whether the loss of artery wall distensibility is caused solely by the increase in blood pressure or that also structural wall changes are involved. In borderline hypertensive patients distensibility and compliance of the elastic arteries are diminished as compared with normotensive subjects. The loss of distensibility already occurs in the fourth age decade and is not homogeneous along the carotid artery bifurcation. The distensibility is significantly lower at all levels in the carotid artery bulb than in the common carotid artery, the proximal part of the bulb, where the baroreceptors are predominantly located, being most affected. This pattern is similar to that observed in normotensive subjects in the sixth age decade, indicating that the carotid arteries age faster in borderline hypertensive than in normotensive subjects.

Urethral pressure--which one?

Urethral pressure was investigated by a method which allowed simultaneous measurement of the cross-sectional area. In healthy women a pressure range of 25-140 cm H2O was recorded at one urethral site as a response to the circumstances under which the measurement was performed. The pressures obtained were related to the degree of urethral distension and to the time after the change in distension. Measuring urethral pressure at one specific degree of distension results in one specific pressure value according to the dimensions of the measuring probe. However, this specific pressure value cannot be considered to supply more information on urethral sphincter function than any other pressures included in a range which can be obtained by changing the circumstances under which the measurement are carried out. More provocative methods of pressure measurement which simulate some of the physiological conditions of the urethra may provide more information on sphincter efficiency.

Small bowel gas in severe ulcerative colitis.

The prognostic significance of excess small bowel gas on a plain abdominal radiograph has been assessed in 75 patients with severe attacks of ulcerative colitis requiring intravenous hydrocortisone. The radiographs were reviewed without knowledge of the subsequent outcome. Small bowel distension was defined as the presence of three or more loops of gas filled small bowel. Forty two patients responded to medical treatment and 33 underwent colectomy. The two groups were comparable for age, sex, and length of history. The surgical group had more extensive disease. Of those who did well on medical therapy, 18 (42.9%) had small bowel distension compared with 24 of 33 (72.7%) who failed medical therapy. The difference was significant (p less than 0.05, odds ratio = 3.55, 95% confidence interval of 2.27-5.87). Of the 24 patients with small bowel distension who came to surgery, five had more than four loops of gas filled small bowel. This degree of distension was not seen in any of the patients settling on medical therapy. Thus the presence of small bowel distension on a plain abdominal radiograph in a patient with severe ulcerative colitis may predict a poor response to medical therapy.

Pulmonary vascular distensibility of arterial, middle, and venous regions in newborn lambs

The pulmonary circulation in the adult is characterized by being relatively distensible, but whether the newborn lung shares this feature is less certain. We perfused isolated lungs treated with indomethacin from lambs of four ages (less than 1, 2-4, 12-14, and 30-32 days) to determine the effects of increasing left atrial pressure on the pulmonary vascular pressures measured by vascular inflow and outflow occlusion. An index of pulmonary vascular distensibility was assessed by comparing the slope of the pulmonary vascular pressure at the upstream end of a region as a function of the pressure at the downstream end of the region. A vascular distensibility index (VDI) of 1 indicates a rigid nondistensible system, whereas a VDI less than 1 indicates some degree of distensibility. During normoxia, lungs from all age groups were relatively indistensible as determined by VDI for the total vasculature (VDItotal) as well as for the different regions based on occlusion pressures (VDIarterial, VDImiddle, and VDIvenous). There were significant effects of age on the VDItotal, with decreases in the normoxic values occurring over the first 12-14 days of age, indicating an increase in pulmonary vascular distensibility. Only the VDIvenous was similarly affected by increasing neonatal age. Hypoxia significantly reduced the VDItotal in these same age groups. In addition, hypoxia, which increased the pressure gradients of the arterial and middle regions, significantly increased the VDIarterial in the youngest and oldest age groups but significantly decreased the VDImiddle at all ages by approximately 50%. In summary, we observed age-related changes in the vascular distensibility of the pulmonary circulation, with the VDItotal decreasing with increasing postnatal age.(ABSTRACT TRUNCATED AT 250 WORDS)

Internal jugular vein cannulation: time required under ultrasonographic guidance with a valsalva maneuver.

Time required for the cannulation of right internal jugular vein (IJV) under ultrasonographic guidance with a Valsalva maneuver was investigated in surgical patients. The degree of distension of the IJV and the changes in blood pressure (BP) during the maneuver were also examined. The required time for the cannulation was 11 +/- 5 sec (mean +/- SD, n = 21), and there was no failure in the cannulation. The mean BP decreased significantly during the maneuver, while the vessels enlarged approximately twofold, which facilitated the cannulation. The decrease in BP and the enlargement of the vessels during a Valsalva maneuver were confirmed in the left side, which indicated the feasibility of left IJV cannulation under ultrasonographic guidance.

Distension-evoked ascending and descending reflexes in the circular muscle of guinea-pig ileum: an intracellular study

Reflex responses evoked by distension of the guinea-pig small intestine were recorded from the circular muscle with intracellular microelectrodes. For this purpose a mechanically stable preparation that allowed the intestinal wall to be distended within 9 mm of the recording site was developed. A segment of intestine was opened along the mesenteric border and pinned mucosa uppermost over a balloon set in the base of an organ bath, so that inflation of the balloon could distend the intestinal wall without simultaneously pushing against the mucosa. Compound excitatory junction potentials (EJPs) and compound inhibitory junction potentials (IJPs) were recorded at sites up to 40 mm oral and anal to the distending stimulus, respectively. The compound EJPs recorded orally had amplitudes of up to 24 mV and declined to baseline during distensions that exceeded 10–15 s. Distensions at intervals of less than 20 s evoked successively smaller oral compound EJPs; after four distensions in 30 s the amplitude of the compound EJP had fallen to less than 10%. The amplitude of the oral compound EJP was reduced by hyoscine (1 μM), but the extent of the reduction depended on the degree of distension; responses to mild stimuli were blocked, whereas those to strong stimuli were only slightly reduced. The amplitude of the hyoscine-resistant component of the compound EJP was markedly reduced by antagonists of substance P receptors in the muscle. In the presence of muscarinic and substance P receptor antagonists, a transient compound IJP could be detected on the oral side of the stimulus. The compound IJPs recorded anal to the distension had amplitudes up to 22 mV but the potential returned to baseline during prolonged distension. In the presence of hyoscine (1 μM) some inhibitory activity continued throughout prolonged stimuli. Compound IJP amplitudes were not significantly reduced by repeated distensions separated by more than 6 s. At anal sites a transient depolarization (off-response) was recorded immediately following the termination of a distension in some preparations. The off-response was unaffected by hyoscine and was more readily observed after the further addition of substance P antagonists. The compound IJPs were almost completely blocked by apamin (0.2 μM). The compound EJPs and IJPs recorded orally were blocked by hexamethonium (100 μM), but the amplitudes of compound IJPs recorded anally were significantly reduced by hexamethonium (100–200 μM) only at recording sites greater than 15 mm from the centre of the balloon. The off-response was reduced by hexamethonium at all sites. All responses to distension were blocked by tetrodotoxin (0.5 μM). Oral compound EJPs and anal compound IJPs of normal amplitude could still be evoked after removal of the mucosa and nearly all circular muscle from the site of distension. Such lesions did not prevent transmission of these reflexes along the intestine. Thus, both sensory neurons and the nervous pathways activated by stretch lie within the myenteric plexus.

Pollen morphology of the Rosaceae of Western Canada

Abstract This paper begins a systematic SEM and LM study of the pollen grains of the Rosaceae in Western Canada with genera Agrimonia, Alchemilla, Amelanchier, Aruncus, Chamaerhodos, and Crataegus. The above genera have tricolporate-tectate pollen grains in monads. Agrimonia gryposepala and A. striata have distinct striate sculpturing perpendicular to the colpus. Alchemilla occidentalis pollen is psilate except in the colpus area which is microechinate. The exine is thickened in the intercolpium. Aruncus Sylvester pollen is very small and exhibits a coarsely striate sculpture. Chamaerhodos erecta pollen has a characteristic protruding pore area with a fusiform operculum over the aperture. The sculpturing consists of patches of short ridges. Crataegus and Amelanchier pollen have pores with a characteristic equatorial bridge or flaps when open. Dimensions of the grains vary with degree of distension. Amelanchier alnifolia pollen exhibits geographic variability. Native North American Crataegus species: C. do...

Depressing Effect of Rumen Distension on Silage Intake of the Lactating Dairy Cow

The numerous factors involved in the control of food intake by ruminants have been reviewed in detail (Baile and Forbes, 1974.). Distension of the rumen is thought to limit the voluntary intake of hay by dry cows (Campling and Balch, 1961) and by lactating cows (Mbanya, Anil and Forbes, 1987). In more recent reports, it is thought that some of these factors which are negative feedback signals combine additively in their effects to induce satiety (Forbes, 1986). Prior to investigating the additive effects of rumen distension to those of other feedback signals on intake of silage by lactating dairy cows, we carried out a preliminary study now reported to establish a response curve to different levels of distension which will enable an appropriate degree of distension to be imposed in future experiments involving combinations of treatments.Animals and Housing - Five rumen fistulated, non-pregnant Friesian cows in early lactation (mean daily milk yield, 25.2 kg) were used in a 5 x 5 Latin square design with a row omitted.