Quantification of smooth muscle in human airways by polarization-sensitive optical coherence tomography requires correction for perichondrium

Quantifying airway smooth muscle (ASM) in patients with asthma raises the possibility of improved and personalized disease management. Endobronchial polarization-sensitive optical coherence tomography (PS-OCT) is a promising quantitative imaging approach that is in the early stages of clinical translation. To date, only animal tissues have been used to assess the accuracy of PS-OCT to quantify absolute (rather than relative) ASM in cross sections with directly matched histological cross sections as validation. We report the use of whole fresh human and pig airways to perform a detailed side-by-side qualitative and quantitative validation of PS-OCT against gold-standard histology. We matched and quantified 120 sections from five human and seven pig (small and large) airways and linked PS-OCT signatures of ASM to the tissue structural appearance in histology. Notably, we found that human cartilage perichondrium can share with ASM the properties of birefringence and circumferential alignment of fibers, making it a significant confounder for ASM detection. Measurements not corrected for perichondrium overestimated ASM content several-fold (P < 0.001, paired t test). After careful exclusion of perichondrium, we found a strong positive correlation (r = 0.96, P < 0.00001) of ASM area measured by PS-OCT and histology, supporting the method's application in human subjects. Matching human histology further indicated that PS-OCT allows conclusions on the intralayer composition and in turn potential contractile capacity of ASM bands. Together these results form a reliable basis for future clinical studies.NEW & NOTEWORTHY Polarization-sensitive optical coherence tomography (PS-OCT) may facilitate in vivo measurement of airway smooth muscle (ASM). We present a quantitative validation correlating absolute ASM area from PS-OCT to directly matched histological cross sections using human tissue. A major confounder for ASM quantification was observed and resolved: fibrous perichondrium surrounding hyaline cartilage in human airways presents a PS-OCT signature similar to ASM for birefringence and optic axis orientation. Findings impact the development of automated methods for ASM segmentation.

Requirements and limitations of imaging airway smooth muscle throughout the lung in vivo

Clinical visualization and quantification of the amount and distribution of airway smooth muscle (ASM) in the lungs of individuals with asthma has major implications for our understanding of airway wall remodeling as well as treatments targeted at the ASM. This paper theoretically investigates the feasibility of quantifying airway wall thickness (focusing on the ASM) throughout the lung in vivo by means of bronchoscopic polarization-sensitive optical coherence tomography (PS-OCT). Using extensive human biobank data from subjects with and without asthma in conjunction with a mathematical model of airway compliance, we define constraints that airways of various sizes pose to any endoscopic imaging technique and how this is impacted by physiologically relevant processes such as constriction, inflation and deflation. We identify critical PS-OCT system parameters and pinpoint parts of the airway tree that are conducive to successful quantification of ASM. We further quantify the impact of breathing and ASM contraction on the measurement error and recommend strategies for standardization and normalization.

Quantitative Ultrasound Detects Smooth Muscle Activity at the Cervical Internal Os in Vitro

The cervix has two biomechanical functions: to remain closed while the fetus develops throughout pregnancy, and to open for delivery of the fetus at full term. This dual function is principally attributed to collagen within the extracellular matrix (ECM). However, recent evidence suggests that other ECM, and non-ECM, components play a role as well. One component is smooth muscle cells arranged circumferentially near the internal os. In this study, we investigate correlations between cervical smooth muscle cell force generation and the effective scatterer diameter (ESD), a quantitative ultrasound parameter directly related to the acoustic impedance distribution and, therefore, a potential biomarker of muscle contractility. Using whole cervical slices (N = 5), we determined significant positive correlations (quantified with Pearson's r) between muscle force generation and ESD immediately after administration of oxytocin (median r = 0.90). In summary, the ESD may prove a useful biomarker for studying structure and function of cervical smooth muscle in vivo.

Bowel wall thickening: inquire or not inquire? Our guidelines

INTRODUCTION

Bowel wall thickening is not an uncommon finding among patient undergoing abdomen CT scan. It may be caused by neoplastic, inflammatory, infectious or ischaemic conditions but also be a normal variant. Although specific radiologic patterns may direct to a precise diagnosis, occasionally misidentification may occur. Thus, in the absence of guidelines, further and not always needed diagnostic procedures (colonoscopy, esophagogastroduodenoscopy or capsule endoscopy) are performed.

PATIENTS AND METHODS

We conducted a retrospective study on data collected from May 2016 to June 2017. We selected 40 adult patients, admitted in Emergency Department with "abdominal pain" and undergone an abdomen CT scan, in which bowel wall abnormalities were founded.

RESULTS

75% patients were found to have a benign condition vs 25% a malignant condition. In the stomach group, 50% were found to have a neoplasm, whilst 33.3% presented an aspecific pattern and 16.7% had an inflammatory disease. In the small bowel cluster, 33.3% patients had an ischaemic disease, 33.3% an aspecific pattern, 22.2% an inflammatory disease and 11.1% was diagnosed with cancer. In the colon group, 36% had an inflammatory disease, 24% a colon cancer, 24% an aspecific pattern and 16% an ischaemic condition.

CONCLUSIONS

We recommend to perform a further endoscopic procedure to all patients with gastric or colonic wall abnormalities on CT scan, on the basis of growing rate of cancer and IBD. Capsule endoscopy should be taken into account in patients with severe symptoms and after a previous negative endoscopic examination.

Non-linear optical imaging and quantitative analysis of the pathological changes in normal and carcinomatous human colorectal muscularis

Non-linear optical (NLO) imaging based on two-photon excitation (2PE) and second harmonic generation (SHG) has been widely used to image microstructures of biomedical specimens over the last two decades. We employed NLO imaging technology to investigate the histology of normal and carcinomatous human colorectal muscularis in transverse and longitudinal views. Results show there are different patterns of pathological changes of muscularis in tissue structure and cell morphology from both views. The NLO imaging provides identical histological information as the H&E images but requires neither stain nor tissue processing. Our study indicates that NLO imaging technology shows more detailed microstructure, which is a critical complementary tool in pathological diagnosis of colorectal tumours. It suggests that NLO imaging could be a very important diagnostic tool to help pathologists realise the real time early detection of human colorectal tumours in the foreseeable future.

Uterus-like Masses in a Rhesus Macaque (Macaca mulatta)

Endometriosis is a relatively common condition in women and some populations of adult female rhesus macaques. However, endometriosis with extensive smooth muscle proliferation, as occurs in endomyometrioma and uterus-like mass (ULM), is rare in women. This report describes a case of endometriosis with extensive smooth muscle metaplasia resembling multiple ULM in a 20-y-old female rhesus macaque. During a protocol-related procedure, a large, smooth, globoid, freely moveable mass was palpated in the midabdomen. Ultrasonography revealed a cystic structure from which dark brown fluid was aspirated. During exploratory laparotomy, an 8-cm spherical mass in the greater omentum and 3 additional masses (diameter, 2 to 5 cm) attached to the omentum were excised. Microscopic examination of the masses revealed numerous foci of ectopic endometrial glands and stroma frequently surrounded by bundles of smooth muscle and fibrous connective tissue. The gross and histologic lesions in this macaque bore many similarities to ULM in women. To our knowledge, this case represents the first report of endometriosis resembling a uteruslike mass in a NHP.

In Vivo Measurements of T2 Relaxation Time of Mouse Lungs during Inspiration and Expiration

Purpose

The interest in measurements of magnetic resonance imaging relaxation times, T1, T2, T2*, with intention to characterize healthy and diseased lungs has increased recently. Animal studies play an important role in this context providing models for understanding and linking the measured relaxation time changes to the underlying physiology or disease. The aim of this work was to study how the measured transversal relaxation time (T2) in healthy lungs is affected by normal respiration in mouse.

Method

T2 of lung was measured in anaesthetized freely breathing mice. Image acquisition was performed on a 4.7 T, Bruker BioSpec with a multi spin-echo sequence (Car-Purcell-Meiboom-Gill) in both end-expiration and end-inspiration. The echo trains consisted of ten echoes of inter echo time 3.5 ms or 4.0 ms. The proton density, T2 and noise floor were fitted to the measured signals of the lung parenchyma with a Levenberg-Marquardt least-squares three-parameter fit.

Results

T2 in the lungs was longer (p<0.01) at end-expiration (9.7±0.7 ms) than at end-inspiration (9.0±0.8 ms) measured with inter-echo time 3.5 ms. The corresponding relative proton density (lung/muscle tissue) was higher (p<0.001) during end-expiration, (0.61±0.06) than during end-inspiration (0.48±0.05). The ratio of relative proton density at end-inspiration to that at end-expiration was 0.78±0.09. Similar results were found for inter-echo time 4.0 ms and there was no significant difference between the T2 values or proton densities acquired with different interecho times. The T2 value increased linearly (p< 0.001) with proton density.

Conclusion

The measured T2 in-vivo is affected by diffusion across internal magnetic susceptibility gradients. In the lungs these gradients are modulated by respiration, as verified by calculations. In conclusion the measured T2 was found to be dependent on the size of the alveoli.

Endobronchial Ultrasound Reliably Quantifies Airway Smooth Muscle Remodeling in an Equine Asthma Model

Endobronchial ultrasonography (EBUS) revealed differences in the thickness of the layer representing subepithelial tissues (L2) between human asthmatics and controls, but whether this measurement correlates with airway smooth muscle (ASM) remodeling in asthma is unknown. In this study, we sought to determine the ability of EBUS to predict histological ASM remodeling in normal and equine asthmatic airways. We studied 109 isolated bronchi from the lungs of 13 horses. They underwent EBUS examination using a 30 MHz radial probe before being processed for histology. ASM remodeling parameters were evaluated in EBUS images (L2 thickness, L2 area, L2 area/internal perimeter [Pi] and L2 area/Pi2) and histological cuts (ASM area/Pi2), and compared. EBUS was then performed ex vivo on the lungs of 4 horses with heaves, an asthma-like condition of horses, and 7 controls to determine whether central bronchial remodeling could be detected with this technique. An optimized approach was developed based on data variability within airways, subjects, and groups, and then validated in 7 horses (3 controls, 4 with heaves) that underwent EBUS in vivo. L2 area was significantly associated to ASM area in isolated lungs (p<0.0001), in the absence of significant bias related to the airway size. Bronchial size significantly affected EBUS ASM-related parameters, except for L2 area/Pi2. L2 area/Pi2 was increased in the airways of asthmatic horses compared to controls, both ex vivo and in vivo (p<0.05). Bronchial histology confirmed our findings (AASM/Pi2 was increased in asthmatic horses compared to controls, p<0.05). In both horses with heaves and controls, L2 was composed of ASM for the outer 75% of its thickness and by ECM for the remaining inner 25%. In conclusion, EBUS reliably allows assessment of asthma-associated ASM remodeling of central airways in a non-invasive way.

Effect of peroral esophageal myotomy for achalasia treatment: A Chinese study

AIM: To assess the safety and feasibility of peroral esophageal myotomy (POEM) in patients with achalasia.

METHODS: From January 2012 to March 2014, 50 patients (28 men, 22 women; mean age: 42.8 years, range: 14-70 years) underwent POEM. Pre- and postoperative symptoms were quantified using the Eckardt scoring system. Barium swallow and esophagogastroscopy were performed before and after POEM, respectively. Esophageal motility was evaluated in all patients, both preoperatively and one month after POEM treatment, using a high-resolution manometry system. Manometry data, Eckardt scores, lower esophageal sphincter pressure and barium swallow results were used to evaluate the effect of the procedure.

RESULTS: POEM was successfully completed for all patients. The mean procedure time was 55.4 ± 17.3 min and the mean total length of myotomy of the circular esophagus was 10.5 ± 2.6 cm. No specific complications occurred, with the exception of two patients that developed asymptomatic pneumomediastinum and subcutaneous emphysema. Clinical improvement in symptoms was achieved in all patients. Approximately 77.5% of patients experienced weight gain 6 mo after POEM, with an average of 4.78 kg (range: 2-15 kg). The lower esophageal sphincter resting pressure, four second integrated relaxation pressure and Eckardt scores were all significantly reduced after POEM (Ps < 0.05). A small segment of proximal esophageal peristalsis appeared postoperatively in two patients, but without normal esophageal peristalsis. The average diameter of the esophageal lumen decreased significantly from 4.39 to 3.09 cm (P < 0.01).

CONCLUSION: POEM can relieve achalasia symptoms, improve gastroesophageal junction relaxation and restore esophageal body motility function, but not normal esophageal peristalsis.

[Significance of ultrasonic detection of muscle layer thickness of cesarean section scar in late pregnancy]

OBJECTIVE

To explore the clinical value of high frequency ultrasound in monitoring muscle layer thickness of cesarean section scar in late pregnancy.

METHODS

A total of 131 patients re-conceived after cesarean section were selected randomly from our hospital.High frequency ultrasound was used for monitoring muscle layer thickness of cesarean section scar. And ultrasonic results and operative findings were compared.

RESULTS

Based upon the ultrasonic results, they were divided into 2 groups: group 1 ( ≤ 2 mm, n = 61), there were confirmed (n = 19) and misdiagnosed (n = 11) uterine rupture; group 2 ( > 2 mm, n = 70), confirmed (n = 5) and misdiagnosed (n = 5) uterine rupture.

CONCLUSION

Monitoring muscle layer thickness of cesarean section scar is of great significance for preventing uterine rupture in late pregnancy.

Anatomical disruption and length-tension dysfunction of anal sphincter complex muscles in women with fecal incontinence

BACKGROUND

Anal sphincter complex muscles, the internal anal sphincter, external anal sphincter, and puborectalis muscles, play an important role in the anal continence mechanism. Patients with symptoms of fecal incontinence have weak anal sphincter complex muscles; however, their length-tension properties and relationship to anatomical disruption have never been studied.

OBJECTIVE

This study aimed to assess the anatomy of the anal sphincter complex muscles with the use of a 3-dimensional ultrasound imaging system and to determine the relationship between the anatomical defects and the length-tension property of external anal sphincter and puborectalis muscles in women with incontinence symptoms and in control subjects.

DESIGN

Severity of anal sphincter muscle damage was determined by static and dynamic 3-dimensional ultrasound imaging. The length-tension property was determined by anal and vaginal pressure with the use of custom-designed probes.

PATIENTS

Forty-four asymptomatic controls and 24 incontinent patients participated in this study.

MAIN OUTCOME MEASURES

The anatomical defects and length-tension dysfunction of anal sphincter complex muscles in patients with fecal incontinence were evaluated.

RESULTS

The prevalence of injury to sphincter muscles is significantly greater in the incontinent patients than in the controls. Eighty-five percent of patients but only 9% controls reveal damage to ≥2 of the 3 muscles of the anal sphincter complex. Anal and vaginal squeeze pressures increased with the increase in the probe size (length-tension curve) in the majority of controls. In patients, the increase in anal and vaginal squeeze pressures was either significantly smaller than in controls or it decreased with the increasing probe size (abnormal length-tension).

LIMITATIONS

We studied patients with severe symptoms. Whether our findings are applicable to patients with mild to moderate symptoms remains to be determined.

CONCLUSIONS

The length-tension property of the external anal sphincter and puborectalis muscles is significantly impaired in incontinent patients. Our findings have therapeutic implications for the treatment of anal incontinence.

[Gallbladder contractility in children with functional abdominal pain or irritable bowel syndrome]

III Rome Criteria of functional gastrointestinal disorders in children, distinguished the disturbances with abdominal pain, to which irritable bowel syndrome, functional abdominal pains, functional dyspepsia and abdominal migraine were included. THE AIM OF THE STUDY was sonographic assessment of the gallbladder and its contractility in functional abdominal pain and irritable bowel syndrome in children.

MATERIAL AND METHODS

The study comprised 96 children aged 6 to 18 years, 59 girls and 37 boys. Depending on diagnosis, the children were divided into three groups. 38 children with functional abdominal pain constituted the first group, 26 children with irritable bowel syndrome were included to the second group, the third group consisted of 32 healthy children (control group). Diagnosis of functional abdominal pain and irritable bowel syndrome was made based on the III Rome Criteria. In irritable bowel syndrome both forms with diarrhea (13) and with constipation (13) were observed. Anatomy and contractility of the gallbladder were assessed by ultrasound examination. The presence of septum, wall thickness, thick bile, vesicle volume in fasting state and 30th and 60th minute after test meal were taken into consideration. Test meal comprised about 15% of caloric requirement of moderate metabolism. Children with bile stones and organic diseases were excluded from the study.

RESULTS

Thickened vesicle wall and thick bile were present more frequently in children with irritable bowel syndrome and functional abdominal pain than in control group (p < 0.02). Fasting vesicle volume was significantly greater in children with functional abdominal pain than in irritable bowel syndrome and control group (p = 0.003, p = 0.05). Vesicle contractility after test meal was greatest in children with functional abdominal pain. Evaluation of diminished (smaller than 30%) and enlarged (greater then 80%) gallbladder contractility at 30th and 60th minute after test meal demonstrated disturbances of contractility in children with irritable bowel syndrome and functional abdominal pain.

CONCLUSIONS

In children with functional abdominal pain and irritable bowel syndrome disturbances of gallbladder anatomy, fasting volume and contractility after test meal were demonstrated. The observed disturbances require further studies for explanation of their role in functional gastrointestinal disturbances with abdominal pain in children.

The role of videofluoroscopy and ultrasound in assessing pharyngoesophageal muscle tone after laryngectomy

The aim of this study was to compare the respective value of videofluoroscopy and ultrasound for assessment of the tonicity of the neoglottis and determination of the exact neolaryngeal segment of hypertonicity. We examined twelve patients who had developed inadequate tracheoesophageal voice following total laryngectomy and installation of tracheoesophageal prosthesis. We assumed that the cause of the unsatisfactory voice quality in our patients was neolaryngeal muscle spasm. After determining the exact hypertonic segment, we administered lidocaine intramuscularly and tried to act on the hypertonic segment. By means of videofluoroscopy as gold standard for comparison with ultrasound examination, we followed the passage of contrast through the neo-larynx and watched for dilatation of the segment during swallowing, phonation and at rest to determine whether there were any tonus disturbances or differences before and after lidocaine injection. In conclusion, a combination of the two methods could yield better results in voice restoration. Videofluoroscopy is the method of choice for initial assessment and determination of the hypertonic segment, while ultrasound is the method to apply to facilitate administering the drug more precisely.

Accuracy of measurement of puborectal contraction by perineal ultrasound in patients with faecal incontinence

AIM

The study aimed to determine the accuracy of measurement of puborectal contraction, measured by perineal ultrasound during anal voluntary contraction in patients with incontinence.

METHOD

Puborectalis sling contraction in 32 consecutive patients investigated for faecal incontinence was determined by two examiners on two occasions (four measurements per patient). The examiners were blinded to each other's results.

RESULTS

The mean anterior movement of the puborectalis sling was between 11 and 12 mm for both examiners on both occasions. The global intraclass correlation coefficient for examiners and occasions together was 0.92. The absolute agreement on the movement exceeding or not 8 mm was 87.5% (28 of 32), and the corresponding κ statistic was 0.84. The differences between the two experts were minimal.

CONCLUSION

The study confirms the reliability of puborectalis sling contraction measurement and its value as a preoperative predictive tool to assess the prognosis of sphincter repair for postdelivery faecal incontinence.

Detrusor wall thickness as a test for detrusor overactivity in women

OBJECTIVE

The measurement of detrusor wall thickness has been used as a screening test for detrusor overactivity and bladder outlet obstruction in men and women. The aim of this study was to determine, using receiver-operating characteristics (ROC) analysis, the diagnostic value of detrusor wall thickness in predicting detrusor overactivity in women.

METHODS

The records of 686 women who attended a tertiary urodynamics service from November 2002 to January 2006 were retrospectively reviewed. The patients had undergone an interview, clinical examination, multichannel urodynamic studies and translabial ultrasound examination. Detrusor wall thickness measurements were taken at the bladder dome, after bladder emptying. ROC analysis was used to identify the optimal cut-off of detrusor wall thickness in predicting detrusor overactivity.

RESULTS

Average detrusor wall thickness in the detrusor overactivity group was 4.7 +/- 1.9 mm (mean +/- SD), compared to 4.1 +/- 1.6 mm in the non-detrusor overactivity group (P < 0.001). Using a cut-off of detrusor wall thickness of 5.0 mm gave a sensitivity of 37% and a specificity of 79% for diagnosing detrusor overactivity. The ROC analysis revealed an area under the curve (AUC) of 0.606 (95% CI, 0.56-0.65).

CONCLUSIONS

There is a statistically significant association between detrusor wall thickness and detrusor overactivity (P < 0.001). However, ROC analysis demonstrated that detrusor wall thickness as measured by translabial ultrasound is of little use as a diagnostic test for detrusor overactivity, giving an AUC of only 0.606. Measurement of detrusor wall thickness should therefore not be used as a diagnostic parameter for detrusor overactivity in women.

Hormone therapy is associated with preserved smooth muscle structure and dilation in the arterial vasculature of the leg in older women

Long-term hormone therapy (HT) is associated with reduced intima-medial thickness (IMT), an established risk factor for atherosclerotic disease, in the femoral artery of healthy older women relative to age-matched non-hormone users. However, the influence of continuous, long-term HT on the relation between age, IMT, and smooth muscle dilation has not been investigated in the popliteal artery, an artery prone to stiffening and calcification. In the present study, popliteal artery IMT and smooth muscle dilation (the increase in diameter to sublingual nitroglycerin, NTG) were assessed with Doppler ultrasound in young (Y: n=16; age 23+/-1 [mean+/-S.E.M.]), older non-HT (O non-HT: n=14; age 69+/-1), and older HT (O HT: n=8; age 67+/-1) healthy women. The approximately 0.5 mm increase in resting diameter observed in older non-HT women relative to young women was absent in older HT women, as was the age-related increase in IMT (Y: 0.52+/-0.02 mm; O non-HT: 0.63+/-0.02 mm; O HT: 0.56+/-0.02 mm; p<0.05 for age and hormone comparisons). NTG dilation (percent change above rest) was similarly attenuated in older non-HT women (Y: 8.6+/-1%; O non-HT: 3.0+/-0.7%; O HT: 7.4+/-1.7%; p<0.05 for age and hormone comparisons), and NTG dilation was inversely related to IMT (p<0.01). Collectively, these results suggest that long-term, continuous HT may alleviate the detrimental effects of aging on both structural changes and smooth muscle dilation of the popliteal artery in healthy women.

Delayed evacuatory function due to specific smooth muscle reactivity in the gastrointestinal tracts of tacrine-treated rats

Most of the side effects induced by tacrine are associated with the gastrointestinal (GI) tract. The aim of the study was to analyze the nature of radiographically registered, tacrine-induced changes in evacuatory function, as well as to find a possible correlation with the immediate in vitro action of the drug on smooth muscles from the GI tracts of rats. The tacrine dose we used reliably delayed GI passage: contrast matter was not fully evacuated, predominantly from the stomach and cecum. The delay resulted from changes in tone and peristaltic activity, specific for the various regions of the tract. These changes were associated with a superposing of the responses due to the anticholinesterase and noncholinergic action of tacrine.

Avulsion of the pubovisceral muscle associated with large vaginal tear after normal vaginal delivery at term

Trauma to the levator ani muscle commonly occurs during vaginal childbirth and is associated with female pelvic organ prolapse in later life. To date, such trauma was thought to be occult. We present a case of intrapartum diagnosis of levator avulsion in a patient who suffered a large vaginal tear at the time of a normal vaginal delivery at term.

Test–retest and intra-observer repeatability of two-, three- and four-dimensional perineal ultrasound of pelvic floor muscle anatomy and function

The aims of the present study were to evaluate test-retest intra-observer repeatability of ultrasound measurement of the morphology and function of the pelvic floor muscles (PFMs). Seventeen subjects were tested twice. Two-, three- and four- dimensional ultrasound recorded cough, huff, muscle morphology and PFM contraction, respectively. Analyses were conducted offline. Measurements of levator hiatal dimensions demonstrated intra-class correlation coefficient (ICC) values of 0.61, 0.72, 0.86 and 0.92, for the anterior-posterior dimension, transverse dimension, resting area and narrowing during contraction, respectively. Muscle thickness showed variable reliability. ICC values for measurement of the position of the bladder neck were 0.86 and 0.82 at rest, in the vertical and horizontal direction. Displacement of the bladder neck during contraction, huff and cough demonstrated ICC values of 0.56, 0.59 and 0.51, respectively. Perineal ultrasound is a reliable method for measuring most of the tested parameters of morphology and function of the PFMs.

Smooth muscle remodeling of the gastroesophageal junction after endoluminal gastroplication

BACKGROUND

Endoluminal gastroplication has been shown to reduce symptoms of gastroesophageal reflux disease and to induce focal hypertrophy of the gastroesophageal junction (GEJ) muscularis propria. Despite suture loss, some patients have persistent symptomatic resolution.

OBJECTIVE

This study was designed to examine the durability of smooth muscle hypertrophy after suture removal.

DESIGN

Seven pigs underwent upper endoscopy with endoscopic ultrasonography (EGD/EUS) at baseline to evaluate GEJ muscularis propria layer. Endoluminal gastroplication was performed at week 1 with placement of 2 sutures at the GEJ. Repeat EGD/EUS was performed at week 3 and week 5. Three of the 7 pigs were killed for histologic analysis. The remaining 4 pigs had sutures removed and survived for 9, 11, and 13 weeks; serial weekly EGD/EUS was performed until the animal was killed.

RESULTS

The GEJ muscularis propria thickness by EUS was 1.1+/-0.1 mm at baseline, 4.7+/-1.9 mm at week 3, and 4.4+/-1.1 mm at week 5. The muscularis propria thickness by histologic examination in the 3 animals with sutures intact were 6.2+/-0.3 mm near the suture site and 4.7+/-0.5 mm at the opposing wall to the suture site. For the 4 animals with sutures removed, the measurements were 6.9+/-0.2 mm (suture site) and 4.7+/-0.5 mm (opposing wall), respectively.

CONCLUSIONS

The GEJ smooth muscle cell hypertrophy induced by endoluminal gastroplication persisted after removal of mucosal sutures. These changes may be responsible for persistent symptomatic response despite suture loss in patients.

Bladder Wall Thickness in Healthy School-Aged Children

OBJECTIVES

To evaluate the effectiveness of transabdominal ultrasonography for bladder volume and detrusor muscle thickness and to research the relationship of these measurements with age, height, and body mass index.

METHODS

We reviewed the records of 244 healthy, school-aged children from February to May 2003. After a complete urologic examination, the weight and height of all children were measured, and their body mass index was determined. Transabdominal ultrasonography with a high-frequency probe was performed to obtain the anterior, posterior, and lateral bladder wall thicknesses.

RESULTS

The mean age of the children was 10.7 +/- 3.6 years (range 7 to 15), and the mean bladder volume was 256 cm3 (range 78 to 790). The relationship between bladder volume and age was significant (P = 0.0001, r = 0.568). The mean anterior, posterior, and lateral detrusor thickness was 1.42 mm (range 0.8 to 2.8), 1.57 mm (range 0.7 to 3.1), and 1.49 mm (range 0.6 to 2.6), respectively. The relationships between increasing age and the anterior and posterior wall thicknesses were significant (P <0.05), but the relationship between age and the lateral wall thickness was not (P >0.05). The relationship between bladder volume and body mass index was significant (P = 0.0001, r = 0.2959). A strong positive and significant correlation was found between the anterior (P = 0.0001) and posterior (P = 0.001) wall thicknesses and body mass index, but the correlation between the lateral wall thickness and body mass index was not significant (P = 0.079, r = 0.113).

CONCLUSIONS

Strong, positive correlations were found between the anterior and posterior wall detrusor thicknesses and increased age and body mass index, but the same correlations for lateral wall detrusor thickness were not found.

Function of longitudinal vs circular muscle fibers in esophageal peristalsis, deduced with mathematical modeling

We summarize from previous works the functions of circular vs. longitudinal muscle in esophageal peristaltic bolus transport using a mix of experimental data, the conservation laws of mechanics and mathematical modeling. Whereas circular muscle tone generates radial closure pressure to create a local peristaltic closure wave, longitudinal muscle tone has two functions, one physiological with mechanical implications, and one purely mechanical. Each of these functions independently reduces the tension of individual circular muscle fibers to maintain closure as a consequence of shortening of longitudinal muscle locally coordinated with increasing circular muscle tone. The physiological function is deduced by combining basic laws of mechanics with concurrent measurements of intraluminal pressure from manometry, and changes in cross sectional muscle area from endoluminal ultrasound from which local longitudinal shortening (LLS) can be accurately obtained. The purely mechanical function of LLS was discovered from mathematical modeling of peristaltic esophageal transport with the axial wall motion generated by LLS. Physiologically, LLS concentrates circular muscle fibers where closure pressure is highest. However, the mechanical function of LLS is to reduce the level of pressure required to maintain closure. The combined physiological and mechanical consequences of LLS are to reduce circular muscle fiber tension and power by as much as 1/10 what would be required for peristalsis without the longitudinal muscle layer, a tremendous benefit that may explain the existence of longitudinal muscle fiber in the gut. We also review what is understood of the role of longitudinal muscle in esophageal emptying, reflux and pathology.

Prevalence of increased esophageal muscle thickness in patients with esophageal symptoms

BACKGROUND

Patients with achalasia, diffuse esophageal spasm (DES), and nutcracker esophagus have a thicker muscularis propria than normal subjects. The goal of our study was to determine the prevalence of increased muscle thickness in a group of unselected patients referred to the esophageal function laboratory for evaluation of the symptoms.

METHODS

We studied 40 normal subjects and 94 consecutive patients. Manometry and ultrasound images were recorded concurrently, using a special custom-built catheter. Esophageal muscle thickness and muscle cross-sectional area were measured at 2 and 10 cm above the lower esophageal sphincter (LES). Patients were assigned manometric diagnosis and determination was made if they had increased muscle thickness and muscle cross-sectional area.

RESULTS

Nearly all patients with well-defined spastic motor disorders, i.e., achalasia, DES, and nutcracker esophagus, revealed (a) an increase in the muscle thickness/cross-sectional area, (b) increase in esophageal muscle thickness/cross-sectional area was also seen, albeit at a lower prevalence rate, in patients with less well-characterized manometric abnormalities, i.e., hypertensive LES, impaired LES relaxation, and ineffective esophageal motility, and (c) 24% of patients with esophageal symptoms but normal manometry were also found to have an increase in muscle thickness/cross-sectional area. Dysphagia was more likely, and heartburn less likely in patients with increased muscle thickness, but there were no differences in chest pain and regurgitation symptoms between the groups.

CONCLUSION

We describe, for the first time, increased muscle thickness in patients with esophageal symptoms and normal manometry. We suggest that increased esophageal muscle thickness is likely to be an important marker of esophageal motor dysfunction.

Esophageal ultrasonography: A new view on esophageal motility

Esophageal manometry has long been the gold standard for assessment of esophageal motility. Recently, high-frequency intraluminal ultrasonography (HFIUS) has been introduced to measure esophageal contractility and the thickness of esophageal muscle. Greater esophageal muscle thickness has been reported in patients with achalasia, diffuse spasm, and hypertensive peristalsis. In this issue of the Journal, Mittal and colleagues report additional observations in patients with esophageal symptoms referred for esophageal manometry. Their findings confirm earlier observations in patients with spastic motor disorders and report new findings of greater muscle thickness in patients with nonspecific motor disorders as well as normal manometry. Greater muscle thickness was associated with a greater prevalence of dysphagia suggesting the possibility that symptoms may be related, at least in part, to alterations in the biomechanics of the esophagus. The place of HFIUS in the assessment of esophageal function remains to be determined, but it offers the possibility of greater insights into esophageal physiology as well as clinical esophageal motor disorders.

Accommodative ciliary body and lens function in rhesus monkeys, I: normal lens, zonule and ciliary process configuration in the iridectomized eye

PURPOSE

The underlying causes of presbyopia, and the functional relationship between the ciliary muscle and lens during aging are unclear. In the current study, these relationships were studied in rhesus monkeys, whose accommodative apparatus and age-related loss of accommodation are similar to those in humans.

METHODS

Centripetal ciliary body and lens equator movements were measured during accommodation in 28 eyes of 21 rhesus monkeys (ages, 5.7-26 years) by goniovideography. Ultrasound biomicroscopy was performed in 21 eyes of 17 monkeys. Narrowing of the angle between the anterior aspect of the ciliary body and the inner aspect of the cornea was used as a surrogate indicator of forward ciliary body movement during accommodation.

RESULTS

Average centripetal ciliary body movement in older eyes (age > or =17 years, n = 16) was approximately 20% (0.09 mm) less than in young eyes (age, 6-10 years, n = 6), but not enough to explain the 60% (0.21 mm) loss in centripetal lens movement nor the 76% (10.2 D) loss in accommodative amplitude. Average forward ciliary body movement was 67% (49 degrees ) less in older (n = 11) versus young (n = 6) eyes. Maximum accommodative amplitude correlated significantly with the amplitude of centripetal lens movement (0.02 +/- 0.003 mm/D; n = 28; P < 0.001) and with forward ciliary body movement (3.34 +/- 0.54 deg/D; n = 21; P = 0.01).

CONCLUSIONS

Decreased lens movement with age could be in part secondary to extralenticular age-related changes, such as loss of ciliary body forward movement. Ciliary body centripetal movement may not be the limiting component in accommodation in the older eye.

In vitro strain measurement in the porcine antrum using ultrasound doppler strain rate imaging

Strain rate imaging (SRI) enables study of deformation in soft tissues. The aim of this study was to evaluate the accuracy of SRI in measuring strain in the porcine antral wall in vitro. An experimental set-up enabled controlled distension of a porcine stomach in a saline reservoir. Radial strain obtained by SRI was compared with radial strain calculated from B-mode ultrasonography. Circumferential strain obtained by SRI was compared with circumferential strain calculated from sonomicrometry. The agreement between radial strain values measured by SRI and B-mode, along and across several ultrasound (US) beams, using US frequency 6.7 MHz and strain length (SL) = 1.9 mm was = -1.0 +/- 12.1% and 0.5 +/- 13.4%, respectively (mean difference +/- 2SD%) and it was better than with SL 1.2 mm. Compared with sonomicrometry, SRI-determined circumferential strain using 6.7 MHz and SL = 1.9 mm was less accurate, whether averaging along or across several US beams (-9.2 +/- 46.7% and 13.8 +/- 51.2%, respectively). In conclusion, SRI gave accurate measurement of radial strain of the antral wall, but seemed to be less accurate for measurement of circumferential strain for this in vitro set-up.

Muscle shortening along the normal esophagus during swallowing

Longitudinal shortening of the esophagus during peristaltic contraction has been previously analyzed globally using spaced mucosal clips. This method gives a relatively crude measurement. In this study, local longitudinal shortening (LLS) was evaluated using simultaneous high-resolution endoluminal ultrasound (HREUS) and manometry based on basic principles of muscle mechanics. We sought to determine if there are regional differences in LLS of the esophageal muscle during swallow-induced peristaltic contraction and evaluate shortening of the circular smooth muscle (CSM) and longitudinal smooth muscle (LSM) of the esophagus. Twenty normal subjects underwent simultaneous HREUS/manometry at 4 levels (5, 10, 15, and 20 cm above the upper border of the lower esophageal sphincter [LES] high-pressure zone) in the esophagus with 5-mL swallows of water. Ultrasound images were recorded with synchronized manometric pressure data. The images were digitized and the cross-sectional surface area (CSA) of the LSM, CSM, and total muscle (TM) were measured at baseline (at rest) and at peak intraluminal pressure (implying peak CSM contraction) during swallowing. LLS was calculated for the CSM and LSM using the principle of mass conservation, whereby the change in CSA relative to the resting CSA is quantitatively equal to the relative change in length of a local longitudinal muscle segment.CSM, LSM, and TM all shortened longitudinally, with the circular muscle shortening more than the longitudinal muscle, LLS of the CSM and TM layers at 5 cm above the LES was significantly greater than at 20 cm (CSM: 30% difference, P < .001; TM: 18% difference, P < .05). The greater shortening of LSM at 5 versus 20 cm was found not to be statistically significant (11% difference, P > .05). Peak intraluminal pressure strongly correlated with peak muscle thickness of all layers at all levels (r = 0.96-0.98).LLS increases from the proximal to the distal esophagus during bolus transport. CSM and LSM both shorten longitudinally, with CSM shortening more than LSM. The increase in LLS increases the efficiency of peristaltic contraction and likely contributes to the axial displacement of the LES preceding hiatal opening and esophageal emptying.

[The microstructure studies of penile cavernous tissue of erectile dysfunction rat models with chronic renal failure]

OBJECTIVE

To investigate the mechanism of erectile dysfunction (ED) in rat models with chronic renal failure (CRF).

METHODS

Chronic renal failure was induced by adult male Sprague-Dawley rats, which were subjected to an excisional 5/6 nephrectomy. The rats in NCRF group and CRF group were divided into three groups randomly. Injected with apomorphine(APO, 80 microg/kg), penile erections of three groups were observed and noted by the 2nd week, 4th week respectively and 6th week from the 14th day of 5/6 nephrectomy and experimental models of ED with CRF were selected; NOS activity was examined and the microstructures of penile were observed under optical microscope with computer configuration image analysis system in selected rat models.

RESULTS

Compared with the controls, the areas of smooth muscle and NOS activity in the penile cavernous tissue of ED rats with CRF decreased significantly (P < 0.01 or P < 0.05) , and collagen fibers slightly increased, and these alterations had close correlations with the duration of CRF. The

CONCLUSIONS

Penile erection is seriously affected in rats with CRF. The decreases of areas of blood sinus had no obvious changes. the number of smooth muscles and NOS activity might be the most important factors.

Oesophageal wall stress and muscle hypertrophy in high amplitude oesophageal contractions

Excessive wall stress is a known stimulus for muscle growth. We recently reported a thickened muscularis propria in patients with high amplitude oesophageal contractions (HAEC). The goal of this study was to determine oesophageal wall stress in normal subjects and patients with HAEC. A manometry catheter equipped with a high frequency ultrasound (US) transducer was used to record pressure and US images simultaneously in 10 healthy subjects and 11 patients with HAEC. Recordings were obtained at 2 and 10 cm above the lower oesophageal sphincter during water swallows. The changes in circumferential wall stress during oesophageal contraction in both groups are relatively small because of an increase in the wall thickness-to-radius ratio during contraction. Patients show a greater muscle thickness than normal subjects at rest and at the peak of contraction. The wall stress in patients is elevated at the 2 cm but not at the 10-cm level as compared to normal subjects. Wall strain is not different between the two groups. Increase in wall thickness during oesophageal contraction maintains low wall stress. A greater wall stress in patients with HAEC may be a stimulus for the increased wall thickness.

Identification of the layers of the bladder wall on high-frequency endoluminal ultrasonography by a needle puncture experiment

The purpose of this study was to identify the layers of the bladder wall on high-frequency endoluminal ultrasonography (ELUS). We performed a needle puncture experiment using five normal pig bladders. The histologic layer structure was compared with the ELUS images obtained using a 30-MHz miniature transducer. The bladder wall was depicted as five layers by ELUS and these corresponded to the histologic layers. The first layer (hyperechoic) was a margin echo that included the epithelium and the upper part of the lamina propria. The second layer (hypoechoic) corresponded to the lamina propria and the third layer (hyperechoic) was a margin echo that included the upper part of the muscle layer. The fourth layer (hypoechoic) corresponded to the muscle layer, and the fifth layer (hyperechoic) was a margin echo that included the upper part of the adventitia.

[Quantitative morphometry of hyperplastic hypoechoic nodules in the prostatic outer gland]

OBJECTIVE

To explore the morphotic characteristics of hypoechoic nodules in the outer gland of the prostate with benign

METHODS

Twenty-two hyperplastic hypoechoic nodules in the prostatic outer gland were biopsied guided by prostatic hyperplasia. transrectal ultrasound. The hematoxylin-eosin (HE) staining and immunohistochemistry combined with computer assisted quantitative image analyses were adopted to examine the mean percentages of the area densities of stroma, epithelium, glandular lumen and smooth muscle cells.

RESULTS

The area densities of stroma, epithelium, glandular lumen and smooth muscle cells were (72.52 +/- 13.14)%, (20.57 +/- 9.01)%, (6.85 +/- 4.51)% and (24.14 +/- 6.31)%, respectively.

CONCLUSION

Hyperplastic hypoechoic nodules may develop in the outer gland as well as in the inner gland of the prostate, but the mean percentages of the components are different between the two kinds of nodules.

[Oxidative metabolism of uterine smooth muscular tissue in norm and neoplastic growth (clinical and experimental studies)]

Complex echoscopic, histological and EPR- (electron paramagnetic resonance)-spectroscopic study of uterine smooth muscular tissue was performed using normal and neoplastic samples obtained from women of reproductive age as well as from experimental animals (guinea pigs) with normo- and hyperestrogenemia. It was found that as compared with normal myometrium, the proliferating uterine myoma had an extensive peripheral vascularization of myomatous nodule with a decreased resistance index, which is a marker of myocyte proliferative activity in the myomatous nodule. These data were supported by histological findings in material obtained at operations, which demonstrated the signs of proliferative growth. Using EPR, it was shown that uterine myoma was characterized by an estrogen-dependent intensification of the processes of free-radical oxidation, which correlated with a degree of hormonal changes. Accumulation of free-radical oxidation activators and of ions of ferritin-unbound iron in the tumor tissue is indicative of the intensification of proliferative activity of the cells of uterine myoma and is one of the risk factors of neoplastic growth. Hyperestrogenemia, characteristic for the myoma development, is one of the reasons for NO synthesis activation, which, in the oxidative stress, is transformed into cytotoxic peroxinitrite, contributing to further intensification of an oxidative stress and malignant transformation of tissues.

Influence of soft tissues on mandibular gray scale levels

The purpose of this study was to analyze the gray levels, expressed in pixels, of the mandibular retromolar region, with regard to the influence of muscular and fat soft tissues near this region. Fifteen dry mandibles were X-rayed with the presence of soft tissue simulators. The radiographs were digitized and evaluated by Digora software. A one cm thick layer of wax was used as a simulator of the muscular soft tissue. Animal fat samples of different thicknesses - 0.5, 1.0, 1.5 and 2.0 cm - were used as a simulator of the fat soft tissue. Results showed that the fat soft tissue simulator influenced the gray level values in pixels of the mandibular retromolar region when analyzed in different thicknesses using the Digora digitized image software.

Radionuclide gastroesophageal motor studies

Disorders of the upper digestive tract have a high impact on modern society, in terms of both direct and indirect health care costs and of social burden. The most common presenting symptom is either dysphagia or dyspepsia. Discriminating specific diagnoses within this wide group of diseases requires sound clinical judgment and application of procedures to distinguish organic from nonorganic disease and to further characterize the functional or motility disturbance of nonorganic diseases. Non-radionuclide-based diagnostic techniques include both noninvasive tests (upper gastrointestinal barium series, ultrasonography, and breath test for gastric emptying) and invasive procedures (fiberoptic endoscopy, esophagogastroduodenoscopy, pharyngeal manometry, stationary esophageal manometry, 24-h pH monitoring, esophageal biliary reflux monitoring, multichannel intraluminal impedance, and electrogastrography). Some of these techniques are not well tolerated by patients or not widely available. Radionuclide transit/emptying scintigraphy provides a means of characterizing exquisite functional abnormalities with a set of low-cost procedures that are easy to perform and widely available, entail a low radiation burden, closely reflect the physiology of the tract under evaluation, are well tolerated and require minimum cooperation by patients, and provide quantitative data for better intersubject comparison and for monitoring response to therapy. Despite the relatively low degree of standardization both in the scintigraphic technique per se and in image processing, these methods have shown excellent diagnostic performance in several function or motility disorders of the upper digestive tract. Dynamic scintigraphy with a radioactive liquid or semisolid bolus provides important information on both the oropharyngeal and the esophageal phases of swallowing, thus representing a useful complement or even a valid alternative to conventional invasive tests (such as stationary esophageal manometry) for evaluating abnormalities of oropharyngoesophageal transit. Clinical applications of esophageal transit scintigraphy include disorders such as nutcracker esophagus, esophageal spasm, noncardiac chest pain of presumed esophageal origin, achalasia, esophageal involvement of scleroderma, and gastroesophageal reflux and monitoring of response to therapy (either medical or surgical treatment of disease-for example, organic disease such as esophageal cancer). Scintigraphy with a radiolabeled test meal represents the gold standard for evaluating gastric emptying, whereas more recent radionuclide methods include dynamic antral scintigraphy and gastric SPECT for assessing gastric accommodation. Clinical applications of gastric-emptying scintigraphy include, among others, evaluation of patients with dyspepsia and evaluation of gastric function in various systemic diseases affecting gastric emptying. The present review includes the proposal of clinical algorithms for evaluating patients with the main disorders of the upper digestive tract. These algorithms, originally derived from available literature, have been developed on the basis of a vast clinical experience in conjunction with the specialists more deeply involved in the care of patients with such disorders (medical and surgical gastroenterologists and nuclear medicine physicians). The role of radionuclide gastroesophageal motor studies is clearly identified in the various steps of patients' management, from the initial diagnostic approach to functional characterization to postoperative follow-up or monitoring of medical therapy.

Nachweis der natürlichen Spontanaktivität der kranioösophagealen und der Kehlkopfmuskulatur durch das PET-CT

The muscles of the cranioesophageal sphincter system feature continuous natural spontaneous resting activity. Thus, they resemble the anorectal sphincter system. We studied metabolic activity and morphology of the proximal sphincter system at rest in 23 individuals (14 females, nine males) using PET-CT scanning. We found that metabolic activity was significantly higher than in other muscle groups of the body at rest (P=0.001). In contrast to the horizontally oriented anal sphincters, the proximal sphincter system is developed as a vertical assembly of long, interlocking muscular tubes. These are innervated by five cranial nerves and three sensory organ nerves and form a functional unit that extends from the orbicularis oris muscle via the pharynx and larynx to the lower esophageal sphincter. The larynx shows only one active muscle, i.e., the posterior cricoarytaenoid muscle, that maintains airway patency. The lower esophageal sphincter can be visualized by PET-CT as a vertically oriented stretching sphincter. It features a spiral-shaped design made up of muscle maxima and minima which correlates well with its asymmetric muscle activity. This complex proximal sphincter system shows great developmental variability among different animal species. However, the general functional principle is similar in all.

Submucosal territory of the direct lymphatic drainage system to the thoracic duct in the human esophagus

OBJECTIVE

To investigate how large submucosal drainage territory extends in lymphatic drainage vessels of the esophagus with and without nodal delay and which morphologies are shown when passing through the muscularis propria.

METHODS

Submucosal territories of the 22 highly selected direct drainage vessels of 17 esophagi were histologically examined using transverse or sagittal serial sections. Afferent vessels from the esophagus to the subcarinal (6 esophagi) and para-esophageal (5 esophagi) nodes were also examined to identify their courses and drainage territories.

RESULTS

We found the direct drainage vessel from the esophagus in 17 of 75 cadavers macroscopically (22.7%). A single submucosal drainage unit gave off 1-3 thick drainage vessels passing through a complete muscle gap of the 2 muscular layers. The unit extended longitudinally for >40 mm but was restricted to the right and/or dorsal quadrants of the esophagus. In contrast, drainage routes with a nodal relay originated from the intermuscular area, except 1 case when the adjacent or concomitant esophageal artery and vein provided the complete muscle gap.

CONCLUSIONS

Due to the extended longitudinal but restricted transverse territory of the direct drainage system without a nodal relay and because of the suggested much more frequent occurrence in patients than in cadavers, when superficial carcinoma is found in the dorsal and/or right quadrants of the esophagus, we recommend detailed presurgical investigations of cervical nodes. In contrast, afferents from the esophagus to the first regional node usually seemed to be less responsible for early nodal metastasis than the direct drainage route because of their intermuscular origins.

Intraocular lens movement caused by ciliary muscle contraction

PURPOSE

To investigate intraocular lens (IOL) movement, measured as a change in anterior chamber depth (ACD) caused by pilocarpine-induced ciliary muscle contraction.

SETTING

Department of Ophthalmology, University of Vienna, Vienna, Austria.

METHODS

In this prospective study, the ACD was measured using high-precision, high-resolution, dual-beam partial coherence interferometry in 62 pseudophakic eyes of 55 patients under pilocarpine- and cyclopentolate-induced ciliary muscle contraction and relaxation. The following were studied: 2 models of a ring-haptic IOL (designed to accommodate), a plate-haptic IOL, and 3 types of 3-piece IOLs. Measurements were performed 3 months after surgery.

RESULTS

The ring-haptic IOLs and plate-haptic IOL showed a forward movement (ring haptic 43A, -116 microm; ring haptic 43E, -222 microm; plate haptic -162 microm). The 3-piece IOLs showed no change in ACD except in 1 IOL type in which there was backward movement (156 microm).

CONCLUSIONS

Pilocarpine-induced ciliary muscle contraction caused forward movement of ring- and plate-haptic IOLs that resulted in an estimated accommodative amplitude of less than 0.50 diopter in most cases. The accommodating ring-haptic IOLs did not perform better than the conventional plate-haptic IOL.

Sonic vibrational analysis provides continuous measurement of arterial properties

OBJECTIVE

We describe a new technology for measuring artery mechanical properties, called Sonic Vibrational Analysis (SVA). We utilize SVA to study the changes in radial artery smooth muscle tone caused by intravenous infusion of vasoactive agents.

METHODS

Six healthy volunteers were monitored with a radial intra-arterial catheter and an SVA sensor during progressively increasing doses of nitroglycerin (NTG), phenylephrine, sodium nitroprusside (SNP), dobutamine, and nicardipine. In SVA, the propagation velocity of an audio-frequency vibration is measured over a short segment of the radial artery. The measurement has sufficient temporal resolution to track the continuous changes in arterial properties that occur due to the natural blood pressure pulse.

RESULTS

Coupled with the measurement of radial blood pressure, SVA allowed determination of the physiological/mechanical state of the artery within a single cardiac cycle. NTG, SNP, and phenylephrine caused significant changes in both blood pressure and the physiological state of the radial artery. Nicardipine and dobutamine altered blood pressure without change in the state of the radial artery.

CONCLUSIONS

The current results are consistent with previous studies of the effects of vasoactive agents on the radial artery. SVA is non-invasive, continuous, localized to a well-defined section of artery, and suitable for the collection of large volumes of time-resolved data in a laboratory or clinical setting.

Strain during gastric contractions can be measured using Doppler ultrasonography

This study was undertaken to explore if strain of the muscle layers within the gastric wall could be measured by transabdominal strain rate imaging (SRI), a novel Doppler ultrasound (US) method. A total of 9 healthy fasting subjects (8 women, 1 man; ages 22 to 55 years) were studied and both grey-scale and Doppler US data were acquired with a 5- to 8-MHz linear transducer in cineloops of 97 to 256 frames. Rapid stepwise inflation (5 to 60 mL) of an intragastric bag was carried out and bag pressure and SRI were measured simultaneously. SRI enabled detailed studies of layers within the gastric wall in all subjects. Great variations in strain distribution of the muscle layers were found. Radial strain was much higher in the circular than in the longitudinal muscle layer. Strains derived from SRI correlated well with strains obtained with B-mode measurements (r = 0.98, p < 0.05). During balloon distension, we found an inverse correlation between pressure and radial strain (r = -0.87, p < 0.05). Intraobserver correlation of strain estimation was r = 0.98 (p < 0.05) and intraobserver agreement was 0.2% +/- 18.6% (mean difference +/- 2SD, % strain). Interobserver correlation was r = 0.84 (p < 0.05) and interobserver agreement was 6.9% +/- 56.8%. SRI enables detailed mapping of radial strain distribution of the gastric wall and correlates well with B-mode measurements and pressure increments.

Monitoring accommodative ciliary muscle function using three-dimensional ultrasound

BACKGROUND

Our objective was to develop a three-dimensional high-resolution ultrasonic imaging technique to be utilized for in-vivo characterization of the ciliary body and the posterior iris. The benefit of this imaging in enhancing the quantification of the configurational changes in the ciliary body during accommodation is demonstrated.

METHODS

Sequential ultrasound biomicroscopic images of the ciliary body region were obtained with a computer-controlled scanning device designed for use with a standard ultrasound biomicroscope for 3D imaging. Custom-made software allows online data collection, data analysis and 3D reconstruction in conjunction with commercially available VoxelView software.

RESULTS

The three-dimensional presentation allows a close approximation of the ciliary muscle inside the ciliary body in vivo. We are able to distinguish and to analyze the changes in the muscle contour in different accommodation states. During accommodation a shift in the ciliary muscle center of gravity in a range of 0.04-0.26 mm (mean 0.13+/-0.06 mm) in the direction of the lens equator, with an interindividual variation and a small decrease with age, was observed.

CONCLUSIONS

High-resolution ultrasound is a well established technique for in-vivo investigation of the anterior segment. Three-dimensional ultrasound biomicroscopy allows an assessment of the individual ciliary muscle activity in consideration of the ciliary processes. In combination with a contour analysis tool we improved the muscle contour determination during different accommodation states. The investigation showed an activity of the ciliary muscle in young volunteers as well as those of presbyopic age.

Intraurethral sonography and the test-retest reliability of urethral sphincter measurements in women

PURPOSE

The purpose of this prospective study was to determine the test-retest reliability of urethral sphincter morphologic measurements obtained with intraurethral sonography.

METHODS

The cross-sectional urethral sphincter anatomy of 29 asymptomatic nulliparous women was studied in a blinded fashion. Each patient returned for a repeat examination on a different day. At the point of maximal rhabdosphincter thickness, the urethral diameter and circumference and the longitudinal smooth muscle and rhabdosphincter thickness, diameter, circumference, and area were measured using the ultrasound scanner's integrated software. For each measured variable, the reliability between patients was assessed with a paired t test. Intraclass correlation coefficients were calculated to assess the reliability of each intraurethral sonographic measurement obtained from the same patient.

RESULTS

On test-retest analysis, the differences for each measured variable between patients were not statistically significant (p > 0.05). Of the measurements obtained from the same patient, however, longitudinal smooth muscle thickness (rho = 0.44; p = 0.006), diameter (rho = 0.49, p = 0.003), circumference (rho = 0.49, p = 0.003), and area (rho = 0.43; p = 0.009) were significantly correlated.

CONCLUSIONS

The urethral longitudinal smooth muscle layer is the only structure that can be measured reliably using sonography for diagnostic use. Sonographic measurements of the rhabdosphincter may not be reliable because the outer portion of that structure lies outside the depth of penetration of a 12.5-MHz transducer.

Relationship between esophageal muscle thickness and intraluminal pressure in patients with esophageal spasm

We previously showed, in normal subjects, a positive correlation between the esophageal contraction amplitude and peak muscle thickness. The goal of this study was to determine the relationship between esophageal muscle thickness and contraction amplitude in patients with high-amplitude peristaltic and simultaneous contractions. Eleven patients with high-amplitude peristaltic contractions, 8 with diffuse esophageal spasm (DES), 7 with nonspecific (NS) motor disorder of the esophagus, and 10 normal subjects were studied using simultaneous pressure and ultrasound imaging. Pressure was recorded by manometry and ultrasound imaging with a high-frequency ultrasound probe catheter. Recordings were performed in the lower esophageal sphincter (LES) and at 2, 4, 6, 8, and 10 cm above the LES during resting state and swallow-induced contractions. Baseline esophageal muscle was thicker in the distal, compared with the proximal esophagus both in normal subjects and patient groups. Patients with DES and nutcracker esophagus (NC) have a higher baseline muscle thickness compared with normal and NS patients. Correlation between the peak pressure and the peak muscle thickness was weaker in patients with NC and DES compared with normal subjects and patients with NS. Whereas normal subjects have good correlation between delta (difference between peak and baseline) muscle thickness and peak pressures, this relationship was absent in patients with NC and DES. Increase in contraction amplitude in patients with NC and DES was associated with an increase in baseline thickness of esophageal muscularis propria. Increase in baseline thickness was specific to patients with spastic motor disorders and was not seen in patients with NS.

Decrease of ultrasound estimated bladder weight during tamsulosin treatment in patients with benign prostatic enlargement

OBJECTIVE

The noninvasive method for estimating bladder weight (UEBW, Ultrasound Estimated Bladder Weight) can be used as a measure of bladder hypertrophy and may have clinical use for evaluating intravesical obstruction in male patients. The aim of this study was to assess whether, in patients with bladder outlet obstruction (BOO), tamsulosin treatment produced any significant change in UEBW.

METHODS

32 male patients with lower urinary tract symptoms (LUTS) suggestive of BOO [benign prostatic hyperflesia (BPH) was the apparent cause of BOO] were enrolled in an open pilot study. At baseline, physical examination, ECG, hematochemical tests, urine analysis, urine culture, urodynamics, urethrocystography, transrectal ultrasound, UEBW and symptom score were performed. Using the International Continence Society (ICS) nomogram, patients were assigned to three different groups: obstructed, not obstructed and equivocal. Only patients in the obstructed and equivocal categories were treated with tamsulosin 0.4 mg once daily for 6 months. Follow-up for all patients took place after 30 days, 3 and 6 months of treatment.

RESULTS

In the obstructed group of patients, the decrease in UEBW was observed at 30 days and maintained up to 6 months, with a significantly improved Qmax. A statistically significant correlation was found between UEBW and postvoid residual urine (PVR) and Abrams-Griffith number (AG).

CONCLUSIONS

The results of this study suggest a significant change in UEBW during tamsulosin treatment. The change observed might be suggestive of a therapeutic effect of tamsulosin on the detrusor muscle. Further and more extensive studies are needed in order to confirm a possible therapeutic effect of tamsulosin on the detrusor muscle.

CT findings in eosinophilic enterocolitis with predominantly serosal and muscular bowel wall infiltration

A 44-year-old female presented with tenderness of her abdomen, vomiting, intestinal obstruction, hypoalbuminemia and blood eosinophilia. Gastroscopy was normal and colonoscopic biopsies showed only non-specific inflammation of the colonic mucosa and submucosa. CT revealed large amounts of ascites and bilateral pleural effusions but eosinophil counts in the ascites were normal. At CT the jejunum was dilated and showed marked prominence of the valvulae whereas the ileum and the colon presented with a diffuse and hypoattenuating bowel wall thickening. The bowel wall thickening was most pronounced in the colon which especially showed also an impressive thickening and hyperenhancement mainly of its outer bowel wall layers. Parasitic infection could be excluded as well as a specific allergic response. In context with the known blood eosinophilia the diagnosis of an eosinophilic enterocolitis was suspected already by CT but finally only surgical full thickness biopsies could confirm the rare diagnosis of an eosinophilic enterocolitis with predominantly serosal and muscular bowel wall infiltration.

Increase in detrusor wall thickness indicates bladder outlet obstruction (BOO) in men

Detrusor wall thickness decreases continuously while the bladder fills to 50% of its capacity and then remains constant until 100%. Therefore, detrusor wall measurements were performed in patients when the bladder was filled to maximum capacity only. Mean detrusor wall thickness for unobstructed (n = 14), equivocal (n=23) and obstructed patients (n=33) were 1.33, 1.62 and 2.4 mm, respectively (P <0.001). With increasing CHESS letters and CHESS numbers, the thickness of the detrusor wall increased as well (P< 0.001). The positive predictive value of detrusor wall measurement (95.5% for a cut-off value greater than or equal to 2 mm) was superior to all other predictors investigated. The thickness of the detrusor wall increases depending on the extent of BOO. Both constrictive and compressive BOO lead to an increase in detrusor wall thickness. BOO is found in 95.5% of men with a detrusor wall thickness greater than or equal to 2 mm. Measuring the thickness of the detrusor wall can be used as a screening test to detect BOO.