CSA Measurements Research Articles

Remote neurodegeneration in the lumbosacral cord one month after spinal cord injury: a cross-sectional MRI study.

To characterize structural integrity of the lumbosacral enlargement and conus medullaris within one month after spinal cord injury (SCI). Lumbosacral cord MRI data were acquired in patients with sudden onset (<7 days) SCI at the cervical or thoracic level approximately one month after injury and in healthy controls. Tissue integrity and loss were evaluated through diffusion tensor (DTI) and T2*-weighted imaging (cross-sectional area [CSA] measurements). Associations with the degree of neurological impairment were assessed using linear mixed-effects models. Twenty-one patients with SCI showed lower white matter (WM) fractional anisotropy (FA) (≤-13.3%) and higher WM radial diffusivity (≤14.6%) compared to 27 healthy controls. Differences were most pronounced in the lateral columns of WM. CSA measurements revealed no group differences. For the lateral columns, lower FA values were associated with lower motor scores and lower amplitudes of motor evoked potentials. For the dorsal columns, lower FA values were associated with lower amplitudes of somatosensory evoked potentials from the lower extremities. One month after SCI, first signs of WM degeneration were apparent, without indication of tissue loss. The more pronounced differences observed in the lateral column could be attributed to anterograde degeneration of the motor tracts. The variability among DTI measurements remote from the lesion site can be partially explained by the degree of the SCI-induced neurological impairment. Together with previous studies, our findings indicate that impaired tissue integrity precedes tissue loss. The presented techniques have potential applications in monitoring the progression of various neurological diseases.

B-267 Validation of the Newly Developed Fully Automated Chemiluminescent Enzyme Immunoassay (CLEIA) Reagent for Measurement of Cyclosporine in the Blood

Abstract Background Cyclosporine (CsA) is an immunosuppressive drug requiring therapeutic drug monitoring (TDM) for its narrow-ranged medication level. Approximately 60% of CsA in the blood exist as molecular complexes with proteins like cyclophilin in lymphocytes and erythrocytes. Measurement of CsA in the blood by immunoassay or liquid chromatography-tandem mass spectrometry (LC-MS/MS) requires an extraction process for CsA from the whole blood specimen, which is often manual complicated and time-consuming process causing a risk of variation in the measurement values among different operators. In addition, the small (cyclic polypeptide composed of 11 amino acids) and hydrophobic property of CsA, make it difficult to establish antibodies for a sandwich immunoassay. In this study, we have validated a novel fully automated sandwich immunoassay reagent for measurement of blood CsA that used a combination of newly-established CsA antibodies and iTACT® (immunoassay for total antigen including complex via pretreatment) technology. Methods The reagent was developed and validated on a fully automated immunoassay system, LUMIPULSE® L2400 (FUJIREBIO INC). Twenty uL whole blood specimens are sampled after mixed with suction/discharge stirring to prevent that blood cells settle to the bottom of a container on the analyzer, and then treated with a pretreatment solution to obtain free CsA. The treated samples are assayed by a two-step sandwich immunoassay. Limit of Detection (LoD), Limit of Quantitation (LoQ), within-laboratory precision, linearity, no interference, and the correlation of this assay and LC-MS/MS were validated, following the current CLSI guidelines protocols. Data were analyzed using Microsoft Excel statistical tool Analyse-it. Results The LoD and the LoQ were 2.7 ng/mL and 10.8 ng/mL respectively. The within-laboratory precision showed CV 1.6-2.9 %. Linearity was demonstrated over the range 13.1-2381.5 ng/mL. No interference was observed with unconjugated (≤19.7 mg/dL) or conjugated bilirubin (≤20.1 mg/dL), chyle (≤1480 FTU), RF (rheumatoid factor, ≤1000 IU/mL), and HAMA (human anti-mouse antibody, ≤1010 ng/mL). The correlation coefficient and the regression slope of this assay and LC-MS/MS were 1.0 and 1.0, respectively (N=120). Conclusions The performance of our novel CsA assay, which use LUMIPULSE L2400, was satisfactory for routine analysis. A unique fully-automated process, including the pretreatment process of whole blood specimens, for measurement would contribute the low LoQ and the low Within-laboratory CV. In addition, the results are obtained in 35-minute. We expect this novel immunoassay could reduce the burden on operators and turnaround time.

Novel and pragmatic exploration of variation in glottic parameters in non-parallel versus parallel vocal cord CT planes with potential reporting pitfalls.

Oblique orientation of vocal cord demands strict compliance, by technicians and clinicians, to the recommended parallel plane CT scan of larynx. Repercussions of non-compliance has never been investigated before. We aimed to observe influence of non-parallel vocal cord plane CT scan on qualitative and quantitative glottic parameters, keeping parallel plane CT as a standard for comparison. Simultaneous identification of potential suboptimal imaging sequelae as a result of unformatted CT plane was also identified. In this study we included 95 normal adult glottides and retrospectively analyzed their anatomy in two axial planes, non-parallel plane ① and parallel to vocal cord plane ②. Qualitative (shape, structures at glottic level) and quantitative (anterior commissure ACom, vocal cord width VCw, anteroposterior AP, transverse Tr, cross-sectional area CSA) glottic variables were recorded. Multivariate statistical analysis was used to predict pattern and their impact on glottic anatomy. Plane ① displayed supraglottic features in glottis; adipose (90.5%) and split thyroid laminae (70.6%). Other categorical variables: atypical shape, submental structures and multilevel vertebral crossing were also in majority. All glottic dimensions varied significantly between two planes with most in ACom (-5.8mm) and CSA (-15.0 mm2). In contrast, plane ② manifested higher VCw (>73%), Tr (66.3%), CSA (64.2%) and AP (44.2%) measurements. On correlation analysis, variation in ACom, CSA, Tr was positively associated with VC or plane obliquity (p<0.05). This variability was more in obese and short necked subjects. Change in one parameter also modified other significantly i.e., ACom versus AP and CSA versus Tr. Results indicated statistically significant change in subjective and objective anatomical parameters of glottis on non-application of appropriate CT larynx protocol for image analysis hence highlighting importance of image reformation.

Validity of ultrasound rectus femoris quantitative assessment: A comparative study between linear and curved array transducers.

Appendicular skeletal mass is commonly used to assess the loss in muscle mass and US represents a valid, and reliable method. However, the procedural protocols are still heterogeneous. The aim of this study was to compare the intertransducers validity of thickness, width, and CSA measurements of RF muscle. The AP, LL and CSA of RF muscle were evaluated with both linear and curve probes in ten healthy subjects and six sarcopenic patients. In the healthy group the mean AP diameters measured with the linear array were significantly higher than those measured with the curved array. AP and CSA were higher in the healthy group compared with the sarcopenic group with both transducers. There was a positive correlation between weight and LL diameter, and a negative correlation between age and muscle AP, measured with the linear probe. Both linear and curved probes represent valid methods in US evaluation of the CSA of the RF muscle. However, in the healthy subjects, the thickness and width of the of the same muscle, are affected by the type of probe.

Deep learning model for measurement of shoulder critical angle and acromion index on shoulder radiographs

Several bone morphological parameters, including the anterior acromion morphology, the lateral acromial angle, the coracohumeral interval, the glenoid inclination, the acromion index (AI), and the shoulder critical angle (CSA), have been proposed to impact the development of rotator cuff tears and glenohumeral osteoarthritis. This study aimed to develop a deep learning tool to automate the measurement of CSA and AI on anteroposterior shoulder radiographs. We used MURA Dataset v1.1, which is a large publicly available musculoskeletal radiograph dataset from the Stanford University School of Medicine. All normal shoulder anteroposterior radiographs were extracted and annotated by an experienced orthopedic surgeon. The annotated images were divided into train (1004), validation (174), and test (93) sets. We use pytorch_segmentation_models for U-Net implementation and PyTorch framework for training the model. The test set was used for final evaluation of the model. The mean absolute error for CSA and AI between human-performed and machine-performed measurements on the test set with 93 images was 1.68° (95% CI 1.406°-1.979°) and 0.03 (95% CI 0.02 - 0.03), respectively. A deep learning model can precisely and accurately measure CSA and AI in shoulder anteroposterior radiographs. A tool of this nature makes large-scale research projects feasible and holds promise as a clinical application if integrated with a radiology software program.

Are differences in shoulder morphology and hand dominance risk factors for rotator cuff tears?

The purpose of this study was to evaluate whether there was a difference in shoulder morphology and hand dominance between a healthy shoulder and a shoulder with rotator cuff tear (RCT) in the same patient. Between 2015 and 2020, 120 shoulders from 60 patients with complete RCT and contralateral intact rotator cuffs were enrolled in this retrospective analysis. Physical examinations, shoulder radiographs, and magnetic resonance imaging (MRI) pictures of the patients were reviewed. On radiographs, the AT, CSA, LAA, and AI values were compared between shoulders with complete RCT and contralateral healthy shoulders from the same individuals. Additionally, the association between hand dominance and RCT was evaluated. This study enrolled 60 patients. 59.17% of the participants are female, and 40.83% are male. The mean age of the patients was 54.5±7.1 years. There were statistically significant differences in AI, CSA, and LAA measurements between the study group (RCT group) and the control group. There was no significant difference in AT between the two groups. There are morphological differences between a healthy shoulder and a shoulder with an RCT in the same patient, and these differences (LAA/CSA/AI/AT) may have an effect on the prevalence of RCT.

Predicting quadruple graft size preoperatively using MRI

ACL is one of the most injured ligaments of the knee in contact sports, ACL reconstruction is one of the most performed procedures. The aim of this study is to assess correlation of intraoperative hamstring quadruple graft diameter with preoperative (MRI) hamstring tendon’s diameter measurements, and demographic characteristics. A total of 32 male patients who were treated with primary ACL reconstruction between 2019 and 2020 in Al-Sadr Medical City in Najaf and al Kafeel hospital in Karbala were included in this study. We collected patients' demographic data (height, weight, BMI, age), and measurements of gracilis CSA, semitendinosus CSA, and combined semitendinosus and gracilis CSA from the MRI scan, and intraoperative graft diameter for all patients.

Prediction of autologous hamstring graft size in ACL reconstruction using gender, activity level, anthropometric parameters &amp; MRI- A prospective &amp; retrospective study

Background: Arthroscopic reconstruction of torn ACL using the quadruple hamstring auto-graft has become the gold standard in treating ACL tears due to its robust stiffness & compatibility with contemporary surgical & fixation techniques. Recently, graft diameter has received increased focus as a source of ACLR failure. A higher failure rate for the reconstructed ACL with grafts smaller than 8 mm in diameter have been noted. Preoperative prediction of the sufficiency of the hamstring graft size for ACL reconstruction would be useful in order to plan alternative graft choices & alternative fixation methods to ensure the graft diameter is minimum 8mm. However, currently there is no well documented standard to accurately predict the diameter & length of quadruple hamstring auto-grafts for ACL reconstruction and existing studies present controversial findings.Materials & Methods: The prospective study consists of 191 patients who had undergone Arthroscopic ACL reconstruction using quadrupled hamstring auto-graft at the Department of Orthopedic Surgery, Manipal Hospital, Bangalore, from January 2011 to May 2015. Several anthropometric preoperative measurements were obtained for each patient including height, weight, BMI, thigh length & thigh circumference. Activity was assessed using the Tegner activity score. A sub-group of patients (44 out of 191), whose MRI of the affected knee was performed in our institute has been included in the study. In these patients, MRI studies were performed using a standardized protocol.Results: In our study, there is no correlation between weight, thigh circumference, activity level & BMI when correlated for males & females combined. There is a positive correlation with height in both males & females when considered separately. Taller patients tended to have thicker quadrupled hamstring grafts. However, weight, thigh circumference, BMI, activity level & CSA of combined ST+GT did not correlate with graft thicknes. There is a positive correlation with MRI measurement of CSA of combined GT+ST graft thickness when measured combined for both sexes. There is a positive correlation with individual CSA of GT & ST with graft thickness when measured combined for both sexes. The regression equation that allows prediction of graft thickness based on individual MRI measurement of CSA of GT & ST is GRAFT THICKNESS= (0.2105) CSA OF GT+ 6.8684; GRAFT THICKNESS= (0.0973) CSA OF ST + 6.9645Conclusion: Our study overwhelmingly concludes that height is the most reliable single predictive parameter for graft diameter & length, both for males & females. MRI done by a standardized protocol is an excellent pre-operative predictor of graft size. Thigh length showed a positive correlation with graft diameter in the combined male & female group & in males & females considered separately. Other anthropometric parameters including body weight, BMI & thigh circumference have no predictive value with regard to graft diameter & length. Preoperative activity level failed to demonstrate a positive correlation with graft dimensions & has no predictive value.

Sarcopenia does not affect clinical outcomes following lumbar fusion

Sarcopenia, defined as decreased skeletal muscle mass or function, has recently been found to have increased perioperative morbidity and mortality. The relationship between sarcopenia and clinical outcomes in patients undergoing lumbar fusion has not been examined. This study investigates whether sarcopenia affects fusion rates and outcomes following single-level lumbar decompression and fusion. A retrospective analysis was undertaken of 97 consecutive patients who underwent a single level lumbar fusion for degenerative spondylolisthesis. Demographics, perioperative data, and patient reported clinical outcomes were collected. Measurements of paraspinal muscle CSA were made using a standardized protocol at the level of the L3-4 disc space on a preoperative lumbar MRI. Univariate analysis was used to compare cohorts with regards to demographics, comorbidities, and clinical outcomes. Of 97 patients, 16 patients (15.8%) were in the sarcopenic cohort utilizing a threshold of 986.1 mm2/m2. Reoperation rates were not significantly different between the two groups (0% vs 3.6%, p = .451). The sarcopenia cohort had lower BMI (28.1 vs 31.8, p = .017) and less male patients (6.3% vs 55.6%, p < .001). Mean follow-up was 18.3 months. There was no significant difference in postoperative Oswestry Disability Index (ODI) (24.7 vs 23.2, p = .794) Short Form 12 Physical (38.0 vs. 40.4, p = .445) Mental scores (55.5 vs. 53.6, p = .503), or visual analog scale (VAS) back pain scores (3.4 vs. 3.3, p = .818). No significant difference was found with regards to outcomes when comparing sarcopenic to non-sarcopenic patients undergoing lumbar fusion. Sarcopenia does not impact the clinical success of lumbar fusion for degenerative spondylolisthesis.

Diagnostic role of neuromuscular ultrasound in cubital tunnel syndrome

Objective: We aim to evaluate the role of Ultrasonography (US) as a diagnostic tool for Cubital Tunnel Syndrome (CuTS) in comparison with the Nerve Conduction Study (NCS). Methods: Twenty elbows with CuTS and twenty asymptomatic controls were assessed by NCS and underwent ultrasonography of elbows. Patient and control data were compared to determine the diagnostic relationship in patients with CuTS and the degree of severity. Results: The NCS of the ulnar nerve, clinical parameters, and variable US measurements had a high degree of correlation. The CSA of the ulnar nerve was the most sensitive and 100% sensitive, 80% specific, and cut-off point of 9.5 mm2 behind the Medial Epicondyle. The diagnostic accuracy of the ulnar nerve ratio (UNR) was 95% sensitive and 85% specific. Conclusion: Ultrasonographic measurements of the ulnar nerve CSA and UNR are equivalent to noninvasive diagnostic measurements, which are an alternative method of CuTS assessment.

P 158 Peripheral nerve ultrasound scoring systems in polyneuropathy – benchmarking and comparative analysis

Much progress has been done in the recent past concerning the additive value of nerve ultrasound in polyneuropathies. Most authors go along, that – generally spoken – the enlarged cross-sectional areas are the most evident pathology in PNP. Overall, demyelinating neuropathies display nerve enlargement, while most axonal types do not or only rarely. CSA measurements alone are not all, however, without CSA measurements all is nothing. Increased nerves are not pathognomonic at all; they appear in inherited (Charcot Marie Tooth), inflammatory (CIDP, GBS) and metabolic neuropathies (amyloidosis, metachromatic leukodystrophy), in focal (MMN, MADSAM) and asymmetric generalized (vasculitis) neuropathies. Therefore, quantification and pattern analysis of nerve enlargement might be the key to success. Scoring systems have been presented bang up-to-date, e.g. the nerve pattern classification in CIDP by Padua and colleagues, the Bochum ultrasound score for immune-mediated neuropathies, the quantification of nerve enlargement in demyelinating neuropathies by Zaidman et al., or the ultrasound pattern sum score and the homogeneity score. All of these scores have their strength in accuracy and exclusion of certain neuropathies, however all fail by incompleteness concerning others, e.g. rarer variants. Although we can assume generalized nerve enlargement in inherited neuropathies, and more regional enlargement in inflammatory neuropathies, the philosopher’s stone is not yet found. Further effort must be done, even including fascicle next to CSA pathology, echogenicity and physiologic aspects (age, height, weight and ethnicity). Nevertheless - to the best of our knowledge – some simple rules can simplify daily practice. First, if any nerve enlargement is found, heredity or immune mediation should be checked with caution. Second, simple critical landmarks could help to preselect certain neuropathies (as shown in Fig. 1): the brachial plexus/the cervical roots and the vagus (particularly for CIDP and GBS), the median and ulnar nerve in the forearm (e.g. for MMN and MADSAM) and the tibial and the sural nerve in the ankle (e.g. for vasculitis). The accuracy of these marks would not be 100%, but can facilitate the following diagnostic steps.

Carpal Tunnel Syndrome in Patients with and without Diabetes Mellitus in Upper Egypt: The Impact of Electrophysiological and Ultrasonographical Studies

Introduction: Reports about median nerve CSA measurements between CTS patients with and without DM are actually scant. This study aimed to correlate the diagnostic accuracy of ultrasonography with electrodiagnosis in both DM and non-DM CTS patients. Patients and Methods: Thirty six non-diabetic patients and twenty five diabetic patients with CTS were assessed. All patients were subjected to electrophysiological assessment of wrists and grayscale ultrasonography (US). Results: High mean cross sectional area of median nerve (CSA) on ultrasonography was detected with nonsignificant difference between both groups. A non-significant difference for flattening ratio was found between two groups. There was a highly significant positive correlation between electrodiagnosis and ultrasonography in diabetic patients. Conclusion: The CSA of median nerve is larger in CTS hands in both DM and non-DM patients. The combination of electrophysiology and ultrasonography provides diagnostic effective tools across the entire spectrum of CTS in diabetic and non-diabetic patients.

Measurement on the structural, morphological, electrical and optical properties of PANI-CSA nanofilms

Abstract Camphorsulfonic acid doped polyaniline (PANI-CSA) prepared by chemical oxidative polymerization is spin coated on glass plates with four different PANI:CSA weight ratios (1:1, 1:2, 1:4 and 1:8) and measurements on the structural and optical properties are done. Thickness of the films measured

Changes in cross-sectional area of pulmonary vessels on chest computed tomography after chemotherapy in patients with advanced non-squamous non-small-cell lung cancer

Chemotherapy is associated with a risk of vascular damage. Novel anti-angiogenic agents, which can directly affect tumor angiogenesis, are increasingly being used. However, the effects of these agents on normal vasculature are not well understood. Here, we evaluated the effects of chemotherapy in general, and the anti-angiogenic agent bevacizumab, more specifically, on the pulmonary vasculature in patients with advanced non-squamous non-small-cell lung cancer (NSCLC). For this, we used the cross-sectional area of pulmonary vessels (CSA), which is an easily measurable indicator of small pulmonary vasculature on non-contrast chest computed tomography (CT). We retrospectively reviewed CT scans of the lungs of 75 chemo-naïve patients with advanced non-squamous NSCLC, for measurement of CSA, before and after first-line platinum-based chemotherapy, using a semi-automatic image-processing program. Measured vessels were classified in two groups: small vessels with CSA<5mm(2) and large vessels with CSA between 5 and 10mm(2). The CSAs for each group of vessels were calculated and summed separately, and expressed as a percentage of the total lung area (%CSA<5 and %CSA5-10). Chemotherapy was associated with a selective decrease in small-diameter vessels, with a significant decrease in %CSA<5, but not %CSA5-10. When comparing chemotherapy with bevacizumab (n=38) and without bevacizumab (n=37), there was no significant difference in the reduction of %CSA<5. Platinum-based chemotherapy might induce small pulmonary vascular damage. Use of bevacizumab does not enhance the reduction in area of pulmonary vessels.

Does trunk muscle strength affect spinal deformity in adult female patients?: Evaluation of cross sectional area of psoas major and lumbar extensor muscles

Material and methods Twenty-five female patients with ASD (mean age 64.3 years) who underwent fusion surgery were included for analysis. Diagnosis was lumbar scoliosis in 10 patients, kyphoscoliosis in 11, and kyphosis in 4. Radiographic measurement of spinal alignment and CSA of lumbar trunk muscles including psoas major and lumbar extensor muscles measured by Magnetic Resonance Imaging (MRI) were evaluated. The CSAs of trunk muscles were measured at the cranial endplate of L4 vertebra for a comparative estimation of muscle size. A negative value indicated lordosis in evaluation of spinal alignment.

The Value of MRI in Idiopathic Tarsal Tunnel Syndrome by Measuring the Cross-Sectional Area of Tarsal Tunnel

mm 2 , 98.2 mm 2 , and 105.2 mm 2 , respectively in the patient group; and 100.0 mm 2 , 113.8 mm 2 , and 127.9 mm 2 in the control group, respectively, in reader 1; and 86.2 mm 2 , 97.6 mm 2 , 105.2 mm 2 , respectively in the patient group; and 99.7 mm 2 , 112.3 mm 2 , 124.4 mm 2 , respectively, in the control group, in reader 2. The mean CSA in the patient group was significantly less than that of the control group at all three levels (p < 0.05). Intra-class correlation coefficient value between reader 1 and reader 2 were 0.98 in group 1, and 0.97 in group 2, respectively. Conclusion: MRI can be helpful in the assessment of idiopathic tarsal tunnel syndrome. CSA measurements of tarsal tunnel at each level may predict TTS even though there are no space occupying lesions in the tarsal tunnel on MRI.

P213 The Impact Of Sleep Disordered Breathing On Peripheral Muscle

Introduction Chronic obstructive pulmonary disease is characterised by peripheral muscle wasting with consequent reduction in muscle strength and function. In this cohort of patients a reduction in muscle strength correlates with morbidity and mortality. Less well known are the characteristics of muscle in patients with sleep disordered breathing (SDB), a disease state that can also be dominated by inflammation, breathlessness and hypoxia. We sought to examine the impact of sleep disordered breathing on peripheral muscle size and strength. Method 51 subjects were recruited: 15 healthy controls (HC) with a normal body mass index (BMI, 2 ), 16 overweight and obese individuals with no SDB controls (SO), and 20 obese subjects with obstructive sleep apnoea (OSA). Subjects underwent measurements of Rectus Femoris Cross Sectional Area (RF CSA ) and quadriceps maximal voluntary contraction (QMVC). Handgrip strength and six minute walk distance (SMWD) were also recorded. Results As expected there were differences in BMI between the groups. There were also significant differences in muscle strength and RF CSA when corrected for body weight between HC and OSA groups and between SO and OSA groups, but no differences between HC and SO groups (Table 1). The SO group demonstrated higher measurements of strength and RF CSA than the HC group, however, the OSA group had lower measurements than both the HC and SO group. This translated to a functional difference as measured by the SMWD, again demonstrating the longest distance in the SO group and shortest in the OSA group. Discussion This study has demonstrated that in those with a BMI ≥25 kg/m 2 there appears to be a beneficial effect of excess weight on peripheral muscle size, strength and function; this may be due to the extra load carried by these individuals exerting a training effect on the muscles. However, in those who are obese with SDB, the SDB seems to exert a negative effect on muscle size, strength and function which may be a result of the inflammation and hypoxia SDB can cause.

Usefulness of Coronal Reconstruction CT Images for Quantitative Evaluation of the Cross-Sectional Area of Small Pulmonary Vessels

Cross-sectional area <5 mm(2) (CSA<5) is a computed tomography (CT) metric that has been used for the evaluation of pulmonary vessel alterations and perfusion. CSA<5 is calculated from three axial slices; thus, whether CSA<5 represents the small pulmonary vessel alterations in the whole lung remains unclear. The purpose of this study was to compare the measurements of CSA<5 using three axial slices and coronal reconstructed slices in the relationship between the measured CSA<5 and pulmonary perfusion measured using lung perfusion scintigraphy. This study comprised 28 subjects who underwent both noncontrast CT and lung perfusion scintigraphy. The present study measured CSA<5 using both three axial CT images and coronal reconstruction images and then obtained the percentage of the CSA in right lung to that in whole lung (R/W-CSA<5). Using anteroposterior and posteroanterior projections on technetium-99m macroaggregated albumin (MAA) lung perfusion scintigraphy, we obtained right and total lung counts and calculated the percentage of the right to whole lung counts (R/W-MAA). The correlations of the R/W-CSA<5 calculated using three axial slices (R/W-CSA(A)x<5) and coronal reconstructed slices (R/W-CSA(COR)<5) with R/W-MAA were evaluated using Spearman rank correlation analysis. Both R/W-CSA(Ax)<5 and R/W-CSA(COR)<5 were significantly correlated with R/W-MAA; however, the correlation coefficient with R/W-CSA(COR)<5 (ρ = 0.842, P < .0001) was greater than that with R/W-CSA(Ax)<5 (ρ = 0.631, P = .0004). Coronal reconstruction images appear suitable for quantitative measurement of CSA of small pulmonary vessels.

Ultrasound assessment of gastric volume in critically ill patients

To assess the feasibility and validity of ultrasonographic measurement of gastric antral cross-sectional area (usCSA) in critically ill patients to predict gastric volume and the use of computed tomography (CT) as a reference to measure gastric volume. This single-center, prospective, cross-sectional study included 55 critically ill patients who had an abdominal CT scan. usCSA measurements were performed within the hour preceding the CT scan. Gastric volumes were measured on the CT scan using semiautomatic software. The feasibility rate, performing conditions (% "good" and "poor"), internal and external validity of antral usCSA measurements, performed by an ICU physician, were assessed to predict gastric volume. Antral usCSA measurements were feasible in 95% of cases and were positively correlated with gastric volume measured by the CT scan when performed in "good" conditions (65%) (r = 0.43). There was good reproducibility of measurements (intraclass correlation coefficient of 0.97, CI 95% 0.96-0.99) and there was clinically acceptable agreement between measurements performed by radiologists and intensivists (bias -0.12 cm(2)). The receiver operating characteristic curve identified a cutoff value of 3.6 cm(2) that discriminated an "at-risk stomach" (volume >0.8 mL/kg) at a sensitivity of 76% and a specificity of 78%. Ultrasonographic measurement of antral CSA is feasible and reliable in the majority of critically ill patients. This technique could be useful to manage critically ill patients at risk of aspiration or with enteral feeding.

Quantitative Differences Between Primary and Secondary Peristaltic Contractions of the Esophagus

Differences in contraction characteristics between primary and secondary peristalsis have only been scarcely studied. Recently new measures of contractile activity in the human esophagus were developed. The study aims were to use combined manometry and impedance planimetry [pressure-cross-sectional area (P-CSA)] recordings from healthy volunteers to examine esophageal peristalsis, and, furthermore, to investigate the effect of the motility enhancing drug erythromycin to study differential effects on the two types of contractions. Sixteen healthy volunteers participated in the study [mean age 23 (range, 19-34) years, 6 females]. An esophageal probe with a bag for CSA measurement was positioned 10 cm above the lower esophageal sphincter. Bag volume was increased stepwise from 5 to 25 ml before and after intravenous infusion of 250 mg erythromycin. Swallow-evoked primary and distension-evoked secondary esophageal peristalsis were compared with regard to (1) pressure amplitude, (2) CSA amplitude, (3) preload tension (wall tension before an evoked contraction), (4) contractile tension, and (5) work outputs. Primary peristalsis induced more efficient contractions as the contraction amplitudes, work output and contractile tension were higher compared to secondary peristalsis (P < 0.001). Erythromycin induced change in CSA during distension-evoked secondary peristalsis (CSA before 212.9 ± 26.8 vs. after 180.5 ± 23.3, P < 0.05). The sensitivity to esophageal distension increased with the distending volume both before and during erythromycin. The sensitivity was not changed by erythromycin (P = 0.6). Esophageal primary peristaltic contractions were more forceful with longer duration, and higher work output compared to secondary peristalsis contractions. Erythromycin affected peristalsis only to a minor degree.