Long-axis Measurements Research Articles

Pancreatic Cyst Size Measurement on Magnetic Resonance Imaging Compared to Pathology.

While multiple cyst features are evaluated for stratifying pancreatic intraductal papillary mucinous neoplasms (IPMN), cyst size is an important factor that can influence treatment strategies. When magnetic resonance imaging (MRI) is used to evaluate IPMNs, no universally accepted sequence provides optimal size measurements. T2-weighted coronal/axial have been suggested as primary measurement sequences; however, it remains unknown how well these and maximum all-sequence diameter measurements correlate with pathology size. This study aims to compare agreement and bias between IPMN long-axis measurements on seven commonly obtained MRI sequences with pathologic size measurements. This retrospective cohort included surgically resected IPMN cases with preoperative MRI exams. Long-axis diameter tumor measurements and the presence of worrisome features and/orhigh-risk stigmata were noted on all seven MRI sequences. MRI size and pathology agreement and MRI inter-observer agreement involved concordance correlation coefficient (CCC) and intraclass correlation coefficient (ICC), respectively. The presence of worrisome features and high-risk stigmata were compared to the tumor grade using kappa analysis. The Bland-Altman analysis assessed the systematic bias between MRI-size and pathology. In 52 patients (age 68 ± 13 years, 22 males), MRI sequences produced mean long-axis tumor measurements from 2.45-2.65 cm. The maximum MRI lesion size had a strong agreement with pathology (CCC = 0.82 (95% CI: 0.71-0.89)). The maximum IPMN size was typically observed on the axial T1 arterial post-contrast and MRCP coronal series and overestimated size versus pathology with bias +0.34 cm. The radiologist interobserver agreement reached ICCs 0.74 to 0.91 on the MRI sequences. The maximum MRI IPMN size strongly correlated with but tended to overestimate the length compared to the pathology, potentially related to formalin tissue shrinkage during tissue processing.

Pebble morphometry and sieve analysis: tools in determining the depositional environments of sediments in oron and environs

Pebble morphometry and grain size analysis were carried out in parts of Benin Formation exposed along Oron and environs to determine the depositional environment of the sediments. Quartz pebbles (900 pebbles) collected from 60 different locations around stream channels and quarries were subjected to axial measurement of long (L), short (S) and intermediate (I) axis. Fifteen (15) sediments were further subjected to sieve analysis. Results from morphometric studies shows that the pebbles are dominantly compact-bladed (CB) and elongate (E) with mean values for flatness ratio (FR), elongation ratio (ER), maximum projection sphericity index (MPSI), oblate-prolate index (OPI) and braided ratio (BR) as 0.48, 0.61, 0.67, 3.54 and 0.63 respectively with mean roundness value of 32%. Sieve analysis revealed that the sediments are dominantly medium-grained, well sorted, skewed to near symmetrical and leptokurtic to mesokurtic. Bivariate Plots of roundness versus elongation ratio, sphericity versus OP index, FI versus MPSI, and skewness versus sorting indicates deposition of the sediments predominantly in the fluvial environment. Thus, this study showed that the sediments in Benin Formation were deposited by fluvial depositional processes.

Three-dimensional Whole-Heart Cardiac MRI Sequence for Measuring Trabeculation in Left Ventricular Noncompaction.

To compare three-dimensional (3D) whole-heart MRI with isotropic submillimeter resolution with standard two-dimensional (2D) cine MRI in measuring the bilayered myocardium in left ventricular noncompaction (LVNC). Twenty-four patients with LVNC (mean age, 42 years ± 16 [SD]) were retrospectively enrolled between October 2011 and July 2020. Compacted myocardium (CM) and noncompacted myocardium (NCM) were measured in long axis (Petersen approach) and short axis (Jacquier approach) at 3D whole-heart and 2D cine MRI by two independent readers. Image quality (1 = excellent, 2 = adequate, 3 = nondiagnostic), considering discrimination between NCM and CM and CM and adjacent tissue, was evaluated. Pearson, Spearman, and intraclass correlation tests were used as statistical tests. In long-axis measurements, the correlation between both sequences was moderate to strong for CM (Pearson, 0.66-0.79; Spearman, 0.61-0.68) and strong to very strong for NCM (Pearson, 0.90-0.97; Spearman, 0.77-0.91). Intraclass correlation coefficient (ICC) in 3D whole-heart MRI was 0.90 (95% CI: 0.78, 0.95) for CM and 0.94 (95% CI: 0.84, 0.97) for NCM, while ICC in 2D cine MRI was 0.77 (95% CI: 0.55, 0.89) for CM and 0.87 (95% CI: 0.72, 0.94) for NCM. Short-axis CM and NCM measurements had a strong to very strong correlation between both sequences (Pearson, 0.86-0.98; Spearman, 0.82-0.98). ICC in 3D whole-heart MRI was 0.96 (95% CI: 0.94, 0.99) for CM and 0.98 (95% CI: 0.97, 0.99) for NCM, while ICC in 2D cine MRI was 0.82 (95% CI: 0.63, 0.92) for CM and 0.87 (95% CI: 0.72, 0.94) for NCM. 3D whole-heart MRI demonstrated higher image quality than did 2D cine MRI (P < .001). 3D whole-heart MRI revealed higher image quality, with better structure discrimination and interobserver agreement in LVNC measurements, compared with standard 2D cine images.Keywords: MR Imaging, Cardiac, Cardiovascular Magnetic Resonance, Left Ventricular Noncompaction, Free-breathing Imaging Technique Supplemental material is available for this article. © RSNA, 2022See also the commentary by Jensen and Petersen in this issue.

Malignant Nodules Detected on Lung Cancer Screening CT: Yield of Short-Term Follow-Up CT in Showing Nodule Growth.

BACKGROUND. Lung-RADS recommends 3-month follow-up for category 4A nodules and downgrading to category 2 of all category 3 or 4 nodules that are unchanged for 3 months or longer, indicating benign behavior. This guidance may be problematic considering the potential for slow-growing cancers in that lack of nodule growth, particularly at short follow-up intervals, may provide false reassurance. OBJECTIVE. The purpose of this study was to evaluate the yield of short-term follow-up CT in showing growth among malignant nodules detected on lung cancer screening CT. METHODS. This retrospective study included 76 patients (53 women, 23 men; median age, 68 years) with a positive lung cancer screening CT result (Lung-RADS category ≥ 3) between June 2015 and May 2021 with a subsequent lung cancer diagnosis and at least one follow-up CT examination at least 3 months before diagnostic or therapeutic intervention. Semiautomated software was used for linear and volumetric nodule measurements. Diameter was defined as the mean of short- and long-axis measurements. For solid nodules, growth was defined as an at least 1.5-mm increase in mean diameter or an at least 25% increase in volume; part-solid nodules, an at least 1.5-mm increase in solid-component mean diameter or an at least 25% increase in volume; and ground-glass nodules, an at least 3-mm increase in mean diameter or development of a new solid component within the nodule. RESULTS. Median time to growth was 13 months by linear and 11 months by volumetric measurement. Frequency of growth at 3 months was 5% by linear and 7% by volumetric measurement. By linear measurement, median time to growth and frequency of growth at 3 months were 13 months and 7% (solid nodules), 18 months and 6% (part-solid nodules), not reached and 0% (ground-glass nodules), not reached and 0% (category 3 nodules), 13 months and 6% (category 4A nodule)s, 6 months and 11% (category 4B nodules), and 12 months and 10% (category 4X nodules). CONCLUSION. Malignant nodules manifest growth slowly on follow-up CT, and 3-month follow-up CT has very low yield. Stability at 3-month follow-up should not instill high confidence in benignancy, and downgrading all such nodules to Lung-RADS category 2 may be problematic. CLINICAL IMPACT. This study highlights the possibility of slow-growing malignancy and associated challenges in application of Lung-RADS to management of unchanged nodules on follow-up imaging.

P63 OPTICAL COHERENCE TOMOGRAPHY–ANGIO CO–REGISTRATION (OCT–ACR) OF LEFT ANTERIOR DESCENDING IN PATIENT WITH ONGOING ANIGNA

Abstract We share the case of a 50–year old man, with no cardiovascular risk factor, presented in ER with ongoing angina and positive exercise stress testing. No clinical evidence of heart failure. EKG and echocardiogram was negative. He was referred for invasive coronary angiography, that showed severe stenosis of mid–LAD and moderate ostial LAD stenosis. Subsequent Optical Coherence Tomography–Angio Co–Registration (OCT–ACR) of Left Anterior Descending was performed. An EBU3.5 guiding catheter was engaged in the left coronary artery, and 8000 units of heparin administered. After a pre–dilatation with a semi–compliant balloon of mid LAD, a plaque rupture with thrombus was documented at mid–LAD and a fibro–lipidic plaque with a severe flow limitation (MLA&amp;lt;4mm2) at the ostium, with no involvement of left main (Fig. 1b). Pre–dilatation with SC and NC balloon (2.5–3.5mm) was performed and then stented with a 4.0 × 26 mm DES. Finally, OCT confirmed correct stent expansion, achieving an excellent angiographic result, without carina shifting and compromise of the circ. Patient was discharged, asymptomatic. OCT–ACR guided PCI, taking advantage of its high spatial resolution, permits to plain better the PCI, establish correct stent size, evaluate early complications especially if left main or bifurcation are involved and thanks to co–registration also measurement of long axis of the vessel are facilitated.

Application of a Series of Two-Dimensional Transesophageal Echocardiographic (2D TEE) Views Across Multiple Axes Improves the Accuracy of Tricuspid Annular Measurements

Quantification of the tricuspid annulus (TA) is an important factor in determining the requirement for tricuspid annuloplasty in cardiac surgery. Three-dimensional echocardiography (3DE) has shown that the TA is biplanar with an antero-posterior longaxis and septo-lateral shortaxis, and that the commonly used 2D TEE (two-dimensional transesophageal echocardiography) four-chamber view (4ChV) underestimates the true TA longaxis. The authors hypothesized that the use of multiple 2D TEE TA views could attain greater TA long-axis measurements and smaller TA short-axis measurements than the 4ChV, and that the 4ChV has a significant but inconsistent bias relative to the maximal TA diameter measured by these views. Prospective observational study. Adult tertiary teaching hospital. 45 adult patients. Multiplanar 2D TEE assessment of the tricuspid annulus. Multiplanar assessment reliably produced larger TA long-axis measurements (93% of patients, 95% confidence interval: 81-98%) of (mean [95% confidence interval]) 40 mm (28-50 mm) compared with the 4ChV (34mm [25-44 mm], p < 0.0001) and smaller TA short-axis measurements (29 mm [20-38 mm], p < 0.0001) compared with the 4ChV. TA diameter by 4ChV assessment yielded an average bias of -5.6 mm, with 95% limits of agreement -15 to +3.9 mm compared with the largest TA long-axis measurement by multiplanar assessment. Multiplanar 2D TEE assessment of the TA long- and short-axis consistently achieves larger and smaller measurements, respectively, than the 4ChV. The 4ChV also is not a reliable index of the TA longaxis. If the time, proficiency, or equipment required for 3DE TA assessment are unavailable, the use of multiple standard and non-standard 2D TEE TA views may offer an alternative for TA assessment.

Two-Dimensional Transesophageal Echocardiography Assessment of the Major Aortic Annulus Diameter in Patients Undergoing Transcatheter Aortic Valve Replacement.

Background:Multidetector computed tomography (MDCT) is the gold standard in annulus sizing before transcatheter aortic valve replacement (TAVR). However, MDCT has limited applicability in specific subgroups of patients, such as those with atrial fibrillation and chronic kidney disease. Two-dimensional transesophageal echocardiography (2DTEE) has traditionally been limited to the long-axis measurement of the anteroposterior diameter of the aortic annulus. We describe a new 2DTEE approach for the measurement of the major diameter of the aortic annulus.Methods:Seventy-six patients with symptomatic severe aortic valve stenosis and high surgical risk underwent MDCT and 2DTEE before TAVR. A modified five-chamber view was used to measure the major aortic annulus diameter. This was obtained starting from a mid-esophageal four chamber and retracting the TEE probe up until the left ventricular outflow tract and the left and noncoronary aortic cusps were visualized: major aortic annulus diameter was measured as the distance between their insertion points in systole.Results:Major aortic annulus diameters measured at 2DTEE showed good correlation with MDCT diameter (r = 0.79; P < 0.001) and perimeter (r = 0.87; P < 0.0001). Using factsheet-derived sizing criteria, 2DTEE alone would have allowed accurate sizing in 75% of patients, with 21% of oversizing predominantly with smaller annuli.Conclusions:We describe a new method for 2DTEE measurement of the major aortic annulus diameter; this approach is simple, correlates with MDCT, and allows adequate TAVR sizing in most patients. These findings may help in the assessment of patients with contraindications to or inadequate MDCT images.

Imaging and Management of Internal Mammary Lymph Nodes.

Internal mammary lymph nodes (IMLNs) account for approximately 10%-40% of the lymphatic drainage of the breast. Internal mammary lymph nodes measuring up to 10 mm are commonly seen on high-risk screening breast MRI examinations in patients without breast cancer and are considered benign if no other suspicious findings are present. Benign IMLNs demonstrate a fatty hilum, lobular or oval shape, and circumscribed margins without evidence of central necrosis, cortical thickening, or loss of fatty hilum. In patients with breast cancer, IMLN involvement can alter clinical stage and treatment planning. The incidence of IMLN metastases detected on US, CT, MRI, and PET-CT ranges from 10%-16%, with MRI and PET-CT demonstrating the highest sensitivities. Although there are no well-defined imaging criteria in the eighth edition of the American Joint Committee on Cancer Staging Manual for Breast Cancer, a long-axis measurement of ≥ 5 mm is suggested as a guideline to differentiate benign versus malignant IMLNs in patients with newly diagnosed breast cancer. Abnormal morphology such as loss of fatty hilum, irregular shape, and rounded appearance (which can be quantified by a short-axis/long-axis length ratio greater than 0.5) also raises suspicion for IMLN metastases. MRI and PET-CT have good sensitivity and specificity for the detection of IMLN metastases, but fluorodeoxyglucose avidity can be seen in both benign conditions and metastatic disease. US is helpful for staging, and US-guided fine-needle aspiration can be performed in cases of suspected IMLN metastasis. Management of suspicious IMLNs identified on imaging is typically with chemotherapy and radiation, as surgical excision does not provide survival benefit and is performed only in rare cases.

Measurement of Mandibular Condylar Height Based on Magnetic Resonance Imaging

The aim of this study was to find out the most appropriate method of measuring condylar height on temporomandibular joint (TMJ) magnetic resonance imaging (MRI). Traditional three-circle method, modified three-circle method and ramal plane (RP) method were used by 2 separate observers for the measurement of condylar height and long axis of condyle on TMJ MRI. Pearson correlation coefficient (PCCs), intra-class correlation coefficient (ICC), paired t test and Bland-Altman analysis were applied for the comparison of CH and long axis of condyle between 2 observers. Thirty-two patients' images were finally included in our study. Comparing the 3 methods, it was revealed that the RP method has the highest consistency among the observers, followed by the modified three-circle method, and the traditional three-circle method has the worst consistency. The RP method is preferred for measuring the condylar height on MRI. If mandible edge cannot be observed on MRI, the modified three-circle method is recommended.

Normal pulmonary artery and branch pulmonary artery sizes in children.

To establish standards for pulmonary artery and branch pulmonary artery (PA and BPA) effective diameter (ED) and cross-sectional area (CSA) by using computed tomography (CT) data in children of a wide range of sizes and investigate the roundness of arteries. The ED (average of short and long axes) and CSA for the PA and BPA were measured using 1-mm collimation double-oblique reconstructions. Ordinary least squares regression was used to investigate models with various functional forms that related ED and CSA to patient size. Aspect ratio (AR), the short axis divided by long axis, was measured to evaluate roundness. The ideal diameter derived from CSA measurements was compared to ED, short axis, and long axis measurements. 108 CT examinations were analyzed in children without reason for abnormal PA size who ranged in age from 0 to 18years (mean, 10.9years; SD, 5.9years). Interrater reliability was excellent. Data were modeled using a natural log-transformed response variable and a linear term for height as the independent variable. AR for the PA, right pulmonary artery, and left pulmonary artery measured < 0.9 for 38, 55, and 37%, respectively, indicating that many arteries are not round. Ideal diameter was not significantly different than ED but was for short- and long-axis diameter measurements. Normal ED and CSA for PA and BPA were determined for children of different sizes. Measurements outside of the normal range are consistent with dilatation or stenosis. Single diameter techniques are likely to introduce error.

Measurement of Parasternal Long-axis and Commissural Mitral Annulus Diameters Improves the Accuracy of Mitral Annular Cross-sectional Area Calculation

Measurement of Parasternal Long-axis and Commissural Mitral Annulus Diameters Improves the Accuracy of Mitral Annular Cross-sectional Area Calculation

Incidence of Internal Mammary Lymph Nodes with Silicone Breast Implants at MR Imaging after Oncoplastic Surgery.

To assess the incidence of benign and malignant internal mammary lymph nodes (IMLNs) at magnetic resonance (MR) imaging among women with a history of treated breast cancer and silicone implant reconstruction. The institutional review board approved this HIPAA-compliant retrospective study and waived informed consent. Women were identified who (a) had breast cancer, (b) underwent silicone implant oncoplastic surgery, and (c) underwent postoperative implant-protocol MR imaging with or without positron emission tomography (PET)/computed tomography (CT) between 2000 and 2013. The largest IMLNs were measured. A benign IMLN was pathologically proven or defined as showing 1 year of imaging stability and/or no clinical evidence of disease. Malignant IMLNs were pathologically proven. Incidence of IMLN and positive predictive value (PPV) were calculated on a per-patient level by using proportions and exact 95% confidence intervals (CIs). The Wilcoxon rank sum test was used to assess the difference in axis size. In total, 923 women with breast cancer and silicone implants were included (median age, 46 years; range, 22-89 years). The median time between reconstructive surgery and first MR imaging examination was 49 months (range, 5-513 months). Of the 923 women, 347 (37.6%) had IMLNs at MR imaging. Median short- and long-axis measurements were 0.40 cm (range, 0.20-1.70 cm) and 0.70 cm (range, 0.30-1.90 cm), respectively. Two hundred seven of 923 patients (22.4%) had adequate follow-up; only one of the 207 IMLNs was malignant, with a PPV of 0.005 (95% CI: 0.000, 0.027). Fifty-eight of 923 patients (6.3%) had undergone PET/CT; of these, 39 (67.2%) had IMLN at MR imaging. Twelve of the 58 patients (20.7%) with adequate follow-up had fluorine 18 fluorodeoxyglucose-avid IMLN, with a median standardized uptake value of 2.30 (range, 1.20-6.10). Only one of the 12 of the fluorodeoxyglucose-avid IMLNs was malignant, with a PPV of 0.083 (95% CI: 0.002, 0.385). IMLNs identified at implant-protocol breast MR imaging after oncoplastic surgery for breast cancer are overwhelmingly more likely to be benign than malignant. Imaging follow-up instead of immediate metastatic work-up may be warranted.

Abstract 19638: Short-Axis Echocardiographic Imaging of the Ascending Aorta is More Accurate than Long-Axis Imaging when Compared to Cardiac Magnetic Resonance Imaging and Computed Tomography

Introduction: Parasternal long-axis echo imaging often underestimates aortic dimensions when compared to CT or MRI. More accurate and reproducible echo methods for determining aortic size would benefit care and reduce cost. We compared novel short-axis aortic echo images to standard long-axis and CT or MRI measurements. Methods: We retrospectively reviewed all cardiac CT/MRI performed in the setting of aortic dilation at Arkansas Children’s Hospital from September 2002 to September 2013. All CT/MRI exams with echocardiograms performed within 3 months were included. One blinded observer reviewed all CT/MRI studies, and measured lateral and anteroposterior dimensions of the aortic sinus (AoS), sinotubular junction (STJ), and ascending aorta (AsAo). Echo measurements were made by 3 independent, blinded observers, and included AoS, STJ, and AsAo in standard long-axis views, as well as novel short-axis measurements: anteroposterior sinus length; maximal left to non-coronary sinus length; and lengths from center right to left coronary sinus or non-coronary sinus. Short-axis anteroposterior and lateral measurements were made of the AsAo at the level of the right pulmonary artery from a high left-parasternal view. All echo measurements were compared to CT/MRI. Pearson product-moment correlation based on Fisher’s transformation was determined for each measure compared to CT/MRI. Results: Fifty MRIs, 17 CTs, and 62 echocardiograms were identified and reviewed. Adequate imaging for long-axis aortic assessment was present in 48/62 (77%) echocardiograms, and 42/62 (68%) had adequate short-axis images. Fifty-three subjects median age 34.7 years met inclusion criteria. Long-axis measurements correlated well with CT/MRI for AoS (r=0.811), but poorly for AsAo (r=0.094). Short-axis measurements correlated equally well with CT/MRI for AoS (r=0.832), and AsAo (r=0.790). Conclusions: Parasternal short-axis echo measurements of the aorta are more accurate than conventional parasternal long-axis measurements when compared to CT/MRI. This simple and reproducible technique should be used routinely for echocardiographic evaluation of the aorta.

Three-dimensional assessment of left atrial appendage orifice geometry and potential implications for device closure

Transcatheter placement of left atrial closure device is an attractive therapy for patients with atrial fibrillation (AF), to avoid anticoagulation and reduce cerebrovascular events; however peri-device leaks occur. The geometry of the left atrial appendage (LAA) is not well understood, largely owing to limitations of 2-dimensional imaging techniques. We sought to better define the LAA orifice geometry, by performing 3-dimensional multi-detector computed tomography measurements. We prospectively recruited 105 consecutive patients referred for pulmonary vein ablation (PVA) and age-matched controls. Area, short and long-axis measurements were performed. Eccentricity was calculated as 1-(short axis/long axis). Multiple clinical variables were tested for their ability to predict appendage orifice eccentricity using univariate linear regression models. The PVA cohort demographics included; 25 (24%) females, mean age 59 years (SD = 10), median height (1.55-2.03), weight 89 (56-139) kg and body surface area 2.1 (1.61-2.58). In the PVA cohort, there was a significant difference between the long and short-axis; median short-axis dimension was 20.5 (12.9-35.4) mm, versus long-axis median 30.4 (17.7-43.8) (p < 0.001). Mean eccentricity score was 0.4. When compared with controls, there was a significant difference in the short and long-axis measurements (p < 0.001) as well as eccentricity (p = 0.04). All clinical variables tested showed limited ability to predict appendage eccentricity (p = NS). LAA ostium is an elliptical structure in the setting of AF with a high eccentricity index and uniformly significant differences between short and long-axis. There were significant differences between these parameters when compared with controls. A deeper appreciation of LAA geometry and eccentricity may allow for reduction in peri-closure leaks.

Right ventricular outflow tract function in chronic obstructive pulmonary disease

It is clinically important to evaluate the severity of right ventricular (RV) overload in patients with chronic obstructive pulmonary disease (COPD), which is often associated with changes in the structure and the function of the right ventricle. Noninvasive and reliable assessment of RV function would be an essential determinant of RV load and a clinically useful factor for assessing cardiovascular risk in COPD patients. The aim of this study was to investigate the clinical application value of right ventricular outflow tract (RVOT) systolic function measured by transthoracic echocardiography in patients with COPD. We prospectively investigated COPD male patients and compared them with healthy controls. In addition to RV conventional echocardiographic parameters, RVOT size and fractional shortening (RVOT-FS) parameters were also assessed. Fifty-five COPD patients (all men; mean age, 62 ± 9years) participated in the study, and were compared with a control group consisting of 21male, healthy, nonsmoking subjects with a mean age of 58 ± 11years. The RVOT-FS was impaired in COPD patients than healthy controls (27.8 ± 15.5 vs. 57.5 ± 8.6, p < 0.001), and was correlated positively with tricuspid annular plane systolic excursion (TAPSE; r = 0.583, p < 0.001) and pulmonary acceleration time (r = 0.666, p < 0.001) and inversely with pulmonary artery systolic pressure (r = 0.605, p < 0.001) and functional capacity(r = - 0.589, p < 0.001). There was a statistically significant difference in RVOT-FS among the COPD subgroups with regard to New York Heart Association functional classification (p < 0.001). The RVOT-FS is a noninvasive easily applicable measure of RV systolic function and is well correlated with functional capacity in COPD patients. Its combination with long-axis measurements via TAPSE and transtricuspid Doppler analysis may provide a comprehensive evaluation of the RV performance in COPD patients.

Comparison of Echocardiographic Measurements of Left Ventricular Volumes to Full Volume Magnetic Resonance Imaging in Normal and Diseased Rats

Clinical two-dimensional (2D) and clinical three-dimensional echocardiography are validated against cardiac magnetic resonance imaging (CMR), the gold standard for left ventricular (LV) volume measurement. In rodents, there is no widely accepted echocardiographic measure of whole LV volumes, and CMR measurements vary among studies. The aim of this study was to compare LV volumes by 2D echocardiography (using a hemisphere-cylinder [HC] model) with HC and full-volume (FV) CMR in normal and diseased rats to measure the impact of geometric models and imaging modalities. Rats (n= 27) underwent ascending aortic banding, myocardial infarction induction by either permanent left anterior descending coronary artery ligation or ischemia-reperfusion, and sham thoracotomy. Subsequently, end-diastolic volume, end-systolic volume, and ejection fraction were measured using an HC 2D echocardiographic model combining parasternal short-axis and long-axis measurements, and these were compared with HC and FV CMR. Diseased groups showed LV dilatation and dysfunction. HC echocardiographic and FV CMR measures of end-diastolic volume, end-systolic volume, and ejection fraction were correlated. On Bland-Altman plots, end-diastolic volumes were concordant between both methods, while HC echocardiography underestimated end-systolic volumes, resulting in a modest overestimation of ejection fractions compared with FV CMR. Other 2D echocardiographic geometric models offered less concordance with FV CMR than HC. HC CMR overestimated LV volumes compared with FV CMR, while HC echocardiography underestimated HC CMR volumes. Echocardiography underestimated corresponding LV dimensions by CMR, particularly short axis. Concordant measures of LV volume and function were obtained using (1) a relatively simple HC model of the left ventricle inclusive of two orthogonal 2D echocardiographic planes and (2) FV CMR in normal and diseased rats. The HC model appeared to compensate for the underestimation of LV dimensions by echocardiography.

Quantitative Estimates of the Variability of In Vivo Sonographic Measurements of the Mouse Aorta for Studies of Abdominal Aortic Aneurysms and Related Arterial Diseases

Burgeoning interest in reducing the morbidity and mortality associated with abdominal aortic aneurysms (AAAs) has led to experimental strategies to elucidate the disease process and attain pharmacologic regression using the apolipoprotein E(-/-) (ApoE(-/-)) mouse model of angiotensin-induced AAAs and in vivo sonography. However, the variability of in vivo sonographic measurements of the mouse aorta has not been established. Thus, our purpose was to determine quantitative estimates of the variability of in vivo sonographic measurements of the mouse aorta as a guide for the design and assessment of studies focused on regression of AAAs and related arterial diseases. We used Bland-Altman, locally weighted scatterplot-smoothing regression, and resampling (bootstrapping) methods for variability analyses of multiple in vivo short- and long-axis sonographic measurements of ApoE(-/-) mouse aortas. We measured distinct aortic sites in vivo at the baseline and after angiotensin-induced AAAs and ex vivo using digital calipers. We analyzed 236 data points from 10 male mice (14 weeks old; mean weight ± SD, 29.7 ± 1.6 g). Overall intramouse differences between short- and long-axis and in vivo and ex vivo measurements were 0.038 (95% confidence interval [CI], 0.031-0.046) and 0.085 (95% CI, 0.062-0.109) mm, respectively. Intermouse differences in short-axis measurements were 0.047 (95% CI, 0.042-0.053), 0.049 (95% CI, 0.044-0.055), and 0.039 (95% CI, 0.036-0.042) mm for infrarenal, suprarenal, and thoracic measurements, respectively; differences in long-axis measurements were 0.054 (95% CI, 0.044-0.064), 0.029 (95% CI, 0.024-0.034), and 0.046 (95% CI, 0.037-0.054) mm. Bland-Altman and locally weighted scatterplot-smoothing analyses showed excellent agreement between measures with no variation in discrepancies vis-à-vis the target measurement. These data establish previously undefined estimates of measurement variability relevant for in vivo sonographic studies of AAA regression in a commonly studied mouse model.

Left atrial volume and geometry in healthy aging: the Cardiovascular Health Study.

The left atrium is a validated marker of clinical and subclinical cardiovascular disease. Left atrial enlargement is often seen among older individuals; however, there are few population-based data regarding normal left atrial size among older persons, especially from those who are healthy, and from women. Furthermore, because the left atrium is a 3D structure, the commonly used parasternal long-axis diastolic diameter often underdiagnoses left atrial enlargement. We evaluated left atrial size in 230 healthy participants (mean age, 76+/-5 years) free of prevalent cardiac disease, rhythm abnormality, hypertension, and diabetes selected from the Cardiovascular Health Study, a prospective community-based study of risk factors for cardiovascular disease in 5888 elderly participants. In addition to the standard long-axis measurement, we obtained left atrial superoinferior and lateral diameters and used these dimensions to estimate left atrial volume. These measurements were used to generate reference ranges for determining left atrial enlargement in older men and women, based on the 95% percentiles of the left atrial dimensions in healthy participants, both unadjusted, and after adjustment for age, height, and weight. In healthy elderly subjects, indices of left atrial size do not correlate with age or height but with weight and other measures of body build. These data provide normative reference values for left atrial size in healthy older women and men. The results should be useful for refining diagnostic criteria for left atrial dilation in the older population and may be relevant for cardiovascular risk stratification.

A Comparison of Echocardiogram Screening for Pulmonary Hypertension in Asymptomatic and Symptomatic Patients with Sickle Cell Disease

Background: Pulmonary hypertension (PHT) is an increasingly recognised complication of sickle cell disease (SCD), even in asymptomatic patients. Studies from the US have shown a prevalence of PHT of between 20–30% and this has been associated with an increased mortality. The prevalence of PHT in the UK sickle cell disease population is unknown.Method: We identified adult patients with a diagnosis of SCD (HbSS, HbSC, HbSB0thalassaemia and HbSB+ thalassaemia) who had screening for PHT using transthoracic echocardiography over a one year period. We compared the echocardiographic findings of symptomatic and asymptomatic patients. Direct measurements of tricuspid regurgitant jet velocity (TRVmax) were recorded, as has been done in previous similar studies with a peak TRV of ≥ 2.5m/s indicating risk of PHT. In order to increase specificity and sensitivity of the echocardiogram recording and as TRVmax is not always measurable other indirect indicators of PHT were also recorded, including ‘time from start of flow to peak velocity’ which is measured by placing the pulsed sample in the centre of the main PA or pulmonary valve annulus; a time of >105ms excluded PHT while a time <80ms made PHT highly likely. Systolic function of the right ventricle was quantified using long-axis measurements: TAPSE (tricuspid annular plane systolic excursion) using a TAPSE <18mmHg as an abnormal threshold and ‘Doppler tissue S velocity’ was measured by placing the Doppler tissue sample in the RV free wall at the tricuspid annulus and recording the peak systolic velocity. A velocity of <10m/s was consistent with a reduced RV ejection fraction or PHT.Results: 32 asymptomatic patients and 40 symptomatic patients had echocardiogram screening for PHT. The asymptomatic group had a mean age (± SD) 36.5 years(± 10.2), 17 patients were men, 20 patients had HbSS, 10 patients had HbSC, 1 patient had HbSB0thalassaemia and 1 patient had HbSB+ thalassaemia. 3/32 (9.4%) of patients had abnormal echocardiograms with a TRV of 2.5, 2.5 and 2.6 m/s respectively. One patient with a TRV = 2.5m/s had a history of chest crisis and was on hydroxyurea. The symptomatic group had a mean age (± SD) 35.8 years (± 11.2), 13 patients were men, 31 patients had HbSS, 8 patients had HbSC, 1 patient had HbSB0thalassaemia. 2 patients who had TRV ≥ 2.5m/s were excluded from analysis as had pulmonary stenosis. 7/38 (18.4%) patients had TRV ≥ 2.5m/s (range 2.5 to 2.7m/s). Of these 7 patients, 6 had HbSS, 1 had HbSC, only one was on hydroxyurea, and only one had a history of chest crisis. In 2 further patients in whom TRV was not measurable, other echocardiographic features were used to identify PHT; 1 patient had a ‘time to peak velocity’ of 58ms and 1 patient had a TAPSE of 17mmHg and a ‘time to peak velocity’ of 80ms. Both patients had HbSS, 1 had a history of chest crisis and none were on hydroxyurea.Conclusion: In the asymptomatic group, 9.4% of patients had abnormal echocardiograms, which were suggestive of PHT. In the symptomatic group, 24% patients had echocardiograms suggestive of PHT with 7 patients having a peak TRV ≥ 2.5m/s and a further 2 patients being identified using other echocardiogram criteria. We conclude that the prevalence of PHT in the asymptomatic group was low but in the symptomatic group, the prevalence of PHT was comparable to figures in the US. In addition, transthoracic doppler echocardiographic screening for PHT should include other criteria apart from TRV.

Use of three-dimensional ultrasonography of the eye and measurement of optical long axis in dog

Summary This study was conducted to determine the use of three-dimensional ultrasonography (3DU) in ocular imaging of the dog and measuring of its optical axis. 12 healthy mixed-breed dogs including 6 males and 6 females were studied. 3DU of the eyes were done using a 5-12 MHz linear trapezoid transducer. 3DU of the eyes were evaluated and the normal optical long axis through a line between the cornea and the optic disc in three-dimensional images were measured. In 3D images, vitreous body, anterior chamber, and lens cortex and its nucleus had a distinct anechogenic to hypoechogenic pattern. Details of the eyes compartments were better observed by rotating the images in all possible angles and planes using 3D facilities. Anterior and posterior lens capsule and the optic disk were hyperechogenic. The mean ± SD optical axis was 20.7 ±0 .9 mm in males and 26.3 ± 0.6 mm in females (P<0.05). No significant difference existed between the measurements made in left and right eyes. We found marked advantages in image acquisition for interpretation of all aspects of the ocular structures.