Left Lung Volume Research Articles

Dosimetric Considerations in Respiratory-Gated Deep Inspiration Breath-Hold for Left Breast Irradiation.

To present our clinical workflow of incorporating AlignRT for left breast deep inspiration breath-hold treatments and the dosimetric considerations with the deep inspiration breath-hold protocol. Patients with stage I to III left-sided breast cancer who underwent lumpectomy or mastectomy were considered candidates for deep inspiration breath-hold technique for their external beam radiation therapy. Treatment plans were created on both free-breathing and deep inspiration breath-hold computed tomography for each patient to determine whether deep inspiration breath-hold was beneficial based on dosimetric comparison. The AlignRT system was used for patient setup and monitoring. Dosimetric measurements and their correlation with chest wall excursion and increase in left lung volume were studied for free-breathing and deep inspiration breath-hold plans. Deep inspiration breath-hold plans had significantly increased chest wall excursion when compared with free breathing. This change in geometry resulted in reduced mean and maximum heart dose but did not impact lung V20 or mean dose. The correlation between chest wall excursion and absolute reduction in heart or lung dose was found to be nonsignificant, but correlation between left lung volume and heart dose showed a linear association. It was also identified that higher levels of chest wall excursion may paradoxically increase heart or lung dose. Reduction in heart dose can be achieved for many left-sided breast and chest wall patients using deep inspiration breath-hold. Chest wall excursion as well as left lung volume did not correlate with reduction in heart dose, and it remains to be determined what metric will provide the most optimal and reliable dosimetric advantage.

A Retrospective Analysis of Lung Volume and Cardiac Dose in Left-Sided Whole Breast Radiotherapy

ObjectiveThe purpose of this study was to assess the variability of lung volume and characterize its relationship with heart dose in women with left-sided breast cancer receiving whole breast radiotherapy. Materials and methodsFree-breathing (FB) computed tomography scans of female left-sided breast cancer patients were retrospectively reviewed. Dose and volume parameters for the lung, heart, and left anterior descending coronary artery were collected from the FB treatment plans of 47 patients treated in FB (PTFB) and 41 patients who exceeded institutional heart dose limits (≥10 cc of heart receiving V50%) and required the breath-hold technique using the active breathing coordinator (ABC) device (PTABC). A two-tailed Student's t-test and Pearson's correlation test were performed for statistical analysis. ResultsVolume of the heart and left anterior descending artery were similar between the groups (P = .102 and P = .548, respectively). Total left lung volume in FB state was significantly smaller for the PTABC group (996.9 cc; standard deviation, 253.1) when compared with the PTFB group (1,207.8 cc standard deviation, 32; P < .001). Mean and maximum heart dose, heart V50%, V30 Gy, and V10 Gy decreased with increasing left lung volume for all patients (P < .001). There was an inverse relationship between left lung volume and mean heart dose (R = −0.586, P < .001). ConclusionsPatients requiring ABC have smaller left lung volumes during FB state. Future study to assess lung volume in conjunction with other anatomic parameters in the development of an ABC screening tool is warranted.

SU‐F‐J‐22: Lung VolumeVariability Assessed by Bh‐CBCT in 3D Surface Image Guided Deep InspirationBreath Hold (DIBH) Radiotherapy for Left‐Sided Breast Cancer

Purpose:With the increasing use of DIBH techniques for left‐sided breast cancer, 3D surface‐image guided DIBH techniques have improved patient setup and facilitated DIBH radiation delivery. However, quantification of the daily separation between the heart and left breast still presents a challenge. One method of assuring separation is to ensure consistent left lung filling. With this in mind, the aim of this study is to retrospectively quantify left lung volume from weekly breath hold‐CBCTs (bh‐CBCT) of left‐sided breast patients treated using a 3D surface imaging system.Methods:Ten patients (n=10) previously treated to the left breast using the C‐Rad CatalystHD system (C‐RAD AG, Uppsala Sweden) were evaluated. Patients were positioned with CatalystHD and with bh‐CBCT. bh‐CBCTs were acquired at the validation date, first day of treatment and at subsequent weekly intervals. Total treatment courses spanned from 3 to 5 weeks. bh‐CBCT images were exported to VelocityAI and the left lung volume was segmented. Volumes were recorded and analyzed.Results:A total of 41 bh‐CBCTs were contoured in VelocityAI for the 10 patients. The mean left lung volume for all patients was 1657±295cc based on validation bh‐CBCT. With the subsequent lung volumes normalized to the validation lung volume, the mean relative ratios for all patients were 1.02±0.11, 0.97±0.14, 0.98±0.11, 1.02±0.01, and 0.96±0.02 for week 1, 2, 3, 4, and 5, respectively. Overall, the mean left lung volume change was ≤4.0% over a 5‐week course; however left lung volume variations of up to 28% were noted in a select patient.Conclusion:With the use of the C‐RAD CatalystHD system, the mean lung volume variability over a 5‐week course of DIBH treatments was ≤4.0%. By minimizing left lung volume variability, heart to left breast separation maybe more consistently maintained.AN Gutierrez has a research grant from C‐RAD AG.

SU‐F‐J‐120: Evaluation of the Combined Effect of Body Orientation and Breathing On Organ Movement in Thorax Using Multi‐Step Deformable Image Registration

Purpose:Use deformable registration to map more complex anatomies that include changes associated with both different body positions and breathing, and evaluate the resultant respiratory excursions for tumors and relevant organs at risk.Methods:Same‐day exhale and inhale datasets from prone and supine 4D CT scans of lung cancer patients have been registered using the Elastix software package through a 3 step process: (1) rigid registration for bony alignment (2) deformable multiresolution B‐Spline registration of entire anatomy (3) deformable multiresolution B‐Spline registration of lung parenchyma (to improve lung vasculature alignment).Manual contours were propagated from the supine‐inhale phase to supine‐exhale, prone‐exhale and prone‐inhale, via the resulting registration transformations. Motion excursions between exhale and inhale for both body orientations were computed for tumors, heart, esophagus, vertebrae (T2, T5, T12).Results:The registration accuracy was evaluated by visual inspection of the deformed contours by physicians and minimal contour adjustments were made where deemed appropriate. The average supine [mm] / prone [mm] motion amplitudes for the initial 5‐patient sample are as follows: Tumor – 5.8/6.5, T5 – 1.4/2.0, T2 – 0.5/1.6, T12 – 1.7/2.9, Heart– 4.9/9.0, Upper esophagus – 1.6/3.8, Middle esophagus – 3.8/5.0, Lower esophagus – 4.1/6.7. Differences between prone and supine excursions for heart, esophagus, T2 and T12 were significant at 95% level (one‐sided Wilcoxon Mann‐Whitney test).On average, the right and left lung volumes increased by 10% at inhale prone and by 5% at exhale prone from their respective values in supine position.Conclusion:A multi‐step deformable registration sequence was implemented and successfully used for supine‐prone image registration of thorax. In prone position, lungs are larger, likely owing to increased pulmonary compliance and decreased compressive force of the heart on lungs when prone. Breathing motion excursion is enhanced in prone, possible consequence of rib cage stabilization and increased diaphragmatic motion.Elisabeth Weiss: Research support from Philips Healthcare and National Institutes of Health; Licensing agreement with Varian Medical Systems, UpToDate royalties.

Predictive equations for lung volumes from computed tomography for size matching in pulmonary transplantation

ObjectiveSize matching for lung transplantation is widely accomplished using height comparisons between donors and recipients. This gross approximation allows for wide variation in lung size and, potentially, size mismatch. Three-dimensional computed tomography (3D-CT) volumetry comparisons could offer more accurate size matching. Although recipient CT scans are universally available, donor CT scans are rarely performed. Therefore, predicted donor lung volumes could be used for comparison to measured recipient lung volumes, but no such predictive equations exist. We aimed to use 3D-CT volumetry measurements from a normal patient population to generate equations for predicted total lung volume (pTLV), predicted right lung volume (pRLV), and predicted left lung volume (pLLV), for size-matching purposes. MethodsChest CT scans of 400 normal patients were retrospectively evaluated. 3D-CT volumetry was performed to measure total lung volume, right lung volume, and left lung volume of each patient, and predictive equations were generated. The fitted model was tested in a separate group of 100 patients. The model was externally validated by comparison of total lung volume with total lung capacity from pulmonary function tests in a subset of those patients. ResultsAge, gender, height, and race were independent predictors of lung volume. In the test group, there were strong linear correlations between predicted and actual lung volumes measured by 3D-CT volumetry for pTLV (r = 0.72), pRLV (r = 0.72), and pLLV (r = 0.69). A strong linear correlation was also observed when comparing pTLV and total lung capacity (r = 0.82). ConclusionsWe successfully created a predictive model for pTLV, pRLV, and pLLV. These may serve as reference standards and predict donor lung volume for size matching in lung transplantation.

Observation of cardiogenic flow oscillations in healthy subjects with hyperpolarized 3He MRI.

Recently, dynamic MRI of hyperpolarized (3)He during inhalation revealed an alternation of the image intensity between left and right lungs with a cardiac origin (Sun Y, Butler JP, Ferrigno M, Albert MS, Loring SH. Respir Physiol Neurobiol 185: 468-471, 2013). This effect is investigated further using dynamic and phase-contrast flow MRI with inhaled (3)He during slow inhalations (flow rate ∼100 ml/s) to elucidate airflow dynamics in the main lobes in six healthy subjects. The ventilation MR signal and gas inflow in the left lower lobe (LLL) of the lungs were found to oscillate clearly at the cardiac frequency in all subjects, whereas the MR signals in the other parts of the lungs had a similar oscillatory behavior but were smaller in magnitude and in anti-phase to the signal in the left lower lung. The airflow in the main bronchi showed periodic oscillations at the frequency of the cardiac cycle. In four of the subjects, backflows were observed for a short period of time of the cardiac cycle, demonstrating a pendelluft effect at the carina bifurcation between the left and right lungs. Additional (1)H structural MR images of the lung volume and synchronized ECG recording revealed that maximum inspiratory flow rates in the LLL of the lungs occurred during systole when the corresponding left lung volume increased, whereas the opposite effect was observed during diastole, with gas flow redirected to the other parts of the lung. In conclusion, cardiogenic flow oscillations have a significant effect on regional gas flow and distribution within the lungs.

Predicting radiation-induced valvular heart damage

Purpose. To develop a predictive multivariate normal tissue complication probability (NTCP) model for radiation-induced heart valvular damage (RVD). The influence of combined heart-lung irradiation on RVD development was included.Material and methods. Multivariate logistic regression modeling with the least absolute shrinkage and selection operator (LASSO) was used to build an NTCP model to predict RVD based on a cohort of 90 Hodgkin lymphoma patients treated with sequential chemo-radiation therapy. In addition to heart irradiation factors, clinical variables, along with left and right lung dose-volume histogram statistics, were included in the analysis. To avoid overfitting, 10-fold cross-validation (CV) was used for LASSO logistic regression modeling, with 50 reshuffled cycles. Model performance was assessed using the area under the receiver operating characteristic (ROC) curve (AUC) and Spearman's correlation coefficient (Rs).Results. At a median follow-up time of 55 months (range 12–92 months) after the end of radiation treatment, 27 of 90 patients (30%) manifested at least one kind of RVD (mild or moderate), with a higher incidence of left-sided valve defects (64%). Fourteen prognostic factors were frequently selected (more than 100/500 model fits) by LASSO, which included mainly heart and left lung dosimetric variables along with their volume variables. The averaged cross-validated performance was AUC-CV = 0.685 and Rs = 0.293. The overall performance of a final NTCP model for RVD obtained applying LASSO logistic regression to the full dataset was satisfactory (AUC = 0.84, Rs = 0.55, p < 0.001).Conclusion. LASSO proved to be an improved and flexible modeling method for variable selection. Applying LASSO, we showed, for the first time, the importance of jointly considering left lung irradiation and left lung volume size in the prediction of subclinical radiation-related heart disease resulting in RVD.

Postmastectomy Chest Wall Radiation of Left-Sided Breast Cancer Patients With Single Energy Electron Beam Versus 3-Dimensional Conformal Radiation Therapy With Photons: Analysis of Dosimetric Parameters

Post mastectomy chest wall radiation is routinely delivered using tangential photon fields. However for left sided tumors underlying heart and left lung form major organs at risk and this report studies the use of single energy electron-beam radiation therapy in these patients. The aim of this study is to compare mean left lung dose, percentage volume of left lung receiving dose more than 20 Gy (V20 Gy), mean heart dose, percentage volume of heart receiving dose more than 25 Gy (V25 Gy) and 45 Gy (V45 Gy), percentage volume of planned target volume (PTV) receiving more than 95% of prescribed dose (V95%).

Scoliosis Surgery in Patients With Adolescent Idiopathic Scoliosis Does Not Alter Lung Volume

Retrospective study of surgically treated patients with adolescent idiopathic scoliosis. To determine the change in lung volume after the surgical correction of scoliosis using a volumetric reconstruction of lung volume from computed tomographic (CT) scans. Previously published studies have shown that pulmonary function tests improve after scoliosis correction; however, these results are not consistent. CT-based volumetric studies in patients with scoliosis have previously shown differences in lung volume and lung volume ratio when compared with a normal population. To date, no study exists that analyzes changes in these parameters after scoliosis surgery. A total of 29 patients with adolescent idiopathic scoliosis who had pre- and postoperative CT scans on file were included in this study. Three-dimensional lung volume reconstruction was performed (TeraRecon software, TeraRecon, Inc., Foster City, CA). Appropriate masking methods were used to isolate the lung tissue. Total lung volumes, left and right lung volumes, and left/right lung volume ratio were obtained from the pre- and postoperative CT scans. Hemithoracic symmetry, pre- and postoperative Cobb angle, and kyphosis were also calculated. Neither total lung volume nor left/right lung volume ratio changed significantly postoperatively. Surgery did not significantly change total lung volume (P = 0.87), right lung volume (P = 0.69), left lung volume (P = 0.70), or the ratio between right and left lung volumes (P = 0.87). Hemithoracic asymmetry was significantly improved (P < 0.001). Median preoperative major Cobb angle was 53.2° and median preoperative kyphosis was 32.8°. Postoperatively, the median major Cobb angle was 15.0°, resulting in a 70% Cobb correction, and mean postoperative kyphosis was 31.1°. Corrective scoliosis surgery does not alter total lung volume or the ratio of right-to-left lung volume. Deformity correction leads to an improvement in the symmetry of the thoracic architecture and costovertebral joint mechanics, as evidenced by the improved hemithoracic asymmetry. Thus, the change in pulmonary function tests, which has been previously documented, may be a dynamic rather than a static phenomenon. 4.

VEGF receptor expression decreases during lung development in congenital diaphragmatic hernia induced by nitrofen

Changes in vascular endothelial growth factor (VEGF) in pulmonary vessels have been described in congenital diaphragmatic hernia (CDH) and may contribute to the development of pulmonary hypoplasia and hypertension; however, how the expression of VEGF receptors changes during fetal lung development in CDH is not understood. The aim of this study was to compare morphological evolution with expression of VEGF receptors, VEGFR1 (Flt-1) and VEGFR2 (Flk-1), in pseudoglandular, canalicular, and saccular stages of lung development in normal rat fetuses and in fetuses with CDH. Pregnant rats were divided into four groups (n=20 fetuses each) of four different gestational days (GD) 18.5, 19.5, 20.5, 21.5: external control (EC), exposed to olive oil (OO), exposed to 100 mg nitrofen, by gavage, without CDH (N-), and exposed to nitrofen with CDH (CDH) on GD 9.5 (term=22 days). The morphological variables studied were: body weight (BW), total lung weight (TLW), left lung weight, TLW/BW ratio, total lung volume, and left lung volume. The histometric variables studied were: left lung parenchymal area density and left lung parenchymal volume. VEGFR1 and VEGFR2 expression were determined by Western blotting. The data were analyzed using analysis of variance with the Tukey-Kramer post hoc test. CDH frequency was 37% (80/216). All the morphological and histometric variables were reduced in the N- and CDH groups compared with the controls, and reductions were more pronounced in the CDH group (P<0.05) and more evident on GD 20.5 and GD 21.5. Similar results were observed for VEGFR1 and VEGFR2 expression. We conclude that N- and CDH fetuses showed primary pulmonary hypoplasia, with a decrease in VEGFR1 and VEGFR2 expression.

Prediction of lethal pulmonary hypoplasia among high-risk fetuses via 2D and 3D ultrasonography

ObjectiveTo compare accuracy between 3D and 2D ultrasonography for predicting lethal pulmonary hypoplasia (LPH) among high-risk fetuses. MethodsIn a cross-sectional prospective study at a fetal medicine referral center in Brazil, bilateral fetal lung scans were evaluated for 54 fetuses with suspected LPH between May 2008 and June 2011. Measurements for predicting LPH were ultrasonographic fetal lung volume/estimated fetal weight ratio (US-FLW), observed/expected thoracic circumference (o/e-TC), observed/expected thoracic circumference/abdominal circumference (o/e-TC/AC), observed/expected thoracic area/heart area (o/e-TA/HA), observed/expected amniotic fluid index (o/e-AFI), and observed/expected total fetal lung volume (o/e-Tot-FLV). To evaluate accuracy in predicting LPH, receiver operating characteristic (ROC) curves were calculated, and areas under the curves (AUCs) were compared. The intraclass correlation coefficient (ICC) was used to assess 3D lung volume reproducibility. ResultsData were compared for 47 newborns, of whom 34 had LPH (perinatal mortality 74.5%). The AUCs for predicting LPH were 0.93, 0.69, 0.55, 0.46, 0.71, and 0.86 for US-FLW, o/e-TC, o/e-TC/AC, o/e-TA/HA, o/e–AFI, and o/e-Tot–FLV, respectively. No significant intraobserver difference was observed in measurements of the right (ICC, 0.973; P<0.0001) or left (ICC, 0.950; P<0.0001) lung volumes. ConclusionAmong high-risk fetuses, US-FLW by 2D/3D and o/e-Tot-FLV by 3D ultrasonography were more accurate than 2D parameters for predicting LPH.

Separating in vivo mechanical stimuli for postpneumonectomy compensation: imaging and ultrastructural assessment

Following right pneumonectomy (PNX), the remaining lung expands and its perfusion more than doubles. Tissue and microvascular mechanical stresses are putative stimuli for compensatory lung growth and remodeling, but their relative contribution remains uncertain. To temporally separate expansion- and perfusion-related stimuli, we replaced the right lung of adult dogs with a customized inflated prosthesis. Four months later, the prosthesis was either acutely deflated (DEF) or kept inflated (INF). Thoracic high-resolution computed tomography (HRCT) was performed pre- and post-PNX before and after prosthesis deflation. Lungs were fixed for morphometric analysis ∼12 mo post-PNX. The INF prosthesis prevented mediastinal shift and lateral lung expansion while allowing the remaining lung to expand 27-38% via caudal elongation, associated with reversible capillary congestion in dependent regions at low inflation and 40-60% increases in the volumes of alveolar sepal cells, matrix, and fibers. Delayed prosthesis deflation led to further significant increases in lung volume, alveolar tissue volumes, and alveolar-capillary surface areas. At postmortem, alveolar tissue volumes were 33% higher in the DEF than the INF group. Lateral expansion explains ∼65% of the total post-PNX increase in left lung volume assessed in vivo or ex vivo, ∼36% of the increase in HRCT-derived (tissue + microvascular blood) volume, ∼45% of the increase in ex vivo septal extravascular tissue volume, and 60% of the increase in gas exchange surface areas. This partition agrees with independent physiological measurements obtained in these animals. We conclude that in vivo signals related to lung expansion and perfusion contribute separately and nearly equally to post-PNX growth and remodeling.

Effect of bra use during radiation therapy for large-breasted women: Acute toxicity and treated heart and lung volumes

PurposeLarge breast size presents special problems during radiation simulation, planning, and patient treatment, including increased skin toxicity, in women undergoing breast-conserving surgery and radiation therapy (BCT). We report our experience using a bra during radiation in large-breasted women and its effect on acute toxicity and heart and lung dosimetry. Methods and MaterialsFrom 2001 to 2006, 246 consecutive large-breasted women (bra size ≥38 or ≥D cup) were treated with BCT using either 3-dimensional conformal radiation therapy (3DCRT) or intensity modulated radiation therapy (IMRT). In 58 cases, at the physicians’ discretion, a custom-fit bra was used during simulation and treatment. Endpoints were acute radiation dermatitis and dosimetric comparison of heart and lung volumes in a subgroup of 12 left-sided breast cancer patients planned with and without a bra. ResultsThe majority of acute skin toxicities were grade 2 and were experienced by 90% of patients in a bra compared with 70% of patients not in a bra (P = .003). On multivariate analysis significant predictors of grade 2 or 3 skin toxicity included the use of 3DCRT instead of IMRT (odds ratio, 3.9; 95% confidence interval, 1.8-8.5) and the use of a bra (odds ratio, 5.5; 95% confidence interval, 1.6-18.8). For left-sided patients, the use of a bra was associated with a volume of heart in the treatment fields decreased by 63.4% (P = .002), a volume of left lung decreased by 18.5% (P = .25), and chest wall separation decreased by a mean of 1 cm (P = .03). ConclusionsThe use of a bra to augment breast shape and position in large-breasted women is an alternative to prone positioning and associated with reduced chest wall separation and reduced heart volume within the treatment field.

Letter to the Editor Rare cardiovascular anomaly: congenital unilateral absence of the pulmonary artery

Letter to the Editor Rare cardiovascular anomaly: congenital unilateral absence of the pulmonary artery

Chronic effects of pulmonary artery stenosis on hemodynamic and structural development of the lungs

Pulmonary artery (PA) stenosis is a difficult obstructive defect to manage since clinicians cannot know a priori which obstructions to treat and when. Prognosis of PA stenosis and its chronic effects on lung development are poorly understood. This study aimed to characterize the hemodynamic and structural effects of PA stenosis during development. Fourteen male Sprague-Dawley rats underwent left PA (LPA) banding at age 21 days, and 13 underwent sham operation. Hemodynamic and structural impacts were studied longitudinally at 20, 36, 52, 100, and 160 days. Chronic LPA banding resulted in a significant reduction in LPA flow (P < 0.0001) and size of both proximal LPA (P < 0.0001) and distal LPA (P < 0.01), as well as a significant increase in flow and size of the right PA (P < 0.05) throughout development. Flows and sizes adapted such that normal levels of wall shear were restored after banding. At 160 days, LPA banding resulted in a significant decrease in left lung volume and an increase in right lung volume but no significant differences in total lung volume. There was an elevation of proximal LPA pressure as well as right ventricular hypertrophy in the banded animals. The banded lung exhibited arterial disorganization, loss of vessels, and enlargement of its bronchial arteries, whereas the contralateral lung showed signs of vascular pathology. There are consequences on development of both lungs in the presence of an LPA stenosis at young age. These results suggest that early intervention may be necessary to optimize left lung growth and minimize right lung vascular pathology.

Patent Ductus Arteriosus Aneurysm: A Rare Cause of Dyspnea in an Adolescent Boy

We report a rare cause of dyspnea in an adolescent boy who presented with complaints of dyspnea on exertion since childhood without any cyanosis. Computed tomography angiography showed a large patent ductus arteriosus aneurysm that was seen compressing on the trachea and a left main bronchus with associated decreased left lung volume.

LINEAR DIMENSIONS AND VOLUMES OF HUMAN LUNGS OBTAINED FROM CT IMAGES

This work provides the results of a collaboration between the Human Monitoring Laboratory (HML) and the Centre Hospitalier de l'Université de Montréal (CHUM) in which CHUM provided CT lung image sets from 166 patients for the analysis of linear dimensions and lung volume. This work has shown that a large amount of data exists in the medical community that can be of value to the health physics community. The intent of this study was to determine the range of linear dimensional parameters that could be used for torso phantom development for males and females; understand and characterize the variability of linear lung dimensions for males and females; replace the brief table in ICRP 23 with more modern data for males and females; identify an empirical formula that would predict linear dimensions of human lungs from age, height and/or weight for males and females; characterize the left, right, and total lung volumes of males and females in this data set; and compare the lung volumes of males and females to published equations for determining lung volumes. It was found that linear dimensions of lungs are essentially independent of age, height, and weight, so predictive equations cannot be formulated; however, the ranges of those parameters have now been established for the population studied herein. The data presented here are more modern than the brief table that appeared in ICRP 23, and the average values could be used as future guidelines. Whole lung volumes have been determined from the voxel lung phantoms, and empirical formulae have been developed for males and females in this data set; these compare favorably with the published values in ICRP 66.

Fetal Lung Volume Measurements using 3D Ultrasonography

The aim of the study was to establish fetal lung, thoracic and heart volume nomograms using three-dimensional (3D) ultrasonographic measurements. For this purpose a total of 300 fetuses were examined between 18 and 34 weeks of gestation using Voluson 530 ME and Voluson 730 PRO (General Electic, USA) ultrasound devices with 5 MHz three-dimensional annular volume transducers. To determine fetal lung volume, each lung was measured separately using a transversal sectional plane in the multiplanar mode. Measurements were performed by area tracing around the fetal lung in cross-sectional planes in different slices. The distance between two represented slices was calculated by computer. Calculated volume data was plotted against gestational age in order to obtain nomograms of fetal lung, heart and thorax volumes. Our nomograms revealed increasing lung, heart and thoracic volume growth between 22 and 34 weeks of gestation. Furthermore, we could demonstrate that there is a statistically significant difference between the growth of the right and left lung volume (right > left). In a group of 12 fetuses with skeletal dysplasias or hydrothorax pulmonary hypoplasia was suspected by ultrasound. Comparing two-dimensional (2D) sonographic measurements of oblique lung diameter and 3D lung volumetry, it was found that these two methods were complementary for the recognition of pulmonary hypoplasia before the 24 weeks of gestation. Using 3D ultrasound it is easy to perform fetal lung volumetry especially before 30 weeks of gestation. The encouraging results suggest that this method could be useful for the early detection of pulmonary hypoplasia even before 24 weeks of gestation.

Influence of Different Rotation Angles in Assessment of Lung Volumes by 3-Dimensional Sonography in Comparison to Magnetic Resonance Imaging in Healthy Fetuses

Three-dimensional (3D) sonographic volumetry is established in gynecology and obstetrics. Assessment of the fetal lung volume by magnetic resonance imaging (MRI) in congenital diaphragmatic hernias has become a routine examination. In vitro studies have shown a good correlation between 3D sonographic measurements and MRI. The aim of this study was to compare the lung volumes of healthy fetuses assessed by 3D sonography to MRI measurements and to investigate the impact of different rotation angles. A total of 126 fetuses between 20 and 40 weeks' gestation were measured by 3D sonography, and 27 of them were also assessed by MRI. The sonographic volumes were calculated by the rotational technique (virtual organ computer-aided analysis) with rotation angles of 6° and 30°. To evaluate the accuracy of 3D sonographic volumetry, percentage error and absolute percentage error values were calculated using MRI volumes as reference points. Formulas to calculate total, right, and left fetal lung volumes according to gestational age and biometric parameters were derived by stepwise regression analysis. Three-dimensional sonographic volumetry showed a high correlation compared to MRI (6° angle, R(2) = 0.971; 30° angle, R(2) = 0.917) with no systematic error for the 6° angle. Moreover, using the 6° rotation angle, the median absolute percentage error was significantly lower compared to the 30° angle (P < .001). The new formulas to calculate total lung volume in healthy fetuses only included gestational age and no biometric parameters (R(2) = 0.853). Three-dimensional sonographic volumetry of lung volumes in healthy fetuses showed a good correlation with MRI. We recommend using an angle of 6° because it assessed the lung volume more accurately. The specifically designed equations help estimate lung volumes in healthy fetuses.

Long-term follow-up of living-donor single-lobe lung transplantation for bronchiolitis obliterans in a four-year-old male: improvement of over-sized lung allograft

We report a long-term outcome of extremely oversized lung allograft. A left lower lobe transplantation from an adult donor was performed on a four-year-old recipient after left pneumonectomy. Lobar lung allograft volume was calculated to be approximately 180% of the recipient's predicted left thoracic capacity. Accordingly, the lung allograft was compressed to 47% of its original size immediately after transplantation. Initial postoperative functional recovery of the allograft was excellent despite this severe compression. As the patient grew physically, both his forced expiratory volume in 1 s (FEV(1)) and his left lung volume increased slowly but steadily during an observation period of two years and four months after transplantation.