Pulmonary Vascularity Research Articles

Pictorial essay. Current evaluation of the patient with abnormal visceroatrial situs.

Patients suspected of having derangement of solitus asymmetry should be evaluated individually to determine abdominal visceral and vascular arrangement and to investigate associated problems. This evaluation should begin with plain films to assess cardiac and gastric positions and pulmonary vascularity. Assessment of the bronchial branching patterns should be attempted in all cases. Sonography will delineate the presence or absence of splenic tissue and the anatomy and relationships of the cava and the portal vein. When no spleen is found and the pulmonary vascularity appears congested, a subdiaphragmatic total anomalous pulmonary venous connection should be suspected and verified. If there are splenuli in the retrogastric area, particular attention should be paid to the status of the gallbladder, especially in children who do not have congenital heart disease. Selective spleen scans can confirm the presence of splenic tissue. The high cost and sedation requirement of MR would suggest that it be reserved for cases in which sonography is unable to answer the pertinent questions.

Pulmonary vascularity in pediatric heart disease.

In children, analysis of pulmonary vascularity can provide useful information about cardiac and noncardiac abnormalities. The abnormal vascular patterns encountered in children with heart disease include (1) active engorgement, (2) passive congestion, (3) diminished pulmonary blood flow, (4) cephalad redistribution, and (5) unequal blood flow. Familiarity with these various patterns enables the clinician to produce relevant differential diagnoses for each. With additional study of the cardiac chambers, great vessels, and other radiographic findings, a specific diagnosis may often be suggested.

Partial anomalous pulmonary venous drainage and intact atrial septum with mitral stenosis: the paradox of a small shunt.

Clinical, hemodynamic, and angiographic features of 10 patients with partial anomalous pulmonary venous drainage, intact atrial septum, and rheumatic mitral stenosis have been presented. Seventeen patients with this combination of anomalies reported in the literature have also been reviewed. The clinical diagnosis of mitral stenosis was possible in each of our 10 cases. Partial anomalous pulmonary venous drainage and intact atrial septum in addition to mitral stenosis was clinically suspected in only four patients. The findings suggesting additional presence of partial anomalous pulmonary venous drainage and intact atrial septum in a patient with mitral stenosis include: wide variable splitting of the second sound, pulmonary ejection systolic murmur with or without a thrill, and radiological evidence of unilateral increase in pulmonary vascularity or unilateral hilar pulsations. Hemodynamic findings were characterized by a relatively modest left to right shunt (Qp/Qs:2.2 +/- 1.4). Elevated pulmonary vascular resistance was found in the anomalously draining as well as the normally draining lung segments (9.1 +/- 4.9 and 6.5 +/- 3.4 units, respectively, t = 1.32;NS). The mechanism of the unexpected high resistance in the anomalously draining lung segments permitting only a small left to right shunt is discussed.

Two-dimensional and Doppler Echocardiographic Evaluation of Heart Disease in the Neonate and Fetus

Two-dimensional and Doppler echocardiography has had a major impact on the diagnostic and therapeutic management of the newborn infant and fetus with a cardiovascular disorder. This article illustrates the use of the ultrasound techniques in the diagnosis of heart disease in the acyanotic newborn infant with a left-to-right shunt or ventricular outflow obstruction and the cyanotic infant with increased or decreased pulmonary vascularity. In addition, echocardiography has proven invaluable in the in utero diagnosis of cardiovascular abnormalities (structural or rhythm disturbances). This article also reviews the indications for and technical aspects of the fetal echocardiographic examination.

Pulmonary vascularity: radiographic considerations.

Distribution of pulmonary vascularity, as imaged on the routine chest radiograph, may be used as an accurate and sensitive indicator of underlying pathophysiologic change. The lungs, like most other human organ systems, have extensive reserve capability. Such reserves exist in terms of excess alveolar capacity in the pulmonary vascular bed to compensate for certain vascular alterations. This available vascular reserve is potentially available to compensate for situations in which there is an imbalance created between the size (capacity) of the vascular bed and the amount of blood (content) that it must accommodate. Such imbalances can result from decrease in the size of the vascular bed secondary to destruction or to normal physiologic response mechanisms or from an increase in the amount of blood coursing through the vascular bed. Either occurrence or combination of occurrences necessitates recruitment of available pulmonary vascular reserves. Recognition of this recruitment phenomenon and understanding of its underlying pathophysiologic significance enable relatively sophisticated diagnostic interpretation of the chest radiograph.

Congenital pulmonary vein stenosis: a radiographic study.

Seven patients with congenital pulmonary venous stenosis were retrospectively evaluated. Chest radiographs and pulmonary angiograms were interpreted without knowledge of anatomic findings, and results were correlated with autopsy data. Bilateral foci of stenosis of varying severity were found in all patients but occurred with greater frequency and severity in the left-sided pulmonary veins. Chest radiographic findings revealed asymmetric pulmonary vascularity in all patients. Shunt vascularity was seen in three right upper zones and three right lower zones but was not observed in any of the left lung zones. In seven patients angiograms revealed asymmetry in the size and number of pulmonary arterial branches. Arterial vascularity was increased in two right upper zones and four right lower zones but was not increased in any of the left lung zones. Pulmonary veins from 22 zones were visualized. Pulmonary venous opacification was delayed, asymmetric, and asynchronous in the majority. Venoatrial stenosis was seen in veins from 18 zones. Congenital pulmonary vein stenosis can be suspected based on chest radiographic findings of asymmetry of pulmonary vascularity between both lungs as well as regional discrepancies in the vascularity within each lung. Pulmonary angiography can support the diagnosis.

The pulmonary vascularity in patients with pulmonary atresia and ventricular septal defect

Pulmonary vascularity in patients with pulmonary atresia and ventricular septal defect varies widely and depends on the anatomic and functional status of the main pulmonary artery and the left and right pulmonary arteries in their central, hilar and intrapulmonary segments. In pulmonary atresia and ventricular septal defect, there are three main patterns of pulmonary vascularity seen on the plain chest radiograph: 1, diminished pulmonary vascularity; 2, plethora with increased pulmonary blood flow often associated with horizontal arteries suggesting aortopulmonary collaterals; and 3, asymmetric vascularity indicating stenosis within the pulmonary arterial tree. A mottled appearance at the periphery of the lungs represents pleural-pulmonary collateral circulation. The anatomic and functional status of the pulmonary circulation can be demonstrated by opacification of the channels that supply the pulmonary arterial system either by selective or nonselective methods or through pulmonary venous wedge retrograde angiography. [See figure in the PDF file]

Magnetic resonance imaging in cystic fibrosis

A clinical dilemma in patients with cystic fibrosis is the determination of the nature of linear areas of decreased aeration in the lungs. It is difficult using chest roentgenograms or even computed tomography to differentiate atelectasis, mucoid impacted bronchi, or peribronchial inflammatory disease from normal pulmonary vascularity. Magnetic resonance imaging is a noninvasive sensitive means that provides the distinction. Pulmonary vessels are easily identified, because with the spin-echo sequence that we use, the rapidly flowing blood within the vessels has no signal intensity. In contradistinction, mucoid-impacted bronchi appear as high-intensity linear branching structures. Peribronchial inflammatory disease appears as curvilinear areas of high intensity, representing inflammatory edema, around central lucencies representing bronchi.

CT of localized lucent lung lesions

OCALIZED lucent lung lesions depicted by the standard chest radiograph are relatively rare, except for those occurring in patients with generalized chronic obstructive pulmonary disease. The standard chest radiograph provides an inexpensive, sensitive means for determining the presence of most clinically significant focal, thinwalled, sharply demarcated areas of avascularity. Some of the limitations of the chest radiograph in this regard are: (a) it permits only a broad differential diagnosis; (b) it sometimes does not define the full extent of disease; (c) it sometimes does not allow localization to the precise anatomic compartment; and (d) it sometimes fails to demonstrate a small accompanying lesion adjacent to or remote from the lesion under investigation. Even with these radiographic limitations, other available data including clinical history, pulmonary function studies, and laboratory results significantly enhance the radiologist’s diagnostic accuracy. For those few but potentially life-threatening localized lucent lesions, more aggressive and risky procedures must be employed for diagnostic or therapeutic purposes, such as biopsy, chest tube insertion, or even thoracotomy. With the advent of CT, considerable improvement in the overall diagnostic accuracy of these localized lucent lung lesions has been obtained. By defining more precisely the location, margins, thickness, contents, and overall configuration, CT significantly narrows the differential diagnosis. If the CT characteristics of the lesion are nondiagnostic, interventional procedures such as bronchoscopy or percutaneous aspiration biopsy can more easily be obtained by CT guidance. The CT cross-sectional display and geometric resolution sometimes more clearly define previously recognized standard radiographic features of complicated versus uncomplicated and benign versus malignant lucent lung lesions. In addition, CT uniquely distinguishes pleural from subpleural lucent lesions. Probably the most important role CT serves is in demonstrating occult opaque or lucent lesions in proximity to the original lucency or in the contralateral lung. The presence or absence of abnormal pulmonary vascularity, adenopathy, calcification, or small pleural

Pulmonary Vascularity on the Plain Chest Radiograph

The most important factor in the interpretation of any heart lesion is the radiographic appearance of the pulmonary vessels (vascularity) and lung parenchyma. The author discusses several abnormalities; he focuses particularly on pulmonary venous hypertension.

Surgical Treatment of Cor Triatriatum

Six patients with cor triatriatum underwent surgical correction. They ranged from 1.5 to 93 months old (mean, 22 months). Congestive heart failure was present in 3 patients. Cardiomegaly and increased pulmonary vascularity were evident roentgenographically in all patients. Cardiac cineangiography demonstrated the subdividing left atrial membrane in 5 patients and suggested the correct diagnosis by revealing an abnormal configuration of the left atrium in the other patient. The opening in the anomalous left atrial membrane was stenotic in every instance. The proximal left atrial chamber communicated with the right atrium through an atrial septal defect in 5 patients and with the systemic venous circuit through a persistent left superior vena cava in the other patient, in whom the atrial septum was intact. A right atrial–transseptal approach provided ample exposure for complete excision of the obstructing membrane and repair of the atrial septum in all patients. One patient died of low cardiac output during the early postoperative period. The other 5 are alive and well at an average of 48 months after operation.

Patent Ductus Arteriosus

Twenty-four of 230 patients with patent ductus arteriosus had hypovascularity and hyperlucency in the left lung on preoperative chest roentgenograms. Two of the 24 patients died shortly after operation, and one was unavailable for follow-up. During the postoperative course (mean, three years), roentgenograms of eight of the remaining 21 patients showed persistent, unequal pulmonary vascularity and hyperlucent left lung, with no evidence of air trapping, and two patients had diminished volume of the hyperlucent left lung compared with that of the right lung.

Lung curve indicating a left-to-right shunt in an infant with a large heart

A 1.5-mo-old boy had episodes of choking accompanied by becoming blue. There was a loud holosystolic murmer heard over the entire precordium. The chest film, Fig. 1, showed a large heart with increased pulmonary vascularity. A shunt study was performed by injecting a 2-mCi bolus of 99mTcDTPA via the left external jugular vein. Time activity histograms at halfsecond intervals, normalized to maximum counts for each histogram, are shown in Fig. 2 for the superior vena cava and left lung. In addition, the first portion of the original lung curve (B) has been extrapolated using a least squares fit of a gamma variate function (C). 1'2 The difference between this idealized curve and the original lung curve is shown in Fig. 2D. Finally, the gamma variate fit of this difference histogram is shown in Fig. 2E. The area under curve C represents the total circulation through the lung, Qp. The area under curve C (pulmonary flow) minus the area under curve E, the shunt flow, represents the systemic blood flow, Qs. The ratio of these areas (Area C) / (Area C Area E) gives the Qp:Qs ratio, which in this case was 1.9:1. It is essential for validity of the technique that a good bolus be achieved. This is shown in the superior vena cava curve in Fig. 2A. The causes for left-to-right shunt in an infant with a large heart are listed below. 3 5 This gamut roughly corresponds to the listing in Edwards et al. 5 of the groupings, Increased pulmonary arterial vasculature; cyanosis absent; (A) extracardiac left-to-right shunts, and (B) intracardiac left-to-right shunts. In this particular case, a brain scan performed because of a bruit heard in the head (Fig. 3) serves to remind us that uncommon extracardiac left-to-right shunts can mimic the more common entities responsible for this finding. 6 The scan shows a left-sided arteriovenous malformation, a portion of which drains to the deep system and causes aneurysmal dilatation of the vein of Galen. This aneurysmal dilatation of the vein of Galen should be separated from a primary aneurysm of the vein of Galen. The very large heart seen in a newborn infant should raise the possibility of a systemic arteriovenous shunt. The shunting in this case occurs with the circulation in fetal condition in utero without waiting for a fall in pulmonary vascular resistance. Thus, the heart has ample time to enlarge and fail by the time of birth.

Recognition of developing left ventricular outflow tract obstruction in complete transposition of the great arteries.

In the months following balloon atrial septostomy for complete transposition of the great arteries (TGA), clinical deterioration is often ascribed to closure of the septostomy. Of 16 neonates with TGA, 5 showed early clinical deterioration. Each had an adequate septostomy at operation. Deterioration was characterized clinically by increasing cyanosis and radiographically by progressive diminution in pulmonary vascularity. Subsequent catheterization and axial cineangiography demonstrated that pulmonary flow had decreased, probably secondary to a progressive form of left ventricular outflow tract obstruction (LVOTO) characterized by bulging of the ventricular septum with mitral valve apposition. It is important to recognize this phenomenon as an aid in predicting which children will need early surgical intervention.

The surgical management of vascular abnormalities associated with supravalvular aortic stenosis

Fourteen patients underwent operative repair of supravalvular aortic stenosis (SVAS) in this hospital during the past 17 years. There were seven female and seven male subjects. The patients ranged in age from 5 to 23 years at the time of the operation. Only two of the patients were asymptomatic. Twelve described exercise intolerance. Four of these 12 also reported syncope or angina. In all patients, a loud systolic murmur was heard over the right second intercostal space. In one patient, a systolic ejection click and a murmur of aortic regurgitation were noted. In another, a murmur of aortic regurgitation was heard. In three patients, blood pressure was higher on the right arm than the left by at least 20 mm. Hg. Mild cardiac enlargement was noted on the thoracic roentgenogram of eight patients, but in only one of them was pulmonary vascularity increased. Electrocardiograms revealed left ventricular hypertrophy in each patient, with T wave inversion in the left precordial leads in seven patients. There were two anatomic forms of SVAS; hourglass (nine cases), and tubular (five cases). The pressure gradient across the supravalvular area ranged from 45 to 125 mm. Hg with a mean gradient of 85 mm. Hg. In 10 patients, abnormalities of the coronary arteries or aortic valve or both were noted at the time of operation. In four patients, aortic valve commissurotomy, dilatation of the coronary ostia, excision of hypertrophic intima, and/or saphenous vein bypass were performed, in addition to repair of SVAS. In those nine patients with associated stenotic lesion of the aortic arch and descending aorta, and of those six patients with peripheral pulmonary vascular stenosis, no surgical repair was attempted. There were four deaths, two early and two late. All deaths occurred in patients with tubular hypoplasia. The survivors are asymptomatic. We have made the following conclusions: (I) Repair of SVAS secondary to tubular hypoplasia is less successful than repair of stenosis secondary to the discrete, hourglass type deformity; (2) the correction of associated aortic stenosis or reflux or both should be deferred until the results of the SVAS repair have been determined: and (3) ostial obstruction of the coronary arteries should be corrected.

Persistence of the fetal circulation: radiologic considerations

Persistence of the fetal circulation is a recently recognized cause of severe cyanosis in newborn full term infants. Abnormally elevated pulmonary vascular resistance apparently stimulated by hypoxia, acidosis, and/or hyperviscosity results in cyanosis due to large right-to-left shunts through persistent fetal channels (patent foramen ovale and patent ductus arteriosus). Initial chest radiographs demonstrate clear lungs, decreased, normal, or mildly prominent pulmonary vascularity, and normal to moderately enlarged cardiac silhouettes. Angiocardiography, when required to rule out cyanotic congenital heart disease, demonstrates normal intracardiac anatomy, normal great vessel relationships, and right-to-left shunting across the patent foramen ovale and patent ductus arteriosus. Significant tricuspid regurgitation occurs in some of these infants, associated with variable right ventricular dilatation; the left ventricle is normal. The majority of babies with this condition ultimately survive. Treatment consists of intensive care including oxygen therapy and correction of acidosis. Vasodilators such as tolazoline may be helpful.

Displaced Mediastinum and Heart Murmur

History A 6-year-old boy had been referred at age 22 months for evaluation of a grade 2/6 systolic ejection murmur at the upper right sternal border. Cardiac catheterization showed mild pulmonic valvular stenosis, with main pulmonary artery pressure of 35/12 mm Hg and right ventricular pressure of 32/5 mm Hg. Cardiovascular history was negative for tachypnea, cyanosis, or squatting. Diagnosis Congenital absence of the left pulmonary artery. Comment The chest roentgenogram (Fig 1) shows the heart and mediastinal structures displaced into the smaller left hemithorax. The left hilum appears small, and pulmonary vascularity is slightly diminished on the affected side. Cardiac size is within normal limits, but a right-sided aortic arch is noted. Pulmonary angiography (Fig 2) illustrates absence of the left pulmonary artery. Aortic angiography (Fig 3) demonstrates a right-sided aortic arch with bronchial arterial collateral supply to the left lung. No additional cardiovascular anomalies were shown. Pulmonary vascular

Neonatal polycythemia and chest roentgenograms.

Chest roentgenograms of 34 newborns with a hematocrit of 75 or more at the age of 12 hours were studied. An analysis was made of the findings during the first four days of life and the results were compared with those of 18 newborns with a hematocrit of 65 or less. The cardiothoracic ratio (CTR) was found to be greater in the polycythemic infants than in the non-polycythemic infants, and greatest of all in infants with symptomatic polycythemia. Prominent pulmonary vascularity and pulmonary hyperaeration were seen more often in polycythemic newborns than in non-polycythemic infants. Eleven infants in the polycythemic group and three in the non-polycythemic group had some symptoms or signs.

Left ventricular function in tricuspid atresia. Angiographic analysis in 28 patients.

Thirty-one left ventricular (LV) biplane angiograms were performed in 28 patients with tricuspid atresia. Measurements of left ventricular end-diastolic volume (LVEDV) and left ventricular end-systolic volume were obtained by the modified Simpson's rule and systolic ejection fraction (EF) calculated. Left ventricular volumes and ejection fractions were also obtained in 19 control patients with no significant heart disease. The patients with tricuspid atresia were classified according to the appearance of the pulmonary vascularity on initial radiologic examination: Group A, decreased pulmonary vascularity; Group B, increased pulmonary vascularity. In the 13 group A infants who were unoperated, LVEDV was increased and EF mildly diminished. In the group B patients LVEDV was increased and EF normal. In the 12 group A patients with surgical shunts LVEDV was elevated. The five group A patients with long-standing systemic artery to pulmonary artery anastomoses (greater than 10 years) showed the largest LVEDV and the poorest EF. The angiographic data indicate that patients with tricuspid atresia experience significant LV dysfunction as a consequence of longstanding LV volume overload. The early detection of LV dysfunction may be an indication for a right ventricular bypass procedure in these patients.

Tricuspid atresia: Clinical course in 101 patients

The clinical profile and course of 101 patients with tricuspid atresia seen at the Children's Hospital Medical Center, Boston, were reviewed; the electrocardiograms, hemodynamic data, associated anomalies, complications of the malformation and surgical results were outlined and a definition of anatomic types and radiologic groups formed in order to facilitate therapeutic decisions. Overall survival to 15 years of age was approximately 50 percent. Tricuspid atresia type I (normally related great arteries), group A (decreased pulmonary vascularity) was the most frequent category (54 percent); without surgery, these patients had only a 10 percent chance of survival beyond the 1st year of life. Surgical intervention improved chance of survival to 15 years of age to 50 percent. Overall surgical mortality was 23 percent. The Waterston shunt is the procedure of choice in symptomatic small infants with diminished pulmonary flow (group A). Type II patients with increased pulmonary blood flow (group B) would benefit from a pulmonary arterial band. In contrast, patients with group B, type I atresia would rarely need a pulmonary arterial band. Patients with spontaneously changing hemodynamics (group C) usually require a shunt later in life than those in group A, with more favorable operative results. Our experience indicates the continued need of early surgical palliation. New surgical approaches, such as the right atrial-pulmonary arterial anastomosis, may result in a more prolonged survival.