Hyperlucent lung secondary to homocystinuria

At 23 months of age, one of a pair of monozygotic twins with radiographic unilateral hyperlucent lung was evaluated by radionuclide ventilation/perfusion pulmonary studies, which revealed a ventilation/perfusion mismatch of an entire lung. This twin died, and autopsy revealed pulmonary arterial thrombosis and histological changes compatible with homocystinuria, which was subsequently shown to be present in the surviving twin as well. A ventilation/perfusion lung scan of the surviving twin revealed multiple ventilation/perfusion mismatched defects, suggestive of pulmonary embolism. The presenting manifestation of homocystinuria in these patients was the pulmonary thrombotic disease. Neither twin had any other stigmata of homocystinuria at the time of initial presentation.     

The immune response and immunopathology in infection with Schistosoma mansoni: a key role of major egg antigen Sm-p40

Two women aged 88 and 70 and a man aged 90 years had become increasingly confused and short of breath over a period of a few weeks. Blood gas analysis revealed serious hypoxia. For lack of an explanation of the respiratory insufficiency, pulmonary emboli were assumed; this assumption could be confirmed by ventilation perfusion scintigraphy. Parallel with the treatment of the emboli the delirium cleared. Because of restlessness, initial treatment with low molecular weight heparin subcutaneously twice daily was preferred.     

A comparison of SPECT and planar ventilation perfusion lung scanning

In order to define the role of Single Photon Emission Computed Tomography (SPECT) in the diagnosis of pulmonary embolus; SPECT and Planar ventilation and perfusion lung studies were performed consecutively on eleven patients referred with suspected embolus. Three patients were shown to have 'high probability' ventilation perfusion mismatches. SPECT imaging allowed segmental localisation of the perfusion defect and revealed additional defects not seen on planar scans. SPECT lung study was performed with minimal technical difficulty and was well tolerated by all patients studied. SPECT is likely to become the method of choice for investigating patients referred with suspected pulmonary embolus.     

A comparative analysis of pulmonary perfusion scans with pulmonary angiograms

Pulmonary angiograms and pulmonary lung perfusion scans on 162 patients with pulmonary embolism were comparatively analyzed. Among the expert angiographic panel members who independently evaluated the studies there was consistent agreement on the diagnosis, size of the emboli, and severity. Consistency of agreement among the expert pulmonary lung perfusion scan panelists was considerably less. These data demonstrate that, in addition to the lack of specificity of the lung perfusion scan for the diagnosis of pulmonary thromboemboli, there is a considerable problem of interpretation in this patient population.     

Value of perfusion lung scan in the diagnosis of pulmonary embolism: results of the Prospective Investigative Study of Acute Pulmonary Embolism Diagnosis (PISA-PED)

To assess the value of perfusion lung scan in the diagnosis of pulmonary embolism, we prospectively evaluated 890 consecutive patients with suspected pulmonary embolism. Prior to lung scanning, each patient was assigned a clinical probability of pulmonary embolism (very likely, possible, unlikely). Perfusion scans were independently classified as follows: (1) normal, (2) near-normal, (3) abnormal compatible with pulmonary embolism (PE+: single or multiple wedge-shaped perfusion defects), or (4) abnormal not compatible with pulmonary embolism (PE-: perfusion defects other than wedge-shaped). The study design required pulmonary angiography and clinical and scintigraphic follow-up in all patients with abnormal scans. Of 890 scans, 220 were classified as normal/or near-normal and 670 as abnormal. A definitive diagnosis was established in 563 (84%) patients with abnormal scans. The overall prevalence of pulmonary embolism was 39%. Most patients with angiographically proven pulmonary embolism had PE+ scans (sensitivity: 92%). Conversely, most patients without emboli on angiography had PE- scans (specificity: 87%). A PE+ scan associated with a very likely or possible clinical presentation of pulmonary embolism had positive predictive values of 99 and 92%, respectively. A PE- scan paired with an unlikely clinical presentation had a negative predictive value of 97%. Clinical assessment combined with perfusion-scan evaluation established or excluded pulmonary embolism in the majority of patients with abnormal scans. Our data indicate that accurate diagnosis of pulmonary embolism is possible by perfusion scanning alone, without ventilation imaging. Combining perfusion scanning with clinical assessment helps to restrict the need for angiography to a minority of patients with suspected pulmonary embolism.     

Bilateral pulmonary artery aneurysms in a patient with Behcet syndrome: evaluation with radionuclide angiography and V/Q lung scanning

The case of a 14-year-old girl with Behcet syndrome is described. Besides painful and recurrent oral ulcerations, the patient had a cough and intermittent hemoptysis. The initial chest roentgenogram revealed bilateral parahilar opacities. CT and MRI scans of the thorax showed bilateral thrombosing aneurysms of the pulmonary arteries. Pulmonary blood flow imaging was performed after technegas ventilation lung scanning and Tc-99m MAA injection using a first-pass radionuclide angiography procedure. Altered blood flow in the left pulmonary artery was shown. Bilateral and well-defined ventilation/perfusion mismatched areas suggested a high probability of pulmonary embolism. Little additional information was obtained on subsequent contrast pulmonary angiography. The high incidence of pulmonary artery hypertension and associated vascular injury risk makes pulmonary angiography an unsafe procedure in patients with pulmonary Behcet syndrome. The need for pulmonary angiography could be obviated in such cases with the use of high-precision MRI and ventilation/perfusion lung scanning, including radionuclide pulmonary angiography.     

A case of meningioma appearing as a cyst with solid parietal nodule. Evaluation using computerized tomography and magnetic resonance

Bilateral sequential lung transplantation was complicated by pulmonary artery anastomotic stenosis and bilateral pulmonary thromboemboli. Pulmonary artery thrombus was eliminated by intrathrombotic but not by systemic administration of urokinase. The pulmonary emboli resulted in localized pulmonary infarctions, supporting the need for thrombolytic intervention to restore pulmonary perfusion in the absence of collateral bronchial blood flow after lung transplantation. Pulmonary artery stenosis was relieved by endovascular stenting, avoiding an early reoperative procedure. This case suggests that direct administration of thrombolytic agent may be superior to intravenous administration in the treatment of pulmonary thromboemboli. Pulmonary arterial anastomotic stenoses after lung transplantation can be relieved by endovascular procedures.     

Two cases of Swyer-James syndrome

Case 1: 55-year-old male was admitted to our hospital for further examination of increased transparency of X-ray in the left lower lung. He had history of pneumonia in his childhood. Left bronchography revealed mild cylindrical bronchi-ectasia in the proximal bronchi but poor filling by contrast in the peripheral bronchi. Case 2: 61-year-old male was referred to our hospital with palpitation and dyspnea. Chest X-ray film revealed hyperlucency of the left lower lung. The ventilation scan showed a marked decrease in ventilation to the left lung and air trapping was present in the left lung. The perfusion scan showed a matched decrease in blood supply to the left lung. In both cases, pulmonary arteriogram showed narrowed and withered-tree-like left pulmonary arteries. From these clinical findings, we diagnosed these two cases as Swyer-James syndrome. We are reporting two cases of Swyer-James syndrome and describing the clinical feature, differential diagnosis and etiology of the syndrome.     

Bronchial adenoma resection with relief of hypoxic pulmonary vasoconstriction

Experimental airway obstruction is known to cause reflex pulmonary artery constriction, but clinical documentation of reversible bronchial obstruction and vasoconstriction is rare. A soft bronchial adenoma obstructed the left main bronchus, and scans showed minimal ventilation and perfusion on the left. Gas aspirated from beyond the tumor was hypoxic. The adenoma was removed and the lung left intact by means of a skin graft in the bronchial wall. Four months later, pulmonary function was normal, and both ventilation and perfusion of the left lung were normal. Reflex pulmonary vasoconstriction resulting from alveolar hypoxia minimizes systemic hypoxemia and also minimizes alveolar tissue hypoxia in the lung itself. The reflex is seen most frequently in perfusion scans in patients with chronic airways disease. This case in important in that it documents reversal of vasoconstriction after ventilation was restored.     

The effect of nitroglycerine medication on the arterial oxygen pressure in obstructive lung disease

Nitroglycerine gains increasing interest because of its favourable hemodynamic effects in patients with left heart failure, especially in those with coronary heart disease. The drug-induced vasodilatation and lowering of pulmonary arterial pressure, is followed by a redistribution of lung perfusion which occasionally may be deletarious. It is shown that in patients with obstructive lung disease, a significant drop in arterial oxygen tension may be observed. This could be due to increased perfusion of the lung, without a concommitant augmentation of ventilation, which results in an increase of right to left-shunt.     

Pulmonary embolization causes hypoxemia by redistributing regional blood flow without changing ventilation

To explore mechanisms of hypoxemia after acute pulmonary embolism, we measured regional pulmonary blood flow and alveolar ventilation before and after embolization with 780-micrometers beads in five anesthetized, mechanically ventilated pigs. Regional ventilation and perfusion were determined in approximately 2.0-cm3 lung volumes by using 1-micrometers-diameter aerosolized and 15-micrometers-diameter injected fluorescent microspheres. Hypoxemia after embolization resulted from increased perfusion to regions with low ventilation-to-perfusion ratios. Embolization caused an increase in perfusion heterogeneity and a fall in the correlation between ventilation and perfusion. Correlation between regional ventilation pre- and postembolization was greater than correlation between regional perfusion pre- and postembolization. The majority of regional ventilation-to-perfusion ratio heterogeneity was attributable to changes in regional perfusion. Regional perfusion redistribution without compensatory changes in regional ventilation is responsible for hypoxemia after pulmonary vascular embolization in pigs.     

Experimentally induced nasal hypersecretion does not reduce the efficacy of intranasal levocabastine

Pulmonary tumor embolism is an often missed antemortem diagnosis in patients with cancer and respiratory failure. Although rare, this complication is an important cause of additional morbidity. Referred for radionuclide pulmonary perfusion and ventilation scintigraphy, a typical pattern of multiple subsegmental peripheral defects on perfusion lung scanning without matching ventilation defects, suggesting a high probability of pulmonary thromboembolism, often leads to false conclusions. We present a case of bilateral multiple subsegmental mismatched defects in lung ventilation perfusion scintigraphy, where autopsy confirmed the diagnosis of pulmonary tumor embolism, secondary to an undifferentiated ductal type adenocarcinoma of the pancreas. Pulmonary tumor embolism is an entity to keep in mind in patients treated for carcinoma presenting with (sub) acute dyspnea.     

Pulmonary histoplasmosis in a Japanese male: report of a case

A case of pulmonary histoplasmosis, which is rare in Japan, is reported herein. A 43-year-old man who had worked in Mexico for 2 years and had come back to Japan 3 months earlier, presented at our hospital because of an abnormal shadow on his chest roentogenogram with no symptoms. His chest roentogenogram as well as chest computed tomograms revealed a 2-cm-diameter nodule in the anterior basal segment of his right lung and an enlargement of the subcarinal lymph node. Although these pictures seemed to indicate an advanced lung cancer, no malignant cells were found based on the brushing cytology findings after bronchoscopy. An exploratory thoracoscopic tumor resection and biopsy of the enlarged lymph node led to a histological diagnosis of an abscess due to histoplasma. The hospital course was uneventful. Postoperatively, amphotericin B was administered for 1 year. This is the eighth case of pulmonary histoplasmosis reported in Japan. A pulmonary nodule together with mediastinal lymphoadenopathy seems to be characteristic in these patients. Histoplasmosis should therefore be considered in the differential diagnosis, since overseas travel has now become common-place for the Japanese.     

Quantification of flumequine enantiomers in plasma by high-performance liquid chromatography

A 62-year-old woman with pulmonary hypertension underwent mitral valve re-replacement through right thoracotomy. Severe adhesion occurred to the right lung. During pleural dissection the lung collapsed under single-lung ventilation, rapidly elevated pulmonary vascular resistance caused hemodynamic instability. When pulmonary hypertension is preoperatively present, this approach under single-lung ventilation is not recommended.     

The adaptive reactions of the cardiorespiratory system in chronic bronchitis and its premorbid forms

AIM: Investigation of pulmonary ventilation, blood flow and cardiodynamics in subjects at risk of chronic nonspecific pulmonary disease (CNPD), prebronchitis (PB) and chronic bronchitis (CB). MATERIALS AND METHODS: 118 workers exposed to toxico-chemical factors underwent zonal rheography. RESULTS: At early stages of CB marked disorders of pulmonary ventilation and blood flow in the lungs were revealed. These disorders in subjects with threatened CNPD were regional and accompanied by a moderate increase in power inputs of the cardiorespiratory system. The maintenance of adequate pulmonary exchange in patients with PB entailed functional tension of the respiratory and cardiovascular systems that contributed to decompensation of adaptive mechanisms and occasionally to development of rheographic signs of pneumosclerosis in the lung zones with damaged ventilation and low perfusion of the pulmonary vessels. CONCLUSION: Overloading and decompensation of respiratory and cardial mechanisms of gas exchange regulation in the lungs in response to external damage may lead to development of myocardiodystrophy and pneumosclerosis which appear to be the "price of adaptation".     

Internal carotid artery dissection causes hypoglossal nerve palsy: CT, MRI, and angiographic findings

Systemic thrombolytic therapy for pulmonary embolism (PAE) is an established and common procedure. Due to increased risk, however, it is not much used in pulmonary embolism combined with thrombotic mass in the right ventricle. We applied it in a 59-year-old male patient with small intracardiac thrombus in the right ventricle (diameter = 1 cm) and peripheral pulmonary embolism whose diagnosis was obtained with transthoracal echocardiography (TTE) and helix lung CT. Twelve hours after thrombolytic treatment, helix lung CT scan showed a reduction in the size of the pulmonary embolism and no thrombotic masses in the right ventricle. In this patient with a small cardiac thrombus and rather peripheral pulmonary emboli, a systemic thrombolytic therapy proved to be effective and safe.     

Evaluation of the respiratory function by lung scintigraphy in patients candidates for pulmonary resection

Sixty-one patients undergoing pulmonary resection were studied pre- and post-operatively by spirometry, arterial gas determination, and quantitative ventilation/perfusion lung scanning. Our results showed that ventilation and/or perfusional scintigraphic scanning is currently the most reliable method in identifying patients at risk for postoperative respiratory insufficiency. Specifically, this technique was successful in detecting pulmonary areas other than those to be resected presenting ventilation or perfusional abnormalities. Therefore, the technique is particularly useful in predicting residual pulmonary function.     

Effect of pulmonary artery stenoses on the cardiopulmonary response to exercise following repair of tetralogy of Fallot

Data from exercise tests, echocardiograms, and lung perfusion scans were analyzed to determine whether the excessive minute ventilation (VE) often encountered among patients with tetralogy of Fallot is due to ventilation-perfusion mismatch secondary to branch pulmonary artery stenoses. Patients with branch PA stenoses had lower peak oxygen consumptions and higher VE during exercise than did patients without stenoses, and a strong correlation existed between the degree of pulmonary blood flow maldistribution on lung perfusion scan and the amount of excessive VE during exercise.     

Asymmetric distribution of the pulmonary blood flow between the right and left lungs in d-transposition of the great arteries

Pulmonary angiograms, radionuclide lung images and chest roentgenograms were evaluated regarding the incidence, magnitude and natural evolution of maldistribution of the pulmonary blood flow between the lungs in 63 patients with dextrotransposition of the great arteries. Approximately half of these patients had some degree of greater perfusion of the right relative to the left lung. A significant correlation was demonstrated between the incidence of this maldistribution of blood flow and the angulation between the main and the right pulmonary arteries. For any given angulation between these vessels, additional pulmonary stenosis increased the incidence of disparity in perfusion. Our observations suggest the following developmental mechanisms: The maldistribution in flow results from the abnormal rightward inclination of the main pulmonary artery in the transposition malformation which straightens the flow axis from the main to the right pulmonary artery. Under these circumstances the momentum of the blood in the main pulmonary artery carries the blood preferentially into the right pulmonary artery. This momentum is increased when there is stenosis of the left ventricular outflow tract. Consequent differences in the mechanical properties of the two pulmonary vascular beds can increase this maldistribution. The disparity in perfusion between the lungs is not present in newborns with d-transposition, appears to be progressive in severity and in time may result in almost complete cessation of effective perfusion of the left lung. The effect of the Mustard operation on this abnormality of flow is discussed.     

Echocardiographic evidence of aortopulmonary collaterals in premature infants after closure of ductus arteriosus

Aortopulmonary collaterals occur in a variety of congenital heart diseases, in chronic pulmonary infection and abscesses, in association with lung tumors, and after multiple pulmonary emboli. In patients with congenital cyanotic heart disease aortopulmonary collaterals mainly occur in conditions with reduced pulmonary blood flow. We investigated 12 preterm low-birth-weight infants, gestational age 29.3+/-3.3 weeks, with respiratory failure who suffered from moderate to severe chronic lung disease after a period of mechanical ventilation. All patients developed aortopulmonary collaterals after closure of a patent ductus arteriosus. Aortopulmonary collaterals could be displayed clearly by color Doppler echocardiography and originated mainly from the descending aorta or the aortic arch. Hypoxic and hypercapnic episodes favored the development of aortopulmonary collaterals, which disappeared after pulmonary hemodynamics and respiratory function had improved. In only one patient coiling of a large col lateral vessel had to be performed. Systemic-to-pulmonary collateral vessels potentially aggravate chronic lung disease by increasing collateral pulmonary blood flow and reducing lung compliance. We conclude that aortopulmonary collaterals occur in bronchopulmonary dysplasia and can cause major problems in ventilated premature infants. Echocardiographic evaluation is important to prevent aggravation of chronic lung disease of infants at risk.