Comparative Analysis of Lung Perfusion Scan and SPECT/CT for the Evaluation of Functional Lung Capacity / 대한핵의학회잡지

PURPOSE: This study aimed to compare lung perfusion scan with single photon emission computed tomography/computed tomography (SPECT/CT) for the evaluation of lung function and to elucidate the most appropriate modality for the prediction of postoperative lung function in patients with lung cancer.METHODS: A total of 181 patients underwent Tc-99m macroaggregated albumin lung perfusion scan and SPECT/CT to examine the ratio of diseased lung and diseased lobe. Forty-one patients with lung cancer underwent both preoperative and postoperative pulmonary function tests within 1 month to predict postoperative pulmonary function. Predicted postoperative forced expiratory volume in 1 s (ppoFEV₁) was calculated by the % radioactivity of lung perfusion scan and SPECT, and the % volume of the residual lung, assessed on CT.RESULTS: The ratios of diseased lung as seen on lung perfusion scan and SPECT showed significant correlation, but neither modality correlated with CT. The ratios of the diseased lung and diseased lobe based on CT were higher than the ratios based on either perfusion scan or SPECT, because CT overestimated the function of the diseased area. The lobar ratio of both upper lobes was lower based on the perfusion scan than on SPECT but was higher for both lower lobes. Actual postoperative FEV₁ showed significant correlation with ppoFEV₁ based on lung perfusion SPECT and perfusion scan.CONCLUSIONS: We suggest SPECT/CT as the primary modality of choice for the assessment of the ratio of diseased lung area. Both perfusion scan and SPECT/CT can be used for the prediction of postoperative lung function.

Estudio de la perfusión pulmonar posterior al cierre percutáneo del conducto arterioso permeable utilizando el dispositivo Amplatzer Duct Occluder en niños / Lung perfusion studies after percutaneous closure of patent ductus arteriosus using the Amplatzer Duct Occluder in children

Objetivo: La reducción en la perfusión pulmonar se ha descrito tras el cierre percutáneo del conducto arterioso permeable con varios dispositivos. Evaluamos la perfusión pulmonar posterior al cierre percutáneo del conducto arterioso con el dispositivo Amplatzer Duct Occluder utilizando la gammagrafía pulmonar de perfusión. Métodos: Treinta pacientes con oclusión transcatéter exitosa del conducto arterioso permeable utilizando el dispositivo Amplatzer Duct Occluder fueron incluidos en este estudio. La gammagrafía pulmonar de perfusión se realizó 6 meses después del procedimiento. Las velocidades de flujo máximo y la protrusión del dispositivo fueron analizadas por ecocardiografía Doppler. Una perfusión pulmonar izquierda < 40% se consideró anormal. Resultados: El implante del dispositivo fue exitoso en todos. La media de perfusión hacia el pulmón izquierdo fue de 44.7 ± 4.9% (37.8-61.4). Cinco pacientes (16.6%) mostraron disminución en la perfusión pulmonar izquierda. Tanto la edad y el peso bajo, así como la longitud del conducto arterioso y la relación diámetro mínimo y máximo con la longitud del conducto arterioso fueron estadísticamente significativos en los pacientes con anomalías de la perfusión pulmonar. Se observó protrusión del dispositivo en 6 pacientes con una velocidad de flujo máximo mayor en la arteria pulmonar izquierda. Conclusión: La perfusión pulmonar izquierda puede comprometerse tras el cierre percutáneo del conducto arterioso con el Amplatzer Duct Occluder. El aumento en la velocidad de flujo en el origen de la arteria pulmonar izquierda puede ser un pobre indicador de la reducción en la perfusión pulmonar y puede ocurrir en ausencia de protrusión del dispositivo.

Objective: The closure of patent ductus arteriosus with multiple devices has been associated with a reduction in lung perfusion. We evaluated the pulmonary perfusion after percutaneous closure of patent ductus arteriosus with the Amplatzer Duct Occluder device using perfusion lung scan. Methods: Thirty patients underwent successful percutaneous patent ductus arteriosus occlusions using the Amplatzer Duct Occluder device were included in this study. Lung perfusion scans were preformed 6 months after the procedure. Peak flow velocities and protrusion of the device were analyzed by Doppler echocardiography. A left lung perfusion < 40% was considered abnormal. Results: The device implantation was successful in all patients. Average perfusion of left lung was 44.7 ± 4.9% (37.8-61.4). Five patients (16.6%) showed decreased perfusion of the left lung. Age, low weight, the length of the ductus arteriosus and the minimum and maximum diameter/length of the ductus arteriosus ratio were statistically significant in patients with abnormalities of lung perfusion. It was observed protrusion the device in 6 patients with a higher maximum flow rate in the left pulmonary artery. Conclusion: The left lung perfusion may be compromised after percutaneous closure of patent ductus arteriosus with the Amplatzer Duct Occluder. The increased flow velocity in the origin of the left pulmonary artery can be a poor indicator of reduction in pulmonary perfusion and can occur in the absence of protrusion of the device.

Is routine screening examination necessary for detecting thromboembolism in childhood nephrotic syndrome? / 소아과

PURPOSE: The incidence of thromboembolic episodes in children with nephrotic syndrome (NS) is low; however, these episodes are often severe. Moreover, both pulmonary thromboembolism (PTE) and renal vein thrombosis (RVT) rarely show clinical symptoms. This study was performed to determine the benefits of routine screening in the detection of thrombosis in childhood NS. METHODS: Among 62 children with nephrotic syndrome, a total of 54 children (43 males, 11 females) were included in this study. When the patients experienced their first NS episode, we performed renal Doppler ultrasonography in order to detect RVT. To rule out the possibility of PTE, a lung perfusion scan was performed. Computed tomographic (CT) pulmonary angiography was recommended to patients who showed possible signs of PTE. All patients were evaluated for clinical signs of thrombosis, biochemical indicators of renal disease, as well as clotting and thrombotic parameters. RESULTS: RVT or related clinical symptoms were not observed in any children. Based on the findings of the lung perfusion scans, 15 patients (27.8%) were observed with as a high probability of PTE. We were able to perform a CT pulmonary angiography only on 12 patients, and 5 patients were diagnosed with PTE (prevalence 8.1%). The serum fibrinogen level in the group with PTE was significantly higher (776.7+/-382.4 mg/dL, p<0.05) than that in the group without PTE, and other parameters were not significantly different between each group. CONCLUSION: Further studies are required for clarifying the role of renal Doppler ultrasonography for the detection of RVT in NS. Children with NS who developed non-specific respiratory symptoms should be evaluated for the diagnosis of PTE. In the management of NS, a lung perfusion scan should be performed at the time of the initial episode of NS regardless of the pulmonary symptoms, since patients having PTE are either often asymptomatic, or present with nonspecific symptoms.

A Case of Pulmonary Embolism After Cesarean Delivery / 대한산부인과학회잡지

During the past 50 years, the maternal mortality ratio has decreased dramatically. The leading causes of maternal deaths were pulmonary embolism, the complications of the pregnancy-induced hypertension, hemorrhage, the complications of the ectopic pregnancy and infection. Pulmonary embolism is one of the most fatal maternal complications that abruptly happen and rapidly progress, and has been a major cause of maternal death recently. Early detection of pulmonary embolism is difficult, because there is not any specific clinical symptoms and signs. We have experienced a case of a fatal pulmonary embolism which was diagnosed by lung perfusion scan on postoperative 1 day after cesarean delivery and managed with heparin therapy. We report this case with a brief review of literatures.

Stenosis of Individual Pulmonary Veins

Pulmonary hypertension may be associated with variable conditions such as the hyperkinetic state or pulmonary vascular obstruction. In these, stenosis of the individual pulmonary veins without any cardiac or vascular malformation is very rare. We experienced stenosis of individual pulmonary veins in a 10 months old boy who was admitted with recurrent dyspnea and cyanosis and then underwent angiogram and a lung perfusion scan.

A Case of Pulmonary Embolism After Cesarean Delivery / 대한산부인과학회잡지

Pulmonary Embolism, one of the causes of maternal death, is a life threatening disease that needs early and accurate diagnosis. We have exprerienced a case of a fatal pulmonary embolism which was diagnosed by lung perfusion scan on the postoperative 1 day after cesarean delivery and was managed with heparin therapy. We present this case with a brief review of literatures.

Effect of Unilateral Diaphragmatic Palsy on Lung Perfusion in Rabbit Model

BACKGROUND: In congenital heart disease, the lung perfusion through stenosed pulmonary artery is usually decreased. And this decrement of lung perfusion also occurs with diaphragmatic palsy after the operation of congenital heart disease. It is difficult to delineate the amount of lung perfusion in case of combination of pulmonary artery stenosis and diaphragmatic palsy. We examined the change of lung perfusion after the induction of diaphragmatic palsy in rabbits. METHODS: We dissected left phrenic nerves in 20 rabbits to induce left diaphragmatic palsy. The lung perfusion scan was performed with 99mTc-MAA and the movement of diaphragm was examined with fluoroscopy. They were performed as baseline data and on 3rd and 10th day postoperatively. The amount of left lung pefusion before and after diaphragmatic palsy was compared and analysed in 12 rabbits which definitely had diaphragmatic palsy. RESULTS: Weight of the rabbits was 1.65+/-0.26 kg. Left lung perfusion percent was 45.93+/-6.42% before operation and these were 32.48+/-6.09% and 37.62+/-3.39% on the 3rd and 10th postoperative day, respectively. Left lung perfusion was significantly decreased just after diaphragmatic palsy but it was not changed thereafter. The decrement of lung perfusion was not affected by the body weight. The decreased amount of left lung perfusion was reciprocally correlated with the body weight of the rabbits on the postoperative 3rd day but not 10th day. CONCLUSION: Left lung perfusion percent of the rabbits was decreased 7% with the induction of diaphragmatic palsy and the decreased amount was reciprocally correlated with the body weight just after the diaphragmatic palsy was induced.

Clinical Study and Diagnostic Value of the Lung Perfusion Scan in Foreign Body Aspiration

PURPOSE: Early diagnosis of foreign body aspiration and removal of the inhaled material may save the patient from chronic illness and may prevent serious complications. At present the diagnostic problems of bronchial foreign bodies are being solved by using the lung scanning technique. Therefore, we investigated the clinical study and diagnositic value of the lung perfusion scan in foreign body aspiration. METHODS: Eighteen cases of airway obstruction due to foreign bodies were treated in the department of pediatrics, Kyung Hee University Hospital. We retrospectively, reviewed patient records to determine the clinical findings, radiologic findings, and findings of the perfusion lung scan. RESULTS: Fifteen cases (83.2%) out of 18 were less than 2 years of age, and the male to female ratio was 1.3:1. Vegetables, especially peanuts were the most common aspirated foreign bodies, and accounted for 72.2% of the cases. Of all foreign body obstructions, 61% were lodged in the main bronchi and there was no significant difference between the right and left main bronchus. In radiologic findings, obstructive emphysema (50%) was most common, followed by atelectasis (33%), mediastinal shifting (23.3%) and pneumonia (22.2%), respectively. There were more severe defects and a higher incidence of abnormalities in cases with prolonged periods after inhalation than that of shorter duration cases. CONCLUSION: Lung perfusion scanning is useful in the diagnosis of foreign body aspiration which presents a vague history of aspiration, insufficient clinical manifestation and normal chest radiologic findings. Our results show that perfusion scan can be helpful particularly in cases of long duration foreign body obstruction.

The Assessment of Pulmonary Parenchymal Damage in Congenital Heart Disease using Lung Perfusion Scan

PURPOSE: In acyanotic congenital heart disease of children with left to right shunt, 99mTc- Macroaggregate albumin (MAA) was employed to determine the scintigraphic severity of pulmonary parenchymal damage. METHODS: These data of lung perfusion scan using 99mTc-MAA were compared with hemodynamic values obtained from cardiac catheterization. RESULTS: The mean Pulmonary arterial pressure (> or = 30mmHg), total pulmonary resistance (> or = 2 Wood unit) & ratio of pulmonary vascular resistance/systemic resistance (Rp/Rs > or = 0.2) were proportionally related to higher perfusion ratio of upper and lower lung field. The diagnostic values of perfusion ratio of upper & lower field of both lung (cut off value > or = 0.8) for pulmonary hypertension were as follows : 60-65% of sensitivity, 75-90% of specificity, 72-86% of positive predictive value & 68-69% of negative predictive value. The mottled perfusion defect was frequently found in patients with pulmonary hypertension (mean pulmonary arterial pressure > or = 30mmHg, Rp > or = 2 Wood unit). The degree of perfusion defect as indicator of severe pulmonary parenchymal damage was utilized clinically as determinator of operability and morbidity for acyanotic shunt lesions perioperatively. CONCLUSION: The scintigraphic severity determined by 99mTc-MAA lung perfusion scan could be valid for evaluating the extent of pulmonary parenchymal damage in acyanotic congenital heart disease complicated by pulmonary hypertension.

Clinical Study of the Patients, in Whom Pulmonary Embolism was Suspected by Lung Perfusion Scan / 결핵

Pulmonary Embolism can develop in variable conditions, and presents with nonspecific symptoms and signs. If diagnosis is delayed, it can be resulted in catastrophic results. Therefore, early diagnosis and adequate treatment is crucial in Pulmonary Embolism. Lung Perfusion Scan is useful screening test. Negative result can exclude pulmonary embolism, But, perfusion defects don't always mean pulmonary embolism. To find the better methods of interpretation of king perfusion scan and To evaluate the clinical course and outcomes of the patients, in whom pulmonary embolism was suspected by lung perfusion scan, we reviewed the clinical records of 49 cases suspected by lung perfusion scan at Seoul National University Hospital during the period of January, 1995 to July, 1996. The results are as follows. First impression of cases in which PE was present at time of admission were pulmonary embolism (63%), heart diseases (26%), and pneumonia (11%) in orders. Underlying diseases of cases in which PE developed during admission were malignancy (36.5%), 10-I (22.7%), sepsis (13.7%), and SLE (9.1%) in orders. The predisposing factors were operation (20%), cancer (16%), immobility (16%), connective tissue disease (16%), heart dis. (10%), old age (10%), and preg/pelvic dis. (8%) The results of lung perfusion scan were HPPE 40cases(26.8%), IPPE 21 cases(14.1%), LPPE 88 cases(59.l %) and cases(%) of treatment in these cases were HPPE 34 cases(85%), IPPE 9 cases(42,9%), IPPE 0 case(0.0%). Treatments were heparin and warfarin (69.5%), heparin alone (8.2%), warfarin alone (2.0%), embolectomy(4.1%), thrombolytics (20%), IVC filter (2.0%), and no treatment (12.2%) In 34 cases (694%), follow up could be done, and 5 cases were recurred (10.2%). The causes of recurrence was incomplete anticoagulant therapy (3 cases) 2rnd recurrence of predisposing factor (2 cases). Expired case due to pulmonary embolism was one who was expired just before trial of thrombolytie therapy. CONCLUSION: Efforts should be made to shorten the interval from onset of Sx to Dx, ie, high index of suspision.

Usefulness of Lung Perfusion Scan for the Evaluation of Pulmonary Arteries after Total Correction of Right Ventricular Outflow Obstructive Disease

BACKGROUND: For the evaluation of pulmonary nrtery branches after operation of right ventricular outflow obstructive disease, we reviewed the usefulness of both simple X-ray and lung perfusion scan with 99mTc-macroaggregated albumin compared with cardiac angiography. METHODS: From March, 1986 to July, 1993, at Seoul National University Children;s Hospital, we chose 23 cases who underwent both simple X-ray and cardiac angiography among the patients who had distinct difference between right and left pulmonary blood flow in lung perfusion scan after operation of right ventricular outflow obstructive disease. So we calculated the ratio of right and left pulmonary blood flow and Spearman correlation coefficient. RESULTS: Of the 23 cases, 17 cases were tetralogy of Fallot, 4 cases pulmonary atresia, 1 case double outlet right ventricle, and 1 case truncus arteriosus. The mean age at poeration was 27 months, and the mean postoperative follow-up period was for 68 months. The correlation coefficient between cardiac angiography and simple X-ray was 0.86(p<0.01), and that beteen cardiac angiography and lung perfusion scan was 0.80(p<0.01). CONCLUSION: The cardiac angiography has been known as the best diagnostic tool for the evaluation of pulmonary artery branches after operation of right ventricular outflow obstructive ddisease, but we proposed that the lung perfusion scan should be widely used because its results were similar with those of cardiac angiography.