Lung Uptake Research Articles

Synthesis and Evaluation of 15-(4-(2-[18F]Fluoroethoxy)phenyl)pentadecanoic Acid: A Potential PET Tracer for Studying Myocardial Fatty Acid Metabolism

15-(4-(2-[¹⁸F]fluoroethoxy)phenyl)pentadecanoic acid ([¹⁸F]7) was synthesized as a PET probe for assessing myocardial fatty acid metabolism. The radiosynthesis of [¹⁸F]7 was accomplished using a two-step reaction, starting with the corresponding tosylate ester, methyl 15-(4-(2-(tosyloxy)ethoxy)phenyl)pentadecanoate (5), and gave the radiolabeled fatty acid, [¹⁸F]7 in a radiolabeling yield of 55-60% and a specific activity of >2000 Ci/mmol (decay corrected to EOB). The biological evaluation of [¹⁸F]7 in rats displayed high uptake in heart (1.94%ID/g at 5 min), which was higher than the uptake (%ID/g) in blood, lung, muscle, pancreas, and brain. MicroPET studies of [¹⁸F]7 in Sprague-Dawley rats demonstrated excellent images of the myocardium when compared with [¹¹C]palmitate images in the same animal. Moreover, the tracer kinetics of [¹⁸F]7 paralleled those seen with [¹¹C]palmitate, with an early peak followed by biphasic washout. When compared to [¹¹C]palmitate, [¹⁸F]7 exhibited a slower early clearance (0.17 ± 0.01 vs 0.30 ± 0.02, P < 0.0001) and a significantly higher late clearance (0.0030 ± 0.0005 vs 0.0006 ± 0.00013, P < 0.01). These initial studies suggest that [¹⁸F]7 could be a potentially useful clinical PET tracer to assess abnormal myocardial fatty acid metabolism.

Preparation of budesonide-loaded porous PLGA microparticles and their therapeutic efficacy in a murine asthma model

Inhaling corticosteroids, such as budesonide (BD), is the most common treatment for asthma. However, frequent steroid administration is associated with many side effects. We hypothesized that porous microparticles containing BD could provide an effective treatment method for asthma, as the sustained delivery of corticosteroid and a reduced number of doses could be achieved using porous polymeric microparticles. Porous microparticles were prepared from poly(lactic-co-glycolic acid) (PLGA) by a water-in-oil-in-water double emulsion method with ammonium bicarbonate as the porogen. Varying the porogen concentration controlled the morphology, particle size, and pore size of the PLGA microparticles, with particle size and pore size increasing as the porogen concentration increased. The BD loading efficiency in the porous PLGA microparticles was about 60%, and BD was released from the porous microparticles in a sustained manner for 24 h in vitro. Lung uptake efficiency of the porous PLGA microparticles in mice was significantly higher than that of non-porous PLGA microparticles. Budesonide-loaded porous PLGA microparticles were delivered to asthmatic mice, and the numbers of inflammatory cells in bronchoalveolar lavage (BAL) fluid and tissue sections were significantly reduced when the drug was administrated every 3 days. We also found significantly reduced bronchial hyperresponsiveness of asthmatic mice after treatment with budesonide-loaded porous PLGA microparticles. This approach to controlling the porous structure of polymeric microparticles, as well as the release behavior of drugs from the microparticles, could have useful applications in the pulmonary delivery of many therapeutic drugs.

Aggressive sporadic histiocytic sarcoma with immunoglobulin heavy chain gene rearrangement and t(14;18)

Histiocytic sarcoma (HS) is a rare but aggressive malignant neoplasm of histiocytic lineage with a poor prognosis. Immunohistochemically, the neoplastic cells are positive for CD163, CD68, and lysozyme, and negative for B and T cell markers. However, molecular studies on the origin of the neoplastic cells remain inconclusive. A 54-year-old woman was admitted to our hospital because of painful swelling of the left knee. Examination revealed generalized lymphadenopathy and splenomegaly. HS was diagnosed according to morphologic and immunohistochemical features observed on biopsy of the left inguinal lymph node. The tumor demonstrated a clonal immunoglobulin heavy chain gene rearrangement and a clonal cytogenetic abnormality including t(14;18) which was confirmed by fluorescence in situ hybridization analysis showing the IgH/BCL2 fusion gene. The neoplastic cells were negative for PAX5, a B cell associated transcription factor, and positive for CEBPβ, a transcription factor mediating macrophage and myeloid differentiation. Positron emission tomography showed disseminated areas of increased 18F-fluorodeoxyglucose uptake in multiple lymph nodes, the liver, spleen, both lungs, both kidneys, and many bony sites. The patient received localized irradiation therapy followed by chemotherapy, she failed to respond and died of the disease progression. The case findings suggest lineage promiscuity or plasticity related to the pathogenesis of HS.

Iodine‐123 metaiodobenzylguanidine scintigraphic assessment of pulmonary vascular status in patients with chronic obstructive pulmonary disease

Lung uptake of iodine-123 metaiodobenzylguanidine (¹²³I-MIBG) is used as an indicator of pulmonary endothelial function. Decreased lung uptake of ¹²³I-MIBG has been demonstrated in patients with COPD as compared with normal subjects. The present study was performed to examine the relationship between lung uptake of ¹²³I-MIBG and pulmonary artery pressure (Ppa) at rest and during exercise, in patients with COPD. ¹²³I-MIBG scintigraphy was performed in 19 patients with COPD. Anterior planar images were acquired 15 min after the injection of ¹²³I-MIBG, and the total lung to upper mediastinum ratio (LMR) was calculated for both lungs. Right heart catheters were used to monitor Ppa continuously at rest and during exercise. Exercise was performed on an electrically braked bicycle ergometer at a constant workload of 25 W for 3 min. In COPD patients the LMR were not correlated with the pulmonary function parameters measured before exercise, including FEV₁, PaO₂, DL(CO), or Ppa at rest. However, the percentage increase in Ppa during exercise was significantly correlated with LMR. Evaluation of the kinetics of lung uptake of ¹²³I-MIBG may be a novel scintigraphic tool for the assessment of exercise-induced pulmonary hypertension in patients with COPD.

Pathophysiologic correlates of 82Rb biodistribution in cardiac PET/CT

PET perfusion imaging with (82)Rb is a powerful tool for evaluating coronary artery disease (CAD). Little is known about normal patterns or significance of (82)Rb lung distribution in the setting of heart disease. Herein, PET/CT hybrid imaging was used to obtain insights into the frequency and potential radiomorphologic correlates of altered (82)Rb distribution. Myocardial perfusion PET/CT studies of 58 patients referred for workup of CAD were analyzed [28 normal and 30 patients with low left ventricular ejection fraction (LVEF)]. Organ regions of interest were placed on PET images, and (82)Rb uptake was measured and compared under resting and stress conditions. Qualitatively increased lung uptake was observed in 13 patients-5 with normal LVEF(R) and 8 with reduced LVEF(R); 12 of 13 had lung infiltrates/atelectasis on CT. Lung to heart ratios in the normal and low EF groups were (mean ± SD) 0.168 ± 0.047 and 0.171 ± 0.075 at rest, and 0.128 ± 0.035 and 0.147 ± 0.067 during stress (p = 0.87 and 0.18, respectively). Lung to liver ratios were not significantly different between the two groups under stress or rest conditions. Increased lung uptake of (82)Rb occurs in a subset of patients referred for workup of CAD by PET/CT and may be influenced by primary parenchymal abnormalities and LV dysfunction. Thus, the relevance of pulmonary (82)Rb uptake as a marker of cardiac outcome may be limited. Larger studies are needed to determine how non-cardiac (82)Rb uptake and CT findings may be integrated to increase the diagnostic and prognostic value of cardiac PET/CT.

A Focal Pulmonary F-18 FDG Uptake Without Pulmonary CT Abnormality in PET/CT Probably Due to Mislocation of the Urine F-18 FDG in the Left Upper Renal Calyx

We experienced a case of a focal pulmonary F-18 fluoro-2-deoxy-D-glucose (FDG) uptake without pulmonary computed tomography (CT) abnormality probably due to the urine FDG in the upper pole calyx of the left kidney. A 76-year-old male patient was referred for evaluation of the postoperative right lung cancer. Positron emission tomography/CT was performed 1 hour after intravenous injection of FDG and showed a small focus of increased uptake in the left lower lung field accompanying no abnormality in the corresponding lung CT images. The lung uptake was not noted in repeated positron emission tomography/CT images taken after 1 hour, suggesting misplacement of the left renal upper calyx into the lower lung.

Radiolabeling of Morphine with 131I and Its Biodistribution in Rats

This study was conducted to determine the possible radiopharmaceutical potential of morphin labeled with (131)I. Morphine was extracted from dry capsules of the opium poppy (Papaver somniferum L.), purified by high-performance liquid chromatography, and characterized with nuclear magnetic resonance and infrared spectroscopy. The purified compound was labeled with (131)I. Male Albino Wistar rats (18) were used for receptor blockage and unblockage biodistribution studies. Tissue distribution studies showed that radiolabeled morphine had higher uptake in lung, liver, small intestines, large intestines, and stomach than the other tissues. The highest uptake of radiolabeled compounds in rats' brain was found to be in the midbrain and hypothalamus. After receptor blockage with morphine, uptake of (131)I-morphine decreased in the lungs, liver, kidney, testis, prostate, spinal cord, cerebellum, hippocampus, striatum, and temporal cortex with respect to receptor unblockage studies of rats. This study concludes that the labeling yield of (131)I-morphine was high, high amount of (131)I-morphine was found in the hypothalamus, and (131)I-morphine has enough stability for diagnostic scanning.

Fluorodeoxyglucose-PET/CT for Diagnosis of Intravascular Large B-Cell Lymphoma

A 39-year-old woman was referred to our hospital with a 1-month history of recurrent fever. On physical examination, her spleen was palpable in the absence of peripheral lymphadenopathy and skin lesions. Laboratory studies yielded elevated values of serum lactate dehydrogenase at 1051 U/L, soluble interleukin 2 receptor at 24,500 pg/mL, and ferritin at 1019 μg/L. Blood cell counts showed a bicytopenia with a hemoglobin level of 7.0 g/dL and a platelet count of 3.7 × 109/L. Although the patient had no subjective symptoms such as dyspnea, her percutaneous oxygen saturation was low at 90%, suggesting hypoxemia. Findings on both chest radiography and computed tomography (CT) of the lungs were unremarkable. However, positron emission tomography (PET)/CT with 18F-fluorodeoxyglucose (FDG) revealed diffuse uptake in the bilateral lung, predominantly in the upper fields (Figure 1, A and B). In addition, FDG uptake was noted in the bilateral renal cortex (Figure 1, C) and vertebrae (Figure 1, A). Bone marrow aspiration yielded large atypical lymphoid cells with the appearance of hemophagocytosis. However, on bone marrow biopsy, lymphoma cells were not confirmed within the lumen of small blood vessels. Random skin biopsy specimens1 from normal-appearing skin on the patient's thigh revealed CD20+ large lymphoid cells filling the small vessels in the subcutaneous tissues (Figure 1, D and E). Intravascular large B-cell lymphoma (IVLBCL) was diagnosed. FIGURE 1. A-C, Positron emission tomography (PET)/computed tomography (CT) findings in a patient with intravascular large B-cell lymphoma. Characteristic pattern of 18F-fluorodeoxyglucose (FDG) uptake with diffuse accumulation in the bilateral lung field (A, B) ... Emerging evidence shows the usefulness of PET/CT in diagnosing lymphoma.2 However, its role in IVLBCL is unknown, mainly because of the rarity and the variety of its clinical presentation. Recently, we performed PET/CT in 4 consecutive patients who fulfilled the early diagnostic criteria for IVLBCL3 and found the characteristic pattern of FDG uptake: (1) diffuse accumulation in the bilateral lung field, (2) accumulation in the bilateral renal cortex, and (3) multiple accumulations in the bones (Figure 2, A-H). From an anatomic viewpoint, lungs and kidneys are affected by IVLBCL cells because these organs are rich in small blood vessels. Indeed, autopsies have revealed the high frequency of lymphomatous involvement in lungs and kidneys. We suggest that FDG-PET/CT be performed for early diagnosis of IVLBCL, which is important for effective therapeutic intervention. FIGURE 2. Positron emission tomography/computed tomography findings in patients with intravascular large B-cell lymphoma. A-C, Uptake of 18F-fluorodeoxyglucose (FDG) in the bilateral lung of a 74-year-old man, especially diffuse accumulation in the left lung field ...

A novel micelle-encapsulated platinum(II) anticancer agent

A hydrophobic and water-insoluble platinum(II) compound, cis-(cha) 2Pt(NO 3) 2 was encapsulated by macromolecular micelles self-assembled from an amphiphilic cyclotriphosphazene [NP(MPEG750)(GlyPheLeu) 2Et] 3 (CP750). The micelle-encapsulated platinum(II) compound exhibited outstanding pharmacokinetics in rats by showing long blood circulation and much larger systemic exposure (AUC = 43.5 μg h/ml) compared with the free carboplatin (AUC = 4.32 μg h/ml). Biodistribution study of the micellar platinum(II) compound using male Sprague–Dawley rats has shown excellent tumor to tissue ratios of 4.03 at 2 h post injection and 4.67 at 24 h post injection. Furthermore, the micellar platinum(II) compound exhibited more than 6 times higher cellular uptake in human cervical (HeLa) and lung (A549) tumor cells compared with the free platinum compound. Also it is surprising that the micellar platinum(II) compound displayed specifically high cytotoxicity against the stomach tumor cells (SNU638), which are one of the least responsive to chemotherapeutic agents currently in clinical use. The acute toxicity study has shown that the LD 50 values of free and the micellar cis-(cha) 2Pt(NO 3) 2 are approximately 70 mg/kg and 90 mg/kg, respectively. Thus the platinum compound encapsulated by cyclotriphosphazene micelles is a promising candidate for preclinical studies.

Contact with the bone marrow microenvironment readdresses the fate of transplanted hematopoietic stem cells

Despite enormous advancements in our comprehension of molecular mechanisms governing hematopoietic stem cells (HSCs) engraftment in the bone marrow, current clinical protocols of intravenous (IV) transplantation suffer from a relatively low seeding efficiency. To solve this problem, intrabone (IB) injection of HSCs has been proposed. However, the mechanisms underlying the benefit provided by this procedure remain unknown. This study aims to evaluate the effect of IB on HSCs trafficking and homing features in the living rat. A total of 35 Lewis rats underwent IB or IV administration of HSCs harvested from syngeneic animals and purified according to CD90 expression. These cells were labeled with 37 MBq 99mTc-exametazime and injected either IV or IB. Cell trafficking and distribution in heart, lung, spleen, liver, and forelimb was evaluated by dynamic radionuclide imaging. Logan graphical approach was used to estimate tissue recruitment of HSCs. More than 90% of cells escaped from the injected bone to the bloodstream in <15 seconds. However, this short contact profoundly modified HSCs kinetics, reducing their lung sequestration and shortening their blood persistence with respect to IV. More importantly, IB passage resulted in reduced lung uptake and in a fourfold increase in homing of remote bone marrow sites. CD90(+) cells transplantation restored hematopoiesis in eight further rats previously exposed to lethal irradiation. The first-entry contact with the hematopoietic microenvironment immediately readdresses the fate of transplanted HSCs, providing them with "the final destination stamp" to define their bone marrow homing.

Simultaneous quantification of myocardial perfusion, oxidative metabolism, cardiac efficiency and pump function at rest and during supine bicycle exercise using 1‐11C‐acetate PET – a pilot study

PET using 1-(11)C-acetate (ACE-PET) applied at rest is used for measuring absolute myocardial blood flow (MBF) and oxidative metabolic rate (k(mono)). We evaluated the feasibility of quantitative ACE-PET during exercise. Five endurance athletes underwent dynamic PET scanning at rest and during supine bicycle stress. Exercise was maintained at a workload of 120 Watt for 17 min. The rate-pressure product (RPP) was recorded repeatedly. MBF, k(mono) in left (LV) and right (RV) ventricular wall, cardiac output (CO), cardiac efficiency and a lung uptake value reflecting left heart diastolic pressures were calculated from the PET data using previously validated models. MBF increased from 0.71 +/- 0.17 to 2.48 +/- 0.25 ml min(-1) per ml, LV-k(mono) from 0.050 +/- 0.005 to 0.146 +/- 0.021 min(-1), RV-k(mono) from 0.023 + 0.006 to 0.087 + 0.014 min(-1), RPP from 4.7 +/- 0.8 to 13.2 +/- 1.4 mmHg x min(-1) x 10(3) and Cardiac Output from 5.2 +/- 1.1 to 12.3 +/- 1.2 l min (-1) (all P < 0.001). Cardiac efficiency was unchanged (P = 0.99). Lung uptake decreased from 1.1 +/- 0.2 to 0.6 +/- 0.1 ml g(-1) (P < 0.001). A number of important parameters related to cardiac function can be quantified non-invasively and simultaneously with a short scanning protocol during steady state supine bicycling. This might open up new opportunities for studies of the integrated cardiac physiology in health and early asymptomatic disease.

18FDG-PET in NSCLC: Relationship between histology and EGFR mutation with metabolic activity.

e18128 Background: 18FDG-PET is a diagnostic and monitoring tool widely used in patients with NSCLC. The uptake value (SUVmax) has been as a prognostic factor in these patients. We analyzed the relationship among histology type, EGFR mutation and tumor metabolic activity in patients with NSCLC. Methods: We retrospective analyzed 113 patients with NSCLC diagnosed at our institution. All patients had a 18 FDG-PET before any treatment. Patients were classifiedaccording to histology as NSCLC (adenocarcinoma, squamous, large cell and unclassified NSCLC). The analysis of the 18 FDG-PET images was performed both qualitatively and quantitatively (calculating the SUVmax in the different sites of disease). In a subgroup of patients with non-squamous lung carcinoma EGFR mutation determination was preformed. Results: 113 patients with NSCLC were analyzed: 62.8% had BAC (and adenocarcinoma, squamous 8%, 15% large cell undifferentiated and 14.2% unclassified NSCLC. The median SUVmax in lung was 8.21 (standard deviation 4.41) in adenocarcinoma, 13.07 (5.75) in squamous, 8.57 (4.23) in large-cell/undifferentiated, 9.12 (6.02) NSCLC unclassified. ANOVA analysis between histology and metabolic activity in the lung localitation and bone metastasis showed statistically significant differences (p < 0.05) for every histological subgroup. No statistically significant relationship was found between the 18FDG uptake in other locations. In 55 of 113 patients with NSCLC, EGFR mutation was determined and 16.4% had the mutation. We found no statistically significant differences in SUVmax between mutated and non-mutated patients. Conclusions: Our study points a relationship between tumor histology and metabolic activity in the lung. EGFR mutation does not seem to have a direct relationship with the degree of 18FDG lung uptake in opposite to Asian reports. Further studies are necessary to corroborate our findings. No significant financial relationships to disclose.

PET/CT: Focal lung uptake of 18F-fluordeoxyglucose on PET but no structural alterations on CT

The combination of positron emission tomography (PET) and computed tomography (CT) in a single device (PET/CT) provides a powerful diagnostic tool opening new horizons for imaging diagnosis. In order to correctly interpret PET/CT studies, knowledge of the biodistribution of 18F-fluorodeoxyglucose (FDG), the physiological variants as well as the pitfalls, including the artefacts which may be found is necessary. We report four cases performed during the follow up diagnosis of an oncology study performed with 18F-FDG-PET/CT. This study showed focal uptake in the lung parenchyma in the PET study in all the cases, with no structural lesions being found on CT scan. Radiotracer extravasation in three of these patients and a recent change in the injection protocol used suggest that an artefact was responsible for these discrepancies.

Reduced expression of angiotensin I-converting enzyme in Caveolin-1 knockout mouse lungs

Reduced lung capillary expression of angiotensin I-converting enzyme (ACE), a key enzyme in cardiovascular pathophysiology, and of caveolin-1, an important regulator of endothelial cell signalling, has been demonstrated in various models of pulmonary arterial hypertension (PAH). We addressed the relationship between PAH and ACE expression in caveolin-1 knockout mice ( Cav1 − / −), which have moderate PAH. Tissue ACE activity was reduced by 50% in lungs from 3-month-old Cav1 − /− mice compared to wild type (WT). A similar reduction in lung endothelial ACE expression was observed by measuring the lung uptake of 125I-labeled monoclonal anti-ACE antibody and by quantitative immunohistochemistry. These alterations in ACE are limited to capillary segments of the pulmonary circulation. Functionally, the increase in pulmonary artery pressure (PAP) in response to ACE conversion of angiotensin I to angiotensin II in isolated, perfused mouse lungs was reduced significantly in Cav1 − /− mice compared to WT. Thus, these complementary approaches demonstrate the dependence of lung microvascular endothelial cell ACE protein expression on caveolin-1 expression and underscore the vital role of caveolin-1-regulated pulmonary vascular homeostasis on endothelial ACE expression and activity. In summary, we have revealed a novel role of caveolin-1 in the regulation of ACE expression in pulmonary capillary endothelial cells. Further understanding of the mechanism by which reduced caveolin-1 expression leads altered pulmonary vascular development, PAH, and reduced ACE expression may have important clinical implications in patients with these severe lung diseases.

Diffuse Pulmonary Uptake of Tc-99m Methylene Diphosphonate in a Patient with Non-tuberculosis Mycobacterial Infection.

Extra-osseous uptake of bone-seeking radiopharmaceuticals has been reported at various sites and it is known to be induced by various causes. Diffuse pulmonary infection, such as tuberculosis, can be a cause of lung uptake of bone-scan agent. Here we report on a patient with non-tuberculosis mycobacterial infection (NTM) who demonstrated diffuse pulmonary uptake on Tc-99m MDP bone scan. After medical treatment for NTM, the patient's lung lesions improved. Extraskeletal lung Tc-99m MDP uptake on bone scan may suggest lung parenchymal damage associated with disease activity.

Multiple dosings wtih acidic retinoids increase retinol stores and expression of retinoid homeostatic genes in the lung of neonatal rats

Previously we have shown that vitamin A (VA) combined with acidic retinoids synergistically increases retinol uptake and retinyl ester (RE) formation in neonatal rat lung, concomitant with the expression of several retinoid homeostatic genes: LRAT (lecithin:retinol acyltransferase), CYP26B1 (a cytochrome P450), and Stra6 (stimulated by retinoic acid gene 6). In the present study we compared the response to VA alone or combined with retinoic acid (RA) or a analog, Am580, in two timing protocols: single early dosing (d 4) vs. multiple dosings throughout the period of lung septation (d 4, 7, 11, 14). Multiple dosing resulted in a higher, cumulative increase in lung RE content for all treatments: vehicle&lt;RA≅VA&lt;Am580&lt;VARA&lt;VAAm580. However, most of the retinoid homeostatic genes were up‐regulated by acidic retinoids to the same extent after a single vs. multiple dosings. Lung functional gene, surfactant protein‐A (SPA1) mRNA remained nearly constant with both treatment and timing. In conclusion, multiple treatments of VA and acidic retinoids in combination during the septation period greatly increased neonatal lung RE content in a synergistic and cumulative manner. Repeated but transient induction of retinoid homeostatic genes by acidic retinoids at the time of each dosing may explain the observed cumulative synergistic enhancement of RE formation.Support: NIH CA90214.Grant Funding Source: NIH CA90214

Correlation of Exercise and Rest Tc-99m MIBI Lung/heart Ratio at Different Areas of Lung with Left Ventricular Ejection Fraction in Patients with Coronary Artery Disease

Increased lung uptake of thallium-201 ( 201Tl) and technetium-99m-methoxyisobutyl isonitrite ( 99mTc-MIBI) in myocardial perfusion imaging has been proved as a reliable marker of left ventricular dysfunction. The goal of this study was to evaluate the lung uptake at the various areas of both the right and left lung (ie, right lung base and both lung apices) and its correlation with the left ventricular dysfunction by calculating lung-to-heart (L/H) uptake ratio in exercise and rest 99mTc-sestamibi myocardial perfusion. There were a total of 63 patients (10 female, 53 male: age range from 30–75 years, mean age 45.3 years, median age 45 years) with chronic coronary artery disease undergoing two-dimensional (2D) echocardiogram to calculate left ventricular ejection fraction (LVEF). Planar images were taken before myocardial perfusion imaging to calculate the L/H at different sites of the lungs. The patients having LVEF ≤40% on 2D echo (32 patients) were included in group A, and the patients having LVEF >40% on 2D echo (31 patients) were included in group B. The L/H differs significantly during stress and rest at the selected lung areas ( P < .05). The uptake ratio at the right lung base was greater than the ratio at apices. In group A, L/H was significantly higher during stress and rest as compared with group B. However, in both the groups, stress uptake counts were greater as compared with rest. A statistically significant inverse correlation was found between the L/H uptake ratio and LVEF during exercise and rest at both the lung base and apices. Useful clinical information regarding left ventricular dysfunction was proved by L/H, irrespective of the area selected at lung.

Clinical significance of 201Tl lung uptake in heart diseases

In order to evaluate the clinical significance of 201Tl lung uptake, 201Tl myocardial scintigraphy was performed in 675 cases with various cardiac diseases. The lung uptake ratio of 201Tl (L/T) was calculated by ratio of the total radioactivity of the unilateral lung to the injected dose of 201Tl in 69 cases. Using both 201Tl scintigraphy and cardiac pool scintigraphy with 99mTc-human serum albumin, images of 201Tl of the intravascular space and extravascular space were obtained in 14 cases. The image of 201Tl of the extravascular space was almost the same as the original 201Tl image as regards the pattern of 201Tl-distribution, and the lung uptake ratio of the former was 95.7 +/- 2.8% of that of the latter. The mean values of L/T of the right and left lung were 1.5 +/- 0.9%, 1.2 +/- 0.6% in the healthy lungs, 2.8 +/- 1.4% and 1.4 +/- 0.7% in heart diseases without left heart failure, and 4.4 +/- 1.8% and 2.6 +/- 1.2% in those with left heart failure, respectively. Increased lung uptake ratio of 201Tl, which was related to post-capillary pulmonary hypertension, prolonged pulmonary circulation time and findings of left heart failure, was observed more frequently in mitral valvular diseases (72.2%) and dilated cardiomyopathies (60.0%). Increased lung uptake of 201Tl was associated with normal or increased pulmonary perfusion in many cases or areas, but with pulmonary hypoperfusion in some cases with post-capillary pulmonary hypertension, in whom both increased lung uptake of 201Tl and pulmonary hypoperfusion were shown in the lower lung fields.(ABSTRACT TRUNCATED AT 250 WORDS)

Study of pathophysiology of pulmonary circulation in polycythemia using scintigraphy

In order to evaluate the pathophysiology of pulmonary circulation in polycythemia, Tl-201 myocardial scintigraphy and perfusion lung scintigraphy with 99m-Tc MAA were performed in 19 cases with polycythemia including polycythemia rubra vera and in 11 cases with secondary polycythemia due to pulmonary diseases. Tl-201 lung uptake, right ventricular visualization and pulmonary perfusion impairment were studied. In the 19 cases, Tl-201 lung uptake was observed in all cases and 54.5% of them showed moderate lung uptake. The grade of right ventricular visualization was moderate in one case and slight in 16 cases; right ventricular hypertrophy was shown in 89.5% of all cases by Tl-201 scintigraphy, only one of which showed right ventricular hypertrophy on electrocardiography. Abnormalities of lung perfusion consisted of scattered small areas of hypoperfusion in 36.8%, peripheral hypoperfusion in 78.9% and uneven distribution of pulmonary perfusion in 94.7%. The degree of hypoperfusion was slightly related to decrease in FEV1.0%, V25 and PaO2 and increase in circulating blood volume and peripheral red blood cell counts. Abnormalities of pulmonary function consisted of increased RV/TLC in 50.0%, increased CV/VC in 35.7% and decreased V25 in 36.8%. Arterial blood gases showed hypoxemia in 57.1%, the degree of which was slightly related to increase in RV/TLC and CV/VC and decrease in V25. Cases of secondary polycythemia due to pulmonary diseases showed more marked right ventricular visualization, pulmonary perfusion impairment and abnormalities of various kinds of pulmonary function than polycythemia rubra vera cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary Pulmonary T-Cell Lymphoma: a Case Report

Primary pulmonary T-cell lymphoma is an extremely rare malady, and we diagnosed this in a 52-year-old male who was admitted to our hospital with cough for the previous two weeks. The chest CT demonstrated multiple variable sized mass-like consolidations with low density central necrosis in the peripheral portion of both the upper and lower lobes. Positron emission tomography (PET) showed multiple areas of hypermetabolic fluorodeoxyglucose (FDG) uptake in both lungs with central metabolic defects, which correlated with central necrosis seen on CT. The histological sample showed peripheral T-cell lymphoma of the not otherwise specified form. The follow-up CT scan showed an increased extent of the multifocal consolidative lesions despite that the patient had undergone chemotherapy.