A regeneração óssea é um importante processo fisiológico e bioquímico que acontece no tecido ósseo em resposta a diferentes tipos de agressões. Sejam elas o trauma, infecções, excessos de demanda de carga, lesões expansivas, malformações vasculares e alterações metabólicas sistêmicas, em quaisquer destas situações a remodelação e regeneração óssea assumem grande importância dada a relevância do esqueleto para a saúde humana. Neste sentido, faz-se importante desenvolver técnicas de pesquisa que permita-nos estudar in vivo as alterações metabólicas que acontecem no tecido ósseo em diferentes condições. Neste sentido, nosso objetivo foi o de utilizar a técnica de cintilografia óssea para avaliar a osteogênese secundaria à osteotomia em um modelo animal de coelho da raça New Zealand. Para tanto desenvolvemos um estudo longitudinal, prospectivo, caso-controle, no qual as variáveis cintilográficas foram mensuradas tanto na pata operada (pata anterior direita) quanto na pata controle (pata anterior esquerda). A amostra foi constituída por um grupo de 10 coelhos, inicialmente, os quais foram submetidos à osteotomia, seguindo-se um período de avaliação de 12 semanas pós-operatórias, divididas em três etapas de imageamento, com 4, 8 e 12 semanas. Como resultados observamos: (A) a pata operada apresentou uma radiação externa significativamente maior do que a controle, ao uso do colimador pinhole, denotando aumento da biodistribuição e tropismo do radiofármaco para a pata operada; (B) Dentre os 3 momentos avaliados, a osteogênese foi máxima em 4 semanas e apresentou declínio significativo nas 8a e 12a semanas, denotando regeneração e resolução da lesão cirúrgica; (C) A pata controle também foi influenciada pela inatividade imposta pela pata operada. Este fato ficou evidenciado notadamente pela também redução da osteogênese na pata anterior esquerda (controle). Concluimos que a técnica da cintilografia óssea foi sensível ao diferenciar semi-quantitativamente a osteogênese na pata operada, nos três marcos temporais avaliados no presente estudo. / Bone healing is an important physiological and biochemical process that occurs in bone tissue in response to different types of aggression. Whether the trauma, infections, excessive load demand, expansive lesions, vascular malformations and systemic metabolic changes in any of these situations remodeling and bone regeneration are very important given the relevance of the skeleton to human health. In this sense, it is important to develop research techniques that allow us to study in vivo the metabolic changes that occur in the bone tissue under different conditions. In this sense, our goal was to use the technique of bone scintigraphy to evaluate osteogenesis secondary to osteotomy in an animal model of New Zealand rabbits. For this purpose we developed a longitudinal, prospective, case-control study, in which the scintigraphic variables were measured both in the operated paw (right paw) and the control paw (left paw). The sample consisted of a group of 10 rabbits, initially, which underwent osteotomy, followed by an evaluation period of 12 weeks after surgery, divided into three stages of imaging, 4, 8 and 12 weeks. As results show: (A) the operated paw external radiation was significantly higher than the control, through pinhole collimator, showing increased radiotracer biodistribution and tropism for the operated paw, (B) Among the three time intervals, the osteogenesis was maximal at 4 weeks and showed significant decline in the 8th and 12th week, showing regeneration and resolution of the surgical lesion, (C) The control paw was also influenced by the inactivity imposed by the operated leg. This fact was also evidenced by markedly reduced osteogenesis in the left paw (control). We conclude that the technique of bone scintigraphy was sensitive to differentiate semiquantitatively osteogenesis in the operated leg in three timeframes in the current study.

Orientador: Marco Antônio Rodrigues Fernandes / Resumo: O câncer de mama permanece como o segundo tipo de câncer mais frequente no mundo, depois do câncer de pele não melanoma, e o primeiro entre as mulheres e responde por cerca de 25% dos casos novos de câncer a cada ano. Em 2018, para o Brasil são esperados cerca de 59.700 casos novos de câncer de mama. A radioterapia é parte integrante no tratamento do câncer de mama como adjuvância de cirurgias de setorectomia ou mastectomia. O coração é um órgão de risco e a parede anterior da área cardíaca está muito próxima do limite interno dos campos de irradiação. A proposta deste estudo é avaliar possíveis alterações na função cardíaca de pacientes submetidas à radioterapia da mama esquerda, comparando os procedimentos radioterápicos realizados com a técnica convencional bidimensional (RT-2D) com a técnica tridimensional conformada (RTC-3D). A pesquisa analisou doze pacientes que foram submetidas à radioterapia, a função cardíaca das pacientes foram avaliadas por cintilografias miocárdicas realizadas previamente e posteriormente à radioterapia. Os parâmetros de análises foram a fração de ejeção (FEVE) e a função ventricular global do ventrículo esquerdo, ambos apontados no laudo do exame de medicina nuclear. Apenas uma paciente apresentou alteração significativa da FEVE entre as duas cintilografias miocárdicas. Para os casos clínicos analisados, não foi possível estabelecer uma relação direta entre alterações da função cardíaca com a técnica radioterápica aplicada. / Abstract: Breast cancer remains the second most common cancer in the world after non-melanoma skin cancer, and the first among women and accounts for about 25% of new cases of cancer each year. In 2018, about 59,700 new cases of breast cancer are expected in Brazil. Radiotherapy is an integral part of the treatment of breast cancer as adjuvant of cosmetic surgery or mastectomy surgeries. The heart is a risk organ and the anterior wall of the cardiac area is very close to the inner boundary of the irradiation fields. The purpose of this study was to evaluate possible alterations in the cardiac function of patients submitted to left-sided radiotherapy, comparing the radiotherapy procedures performed with the conventional two-dimensional technique (RT-2D) with the conformal three-dimensional technique (RTC-3D). The study analyzed twelve patients who underwent radiotherapy, and the patients' cardiac function was assessed by myocardial scintigraphy performed before and after radiotherapy. The parameters of analysis were ejection fraction (LVEF) and left ventricular global ventricular function, both of which were pointed out in the nuclear medicine examination report. Only one patient had a significant alteration of the LVEF between the two myocardial scintigraphies. For the clinical cases analyzed, it was not possible to establish a direct relationship between cardiac function changes and the applied radiotherapy technique. / Mestre

Purpose: To evaluate the diagnostic performance of Coronary Computed Tomography Angiography (CCTA) in predicting Myocardial Perfusion Scintigraphy (MPS) perfusion defects in low likelihood patients with End Stage Renal Disease (ESRD) awaiting transplant. Materials and Methods: In total, 131 consecutive patients with ESRD awaiting transplant were prospectively enrolled in this study (86 men; 54±9years). All patients underwent MPS as per standard of care and in addition non-enhanced CT for calcium scoring (CAC score) and Coronary Computed Tomography Angiography (CCTA). Results: The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CAC score in predicting MPS perfusion defects were 88%, 35%, 28% and 92%, respectively. The sensitivity, specificity, PPV and NPV of CCTA in predicting MPS perfusion defects at the patient level were 55%, 87%, 57% and 87%, respectively, and 48%, 92%, 41% and 94% at the vessel level. The diagnostic performance of CCTA in predicting MPS perfusion defects improved when patients with CAC score higher than 1000 (15/70, 21%) were excluded from the analysis. In patients with positive CAC score up to 1000 sensitivity, specificity, PPV and NPV at the patient level were 60%, 93%, 75% and 86% respectively. These were 53%, 91%, 36% and 95%, respectively, at the vessel level. Conclusion: Non-enhanced CT for CAC score and CCTA can be considered useful diagnostic tools in the ESRD population, particularly in identifying patients without coronary artery disease. This approach however had limitations in the presence of high CAC score.

Introdução: Os benefícios da cistocintilografia direta (CD) cíclica no diagnóstico de refluxo vesicoureteral (RVU) são pouco estudados. O objetivo deste estudo foi investigar a influência da CD cíclica em crianças e adultos, além da avaliação da classificação e lateralidade do refluxo, o tempo de duração total do exame e de cada ciclo, e a ocorrência de refluxo nas fases de enchimento e/ou micção. Métodos: Foram estudados 362 exames em pacientes com idade de 15,8 ± 17,2 anos (2 meses a 76,4 anos), sendo 89,5% do gênero feminino. Os exames foram divididos em três grupos: crianças até cinco anos (A), crianças maiores de cinco e até 14 anos (B), e maiores de 14 anos (C). Resultados: A distribuição da quantidade de ciclos na CD indicou maior ocorrência de 2 ciclos (37,6%) e 3 ciclos (56,6%). O RVU foi diagnosticado em 21% dos exames desde o primeiro ciclo, em 5,5% no 2º ciclo, e, em 2,5% apenas no 3º ciclo. Em nenhum exame o 4º, 5º ou 6º ciclos permitiram diagnóstico adicional de RVU. A maioria dos exames com RVU correspondeu ao grau II. O refluxo ocorreu apenas na fase de enchimento em 10%, na fase de micção em 27% e em ambas as fases, em 63% dos exames. Houve maior ocorrência de refluxo nos grupos A e B do que no C, desde o 1º ciclo. O segundo ciclo foi igualmente eficaz no diagnóstico de RVU nos três grupos. No grupo A, a realização do terceiro ciclo foi mais eficaz, quando comparado aos demais grupos. Não houve diferenças significantes quanto à lateralidade do refluxo. Conclusão: No grupo A, observou-se menor tempo de duração dos exames embora com maior quantidade de ciclos e maior eficácia diagnóstica quanto à realização de terceiro ciclo. A adição de segundo ciclo foi útil no diagnóstico do RVU nos grupos A e B, assim como a ocorrência de RVU foi maior nessa faixa etária, quando comparado a adultos. No grupo C, observou-se eficácia semelhante aos demais grupos quanto à realização de segundo ciclo de enchimento e micção, entretanto não houve benefício com a adição / Introduction: The benefits of cyclic direct cystoscintigraphy (CD) for the diagnosis of vesicoureteral reflux (VUR) are poorly studied. The aim of this study was to investigate the influence of cyclic CD in children and adults and evaluate the classification and laterality of reflux, the total duration of the examination and of each cycle and the occurrence of reflux in the filling and/or voiding phases. Methods: A total of 362 examinations were performed in patients with a mean age of 15.8 ± 17.2 years (2 months to 76.4 years, 89.5% female). The examinations were divided into three groups: children younger than five years old (A), children older than five and younger than 14 (B) and patients older than 14 (C). Results: The distribution of the number of cycles in the CD examinations indicated that there were higher occurrences of two (37.6%) and three cycles (56.6%). VUR was diagnosed in 21% of patients based on the 1st cycle, 5.5% in the 2nd cycle and 2.5% only in the 3rd cycle. No examinations yielded additional VUR diagnoses with the 4th, 5th or 6th cycles. Most examinations showing VUR corresponded to grade II. Reflux occurred in only the filling phase in 10%, only the voiding phase in 27% and both phases in 63% of patients. There was a higher incidence of reflux in groups A and B than group C following the 1st cycle. The 2nd cycle was equally effective in diagnosing VUR in all three groups. In group A, the 3rd cycle was more effective compared to the other groups. There were no significant differences in the laterality of reflux. Conclusions: In group A, the examination duration was shorter, although there were more cycles and a greater diagnostic efficacy when a 3rd cycle was performed. The addition of a 2nd cycle was useful for diagnosing VUR in groups A and B, and the occurrence of VUR was higher in these age groups compared to adults. In group C, there was similar efficiency compared to others groups relative to the 2nd filling and voiding cycle; however, there were no benefits to adding a 3rd cycle

The use of nebulization is becoming increasingly frequent in treatment of acute or chronic lung diseases for delivery of topically active drugs and is also an attractive way to deliver systemic drugs. A nebulizer can be defined by the aerodynamic properties of the emitted particles which are directly related to the lung deposition and the clinical response to a nebulized drug. New guidelines elaborated by an European norm (ENFR13544-1) aim to participate to a better control on quality and efficiency of existing devices and inspired the elaboration of the studies of this thesis. The aim of these works was to evaluate the nebulization function of a new kind of modality, the intrapulmonary percussive ventilation which contrarily to classical jet nebulizers nebulizes drugs under superimposed percussion conditions. In vitro measurements were realized by cascade impaction and laser diffraction. Lung deposition was investigated by imagery techniques and pharmacokinetic study. Aerodynamic properties were different between the in vitro methods. When measured by cascade impaction, MMAD and FPF were smaller for IPV comparatively to SST. By laser diffraction, FPF remained lower but MMAD was higher with IPV than with SST. The effect of percussions was greater on MMAD than on FPF. An irregular intrapulmonary deposition and a higher whole body deposition due to a higher extrapulmonary deposition with the IPV were measured by scintigraphy. The pharmacokinetic study highlighted that the drug output and the lung dose were lower when amikacin was delivered by IPV comparatively to SST. All results of these different studies seem unfavourable to the use of intrapulmonary percussive ventilation as modality of administration for nebulized drugs without further investigations. Results presented in this thesis concerning exclusively healthy subjects, we hope that they encouraged to perform complementary analysis and observations in different conditions such as patients with lung disease.

Our goal was to develop a mucoadhesive, oral vaccination delivery platform designed to target Peyer’s patches at ileum. In order to achieve this, we prepared poly(methyl methacrylate) (PMMA) particles of various sizes using W/O/W emulsification solvent evaporation and surface polymerization methods. We then coated and employed mucoadhesive polymers into the carrier system to enhance the residence time in the targeted site. Also we developed our own in vitro mucoadhesion testing ramp as an evaluation tool. Finally, nano- and micro-structured particles were manufactured as two different oral vaccine delivery systems (Solid Lipid Nanoparticles, SLNs; and Protein Coated Microcrystals, PCMC). After the model antigen, bovine serum albumin (BSA) was loaded into the SLNs or PCMC; mucoadhesive polymers were then incorporated and formulated the mixture into pellets. The pellets were then layered with an enteric coating, which was composed of a mixture of Eudragit® FS 30 D/Eudragit® L 30 D-55 for ileum targeted delivery. The in vitro mucoadhesion test ramp was capable of investigating the mucoadhesive properties of tablets and pellets, providing a rank order for study. Most important of all, it was anticipated that this might reduce the burden of testing animals for future proposed mucoadhesive studies. Microcapsules/beads of specific size were manufactured reproducibly by solvent evaporation and surface polymerization. Although we could not specify the cut-off size at the pyloric sphincter in mice, we concluded that the cut-off size at the pyloric sphincter in rats was approximately 2.5-3 mm, which was supported by both the biodistribution data and the direct image results from scintigraphy scanning. Moreover, we found that the particle size significantly alters the gastric emptying time in both rodent models. The small microcapsules/beads were hindered in the folds of the stomach (size 50-100μm for mice and size 0.5-1 mm for rats) and emptied the slowest, followed by the large particles, then the medium particles. Finally, PCMC and SLNs we manufactured were suitable carriers for protein API, such as BSA. These particles were of fitting size for M cell uptake, which would possibly induce mucosal immune responses. Therefore, an antigen containing PCMC and SLNs might be suitable platforms for oral vaccination. / text

This thesis is an investigation of diagnostic staging and palliative radiation therapy (RT) for appendicular osteosarcoma (OSA) in dogs. Osteosarcoma is a common, highly metastatic primary bone tumour of dogs. The purpose of the first study was to assess the utility of whole body computed tomography (CT) in evaluation of metastasis in dogs with primary appendicular OSA. The objectives were to determine the utility of whole body CT as a staging tool for dogs with appendicular OSA, compare the lesion detection rate of bone scintigraphy, long bone survey radiography and whole body CT in dogs with appendicular OSA and determine the prevalence of CT-detected lung metastasis in dogs with appendicular OSA that have normal thoracic radiographs. This was a prospective cross-sectional observational study involving fifteen dogs. Test modalities were assessed against a construct reference standard for detection of bone metastasis and thoracic radiographs negative for metastatic lesions were compared against thoracic CT. Bone scintigraphy identified 5 bone lesions in 4 dogs with 2 false positive and 2 false negative results. No lesions were identified on survey radiographs or CT during blinded assessment. CT was useful for further characterizing lesions identified by bone scintigraphy. Thoracic CT identified both definitive and equivocal lesions not visible radiographically. Four dogs had equivocal ground glass pulmonary lesions on CT; 3 of these lesions progressed to radiographically discrete nodules. Overall, bone scintigraphy was the only modality that identified metastatic bone lesions. Whole body CT did not appear to be useful as alternative to bone scintigraphy; however, it may have some utility as an adjunctive diagnostic modality. Thoracic CT identified pulmonary lesions that were not visible radiographically. Ground glass pulmonary lesions in dogs should be considered suspicious for metastasis and serially monitored. The purpose of the second study was to retrospectively assess factors affecting survival time in dogs undergoing palliative RT for appendicular OSA. Fifty dogs undergoing a palliative RT protocol for spontaneous primary appendicular bone tumours were included and divided into treatment groups based on treatments administered in addition to RT. Median survival times (MST) were longest for dogs receiving RT and chemotherapy (307 days; 95%CI= 279-831) and shortest in dogs receiving RT and pamidronate (69 days; 95%CI=47-112 days). The difference in MST between dogs who received pamidronate and those who did not in this population was statistically significant on univariate (p=0.039) and multivariate analysis (p=0.0015). The addition of chemotherapy into any protocol improved survival (p<0.001). Based on the findings in this study, chemotherapy should be recommended in addition to a palliative RT protocol to improve survival of dogs with primary appendicular bone tumours. When combined with RT +/- chemotherapy, pamidronate decreased MST. / Ontario Veterinary College Pet Trust Fund

Im Rahmen der szintigraphischen Untersuchung der Halswirbelsäule gibt es unterschiedliche Aussagen zum physiologischen Speicherungsverhalten, insbesondere der kaudalen Facettengelenke. Eine Objektivierung der Szintigramme und Ermittlung von Normalbereichen der entsprechenden Speicherquotienten ist daher wichtig und stellt das Ziel dieser Arbeit dar. Zur Untersuchung kamen dafür 31 Pferde, bei denen es sich um Patienten der Chirurgischen Tierklinik in Leipzig aus dem Jahr 2008 handelte. Falls bei einem Pferd eine Lahmheit der Vordergliedmaße vorhanden war, wurde mit Hilfe der klinischen und szintigraphischen Untersuchung, sowie mittels diagnostischer Anästhesien als deren Ursache die Halswirbelsäule ausgeschlossen. Alle Pferde wiesen eine freie Beweglichkeit des Halses in alle Richtungen auf. Zur Bildung von Speicherquotienten wurden die als Interessenareale dienenden Facettengelenke C3/C4 bis C7/Th1, sowie der Wirbelkörper des sechsten Halswirbels zu verschiedenen Referenzarealen ins Verhältnis gesetzt. Als Referenzareale wurden dabei der Wirbelkörper des dritten und des vierten Halswirbels, sowie das auch als Interessenareal dienende Facettengelenk C3/C4 getestet. Anschließend wurden Normalbereiche für die Speicherquotienten ermittelt. Nach sonographischer Muskeldickenmessung über den Facettengelenken wurden deren Speicherquotienten mit Hilfe einer Formel auf einen Nullwert korrigiert, und für diese korrigierten Werte wurden ebenfalls Normalbereiche ermittelt. Es zeigte sich, dass die Speicherquotienten nach der Muskeldickenkorrektur gegenüber den nativen Speicherquotienten eine größere Streuung aufwiesen und somit größere und ungenauere Normalbereiche hervorbrachten. Dementsprechend sollten die nativen Speicherquotienten bevorzugt werden. Als das am besten geeignete Referenzareal für die Interessenareale C4/C5 bis C7/Th1 erweist sich hierbei die Isokontur-ROI auf dem Facettengelenk C3/C4. Für das Interessenareal C3/C4 eignet sich sowohl der Vergleich mit dem Referenzareal C3, als auch der mit dem Referenzareal C4. Das Interessenareal auf dem Wirbelkörper C6 wird am besten zum Referenzareal C4 ins Verhältnis gesetzt. Hervorzuheben sind die nativen Werte der Normalbereiche für die Gelenke C5/C6 und C6/C7, da hier am häufigsten röntgenologische Veränderungen zu finden sind. Sie betragen für das Gelenk C5/C6 auf der linken Halsseite 0,82-1,10 und auf der rechten Halsseite 0,86-1,10. Für das Gelenk C6/C7 beträgt der Normalbereich für die linke Halsseite 0,75-1,23 und für die rechte Halsseite 0,81-1,17. Zusammenfassend ist zu sagen, dass die quantitative Auswertung mittels der „Regions of Interest“-Technik an der Halswirbelsäule durchaus möglich ist und mit dieser Arbeit akzeptable Normalbereiche für die Facettengelenke C3/C4 bis C7/Th1 und für den Wirbelkörper C6 ermittelt werden konnten. Es fehlen nun noch Werte von Pferden mit einer klinischen Halswirbelsäulenproblematik, um die Aussagekraft der hier ermittelten Normalbereiche zu überprüfen.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2006. / Härtill 4 uppsatser.

As dilatações vasculares intrapulmonares (DVIP) constituem a anormalidade vascular pulmonar mais freqüente e a principal causa de hipoxemia grave em hepatopatas. A associação de doença hepática, aumento do gradiente alvéoloarterial de oxigênio e DVIP é chamada de "síndrome hepatopulmonar". O objetivo principal deste estudo foi verificar se os níveis de DVIP aferidos por ecocardiografia com contraste estão relacionados à intensidade de shunt intrapulmonar, medida por dois diferentes métodos: cintilografia com 99mTc-MAA e gasometria com O2 a 100%. Foram estudados 28 candidatos a transplante hepático portadores com DVIP identificadas e graduadas por ecocardiografia conforme escala semi-quantitativa (graus I a IV). A idade média foi de 47,5 anos, e a doença hepática foi classificada como Child-Pugh B na maioria dos casos (60,7%). A intensidade das DVIP foi classificada como I, II, III e IV em 13 (46,4%), 9 (32,1%), 2 (7,1%) e 4 (14,3%) casos, respectivamente. Dos 28 pacientes, 21 (75%) tiveram quantificação de shunt pelo método cintigráfico e gasométrico, 6 (21,4%) apenas pelo método cintigráfico e 1 caso (3,6%) pelo método gasométrico apenas. A PaO2 média entre os pacientes com DVIP graus I e II por ecocardiografia foi 89,1 ± 11,0mmHg, enquanto naqueles com DVIP classificadas como graus III e IV foi 74,7 ± 13,2mmHg (p = 0,01). A média dos valores de shunt por cintilografia nos 27 pacientes submetidos ao exame foi 14,9 ± 9,0% do débito cardíaco (mínimo 6,9% e máximo 39%), sendo 11,7 ± 3,8% nos pacientes com DVIP graus I e II, e 26,3 ± 9,7% nos pacientes com DVIP graus III e IV (p = 0,01). A média dos valores de shunt pelo teste com O2a 100% foi 9,8 ± 3,9%, sendo 8,3 ± 2,3% nos pacientes com DVIP graus I e II, e 16,3 ± 2,6% nos pacientes com DVIP graus III e IV (p < 0,001). Observou-se uma relação estatisticamente significativa entre a graduação de DVIP por ecocardiografia e o valor de shunt aferido por gasometria com O2 a 100% (rs = 0,609, p < 0,01) e por cintilografia (rs = 0,567, p < 0,001). Observou-se relação estatisticamente significativa entre os valores de shunt medidos por cintilografia e aqueles medidos por gasometria com O2 a 100% nos 21 pacientes que se submeteram à quantificação de shunt pelos 2 métodos (rs = 0,666, p < 0,001). A avaliação semi-quantitativa do grau de DVIP por ecocardiografia apresentou correlação moderada a boa com os valores de shunt aferidos pelos dois outros métodos estudados, sendo que a melhor correlação foi observada com o teste com O2 a 100%. / Intrapulmonary vascular dilatations (IPVD) are the most common pulmonary vascular abnormality and the main cause of acute hypoxemia in patients with severe liver disease. The association of liver disease, increased alveolar-arterial oxygen gradient and IPVD is known as "hepatopulmonary syndrome". The chief aim of this study was to determine whether IPVD levels, as determined by contrast echocardiography, are related to intrapulmonary shunt intensity, as measured by Tc- 99m MAA scintigraphy and by 100% oxygen gasometry. Twenty-eight IPVD patients, all candidates for liver transplant, were studied. IPVD were identified using echocardiography and graded on the semiquantitative scale (levels I to IV). The mean age was 47.5 years. Liver disease was classified as Child-Pugh B in 60.7% of cases. IPVD intensity was classified as level I, II, III and IV in 13 (46.4%), 9 (32.1%), 2 (7.1%) and 4 (14.3%) cases, respectively. Of the 28 patients, shunt intensity was determined using both scintigraphy and gasometry in 21 patients (75%), by scintigraphy only in 6 (21.4%) and by gasometry only in 1 (21.4%). Mean PaO2 was 89.1 ± 11.0mmHg among level I and II patients and 74.7 ± 13.2mmHg among level III and IV patients (p = 0.01). The mean shunt by scintigraphy was 14.9 ± 9.0% of cardiac output (minimum 6.9% and maximum 39%), being 11.7 ± 3.8% among level I and II patients and 26.3 ± 9.7% among level III and IV patients (p = 0.01). The mean shunt by gasometry was 9.8 ± 3.9%, being 8.3 ± 2.3% among level I and II patients and 16.3 ± 2.6% among level III and IV patients (p < 0.001). There was a significative correlation between IPVD level and shunt intensity: rs = 0.609; p < 0.01 by gasometry and rs = 0.567; p < 0.001 by scintigraphy. In those patients undergoing both tests, a significant relation was found between shunt intensity as measured by scintigraphy and by gasometry: rs = 0.666; p < 0.001. Hypoxemic individuals had significantly higher levels of intrapulmonary vascular dilatation than did nonhypoxemic individuals. Semiquantitative evaluation of IPVD level showed moderate to good correlation with shunt intensity under each of the two methods used, with the better correlation being found under 100% oxygen gasometry.