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1.
Pediatr Radiol ; 53(6): 1076-1084, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36737516

RESUMO

BACKGROUND: The most common chronic complication of preterm birth is bronchopulmonary dysplasia (BPD), widely referred to as chronic lung disease of prematurity. All current definitions rely on characterizing the disease based on respiratory support level and do not provide full understanding of the underlying cardiopulmonary pathophysiology. OBJECTIVE: To evaluate a rapid functional lung imaging technique in premature infants and to quantitate pulmonary ventilation using 1.5 Tesla magnetic resonance imaging (MRI). MATERIALS AND METHODS: We conducted a prospective MRI study of 12 premature infants in the neonatal intensive care unit (NICU) using the phase resolved functional lung MRI technique to calculate pulmonary ventilation parameters in preterm infants with and without BPD grade 0/1 (n = 6) and grade 2/3 (n = 6). RESULTS: The total ventilation defect percentage showed a significant difference between groups (16.0% IQR (11.0%,18%) BPD grade 2/3 vs. 8.0% IQR (4.5%,9.0%) BPD grade 0/1, p = 0.01). CONCLUSION: Phase-resolved functional lung MRI is feasible for assessment of ventilation defect percentages in preterm infants and shows regional variation in localized lung function in this population.


Assuntos
Displasia Broncopulmonar , Nascimento Prematuro , Lactente , Feminino , Recém-Nascido , Humanos , Recém-Nascido Prematuro , Displasia Broncopulmonar/diagnóstico por imagem , Estudos Prospectivos , Pulmão/patologia , Imageamento por Ressonância Magnética/métodos
2.
NMR Biomed ; 32(6): e4088, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30908743

RESUMO

PURPOSE: To test the feasibility of regional fully quantitative ventilation measurement in free breathing derived by phase-resolved functional lung (PREFUL) MRI in the supine and prone positions. In addition, the influence of T2 * relaxation time on ventilation quantification is assessed. METHODS: Twelve healthy volunteers underwent functional MRI at 1.5 T using a 2D triple-echo spoiled gradient echo sequence allowing for quantitative measurement of T2 * relaxation time. Minute ventilation (ΔV) was quantified by conventional fractional ventilation (FV) and the newly introduced regional ventilation (VR), which corrects volume errors due to image registration. ΔVFV versus ΔVVR and ΔVVR versus ΔVVR with T2 * correction were compared using Bland-Altman plots and correlation analysis. The repeatability and physiological plausibility of all measurements were tested in the supine and prone positions. RESULTS: On global and regional scales a strong correlation was observed between ΔVFV versus ΔVVR and ΔVVR versus ΔVVRT2* (r > 0.93); however, regional Bland-Altman analysis showed systematic differences (p < 0.0001). Unlike ΔVVRT2* , ΔVVR and ΔVFV showed expected physiologic anterior-posterior gradients, which decreased in the supine but not in the prone position at second measurement during 3 min in the same position. For all quantification methods a moderate repeatability (coefficient of variation <20%) of ventilation was found. CONCLUSION: A fully quantified regional ventilation measurement using ΔVVR in free breathing is feasible and shows physiologically plausible results. In contrast to conventional ΔVFV, volume errors due to image registration are eliminated with the ΔVVR approach. However, correction for the T2 * effect remains challenging.


Assuntos
Pulmão/fisiologia , Imageamento por Ressonância Magnética , Ventilação Pulmonar/fisiologia , Respiração , Adulto , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Pulmão/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Postura , Reprodutibilidade dos Testes
3.
Am J Transplant ; 18(8): 2050-2060, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29607606

RESUMO

Chronic lung allograft dysfunction (CLAD) remains the leading cause of morbidity and mortality after lung transplantation. Diagnosis requires spirometric change, which becomes increasingly difficult with advancing CLAD. Fourier decomposition magnetic resonance imaging (FD-MRI) permits acquisition of ventilated-weighted images during free-breathing. This study evaluates FD-MRI in detecting CLAD in selected patients after bilateral lung transplantation (DLTx). DLTx recipients demonstrating CLAD at various stages participated. Radiologists remained blinded to clinical status until completion of image analysis. Image acquisition used a 1.5-T MR scanner using a spoiled gradient echo sequence. After FD processing and regional fractional ventilation (RFV) quantification, the volume defect percentage at 2 thresholds (VDP1,2 ), median lung RFV and quartile coefficient of dispersion (QCD) were calculated. Sixty-two patients participated. CLAD was present in 29/62 (47%) patients, of whom 17/62 (27%) had forced expiratory volume in 1 second ≤65% at image acquisition. VDP1 was higher among these participants compared to other groups (P < .001). Increased VDP1 was associated with subsequent graft loss, with values >2% showing reduced survival, independent of degree of graft dysfunction (P = .005). VDP2 discriminated between presence or absence of CLAD (area under the curve = 0.71; P = .03). QCD increased significantly with advancing disease (P < .001). In conclusion, FD-MRI-derived parameters demonstrate potential in quantitative CLAD diagnosis and assessment after DLTx.


Assuntos
Bronquiolite Obliterante/cirurgia , Rejeição de Enxerto/diagnóstico , Transplante de Pulmão/efeitos adversos , Imageamento por Ressonância Magnética/métodos , Complicações Pós-Operatórias , Disfunção Primária do Enxerto/diagnóstico , Adulto , Aloenxertos , Doença Crônica , Estudos Transversais , Feminino , Seguimentos , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto , Humanos , Masculino , Pessoa de Meia-Idade , Disfunção Primária do Enxerto/etiologia , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
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