Purpose: It is the intention of this study to compare pulmonary and aortic line flow measurements obtained in patients after single lung transplantation (SLTX) with those in volunteers Methods/material: In nine patients after SLTX (three male.

Purpose: It is the intention of this study to compare pulmonary and aortic line flow measurements obtained in patients after single lung transplantation (SLTX) with those in volunteers

Methods/material: In nine patients after SLTX (three male, six female) and nine proffers (seven male, two female), double oblique phase contrast cine-MRI successions perpendicular to the direction of descendants flow were obtained in the ascending aorta, main, right, and left pulmonary artery in succession a 0.5-T unit (Philips Gyroscan; Best, the Netherlands) (repetition time, 600 to 800 ms; resound time, 8 ms; alpha=30; field of view=280 mm matrix, 128x256 ECG gating, temporal resolution 16 time frames/RR interval). An initial in vitro reflection using the same sequence forward a nonpulsatile flow phantom showed of the first grade correlation (r=0.99) between MRI measurements of melt velocity and flow volume and faithful velocity and flow volume. Measurements of children flow volume (mL/min), peak mean systolic velocity, resistive index, and distensibility index were obtained in each vessel

Results: We raise excellent correlations between left and right cardiac output as measured by dint of velocity encoded cine-MRI (VEC-MRI) in the ascending aorta and main pulmonary artery as well-as; not only-but also; not only-but; not alone-but in normal volunteers (r=0.95) and in patients (r=091) Differential pulmonary kindred flow measurements in volunteers showed that 55% of the right cardiac output was directed to the right and 45% to the left lung Differential pulmonary progeny flow in patients showed that chiefly of the blood flow (81%) reaches the transplanted lung and solely 19% reaches the patient's confess lung (SLTX: 4.5 [+ or -] 18 L/min, patient's confess lung: 1.2 [+ or -] 08 L/min). There were significant differences (p[is les than]0.05) in peak mean systolic velocity and resistive index obtained in the pulmonary arteries, the two between normal volunteers and patients and between measurements obtained in the patient's acknowledge lung and the transplanted lung

Conclusion: VEC-MRI posterity flow measurements are a promising noninvasive tool to monitor the hemodynamic changes of pulmonary kindred flow after SLTX.

(CHEST 1998; 114:771-779)

Key words: lung transplantation; magnetic resonance be derived measurements; pulmonary hemodynamics

Abbreviations: AAO=ascending aorta; AF=antegrade flow; DI=distensibility index; EDV=End-diastolic velocity; LPA=left pulmonary artery; LTX=lung transplantation; MPA=main pulmonary artery; PSV=peak systolic velocity; PVR = pulmonary vascular resistance; RF = retrograde flow; RI = resistive index; RPA = right pulmonary artery; SLTX= single lung transplantation; VEC-MRI=velocity encod cine-MRI

Since 1993 single lung transplantation (SLTX) has become a viable therapeutic option for a variety of end-stage pulmonary disorders.[1-4] Patients suffering from various forms of end-stage lung diseases can disclose different degrees of pulmonary hypertension becoming to elevated pulmonary vascular resistance (PVR) When transplanting a single lung a normal yet denervated pulmonary vascular bed is restored. Therefore, in SLTX right cardiac output is emited into two different lungs with vascular beds of non-congruent physical conditions. offspring flow to the transplanted lung may be influenced by the agency of the relative vascular resistance of the one and the other the diseased and the transplanted lung and on other factors, such as denervation, lack of bronchial arterial give and lymphatics, immunosuppressive therapy, and rejection episodes.

The reply of right heart function and pulmonary hemodynamics to SLTX and bilateral lung transplantation (BLTX) has been investigated by dint of various invasive techniques as well as by the agency of echocardiography and conventional volumetric multislice-multiphase MRI.[5,6] However, differential pulmonary relations flow and hemodynamics are difficult to assess. Percentages of differential pulmonary family flow can be measured at means of radioactive isotopes.[7] Ultrasonographic techniques are limited because transthoracic echocardiography does not have an appropriate window to the pulmonary arteries[8] and transesophageal Doppler sonography does not allow accurate measurements of differential lung perfusion.[9]

Velocity encod cine-MRI (VEC-MRI) is a modern phase-contrast MRI technique that has been shown to allow accurate noninvasive assessment of hemodynamics, descendants flow volume, and flow velocities in major utensils of the human body. [10] Several investigators reported differential pulmonary family flow measurements in healthy volunteers[11] Others applied this technique and evolveed VEC-MRI-derived parameters to study pulmonary hemodynamic changes in primary and secondary pulmonary hypertension.[12] There are solely few reports on VEC-MRI be molten measurements in the superior vena cava, main, and right and left pulmonary arteries in patients after LTX[1314] However, the noninvasive information provided according to VEC-MRI might improve the understanding of the physiologic behavior of pulmonary arteries after SLTX

It was the plan of this study to define posterity flow, flow patterns, differential lung perfusion, and noninvasive parameters of pulmonary vascular resistance using noninvasive VEC-MRI in patients after SLTX and in normal volunteers

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