T1 and T2 Mapping by Cardiac MRI: A Novel Tool for Detecting Acute Rejection After Heart Transplantation

Presenting Author(s)

• 

  Natassia SSC Gomes, MD

  Doctor
  Instituto Dante Pazzanese de Cardiologia
  São Paulo, Sao Paulo, Brazil

Primary Author(s)

• 

  Natassia SSC Gomes, MD

  Doctor
  Instituto Dante Pazzanese de Cardiologia
  São Paulo, Sao Paulo, Brazil

Co-Author(s)

• 

  Marina R. Cavallari, MD

  Doctor
  Instituto Dante Pazzanese de Cardiologia
  São Paulo, Sao Paulo, Brazil
• 

  Alice Cunha Darzé, MD

  Cardiologist
  Instituto Dante Pazzanese de Cardiologia
  São Paulo, Sao Paulo, Brazil
• 

  Amanda Marsiaj Rassi, MD

  Cardiologist
  Instituto Dante Pazzanese de cardiologia
  São Paulo, Sao Paulo, Brazil
• 

  Camilla F. Reimberg, MD

  Doctor
  Instituto Dante Pazzanese de Cardiologia
  São Paulo , Sao Paulo, Brazil
• GM

  Gustavo R. Modolo, MD

  Doctor
  Instituto Dante Pazzanese de Cardiologia, Brazil
• JR

  João M. Rossi, MD, PhD

  Chief of the Cardiac Transplantation Department
  Instituto Dante Pazzanese de Cardiologia, Brazil
• MA

  Marco Aurélio Finger, MD, PhD

  Doctor of Cardiac Transplantation Department
  Instituto Dante Pazzanese de Cardiologia, Brazil
• CC

  Carolina Casadei, MD

  Doctor of Cardiac Transplantation Department
  Instituto Dante Pazzanese de Cardiologia, Brazil
• RR

  Raphael Rossi, MD

  Doctor of Cardiac Transplantation Department
  Instituto Dante Pazzanese de Cardiologia, Brazil
• PW

  Plínio Wolf, MD

  Doctor
  Instituto Dante Pazzanese de Cardiologia, Brazil
• HG

  Haissa Geraldo, MD

  Doctor
  Instituto Dante Pazzanese de Cardiologia, Brazil
• JC

  João Marcelo Caneschi, MD

  Cardiologist
  Instituto Dante Pazzanese de Cardiologia
  São Paulo, Sao Paulo, Brazil
• EB

  Everton R. Barbosa, MD

  MD
  Instituto Dante Pazzanese de Cardiologia, Brazil
• RH

  Rafael Hendges, MD

  Doctor
  Instituto Dante Pazzanese de Cardiologia, Brazil
• 

  Paul Salvador Salvador Morales, MD

  Cardiologist
  Instituto Dante Pazzanese de Cardiologia
  São Paulo, Sao Paulo, Brazil
• LP

  Luciano G. Possa, MD

  Doctor
  Instituto Dante Pazzanese de Cardiologia, Brazil
• CP

  Carlos Eduardo E E D Prazeres, MD

  Doctor
  Instituto Dante Pazzanese de Cardiologia, Brazil
• 

  Antonio Tito 3. Paladino Filho, MD, PhD

  Cardiologist
  Hospital Vila Nova Star, Rede D’or São Paulo-SP
  Sao Paulo, Sao Paulo, Brazil
• 

  Tiago Senra, MD, PhD

  Physician
  Dante Pazzanese Institute of Cardiology
  Sao Paulo, Sao Paulo, Brazil
• 

  Ibraim Masciarelli Pinto, MD, PhD

  Director, Non Invasive Cardiology
  Instituto Dante Pazzanese de Cardiologia
  Sao Paulo, Sao Paulo, Brazil

Description of Clinical Presentation: We report the case of a 29-year-old female with a history of genetic cardiomyopathy due to TNNI3 mutation, who underwent orthotopic heart transplantation in 2023. During outpatient follow-up, she was asymptomatic and maintained on therapeutic doses of immunosuppressive therapy. However, echocardiography revealed progressive worsening of global longitudinal strain, accompanied by increased NT-proBNP and troponin levels, while biventricular systolic function remained preserved. She was referred for cardiac magnetic resonance (CMR) to assess myocardial involvement and characterize tissue abnormalities. Endomyocardial biopsy and antibody reactivity panel were both consistent with severe antibody-mediated rejection.

Diagnostic Techniques and Their Most Important Findings: The patient underwent CMR on a Philips MR5300 1.5 Tesla scanner with the following protocol:

• 
  Cine imaging: Preserved cardiac chamber dimensions and biventricular systolic function.
  
  


• 
  Native T1 and T2 mapping: Globally increased values consistent with diffuse edema and increased extracellular myocardial volume.
  
  

• 
  Inversion recovery (triple IR): Demonstrated marked diffuse myocardial edema.
  
  


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  First-pass perfusion at rest: No perfusion defects.
  
  


• 
  Late gadolinium enhancement (LGE): No evidence of replacement fibrosis or necrosis.
  
  

Learning Points from this Case: Endomyocardial biopsy remains the gold standard for diagnosing rejection after heart transplantation, but it is invasive and subject to sampling error and interobserver variability. Cardiac MRI, particularly through T1 and T2 mapping, allows non-invasive tissue characterization and provides valuable information on myocardial edema, inflammation, and extracellular expansion, which reflect ongoing graft injury. Notably, the absence of fibrosis on late gadolinium enhancement does not exclude active rejection. In this case, the correlation between mapping abnormalities and biopsy findings underscores the incremental role of CMR as a complementary diagnostic tool in antibody-mediated rejection. By offering quantitative parameters with lower interobserver variability, CMR increases diagnostic reliability and may ultimately reduce reliance on repeated invasive procedures. As evidence accumulates, CMR mapping has the potential to emerge as a future standard in heart transplant surveillance, redefining the paradigm of rejection monitoring.

Diffuse biventricular myocardial hyperintensity on T2-weighted sequences, suggestive of myocardial edema. Absence of late gadolinium enhancement.
T1 mapping and T2 mapping: elevated values in all left ventricular segments.