Magnetic Resonance Imaging in the Study of Cardiac Masses: A Case Series

Round 1

Reviewer 1 Report

After reading the manuscript titled "Magnetic Resonance Imaging in the Study of Cardiac Masses: A Case Series" submitted to Medicina, I found the presented cases to be informative, showcasing cardiac masses detected using CMR. However, the cases appeared to be commonplace, lacking any exceptional images or noteworthy clinical findings. Furthermore, while the discussion did touch upon various aspects of CMR and cardiac masses, it would benefit from additional material to fully explore the topic.

Author Response

Dear reviewer, thank you for your recommendations; they enrich the manuscript content. We hope our publication will be didactic for the differential diagnosis of cardiac tumors and accessible to physicians interested in this subject.

We made a point-by-point response to your comments and brought indications of the corrections on the second version of the manuscript.

 

Cardiac tumors are rare entities, and the published literature on this subject is not extensive compared to the study of other cardiovascular pathologies. The cohort studies of cardiac masses assessed by magnetic resonance imaging are scarce, and most of them present a small number of cases. For this reason, even though the images are not exceptional by themselves, it allows us to record a new case series in the literature. It is highlighted, the value of MRI, combined with other techniques, to establish a definitive diagnosis and also guide therapeutic decision-making in this scenario.

Regarding your suggestion to introduce additional material to enrich the text, we have included a table that lists the main characteristics of the different types of cardiac masses assessed by magnetic resonance. This manuscript is intended to be useful and didactic to facilitate differential diagnosis when a case of cardiac mass is presented. It is not only focused on radiologists and cardiologists, the information is accessible to physicians who are not specialists in this field.

Author Response File: Author Response.docx

Reviewer 2 Report

This is a well written case series on MRI for the diagnosis of cardiac masses. However, there are some comments.

I am surprised that there are no cardiac surgeons among the authors.

Any follow-up info for patients 1,2, and 3?

Case 1: Can you explain in detail the surgical technique performed by the heart surgeon for resection of the atrial mass in case 1?  

Discussion:

“Similarly, masses found in the left heart chamber are more frequently benign than those in right heart chambers, where more secondary metastatic tumors are found, or in the pericardium.” Do you have an explanation for this statement?

What are the limitations of MRI in the diagnosis of cardiac masses?

Conclusions:

 

“In all four cases in this series, cardiac MRI favorably affected management.” Can you explain in detail how the cardiac MRI affected the management?

Author Response

Dear Reviewer, thank you for your recommendations; they enrich the manuscript content. We hope our publication will be didactic for the differential diagnosis of cardiac tumors and accessible to physicians interested in this subject.

We made a point-by-point response to your comments and brought indications of the corrections on the second version of the manuscript

 

• This is a well written case series on MRI for the diagnosis of cardiac masses. However, there are some comments. I am surprised that there are no cardiac surgeons among the authors.

Indeed, among the authors of the article, there is no cardiac surgeon or thoracic surgeon. All the authors of the text belong to a cardiac imaging unit of our institution.

• Any follow-up info for patients 1,2, and 3?

The patient in case number 1 has been followed up for six months after discharge. She remains asymptomatic (NYHA I). Subsequent echocardiographic studies describe the absence of left atrial mass, with preserved left ventricular ejection fraction and no valvular heart disease.

The patient in case 2 has been closely followed up by the cardiology and oncology services. The patient has remained asymptomatic. In the control cardiac MRI at six months, the mass persisted at the atrial level but with similar dimensions to those previously described. She continues under chemotherapy with palliative intent.

In the case of the third patient, given the absence of data suggesting malignancy, a strategy of watchful waiting with periodic echocardiographic studies has been decided. During this time, the cardiac mass has maintained the same diameters. Once the double antiplatelet regimen has been completed after 6 months, the situation will be reassessed with the intention of surgical resection.

The follow-ups are highlighted on pages 3,4 and 6.

• Can you explain in detail the surgical technique performed by the heart surgeon for resection of the atrial mass in case 1?
  
  

Median sternotomy with pericardiotomy was the surgical approach. Extracorporeal circulation protocol was established and left atriotomy was performed for the atrial myxoma resection and subsequent endocardial repair with loose stitches. Simple suture was used for atria closing. Myocardial revascularization was then performed with a double bridge of saphenous vein the obtuse marginal artery and another saphenous vein to the posterior descending artery

The corrections are highlighted on page 3.

• What are the limitations of MRI in the diagnosis of cardiac masses?

Despite all the benefits described, MRI use in the study of cardiac masses has certain limitations. These include those specific to the patients, such as carrying metal devices that make it impossible to perform the test, excess abdominal circumference, claustrophobia, inability to collaborate or perform apneas;  and those derived from the health system, such as the high costs of its installation, lack of availability or the requirement of highly trained personnel in the interpretation of images, and intrinsic limitations of the technique. There is no feature in any MRI sequence that is capable of determining the diagnosis of cardiac mass with absolute precision. The combination of characteristics in the different sequences allows us to approach a specific diagnosis, but pathological anatomy provides histological certainty.

The corrections are highlighted on page 11.

• “Similarly, masses found in the left heart chamber are more frequently benign than those in right heart chambers, where more secondary metastatic tumors are found, or in the pericardium.” Do you have an explanation for this statement? ,.

The higher prevalence of secondary metastatic tumors in right cardiac chambers can be explained as the neoplastic spread is achieved through the venous return system, similar to right-sided endocarditis in predisposed patients. In the literature reviewed, no further explanation is given. Thanks for your suggestion; we have already modified the original text.  It is highlighted on page 9.

• “In all four cases in this series, cardiac MRI favorably affected management.” Can you explain in detail how the cardiac MRI affected the management?"

All four cases presented here have in common an intracardiac mass in the atrium. The information provided by MRI was valuable in all of them for clinical decision-making based on a multimodal approach using different imaging techniques.

In case 1, TTE enabled us to identify the origin of the patient's dyspnea and observe how the intracardiac mass was protruding into the left ventricle and interfering with adequate mitral valve function. Once the etiological diagnosis was established, MRI could characterize the intracardiac tumor as benign. Given the good prognosis due to the benign nature of the mass, it was decided to perform the same surgical act, the excision of the mass due to the hemodynamic repercussion and symptomatology that it produced in the patient, in addition to the coronary revascularization of the myocardium at ischemic risk. The histological study confirmed the accuracy of the imaging technique.

In case 2, routine TTE after acute myocardial infarction revealed the presence of a cardiac mass. Despite being initially an incidental finding, it later adquired clinical relevance. TTE could not accurately distinguish between a thrombus or  tumor. TEE provided relevant information as it pointed towards cancer due to the broad implantation base and followed the atrial wall's movement. Finally, MRI detected characteristics highly suggestive of malignancy, such as infiltration of the atrial wall, enhanced uptake after gadolinium administration, heterogeneity, and multiple small calcifications. Although T2 hyperenhancement is more common in benign than malignant tumors, it is not an exclusive characteristic of the latter. In this case, the image was hyperintense on T2, but the characteristics found in the different sequences pointed towards malignancy. This example shows that no characteristic can be used alone to distinguish benign from malignant tumors; therefore, the information should be integrated. This cardiac mass and bone metastases led to the decision, jointly with the Oncology Department, to continue with chemotherapy and avoid surgical treatment.

In case 3, the high likelihood of benignity indicated by this imaging prevented, at first, subjecting the patient to a high-risk surgical procedure due to the recent infarction. In addition, CT ruled out the presence of satellite images indicative of a primary tumor, further reducing the probability of malignancy. It was decided to postpone surgical excision of the intracardiac mass until after a convalescence period and allow a minimum period of double antiplatelet therapy given the recent percutaneous revascularization procedure with stent implantation, with initially conservative watch-and-wait management and follow-up. Subsequent studies and clinical evolution will determine the need for resection of the mass in the future.

In the last case, an image suggestive of metastasis in the cardiac region, well characterized by different MRI sequences, provided a poor prognosis for the patient. It was decided, at that time, to start palliative care, avoiding subjecting the patient to more futile treatments. The patient died less than a month after the diagnosis.

Author Response File: Author Response.docx

Reviewer 3 Report

This case report was well-written and easy to read, but this article is a review article.

 

It would be helpful for readers to add a table showing some essential tips to distinguish entities in terms of MRI characteristics.

Author Response

Dear Reviewer, thank you for your recommendations; they enrich the manuscript content. We hope our publication will be didactic for the differential diagnosis of cardiac tumors and accessible to physicians interested in this subject.

We made a point-by-ppint response to your comments and brought indications of the corrections on the second version of the manuscript.

 

• It would be helpful for readers to add a table showing some essential tips to distinguish entities in terms of MRI characteristics."

Dear Revisor, thank you for your recommendation. Table 2 on page 10 summarizes the main characteristics of the MRI sequences between the different types of cardiac masses.

 

Lesion	Thrombus Acute/Subacute	Thrombus Chronic	Neoplasic Benign	Neoplasic Malign
Location	Mural/intraluminal	Mural/intraluminal	More common left heart	More common right heart / pericardium
T1 Weighted	Iso-hyper	Hypo	Iso   No variable intensity   Myxoma heterogeneous	Iso   Variable intensity
T2 Weighted	Iso-hyper	Hypo	Hyper   No variable intensity   Myxoma heterogeneous	Hyper/Iso   Variable intensity
LGE	Hypointense border and brighter central zone	Rarely heterogeneous	Minimal uptake	Marked and heterogeneous
Perfusion (FPP)	No enhacement	Rare	No enhancement or mild	Strong enhancement
Pericardial Effusion	-	-	Uncommon	Common

 

Table 2: Cardiovascular magnetic resonance characteristic (location, signal intensity and contrast contrast-enhanced relative to that of adjacent normal myocardium of  thrombus acute, thrombus chronic, benign and malignant cardiac masses. FPP: First Pass Perfusion. LGE: Late gadolinium enhancement; Hypo: Hypointense; Iso: Isointense; Hyper: Hyperintense;

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Lesion		Location	T1 Weighted	T2 Weighted	Cine-SSFP	Perfusion	EGE	LGE
Non-neoplastic
	Thrombus Acute/subacute	Mural or intraluminal	Iso-Hyper	Iso-Hyper	Iso-hypo	No enhancement	No enhancement	Hypointense border and brighter central zone
	Thrombus Chronic	Mural or intraluminal	Hypo	Hypo	Iso-hypo	Rare	No enhancement	Rarely heterogeneous
Neoplastic - Benign
	Myxoma	Left atrium, arising from the interatrial septum	Iso (heterogeneous)	Hyper (heterogeneous)	Hypo	Heterogeneous	Heterogeneous	Heterogeneous
	Papillary fibroelastoma	Atrial side of the mitral valve and the aortic surface of the aortic valve leaflet	Iso	Iso	Hypo	Usually not assessable	Mild and homogeneous or no enhancement	Homogeneous or no enhancement
	Lipoma	Atrial septum and epicardium, but it may occur anywhere in the heart	Hyper	Hyper (Hypo on STIR images)	Hyper (with black boundary artifact or India ink artifact)	No enhancement	No enhancement	No enhancement
	Hemangioma	Every cardiac chamber and also from pericardial space	Iso	Hyper	Hyper	Heterogeneous, intense and prolonged	Homogeneous or heterogeneous	Homogeneous or heterogeneous
	Fibroma	Intramural growth in the ventricles (interventricular septum or the ventricular free wall)	Iso	Hypo	Iso-hypo	Mild and homogeneous	Mild and homogeneous	No enhancement or minimal uptake
	Rhabdomyoma	Intramyocardial or intracavitary, with intraventricular growth that may cause outflow obstruction	Iso	Mildly Hyper	Iso-hypo	No enhancement or minimal uptake	No enhancement or minimal uptake	No enhancement or minimal uptake
	Cardiac teratomas	Intrapericardial (usually compressing superior vena cava and/or right atrium)	Iso or Hypo	Hyper	Iso or Slightly hyper	No enhancement	Mild and heterogeneous	Heterogeneous
	Paraganglioma	On the roof of left atrium	Iso-Hypo with “salt and pepper” appearance	Hyper with “salt and pepper” appearance	Hyper	Strong enhancement	Heterogeneous Peripheral	Heterogeneous Peripheral
Neoplastic - malignant: Primary cardiac tumor
	Angiosarcoma	Right atrium close to atrio-ventricular sulcus	Iso-Hyper (heterogeneous)	Hyper (heterogeneous)	Iso (heterogeneous)	Strong enhancement	Marked and Heterogeneous	Marked and Heterogeneous
	Leiomyosarcoma	Typically involve the left atrium	Iso	Iso-Hyper	Iso	Heterogeneous, intense	Marked and Heterogeneous	Marked and Heterogeneous
	RMS	Multiple masses and not any predilection in terms of cardiac structures involved	Iso	Iso-Hyper (hyper on STIR images)	Iso	Heterogeneous, intense	Marked and Heterogeneous	Marked and Heterogeneous
	Lymphoma	Right chambers, often right ventricle and are associated with pericardial effusion	Hypo-Iso	Mildly Hyper (more evident on STIR images)	Iso	Mild	Heterogeneous	No or mild heterogeneous enhancement
	Mesothelioma	Pericardium	Iso	Hyper (heterogeneous)	Iso	Progressive enhancement	Intense enhancement	Intense enhancement
Malignant - Malignant: metastatic disease		Mainly involve myocardium and pericardium	Low (except for Melanoma which is Hyper)	Hyper	Iso	Heterogeneous	Heterogeneous	Heterogeneous

 

Table 2. Cardiovascular magnetic resonance characteristic (location, signal intensity and contrast contrast-enhanced relative to that of adjacent normal myocardium) of benign and malignant cardiac masses. STIR: Short tau inversion recovery; Cine-SSFP: Cine-steady state free precession; EGE: Early gadolinium enhancement; LGE: Late gadolinium enhancement; Hypo: Hypointense; Iso: Isointense; Hyper: Hyperintense; RMS, rhabdomyosarcoma.

Gatti M, D'Angelo T, Muscogiuri G, Dell'aversana S, Andreis A, Carisio A, Darvizeh F, Tore D, Pontone G, Faletti R. Cardiovascular magnetic resonance of cardiac tumors and masses. World J Cardiol. 2021 Nov 26;13(11):628-649. doi: 10.4330/wjc.v13.i11.628. PMID: 34909128; PMCID: PMC8641001.

 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

 

Dear authors,

I have read with interest your revised manuscript you submitted in the journal. I recognize the improvements you have made in the manuscript. However, there are serious flaws that cannot be improved, as I have stated previously.