MRI Evaluation of Vestibular Endolymphatic Space in Patients with Isolated Cystic Lateral Semicircular Canal Malformation

Round 1

Reviewer 1 Report

Although, this study involves few numbers of patient, but the imaging and calculation using ELR is good method. But, this congenital disease is not common. If more patients are collected, nice paper will be produced for the readers. 

I think this paper will be helpful for the readers especially doctors who are interested in vestibular disease.  

Author Response

Point 1: Although, this study involves few numbers of patient, but the imaging and calculation using ELR is good method. But, this congenital disease is not common. If more patients are collected, nice paper will be produced for the readers. 

I think this paper will be helpful for the readers especially doctors who are interested in vestibular disease. 

Response 1: Thank you very much for you comment. As you say, two main points converge here with the result of a small number of patients. First, LSSCD is a congenital and fairly uncommon finding. Moreover, only a tiny piece of these patients are referred for hydrops imaging. Indeed, patients number 1 and 2 in Table 1 have LSSCD on CT but they lack MRI hydrops imaging.

Author Response File: Author Response.docx

Reviewer 2 Report

The first sentence of the introduction needs a citation

I think that the Endolymphatic ratio of the dysplastic LSCC should be compared with that of the other exams performed by the authors with dedicated hydrops sequences in case of normal anatomy, to see if there is a correlation with clinical symptoms 

I wonder if the radiologist who manually delineated the boundaries of the vestibule was aware of the symptoms of the patients

Author Response

Point 1: 
The first sentence of the introduction needs a citation

Response 1: Thank you very much for your comment. A citation (cited as reference 1, line 38) has been added as suggested, highlighted in yellow.

Point 2: I think that the Endolymphatic ratio of the dysplastic LSCC should be compared with that of the other exams performed by the authors with dedicated hydrops sequences in case of normal anatomy, to see if there is a correlation with clinical symptoms 

Response 2: Thank you very much for your comment. As shown in Table 1, 2 patients with LSCCD on CT had no hydrops MR imaging.

The patient with Bilateral LSCCD (patient #4 in Table 1) and with right unilateral Definite MD had an endolymphatic ratio of 81% in the symptomatic ear and of 22% in the asymptomatic ear.

In patients with UNIlateral LSCCD and available hydrops MR imaging (patients 3 and 5), the contralateral “normal anatomy” inner ear showed no signs of endolymphatic hydrops with endolymphatic ratios of less than 25% (not shown on table 1). The contralateral “normal anatomy” inner ear was asymptomatic.

This explanation is added as footnote in Table 1 and highlighted in yellow, lines 120-123.

Point 3: I wonder if the radiologist who manually delineated the boundaries of the vestibule was aware of the symptoms of the patients

Response 3: The delineation of the boundaries of the vestibule (and also the endolymph in the Real IR sequence) were performed by the same radiologist. Clinical information was not provided during the process of volume segmentation. Line 96, highlighted in yellow.

Author Response File: Author Response.docx