Journal of Clinical and Diagnostic Research, ISSN - 0973 - 709X

Users Online : 73391

ConclusionAcknowledgementReferencesDOI and Others
Article in PDF How to Cite Citation Manager Readers' Comments (0) Audio Visual Article Statistics Link to PUBMED Print this Article Send to a Friend
Advertisers Access Statistics Resources

Dr Mohan Z Mani

"Thank you very much for having published my article in record time.I would like to compliment you and your entire staff for your promptness, courtesy, and willingness to be customer friendly, which is quite unusual.I was given your reference by a colleague in pathology,and was able to directly phone your editorial office for clarifications.I would particularly like to thank the publication managers and the Assistant Editor who were following up my article. I would also like to thank you for adjusting the money I paid initially into payment for my modified article,and refunding the balance.
I wish all success to your journal and look forward to sending you any suitable similar article in future"



Dr Mohan Z Mani,
Professor & Head,
Department of Dematolgy,
Believers Church Medical College,
Thiruvalla, Kerala
On Sep 2018




Prof. Somashekhar Nimbalkar

"Over the last few years, we have published our research regularly in Journal of Clinical and Diagnostic Research. Having published in more than 20 high impact journals over the last five years including several high impact ones and reviewing articles for even more journals across my fields of interest, we value our published work in JCDR for their high standards in publishing scientific articles. The ease of submission, the rapid reviews in under a month, the high quality of their reviewers and keen attention to the final process of proofs and publication, ensure that there are no mistakes in the final article. We have been asked clarifications on several occasions and have been happy to provide them and it exemplifies the commitment to quality of the team at JCDR."



Prof. Somashekhar Nimbalkar
Head, Department of Pediatrics, Pramukhswami Medical College, Karamsad
Chairman, Research Group, Charutar Arogya Mandal, Karamsad
National Joint Coordinator - Advanced IAP NNF NRP Program
Ex-Member, Governing Body, National Neonatology Forum, New Delhi
Ex-President - National Neonatology Forum Gujarat State Chapter
Department of Pediatrics, Pramukhswami Medical College, Karamsad, Anand, Gujarat.
On Sep 2018




Dr. Kalyani R

"Journal of Clinical and Diagnostic Research is at present a well-known Indian originated scientific journal which started with a humble beginning. I have been associated with this journal since many years. I appreciate the Editor, Dr. Hemant Jain, for his constant effort in bringing up this journal to the present status right from the scratch. The journal is multidisciplinary. It encourages in publishing the scientific articles from postgraduates and also the beginners who start their career. At the same time the journal also caters for the high quality articles from specialty and super-specialty researchers. Hence it provides a platform for the scientist and researchers to publish. The other aspect of it is, the readers get the information regarding the most recent developments in science which can be used for teaching, research, treating patients and to some extent take preventive measures against certain diseases. The journal is contributing immensely to the society at national and international level."



Dr Kalyani R
Professor and Head
Department of Pathology
Sri Devaraj Urs Medical College
Sri Devaraj Urs Academy of Higher Education and Research , Kolar, Karnataka
On Sep 2018




Dr. Saumya Navit

"As a peer-reviewed journal, the Journal of Clinical and Diagnostic Research provides an opportunity to researchers, scientists and budding professionals to explore the developments in the field of medicine and dentistry and their varied specialities, thus extending our view on biological diversities of living species in relation to medicine.
‘Knowledge is treasure of a wise man.’ The free access of this journal provides an immense scope of learning for the both the old and the young in field of medicine and dentistry as well. The multidisciplinary nature of the journal makes it a better platform to absorb all that is being researched and developed. The publication process is systematic and professional. Online submission, publication and peer reviewing makes it a user-friendly journal.
As an experienced dentist and an academician, I proudly recommend this journal to the dental fraternity as a good quality open access platform for rapid communication of their cutting-edge research progress and discovery.
I wish JCDR a great success and I hope that journal will soar higher with the passing time."



Dr Saumya Navit
Professor and Head
Department of Pediatric Dentistry
Saraswati Dental College
Lucknow
On Sep 2018




Dr. Arunava Biswas

"My sincere attachment with JCDR as an author as well as reviewer is a learning experience . Their systematic approach in publication of article in various categories is really praiseworthy.
Their prompt and timely response to review's query and the manner in which they have set the reviewing process helps in extracting the best possible scientific writings for publication.
It's a honour and pride to be a part of the JCDR team. My very best wishes to JCDR and hope it will sparkle up above the sky as a high indexed journal in near future."



Dr. Arunava Biswas
MD, DM (Clinical Pharmacology)
Assistant Professor
Department of Pharmacology
Calcutta National Medical College & Hospital , Kolkata




Dr. C.S. Ramesh Babu
" Journal of Clinical and Diagnostic Research (JCDR) is a multi-specialty medical and dental journal publishing high quality research articles in almost all branches of medicine. The quality of printing of figures and tables is excellent and comparable to any International journal. An added advantage is nominal publication charges and monthly issue of the journal and more chances of an article being accepted for publication. Moreover being a multi-specialty journal an article concerning a particular specialty has a wider reach of readers of other related specialties also. As an author and reviewer for several years I find this Journal most suitable and highly recommend this Journal."
Best regards,
C.S. Ramesh Babu,
Associate Professor of Anatomy,
Muzaffarnagar Medical College,
Muzaffarnagar.
On Aug 2018




Dr. Arundhathi. S
"Journal of Clinical and Diagnostic Research (JCDR) is a reputed peer reviewed journal and is constantly involved in publishing high quality research articles related to medicine. Its been a great pleasure to be associated with this esteemed journal as a reviewer and as an author for a couple of years. The editorial board consists of many dedicated and reputed experts as its members and they are doing an appreciable work in guiding budding researchers. JCDR is doing a commendable job in scientific research by promoting excellent quality research & review articles and case reports & series. The reviewers provide appropriate suggestions that improve the quality of articles. I strongly recommend my fraternity to encourage JCDR by contributing their valuable research work in this widely accepted, user friendly journal. I hope my collaboration with JCDR will continue for a long time".



Dr. Arundhathi. S
MBBS, MD (Pathology),
Sanjay Gandhi institute of trauma and orthopedics,
Bengaluru.
On Aug 2018




Dr. Mamta Gupta,
"It gives me great pleasure to be associated with JCDR, since last 2-3 years. Since then I have authored, co-authored and reviewed about 25 articles in JCDR. I thank JCDR for giving me an opportunity to improve my own skills as an author and a reviewer.
It 's a multispecialty journal, publishing high quality articles. It gives a platform to the authors to publish their research work which can be available for everyone across the globe to read. The best thing about JCDR is that the full articles of all medical specialties are available as pdf/html for reading free of cost or without institutional subscription, which is not there for other journals. For those who have problem in writing manuscript or do statistical work, JCDR comes for their rescue.
The journal has a monthly publication and the articles are published quite fast. In time compared to other journals. The on-line first publication is also a great advantage and facility to review one's own articles before going to print. The response to any query and permission if required, is quite fast; this is quite commendable. I have a very good experience about seeking quick permission for quoting a photograph (Fig.) from a JCDR article for my chapter authored in an E book. I never thought it would be so easy. No hassles.
Reviewing articles is no less a pain staking process and requires in depth perception, knowledge about the topic for review. It requires time and concentration, yet I enjoy doing it. The JCDR website especially for the reviewers is quite user friendly. My suggestions for improving the journal is, more strict review process, so that only high quality articles are published. I find a a good number of articles in Obst. Gynae, hence, a new journal for this specialty titled JCDR-OG can be started. May be a bimonthly or quarterly publication to begin with. Only selected articles should find a place in it.
An yearly reward for the best article authored can also incentivize the authors. Though the process of finding the best article will be not be very easy. I do not know how reviewing process can be improved. If an article is being reviewed by two reviewers, then opinion of one can be communicated to the other or the final opinion of the editor can be communicated to the reviewer if requested for. This will help one’s reviewing skills.
My best wishes to Dr. Hemant Jain and all the editorial staff of JCDR for their untiring efforts to bring out this journal. I strongly recommend medical fraternity to publish their valuable research work in this esteemed journal, JCDR".



Dr. Mamta Gupta
Consultant
(Ex HOD Obs &Gynae, Hindu Rao Hospital and associated NDMC Medical College, Delhi)
Aug 2018




Dr. Rajendra Kumar Ghritlaharey

"I wish to thank Dr. Hemant Jain, Editor-in-Chief Journal of Clinical and Diagnostic Research (JCDR), for asking me to write up few words.
Writing is the representation of language in a textual medium i e; into the words and sentences on paper. Quality medical manuscript writing in particular, demands not only a high-quality research, but also requires accurate and concise communication of findings and conclusions, with adherence to particular journal guidelines. In medical field whether working in teaching, private, or in corporate institution, everyone wants to excel in his / her own field and get recognised by making manuscripts publication.


Authors are the souls of any journal, and deserve much respect. To publish a journal manuscripts are needed from authors. Authors have a great responsibility for producing facts of their work in terms of number and results truthfully and an individual honesty is expected from authors in this regards. Both ways its true "No authors-No manuscripts-No journals" and "No journals–No manuscripts–No authors". Reviewing a manuscript is also a very responsible and important task of any peer-reviewed journal and to be taken seriously. It needs knowledge on the subject, sincerity, honesty and determination. Although the process of reviewing a manuscript is a time consuming task butit is expected to give one's best remarks within the time frame of the journal.
Salient features of the JCDR: It is a biomedical, multidisciplinary (including all medical and dental specialities), e-journal, with wide scope and extensive author support. At the same time, a free text of manuscript is available in HTML and PDF format. There is fast growing authorship and readership with JCDR as this can be judged by the number of articles published in it i e; in Feb 2007 of its first issue, it contained 5 articles only, and now in its recent volume published in April 2011, it contained 67 manuscripts. This e-journal is fulfilling the commitments and objectives sincerely, (as stated by Editor-in-chief in his preface to first edition) i e; to encourage physicians through the internet, especially from the developing countries who witness a spectrum of disease and acquire a wealth of knowledge to publish their experiences to benefit the medical community in patients care. I also feel that many of us have work of substance, newer ideas, adequate clinical materials but poor in medical writing and hesitation to submit the work and need help. JCDR provides authors help in this regards.
Timely publication of journal: Publication of manuscripts and bringing out the issue in time is one of the positive aspects of JCDR and is possible with strong support team in terms of peer reviewers, proof reading, language check, computer operators, etc. This is one of the great reasons for authors to submit their work with JCDR. Another best part of JCDR is "Online first Publications" facilities available for the authors. This facility not only provides the prompt publications of the manuscripts but at the same time also early availability of the manuscripts for the readers.
Indexation and online availability: Indexation transforms the journal in some sense from its local ownership to the worldwide professional community and to the public.JCDR is indexed with Embase & EMbiology, Google Scholar, Index Copernicus, Chemical Abstracts Service, Journal seek Database, Indian Science Abstracts, to name few of them. Manuscriptspublished in JCDR are available on major search engines ie; google, yahoo, msn.
In the era of fast growing newer technologies, and in computer and internet friendly environment the manuscripts preparation, submission, review, revision, etc and all can be done and checked with a click from all corer of the world, at any time. Of course there is always a scope for improvement in every field and none is perfect. To progress, one needs to identify the areas of one's weakness and to strengthen them.
It is well said that "happy beginning is half done" and it fits perfectly with JCDR. It has grown considerably and I feel it has already grown up from its infancy to adolescence, achieving the status of standard online e-journal form Indian continent since its inception in Feb 2007. This had been made possible due to the efforts and the hard work put in it. The way the JCDR is improving with every new volume, with good quality original manuscripts, makes it a quality journal for readers. I must thank and congratulate Dr Hemant Jain, Editor-in-Chief JCDR and his team for their sincere efforts, dedication, and determination for making JCDR a fast growing journal.
Every one of us: authors, reviewers, editors, and publisher are responsible for enhancing the stature of the journal. I wish for a great success for JCDR."



Thanking you
With sincere regards
Dr. Rajendra Kumar Ghritlaharey, M.S., M. Ch., FAIS
Associate Professor,
Department of Paediatric Surgery, Gandhi Medical College & Associated
Kamla Nehru & Hamidia Hospitals Bhopal, Madhya Pradesh 462 001 (India)
E-mail: drrajendrak1@rediffmail.com
On May 11,2011




Dr. Shankar P.R.

"On looking back through my Gmail archives after being requested by the journal to write a short editorial about my experiences of publishing with the Journal of Clinical and Diagnostic Research (JCDR), I came across an e-mail from Dr. Hemant Jain, Editor, in March 2007, which introduced the new electronic journal. The main features of the journal which were outlined in the e-mail were extensive author support, cash rewards, the peer review process, and other salient features of the journal.
Over a span of over four years, we (I and my colleagues) have published around 25 articles in the journal. In this editorial, I plan to briefly discuss my experiences of publishing with JCDR and the strengths of the journal and to finally address the areas for improvement.
My experiences of publishing with JCDR: Overall, my experiences of publishing withJCDR have been positive. The best point about the journal is that it responds to queries from the author. This may seem to be simple and not too much to ask for, but unfortunately, many journals in the subcontinent and from many developing countries do not respond or they respond with a long delay to the queries from the authors 1. The reasons could be many, including lack of optimal secretarial and other support. Another problem with many journals is the slowness of the review process. Editorial processing and peer review can take anywhere between a year to two years with some journals. Also, some journals do not keep the contributors informed about the progress of the review process. Due to the long review process, the articles can lose their relevance and topicality. A major benefit with JCDR is the timeliness and promptness of its response. In Dr Jain's e-mail which was sent to me in 2007, before the introduction of the Pre-publishing system, he had stated that he had received my submission and that he would get back to me within seven days and he did!
Most of the manuscripts are published within 3 to 4 months of their submission if they are found to be suitable after the review process. JCDR is published bimonthly and the accepted articles were usually published in the next issue. Recently, due to the increased volume of the submissions, the review process has become slower and it ?? Section can take from 4 to 6 months for the articles to be reviewed. The journal has an extensive author support system and it has recently introduced a paid expedited review process. The journal also mentions the average time for processing the manuscript under different submission systems - regular submission and expedited review.
Strengths of the journal: The journal has an online first facility in which the accepted manuscripts may be published on the website before being included in a regular issue of the journal. This cuts down the time between their acceptance and the publication. The journal is indexed in many databases, though not in PubMed. The editorial board should now take steps to index the journal in PubMed. The journal has a system of notifying readers through e-mail when a new issue is released. Also, the articles are available in both the HTML and the PDF formats. I especially like the new and colorful page format of the journal. Also, the access statistics of the articles are available. The prepublication and the manuscript tracking system are also helpful for the authors.
Areas for improvement: In certain cases, I felt that the peer review process of the manuscripts was not up to international standards and that it should be strengthened. Also, the number of manuscripts in an issue is high and it may be difficult for readers to go through all of them. The journal can consider tightening of the peer review process and increasing the quality standards for the acceptance of the manuscripts. I faced occasional problems with the online manuscript submission (Pre-publishing) system, which have to be addressed.
Overall, the publishing process with JCDR has been smooth, quick and relatively hassle free and I can recommend other authors to consider the journal as an outlet for their work."



Dr. P. Ravi Shankar
KIST Medical College, P.O. Box 14142, Kathmandu, Nepal.
E-mail: ravi.dr.shankar@gmail.com
On April 2011
Anuradha

Dear team JCDR, I would like to thank you for the very professional and polite service provided by everyone at JCDR. While i have been in the field of writing and editing for sometime, this has been my first attempt in publishing a scientific paper.Thank you for hand-holding me through the process.


Dr. Anuradha
E-mail: anuradha2nittur@gmail.com
On Jan 2020

Important Notice

Reviews
Year : 2012 | Month : June | Volume : 6 | Issue : 5 | Page : 915 - 918

Intralabyrinthine Schwannomas: Review of Anatomy, Pathology, Clinical Features from an Imaging Perspective

Tashfeen Ekram, Spencer R. Koch, Rajan Jain

1. Departments of Radiology, Henry Ford Health System, Detroit, MI 48202 USA. 2. Departments of Radiology, Duke University Medical Center, Durham, NC. 3. Departments of Radiology and Neurosurgery, Henry Ford Health System, Detroit, MI 48202 USA.

Correspondence Address :
Dr. Rajan Jain, MD Division of Neuroradiology Department of Radiology Henry Ford Health System 2799 West Grand Blvd, Detroit MI 48202 Phone 313-916-9062; Fax 313-916-1444 Email rajanj@rad.hfh.edu

Introduction
Intralabyrinthine schwannomas (ILSs) are primary neoplasms of the vestibulocochlear nerve that arise de novo in the cochlea, vestibule and the semi-circular canal, or in a combination of these structures (1),(2). It represents a rare entity with a prevalence of 0.1% to 1% in autopsy reviews (3). ILSs have also been shown to cross into both the middle ear and the internal auditory canal (4). Prior to high-resolution MRI of the inner ear, ILS was commonly diagnosed as an incidental finding during labyrinthectomy or autopsy, with the first case being reported in 1917 (5). In 1972, Wanamaker discovered a case of ILS at the time of labyrinthectomy in a patient who was presumed to have Menier’s disease (6). In the same year, Karlan reported the first patient with the identification of ILS by using computed tomography (7). It was not until 1994, that the utility of contrast enhanced MRI was realized in the diagnosis of ILS. With the advent of high-resolution T2 weighted imaging with gadolinium contrast-enhanced T1 weighted imaging, ILSs are being diagnosed in patients as incidental findings, as well as on dedicated imaging in the workup of patients with senorineural hearing loss and vertigo (4),(8),(9). A recent retrospective review has shown that up to 10% of all the vestibulocochlear schwannomas are intralabryinthine, and that they are most frequently found in the cochlea. However, this may slightly overestimate the actual prevalence, as the study took place a referral centre (10). Additionally, this same study also demonstrated that these lesions can grow over time, often crossing into anatomically distinct portions of the inner ear, as well as into the internal auditory canal. The management of ILS typically consists of serial observations. Surgical excision is recommended for intractable vertigo, for the extension of an ILS into the cerebellopontine angle cistern, or for any evidence of tumour growth in a patient who is fit for surgery (11),(12). Thus, a working knowledge of the anatomy of the cochlea, vestibule and internal auditory canal are critically important when these neoplasms are being evaluated.While ILS does have a typical appearance on MRI with intravenous gadolinium contrast injection, the mimics to ILS do often present on MR imaging. In the present review, we will discuss the ILSs from an imaging perspective, particularly correlating them with their anatomical classifications and clinical features.

Imaging Protocols

MR images the endolymph and the perilymph within the membranous labyrinth via high-resolution T2 weighted images, as opposed to CT, which images the bony labyrinth with high-resolution axial images. Most of these sequences are based on either a constructive interference in the steady state (CISS) or on the fast spin-echo (FSE) technique. Each technique has inherent shortcomings when it images the small structures of the membranous labyrinth. The balanced- steady state free precession sequences which are often used, suffer from a susceptibility artifact at the air-bone and the bone–soft tissue interfaces. The artifact is accentuated at the skull base and with an imaging at 3T. This artifact can be mitigated with CISS, which sums the successive phase-cycled acquisitions which are reconstructed with a maximum intensity projection (13). However, the interface related artifacts remain problematic with the very small field of views which is required for temporal bone imaging and minute portions of the membranous labyrinth. The FSE sequences are limited by image blurring, which is secondary to a higher noise to signal ratio, from the shorter imaging times which is accentuated at 3T (13).

The 3D variable flip-angle FSE technique has been recently described as a technique which reduces both the susceptibility artifacts and image blurring (14). In contrast to the standard FSE, where the flip angle remains constant (eg, 180°), the flip angle of the refocusing pulses in 3D VFA FSE is varied to achieve a desired image contrast. This technique allows longer echo trains and it reduces the change in the signal intensity through the echo train. This results in a higher signal to noise ratio, allowing high-resolution single slab isotropic acquisition. The image blurring is also reduced by the consistent echo-to-echo signal intensity which is particularly problematic in tissues with a relatively short T2. Finally, the smaller flip angles allow this technique to be utilized at 3T with a reduced radiofrequency heating, as can be measured by the specific absorption rate (SAR) as compared to the standard FSE technique (15).

The imaging anatomy of the labyrinth and the classification of ILS

The classification of ILS is primarily based upon which anatomic portion of the membranous labyrinth is occupied by the lesion. This classification is shown in (Table/Fig 1) (4). In order to properly evaluate and characterize ILS, a basic working knowledge of the membranous labyrinth is required. The membranous labyrinth which is enclosed in a bony labyrinth within the petrous portion of the temporal bone, is a continuous structure which consists of the cochlea and the vestibule. The membranous labyrinth contains endolymph and it is surrounded by perilymph. The perilymph can be formed from an ultrafiltrate of blood or cerebrospinal fluid. The vestibule can then be further divided into the utricle, saccule, and the three semicircular canals (horizontal, superior and posterior). The utricle lies in the elliptical recess of the medial wall of the vestibule and it contains five openings form the semicircular canals, as the superior and the posterior canals share a common crus. The vestibule communicates with the fundus of the internal auditory canal via the macula cribrosa (23). The cochlea contains two and a half turns with an opening into the fundus of the internal auditory canal, which is known as the cochlear aperture via the modiolus. The cochlea communicates with the vestibule via the ductus reuniens to the cochlear recess of the vestibule. The cochlear nerve communicates directly with the internal auditory canal through the cochlear niche. The inner structure of the cochlea can be further divided into three spiral chambers: the scala tympani, scala vestibule, and the scala media. The cochlear nerve travels in closer proximity to the scala tympani, in the region where it leaves the osseus spiral lamina which is called the habenula perforate, which runs towards the organ of Corti. The anterior saccular port of the vestibule has an anatomic connection with the scala vestibule. The scala tympani ends at the round window and it does not have a connection with the saccule (23). Recent studies have demonstrated in exquisite detail, the ability to visualize the anatomy of the inner ear at both 3T and 9.4T (15). ILSs can extend from one seemingly anatomically distinct portion of the middle ear to another, or even the IAC or the middle ear cavity. This is possible, given the anatomic communications between the distinct parts. The previously mentioned routes provide potential routes of spread as the ILS grows. An understanding of these anatomic connections can help in clarifying the classification system of ILS and in identifying the predictable growth patterns.

The imaging features of ILS

ILSs have a typical imaging appearance on gadolinium contrast-enhanced MRI. The typical appearance is a T2 hypointense, sharply circumscribed filling defect which is seen on the high-resolution T2 weighted images, which displaces the normal high T2 signal from the intralabryinthine endolymphatic and perilymphatic fluids. The lesion also demonstrates enhancement on the post-contrast T1 weighted images (3),(16). The region of enhancement on the T1-weighted images should correlate with the T2 filling defect on the high-resolution images to ensure that the enhancement does in fact represent a space-occupying lesion rather than an infectious, inflammatory or a haemorrhagic aetiology (10). As has been discussed later, the sharply circumscribed margins set apart ILS from other intralabryinthine entities. In the same retrospective case series, they found an increased, unenhanced T1-weighted signal within a predominate number of lesions. However, the level of the increased, unenhanced T1-weighted signal depends on the size of the tumour, with the smaller tumours demonstrating no significant abnormal signs due to the volume averaging. An increase in the T1 signal is nonspecific; however, it can be used to further confirm the diagnosis. It is important to note the extent of the enhancement, as it relates to the normal anatomy of the IAC, cochlea, labyrinth and the middle ear cavity. Imaging in both the axial and the coronal planes can help in delineating the extent of the tumour, as shown in (Table/Fig 1).



ILSs can range from simple to complex forms. The simplest form of ILS is intracochlear schwannoma. [Table/Fig-2] demonstrates an intracochlear schwannoma as an enhancing lesion in the basal turn of the cochlea, with a corresponding T2 filling defect on the high-resolution axial images. (Table/Fig 3) shows a variant of an intracochlear schwannoma, affecting only the middle turn of the cochlea. Tielman et al., (10) reported in their series, that eighty percent of the ILSs were confined to the cochlea. Of these, half of them were situated near the transition between the basal and the second turn. Based on the high-resolution T2-weighted imaging, the lesions were further characterized to always involve the scala tympani with some demonstrating extension to the scala vestibuli, which concurred with the above mentioned anatomy.

The utility of post-contrast imaging in the two planes is demonstrated in (Table/Fig 4). The axial T1 post-contrast image easily demonstrates the enhancement of the right vestibule, but the coronal T1-weighted images clearly show the enhancement extending into the superior semi-circular canals. Teilman at al. reported the vestibular involvement to be far less frequent and to represent about 13.5% in their series. They noted that most of the intravestibular schwannomas typically involved the vestibule and the superior SCC. Exclusive involvement of either remaining SCC in addition to the vestibule is much less common.

(Table/Fig 5) demonstrates a vestibulocochlear schwannoma with abnormal enhancement, which involved the cochlea and extended into the superior and the lateral SCCs. A typical growth pattern for a vestibulocochlear schwannoma is having its origin in the cochlea within the scala tympani with an extension into the scala vestibuli. Once the intracochlear space has been completely occupied, the disease extends via the perilymph communication from the scala vestibule to the anterior saccular part of the vestibule. Vestibulocochlear schwannomas have a tendency to involve the superior SCC, because their spread in the vestibule involves the anterior most portion which is nearer to the opening of the superior SCC (10). This pattern of growth also explains the extension of the schwannomas which originate in the vestibule, which will first involve the scala vestibule prior to their extension into the scala tympani. An understanding of this growth pattern can increase the reader’s sensitivity for detecting their growth and extension. (Table/Fig 6) demonstrates another example of vestibulocochlear schwannomas with involvement of the superior and the horizontal SCCs.

(Table/Fig 7) demonstrates a transmodiolar schwannoma with a T1-weighted image which shows enhancement in the IAC and extension into the middle turn of the cochlea.

the schwannomas which originate in the vestibule, which will first involve the scala vestibule prior to their extension into the scala tympani. An understanding of this growth pattern can increase the reader’s sensitivity for detecting their growth and extension. (Table/Fig 6) demonstrates another example of vestibulocochlear schwannomas with involvement of the superior and the horizontal SCCs.

(Table/Fig 7) demonstrates a transmodiolar schwannoma with a T1-weighted image which shows enhancement in the IAC and extension into the middle turn of the cochlea.

Mimics of ILS
Not all enhancing lesions within the membranous labyrinth represent ILS. Unfortunately, the symptoms of the mimics of ILS are similar, which include hearing loss and vertigo. The imaging characteristics as well as the patient history can be used to differentiate some of the mimics from ILS, but surgical excision and pathological studies are often needed to make the final diagnosis.

Labyrinthitis is a non-specific term for the inflammation of the membranous labyrinth. The common aetiologies include spontaneous haemorrhage and bacterial and viral infections (11). Haemorrhagic labyrinthitis demonstrates an abnormal high T1 signal with a normal increased T2 signal, without contrast enhancement (17).The patients with haemorrhagic labyrinthitis often present with a sudden hearing loss or a roaring or “whooshing” sensation. (Table/Fig 8) shows haemorrhagic labyrinthitis as an increased T1 signal without an enhancement or a space occupying lesion on the T2 weighted images. Haemorrhagic labyrinthitis can also be a sequela of radiation therapy. An increased T2 signal in the brain, in the radiation port, can be seen along with the typical findings of haemorrhagic labyrinthitis, as has been demonstrated in (Table/Fig 9). Viral labyrinthitis will show a normal, non-contrast T1 signal without contrast, but an enhancement of the labyrinth without a T2 filling defect (11).

The other obvious aetiologies of the mimics for ILS include enhancing masses that are not primary to the inner ear. Metastases to the inner ear have previously been reported, including lung carcinoma (18). The enhancing lesion in (Table/Fig 10) was originally suspected to be a transmodiolar transmacular ILS. However, on biopsy, the pathology returned as undifferentiated adenocarcinoma. Upon additional imaging of the chest, abdomen and the pelvis, an adenocarcinoma of the lung was identified. Other metastases have been reported to involve the internal auditory canal, which include metastatic rhabdomyosarcoma, malignant melanoma, and carcinoma of the breast (19), (20), (21). (Table/Fig 11) demonstrates a rare case of an intralabrynthine meningioma which has features that are entirely indistinguishable from those of a schwanomma. The images were reproduced with the author’s permission (22). The T1 weighted images show an enhancing lesion which involved the cochlea (thick arrow), vestibule (thin arrow) and the fundus of the IAC (23).

Conclusion

ILS is a rare primary tumour of the inner ear that typically presents with sensorineural hearing loss with or without vertigo. These lesions are typically followed with serial imaging exams to ensure their stability. A careful examination of the patient’s history, as well as inspection of the post-contrast T1 weighted images can lead the reader to the diagnosis of ILS. Care should be taken to verify a T2 filling defect on the high-resolution images, to ensure that one is not diagnosing one of the common mimics as a benign aetiology such as ILS.

Acknowledgement

We would like to acknowledge the help of David Brown and Christina Nelson of the Henry Ford Hospital, Department of Radiology 3D Laboratory, for their help in generating the source images for the anatomy drawings.

References

1.
amed A, Linthicum. Intralabyrinthine schwannoma. Otol Neurotol. 2005; 26(5):1085-6.
2.
Neff BA, Willcox Jr TO, Sataloff RT. Intralabyrinthine schwannomas. Otol Neurotol. 2003;24(2):299-307.
3.
Montague ML, Kishore A, Hadley DM, et al. MR findings in intralabyrinthine schwannomas. Clin Radiol. 2002;57(5):355-8.
4.
Kennedy RJ, Shelton C, Salzman KL, et al. Intralabyrinthine schwannomas: diagnosis, management, and a new classification system. Otol Neurotol. 2004;25(2):160-7.
5.
Sataloff RT, Roberts BR, Feldman M. Intralabrynthine schwanoma. Am J Otol. 1988;9(4):323-26.
6.
Wanamaker HH. Acoustic primary neuroma arising in the vestibule. Laryngoscope. 1972;82:1040-44.
7.
Karlan MS, Basek M, Potter GB. Intracochlear neurilemoma. Arch Otolaryngol. 1972;96:573-75.
8.
Green JD Jr, McKenzie. Diagnosis and management of intralabyrinthine schwannomas. Laryngoscope. 1999;109(10):1626-31.
9.
Lane JI, Witte RJ, Bolster B, et al. State of the art: 3T imaging of the membranous labyrinth. AJNR Am J Neuroradiol. 2008;29(8):1436-40.
10.
Tieleman A, Casselman JW, Somers T, et al. Imaging of intralabyrinthine schwannomas: a retrospective study of 52 cases with an emphasis on the lesion growth. AJNR Am J Neuroradiol. 2008;29(5):898-905.
11.
Kennedy RJ, Shelton C, Salzman KL, et al. Intralabyrinthine schwannomas: diagnosis, management, and a new classification system. Otol Neurotol. 2004;25(2):160-07.
12.
Magliulo G, Colicchoi G, Romana AF, et al. Intracochlear schwannoma. Skull Base. 2010;20(2):115-18.
13.
Lane JI, Ward H, Witte RJ, et al. 3-T imaging of the cochlear nerve and the labyrinth in cochlear-implant candidates: 3D Fast Recovery Fast Spin-Echo versus the 3D Constructive Interference in the steady state techniques. AJNR Am J Neuroradiol 2004;25:618–22.
14.
Lane JI, Witte RJ, Henson OW, et al. Imaging microscopy of the middle and the inner ear: Part II: MR microscopy. Clin Anat 2005;18:409–15.
15.
Lane JI, Ward H, Witte RJ, et al. 3-T Imaging of the cochlear nerve and labyrinth in cochlear-implant candidates: 3D Fast Recovery Fast Spin-Echo versus the 3D Constructive Interference in the steady state techniques. AJNR Am J Neuroradiol. 2004;25(4):618-22.
16.
Davidson HC. The imaging evaluation of sensineural hearing loss. Semin Ultrasound CT MR. 2001;22(3):229-49.
17.
Rangheard AS, Marsot-Dupuch K, Mark AS, et al. The postoperative complications of otospongiosis: the usefulness of MR imaging. AJNR Am J Neuroradiolog. 2991;22:1171-78.
18.
Schrock A, Laffers W, Bootz F. Solitary metastasis of lung carcinoma to the internal auditory canal. Am J Otolaryngol. 2006;27(3):214-16.
19.
Kirya S, Cureoglu S, Schachern PA, et al. Histopathological temporal bone study of metastatic rhabdomyosarcoma. Auris Nasus Larynx. 2009;36(2):221-23.
20.
Gerganov VM, Hore N, Herold C, et al. Bilateral malignant melanoma metastases to the internal auditory canal/cerebellopontine angle: surgical management and preservation of the function. J Neurosurg. 2008;108(4):803-07.
21.
Guilemany JM, Alboid I, Gaston F, et al. The cerebellopontine angle and internal auditory canal metastasis from a ductal carcinoma of the breast. Acta Otolaryngol. 2005;125(9):1004-07.
22.
Aho TR, Daspit CP, Dean BL, et al. Intralabrynthine meningioma. AJNR Am J Neuroradiolog. 2003;24(8):1642-45.
23.
Coutsoukis P, “1d. 4. The Internal Ear or Labyrinth”, Theodora, 2007, http://www.theodora.com/anatomy/the_internal_ear_or_labyrinth. html, accessed on 3/23/2012.

DOI and Others

DOI: JCDR/2012/3590:0000

Date of Submission: Jan 11, 2012
Date of Peer Review: Mar 11, 2012
Date of Acceptance: May 16, 2012
Date of Publishing: Jun 22, 2012

JCDR is now Monthly and more widely Indexed .
  • Emerging Sources Citation Index (Web of Science, thomsonreuters)
  • Index Copernicus ICV 2017: 134.54
  • Academic Search Complete Database
  • Directory of Open Access Journals (DOAJ)
  • Embase
  • EBSCOhost
  • Google Scholar
  • HINARI Access to Research in Health Programme
  • Indian Science Abstracts (ISA)
  • Journal seek Database
  • Google
  • Popline (reproductive health literature)
  • www.omnimedicalsearch.com