Role of non-echo-planar diffusion-weighted images in the identification of recurrent cholesteatoma of the temporal bone

Early non-EPI DW-MRI after cholesteatoma surgery

OBJECTIVE

Middle ear cholesteatoma may lead to the erosion of the bony structures of the temporal bone, possibly causing intra- and extracranial complications. Surgical treatment is mandatory, and due to possible residual/recurrent disease, the use of reliable diagnostic methods is essential. Our study aimed to evaluate the reliability of non-EPI DW-MRI for the follow-up of cholesteatoma after surgery.

METHODS

In a study group including 53 consecutive patients who underwent surgery for cholesteatoma at a tertiary university hospital, an imaging protocol was applied, including non-echo planar diffusion-weighted imaging magnetic resonance (MR) at 1 month after surgery and then at 6 and 12 months after surgery. Based on the combination of preoperative assessment and intraoperative findings, the study group was divided into 3 subgroups: petrous bone (PB) cholesteatoma, complicated cholesteatoma and uncomplicated cholesteatoma. PB cholesteatoma patients were treated by a subtotal petrosectomy, whereas complicated and uncomplicated cholesteatoma patients were treated either by a canal wall up procedure or a retrograde (inside-out) canal wall down technique with bone obliteration technique (BOT).

RESULTS

The results show that patients who had positive findings on non-EPI DW-MRI scans 1 month after surgery consequently underwent revision surgery during which residual cholesteatoma was noted. All the patients who displayed negative findings on non-EPI DWI-MRI scan at 1 month after surgery did not show the presence of a lesion at the 6- and 12-month evaluations. The 6 patients who displayed residual cholesteatoma at the 1-month follow-up presented dehiscence/exposure of the facial nerve canal at the primary surgery, mostly at the level of the labyrinthine segment.

CONCLUSION

Non-EPI DW-MRI is a useful and reliable tool for follow-up cholesteatoma surgery, and when applied early, as was done in the protocol proposed in the present study, this tool may be used to detect the presence of residual cholesteatoma in some patients, prompting the planning of early revision surgery.

Evaluation of magnetic resonance imaging to detect cholesteatoma in clinical healthcare

BACKGROUND

Non-Echo-Planar Diffusion Weighed Magnetic Resonance Imaging (non-EPI DW MRI) plays a role in the planning of cholesteatoma surgery.

OBJECTIVES

To outline the usage of Non-EPI DW MRI in cholesteatoma diagnostics and to determine its accuracy, using otosurgery diagnostics as reference standard.

MATERIAL AND METHODS

A retrospective descriptive study. All subjects operated, with suspicion of cholesteatoma as indication, that had a preceding examination with non-EPI DW MRI, between October 2010 and March 2019. Calculating sensitivity, specificity, predicative values, and likelihood ratios, using non-EPI DW MRI as index test and diagnosis from otosurgery as reference standard.

RESULTS

Fifty-two subject episodes were included. Non-EPI DW MRI had a sensitivity of 0.50, specificity of 0.75, positive and negative predictive values of 0.74 and 0.52 and, positive and negative likelihood ratios of 2.0 and 0.67 respectively.

CONCLUSIONS AND SIGNIFICANCE

There is a clear annual trend with increased numbers of executed examinations during the study period. The diagnostic accuracy of non-EPI DW MRI does not reach acceptable levels in the existing everyday routine practice conditions. The accuracy of the examination increases when interpreted by an experienced radiologist and when using the definition of cholesteatoma recommended by EAONO/JOS.

Imaging in children with hearing loss

BACKGROUND

Since the introduction of hearing screening in Germany in 2009, pediatric hearing disorders are detected at an early stage. Early therapy is essential for language development. Imaging plays a central role in diagnosis and therapy planning.

METHOD

Imaging findings of the most relevant causes of pediatric hearing disorders are presented. Specific attention is given to the method used in each case - CT or MRI.

RESULTS AND CONCLUSIONS

While CT is the method of choice for conductive hearing loss, a combination of CT and MRI with high-resolution T2-3D sequences has been established as the best diagnostic method for sensorineural hearing loss. The most common causes of conductive hearing loss in childhood are chronic inflammation and cholesteatoma. Congenital malformations of the outer or middle ear are less frequent. In the case of sensorineural hearing loss, the cause is located in the inner ear and/or the cochlear nerve or the cerebrum. In these cases, congenital malformations are the most common cause.

KEY POINTS

· CT and MRI are necessary to identify morphological causes of hearing disorders and to clarify the possibility of hearing-improving ear surgery or cochlear implantation.. · Contraindications for surgical procedures must be excluded.. · Anatomical variants that may be risk factors for surgery must be described..

CITATION FORMAT

· Sorge I, Hirsch F, Fuchs M et al. Imaging diagnostics for childhood hearing loss. Fortschr Röntgenstr 2023; 195: 896 - 904.

Performance of 2D BLADE turbo gradient- and spin-echo diffusion-weighted imaging in the quantitative diagnosis of recurrent temporal bone cholesteatoma

BACKGROUND

Diffusion-weighted imaging (DWI) has become an important tool for the detection of cholesteatoma. The purpose of this study was to explore the value of 2D BLADE turbo gradient- and spin-echo imaging (TGSE BLADE) DWI in the quantitative diagnosis of recurrent temporal bone cholesteatoma (CS).

METHODS

From March 2018 to October 2021, 67 patients with suspected recurrence of temporal bone CS after assessment by clinical otorhinolaryngologists who had undergone previous ear surgery for CS were prospectively evaluated by magnetic resonance imaging (MRI). Two radiologist assessed images independently. Quantitative parameters such as signal intensity ratio (SIR) calculated using, as a reference, the inferior temporal cortex (SIRT) and the background noise (SIRN), apparent diffusion coefficient (ADC) value, and ADC ratio (with pons as reference) measured on TGSE BLADE sequences were assessed. Using receiver operating characteristic (ROC) curve analysis, the optimal threshold and diagnostic performance for diagnosing recurrent CS were determined. Pair-wise comparison of the ROC curves was performed using the area under the ROC curve (AUC).

RESULTS

Finally, 44 patients were included in this study, including 25 CS and 19 non-cholesteatoma (NCS). Mean SIRT and mean SIRN on TGSE BLADE DWI were significantly higher for CS than NCS lesions (p < 0.001). Meanwhile, mean ADC values and mean ADC ratios on ADC maps were significantly lower in the CS group than in the NCS group (p < 0.001). According to ROC analysis, the diagnostic efficacy of quantitative parameters such as SIRT (AUC = 0.967), SIRN (AUC = 0.979), ADC value (AUC = 1.0), and ADC ratio (AUC = 0.983) was significantly better than that of qualitative DWI (AUC = 0.867; p = 0.007, 0.009, 0.011 and 0.037, respectively).

CONCLUSIONS

Residual/recurrent temporal bone CS can be accurately detected using quantitative evaluation of TGSE BLADE DWI.

Proposal of a magnetic resonance imaging follow-up protocol after cholesteatoma surgery: a prospective study

BACKGROUND

Non-echo planar (EPI) diffusion-weighted (DW) MRI has become an effective tool for the follow-up after cholesteatoma surgery and decreased the rate of second-look surgeries.

OBJECTIVES

To shed light on the optimal imaging follow-up protocol to detect postoperative residual or recurrent cholesteatoma.

MATERIALS AND METHODS

64 patients were included in this prospective study. Three different surgical procedures were considered: canal-wall-up (26 patients), canal-wall-down (20 patients), and obliterative (18 patients). The imaging follow-up protocol included non-EPI DW MRI during the following postoperative periods: 1 month, 6 months, and 1, 3, 5, and 7 years after the primary surgery.

RESULTS

MRI-positive lesions were present in 18.75% of patients. 50% of the MRI-positive findings occurred at the 1-month follow-up. The other peak of MRI positivity occurred at the 3-year follow-up. The last MRI-positive finding appeared at the 5-year follow-up.

CONCLUSIONS

The timing for the imaging protocol proposed by this prospective study to detect recidivism after cholesteatoma surgery stressed the importance of performing non-EPI DW MRI for detecting residual, though rare, disease. Likewise, extending the follow-up to a least 5 years after primary surgery was also recommended to detect any recurrent cholesteatoma that would appear unlikely to be present beyond this time set.

Lymph Nodes Evaluation in Rectal Cancer: Where Do We Stand and Future Perspective

The assessment of nodal involvement in patients with rectal cancer (RC) is fundamental in disease management. Magnetic Resonance Imaging (MRI) is routinely used for local and nodal staging of RC by using morphological criteria. The actual dimensional and morphological criteria for nodal assessment present several limitations in terms of sensitivity and specificity. For these reasons, several different techniques, such as Diffusion Weighted Imaging (DWI), Intravoxel Incoherent Motion (IVIM), Diffusion Kurtosis Imaging (DKI), and Dynamic Contrast Enhancement (DCE) in MRI have been introduced but still not fully validated. Positron Emission Tomography (PET)/CT plays a pivotal role in the assessment of LNs; more recently PET/MRI has been introduced. The advantages and limitations of these imaging modalities will be provided in this narrative review. The second part of the review includes experimental techniques, such as iron-oxide particles (SPIO), and dual-energy CT (DECT). Radiomics analysis is an active field of research, and the evidence about LNs in RC will be discussed. The review also discusses the different recommendations between the European and North American guidelines for the evaluation of LNs in RC, from anatomical considerations to structured reporting.

Advanced Magnetic Resonance Imaging (MRI) Techniques: Technical Principles and Applications in Nanomedicine

Simple Summary

Magnetic Resonance Imaging (MRI) is a consolidated imaging tool for the multiparametric assessment of tissues in various pathologies from degenerative and inflammatory diseases to cancer. In recent years, the continuous technological evolution of the equipment has led to the development of sequences that provide not only anatomical but also functional and metabolic information. In addition, there is a growing and emerging field of research in clinical applications using MRI to exploit the diagnostic and therapeutic capabilities of nanocompounds. This review illustrates the application of the most advanced magnetic resonance techniques in the field of nanomedicine.

Abstract

In the last decades, nanotechnology has been used in a wide range of biomedical applications, both diagnostic and therapeutic. In this scenario, imaging techniques represent a fundamental tool to obtain information about the properties of nanoconstructs and their interactions with the biological environment in preclinical and clinical settings. This paper reviews the state of the art of the application of magnetic resonance imaging in the field of nanomedicine, as well as the use of nanoparticles as diagnostic and therapeutic tools, especially in cancer, including the characteristics that hinder the use of nanoparticles in clinical practice.

Non-EPI versus Multishot EPI DWI in Cholesteatoma Detection: Correlation with Operative Findings

BACKGROUND AND PURPOSE

Although multishot EPI (readout-segmented EPI) has been touted as a robust DWI sequence for cholesteatoma evaluation, its efficacy in disease detection compared with a non-EPI (eg, HASTE) technique is unknown. This study sought to compare the accuracy of readout-segmented EPI with that of HASTE DWI in cholesteatoma detection.

MATERIALS AND METHODS

A retrospective review was completed of consecutive patients who underwent MR imaging for the evaluation of suspected primary or recurrent/residual cholesteatomas. Included patients had MR imaging examinations that included both HASTE and readout-segmented EPI sequences and confirmed cholesteatomas on a subsequent operation. Two neuroradiologist reviewers assessed all images, with discrepancies resolved by consensus. The ratio of signal intensity between the cerebellum and any observed lesion was noted.

RESULTS

Of 23 included patients, 12 (52.2%) were women (average age, 47.8 [SD, 25.2] years). All patients had surgically confirmed cholesteatomas: Six (26.1%) were primary and 17 (73.9%) were recidivistic. HASTE images correctly identified cholesteatomas in 100.0% of patients. On readout-segmented EPI sequences, 16 (69.6%) were positive, 5 (21.7%) were equivocal, and 2 (8.7%) were falsely negative. Excellent interobserver agreement was noted between reviews on both HASTE (κ = 1.0) and readout-segmented EPI (κ = 0.9) sequences. The average signal intensity ratio was significantly higher on HASTE than in readout-segmented EPI, facilitating enhanced detection (mean difference 0.5; 95% CI, 0.3-0.8; P = .003).

CONCLUSIONS

HASTE outperforms readout-segmented EPI in the detection of primary cholesteatoma and disease recidivism.

Correlation of pre-operative computed tomography, intra-operative findings and surgical outcomes in revision tympanomastoidectomy

OBJECTIVE

To correlate pre-operative computed tomography findings, intra-operative details and surgical outcomes with cholesteatoma recurrence in revision tympanomastoidectomy.

METHODS

This retrospective, non-randomised, single-institution cohort study included 42 patients who underwent pre-operative computed tomography imaging and revision surgery for recurrent chronic otitis media. Twelve disease localisations noted during revision surgery were correlated with pre-operative temporal bone computed tomography scans. A matched pair analysis was performed on patients with similar intra-operative findings, but without pre-operative computed tomography scans.

RESULTS

Pre-operative computed tomography identified 25 out of 31 cholesteatoma recurrences. Computed tomography findings correlated with: recurrent cholesteatoma when attic opacification and ossicular chain involvement were present; and revision surgery type. Sinodural angle disease, posterior canal wall erosion and dehiscent dura were identified as predictors of canal wall down tympanomastoidectomy. Patients with pre-operative computed tomography scans had a higher rate of cholesteatoma recurrence, younger age at diagnosis of recurrent disease, more revision surgical procedures and less time between previous and revision surgical procedures (all p < 0.05).

CONCLUSION

Pre-operative imaging and intra-operative findings have important clinical implications in revision surgery for chronic otitis media. Performing pre-operative computed tomography increases diagnosis accuracy and reduces the time required to diagnose recurrent disease.

Multimodal MRI Assessment of Thalamic Structural Changes in Earthquake Survivors

Moving from the central role of the thalamus in the integration of inner and external stimuli and in the implementation of a stress-related response, the objective of the present study was to investigate the presence of any MRI structural and volumetric changes of the thalamic structures in earthquake witnesses. Forty-one subjects were included, namely 18 university students belonging to the experimental earthquake-exposed group (8 males and 10 females, mean age 24.5 ± 1.8 years) and a control group of 23 students not living in any earthquake-affected areas at the time of the earthquake (14 males and 9 females, mean age 23.7 ± 2.0 years). Instrumental MRI evaluation was performed using a 3-Tesla scanner, by acquiring a three-dimensional fast spoiled gradient-echo (FSPGR) sequence for volumetric analysis and an EPI (echoplanar imaging) sequence to extract fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values. As compared to the control one, the experimental group showed significantly lower gray matter volume in the mediodorsal nucleus of the left thalamus (p < 0.001). The dominant hemisphere thalamus in the experimental group showed higher mean ADC values and lower mean FA values as compared to the control group.