Evaluation of the sacral nerve plexus in pelvic endometriosis by three-dimensional MR neurography

ACR Appropriateness Criteria® Endometriosis

Endometriosis is a common condition impacting individuals assigned female at birth. Though incompletely understood, the disorder is caused by endometrial-like tissue located outside of the endometrial cavity, associated with inflammation and fibrosis. Clinical presentation is variable, ranging from asymptomatic to severe pelvic pain and infertility. Treatment is determined by the patient's individualized goals and can include medical therapies to temporize symptoms or definitive surgical excision. Imaging is used to help diagnose endometriosis and for treatment planning. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Clinical and ultrasound characteristics of deep endometriosis affecting sacral plexus

OBJECTIVE

To describe the sonomorphological changes and appearance of deep endometriosis (DE) affecting the nervous tissue of the sacral plexus (SP).

METHODS

This was a retrospective study of symptomatic patients who underwent radical resection of histologically confirmed DE affecting the SP and who had undergone preoperative transvaginal sonography (TVS) between 2019 and 2023. Lesions were described based on the terms and definitions of the International Deep Endometriosis Analysis (IDEA), International Ovarian Tumor Analysis (IOTA) and Morphological Uterus Sonographic Assessment (MUSA) groups. A diagnosis of DE affecting the SP on TVS was made when the sonographic criteria of DE were visualized in conjunction with fibers of the SP and the presence of related symptoms corresponding to sacral radiculopathy. Clinical symptoms, ultrasound features and histological confirmation were analyzed for each patient included.

RESULTS

Twenty-seven patients with DE infiltrating the SP were identified in two contributing tertiary referral centers. Median age was 37 (range, 29-45) years and all patients were symptomatic and presented one or more of the following neurological symptoms: dysesthesia in the ipsilateral lower extremity (n = 17); paresthesia in the ipsilateral lower extremity (n = 10); chronic pelvic pain radiating in the ipsilateral lower extremity (n = 9); chronic pain radiating in the pudendal region (n = 8); and motor weakness in the ipsilateral lower extremities (n = 3). All DE lesions affecting the SP were purely solid tumors in the posterior parametrium in direct contact with, or infiltrating, the S1, S2, S3 and/or S4 roots of the SP. The median of the largest diameter recorded for each of the DE nodules was 35 (range, 18-50) mm. Echogenicity was non-uniform in 23 (85%) of the DE nodules, with all but one of these nodules containing hyperechogenic areas. The shape of the lesions was irregular in 24 (89%) cases. Only one lesion exhibited a lobulated form, with all other irregular lesions showing a spiculated appearance. An acoustic shadow was produced in 20 (74%) of the nodules, all of which were internal. On color or power Doppler examination, 21 (78%) of the nodules showed no signal (color score of 1). The remaining six (22%) lesions showed a minimal color content (color score of 2). According to pattern recognition, most DE nodules were purely solid, non-uniform, hypoechogenic nodules containing hyperechogenic areas, with internal shadows and irregular spiculated contours, and were poorly vascularized on color/power Doppler examination.

CONCLUSION

The ultrasound finding of a parametrial, unilateral, solid, non-uniform, hypoechogenic nodule with hyperechogenic areas and possible internal shadowing, as well as irregular spiculated contours, demonstrating poor vascularization on Doppler examination in proximity to or involving the structures of the SP, indicates DE affecting the SP. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Improved visualization of median, ulnar nerves, and small branches in the wrist and palm using contrast-enhanced magnetic resonance neurography

Background

Magnetic resonance imaging of peripheral nerves in the wrist and palm is challenging due to the small size, tortuous course, complex surrounding tissues, and accompanying blood vessels. The occurrence of carpal palmar lesions leads to edema, swelling, and mass effect, which may further interfere with the display and identification of nerves.

Objective

To evaluate whether contrast-enhanced magnetic resonance neurography (ceMRN) improves the visualization of the morphology and pathology of the median, ulnar nerves, and their small branches in the wrist and palm.

Design

An observational study.

Methods

In total 57 subjects, including 36 volunteers and 21 patients with carpal palmar lesions, were enrolled and underwent ceMRN and non-contrast MRN (ncMRN) examination at 3.0 Tesla. The degree of vascular suppression, nerve visualization, diagnostic confidence, and lesion conspicuity was qualitatively assessed by two radiologists. Kappa statistics were obtained for inter-reader agreement. The signal-to-noise ratio, contrast ratio (CR), and contrast-to-noise ratio (CNR) of the median nerve were measured. The subjective ratings and quantitative measurements were compared between ncMRN and ceMRN.

Results

The inter-reader agreement was excellent (k > 0.8) for all qualitative assessments and visualization assessment of each nerve segment. Compared with ncMRN, ceMRN significantly improved vascular suppression in volunteers and patients (both p < 0.001). The ceMRN significantly enhanced nerve visualization of each segment (all p < 0.05) and diagnostic confidence in volunteers and patients (both p < 0.05). The ceMRN improved lesion conspicuity (p = 0.003) in patients. Quantitatively, ceMRN had significantly higher CRs of nerve versus subcutaneous fat, bone marrow, and vessels and CNR of nerve versus vessel than ncMRN (all p < 0.05).

Conclusion

The ceMRN significantly improves the visualization of peripheral nerves and pathology in the wrist and palm by robustly suppressing the signals of fat, bone marrow, and especially vessels in volunteers and patients.

Comparison Between a Modified Fast 3-Dimensional Turbo Spin-Echo and Diffusion-Weighted Imaging With Background Suppression in Evaluation of Lumbosacral Plexus and Its Branches

OBJECTIVES

To compare the fast 3-dimensional NerveVIEW (3D NerveVIEW) with diffusion-weighted imaging with background suppression (DWIBS) in imaging of lumbosacral plexus and its branches.

METHODS

A prospective study was performed on 30 healthy volunteers and patients who had undergone compressed sensing 3D NerveVIEW and DWIBS scans. There were 11 healthy subjects, 15 patients with lumbar disc herniation, and 4 patients with chronic inflammatory demyelinating polyradiculoneuropathy. Image quality was rated using a 4-point subjective scale. Quantitative evaluation of the nerves was done by measuring signal-to-noise ratio, contrast-to-noise ratio, and signal-to-background ratio, and the consistency in the measurements of nerve root cross-sectional areas was also assessed. The differences of signal-to-noise ratio, contrast-to-noise ratio, signal-to-background ratio, and the scores of image quality between 2 sequences were compared.

RESULTS

The overall average image quality score of 3D NerveVIEW was significantly higher than that of DWIBS (2.72 ± 0.45 and 2.45 ± 0.81, respectively; P < 0.01). In terms of individual nerves, there was no significant difference between the 2 sequences in the display of the nerves from L2 to S1; however, 3D NerveVIEW was significantly better than DWIBS in demonstration of the S2-S3 nerves, as well as the nerve details. Regarding quantitative measurements, these sequences achieved comparable results with excellent interobserver agreements.

CONCLUSION

Fast 3D NerveVIEW was superior to DWIBS with improved conspicuity of small distal nerves of S2-S3 and nerve details.

Society of skeletal radiology position paper - recommendations for contrast use in musculoskeletal MRI: when is non-contrast imaging enough?

The following White Paper will discuss the appropriateness of gadolinium administration in MRI for musculoskeletal indications. Musculoskeletal radiologists should consider the potential risks involved and practice the judicious use of intravenous contrast, restricting administration to cases where there is demonstrable added value. Specific nuances of when contrast is or is not recommended are discussed in detail and listed in table format. Briefly, contrast is recommended for bone and soft tissue lesions. For infection, contrast is reserved for chronic or complex cases. In rheumatology, contrast is recommended for early detection but not for advanced arthritis. Contrast is not recommended for sports injuries, routine MRI neurography, implants/hardware, or spine imaging, but is helpful in complex and post-operative cases.

The clinical value of using magnetic resonance contrast-enhanced three-dimensional nerve view in the diagnosis and management of sacral fracture accompanied by sacral plexus injury

BACKGROUND

The treatment of sacral fractures accompanied by nerve injury is complex and often leads to an unsatisfactory prognosis and poor quality of life in patients.

OBJECTIVE

The present study aimed to investigate the clinical value of using 3.0T magnetic resonance contrast-enhanced three-dimensional (MR CE-3D) nerve view magnetic resonance neurography (MRN) in the diagnosis and management of a sacral fracture accompanied by a sacral plexus injury.

METHODS

Thirty-two patients with a sacral fracture accompanied by a sacral plexus injury, including 24 cases of Denis spinal trauma type II and 8 cases of type III, were enrolled in the study. All patients had symptoms or signs of lumbosacral nerve injury, and an MRN examination was performed to clarify the location and severity of the sacral nerve injury. Segmental localization of the sacral plexus was done to indicate the site of the injury as being intra-spinal (IS), intra-foraminal (IF), or extra-foraminal (EF), and the severity of the nerve injury was determined as being mild, moderate, or severe. Surgical nerve exploration was then conducted in six patients with severe nerve injury. The location and severity of the nerve injury were recorded using intra-operative direct vision, and the results were statistically compared with the MRN examination results.

RESULTS

MRN showed that 81 segments had mild sacral plexus injuries (8 segments of IS, 20 segments of IF, 53 segments of EF), 78 segments had moderate sacral plexus injuries (8 segments of IS, 37 segments of IF, and 33 segments of EF), and 19 segments had severe sacral plexus injuries (7 segments of IS, 9 segments of IF, and 3 segments of EF). The six patients who underwent surgery had the following intra-operative direct vision results: 3 segments of moderate injury (IF) and 20 segments of severe injury (7 segments of IS, 10 segments of IF, 3 segments of EF). There was no statistically significant difference in the results between the intra-operative direct vision and those of the MRN examination (p> 0.05).

CONCLUSION

MR CE-3D nerve view can clearly and accurately demonstrate the location and severity of sacral nerve injury accompanied by a sacral fracture, and has the potential for being the first choice of examination method for this kind of injury, which would be of important clinical value.

MRI in the Diagnosis of Endometriosis and Related Diseases

Endometriosis, a common chronic inflammatory disease in female of reproductive age, is closely related to patient symptoms and fertility. Because of its high contrast resolution and objectivity, MRI can contribute to the early and accurate diagnosis of ovarian endometriotic cysts and deeply infiltrating endometriosis without the need for any invasive procedure or radiation exposure. The ovaries, which are the most frequent site of endometriosis, can be afflicted by multiple related conditions and diseases. For the diagnosis of deeply infiltrating endometriosis and secondary adhesions among pelvic organs, fibrosis around the ectopic endometrial gland is usually found as a T2 hypointense lesion. This review summarizes the MRI findings obtained for ovarian endometriotic cysts and their physiologically and pathologically related conditions. This article also includes the key imaging findings of deeply infiltrating endometriosis.

Indirect and atypical imaging signals of endometriosis: A wide range of manifestations

Background

Whilst some imaging signs of endometriosis are common and widely accepted as ‘typical’, a range of ‘subtle’ signs could be present in imaging studies, presenting an opportunity to the radiologist and the surgeon to aid the diagnosis and facilitate preoperative surgical planning.

Objective

To summarise and analyse the current information related to indirect and atypical signs of endometriosis by ultrasound (US) and magnetic resonance imaging (MRI).

Methods

Through the use of PubMed and Google scholar, we conducted a comprehensive review of available articles related to the diagnosis of indirect signs in transvaginal US and MRI. All abstracts were assessed and the studies were finally selected by two authors.

Results

Transvaginal US is a real time dynamic exploration, that can reach a sensitivity of 79-94% and specificity of 94%. It allows evaluation of normal sliding between structures in different compartments, searching for adhesions or fibrosis.

MRI is an excellent tool that can reach a sensitivity of 94% and specificity of 77% and allows visualisation of the uterus, bowel loop deviation and peritoneal inclusion cysts. It also allows the categorisation and classification of ovarian cysts, rectovaginal and vesicovaginal septum obliteration, and small bowel endometriotic implants.

Conclusion

The use of an adequate mapping protocol with systematic evaluation and the reporting of direct and indirect signs of endometriosis is crucial for detailed and safe surgical planning.

Diagnostic contribution of contrast-enhanced 3D MR imaging of peripheral nerve pathology

OBJECTIVE

To assess the diagnostic contribution of contrast-enhanced 3D STIR (ce3D-SS) high-resolution magnetic resonance (MR) imaging of peripheral nerve pathology relative to conventional 2D sequences.

MATERIALS AND METHODS

In this IRB-approved retrospective study, two radiologists reviewed 60 MR neurography studies with nerve pathology findings. The diagnostic contribution of ce3D-SS imaging was scored on a 4-point Likert scale (1 = no additional information, 2 = supports interpretation, 3 = moderate additional information, and 4 = diagnosis not possible without ce3D-SS). Image quality, nerve visualization, and detection of nerve pathology were also assessed for both standard 2D neurography and ce3D-SS sequences utilizing a 3-point Likert scale. Descriptive statistics are reported.

RESULTS

The diagnostic contribution score for ce3D-SS imaging was 2.25 for the brachial plexus, 1.50 for extremities, and 1.75 for the lumbosacral plexus. For brachial plexus, the mean consensus scores for image quality, nerve visualization, and detection of nerve pathology were 2.55, 2.5, and 2.55 for 2D and 2.35, 2.45, and 2.45 for 3D. For extremities, the mean consensus scores for image quality, nerve visualization, and detection of nerve pathology were 2.60, 2.80, and 2.70 for 2D and 1.8, 2.20, and 2.10 for 3D. For lumbosacral plexus, the mean consensus scores for image quality, nerve visualization, and detection of nerve pathology were 2.45, 2.75, and 2.65 for 2D and 2.0, 2.45, and 2.25 for 3D.

CONCLUSION

Overall, our study supports the potential application of ce3D-SS imaging for MRN of the brachial plexus but suggests that 2D MRN protocols are sufficient for MRN of the extremities and lumbosacral plexus.

ACR Appropriateness Criteria® Plexopathy: 2021 Update

Plexopathy may be caused by diverse pathologies, including trauma, nerve entrapment, neoplasm, inflammation, infection, autoimmune disease, hereditary disease, and idiopathic etiologies. For patients presenting with brachial or lumbosacral plexopathy, dedicated plexus MRI is the most appropriate initial imaging modality for all clinical scenarios and can identify processes both intrinsic and extrinsic to the nerves. Other imaging tests may be appropriate for initial imaging depending on the clinical scenario. This document addresses initial imaging strategies for brachial and lumbosacral plexopathy in the following clinical situations: nontraumatic plexopathy with no known malignancy, traumatic plexopathy (not perinatal), and plexopathy occurring in the context of a known malignancy or posttreatment syndrome. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Structured report for dynamic ultrasonography in patients with suspected or known endometriosis: Recommendations of the International Society for Gynecologic Endoscopy (ISGE)

OBJECTIVE

The International Society for Gynecologic Endoscopy (ISGE) developed this project to establish the recommendations for structured reporting of dynamic ultrasound findings, promoting on this manner the practice of standardized, comprehensive and systematic evaluation and reporting of endometriosis in pelvic structures, in correlation with the #Enzian classification.

STUDY DESIGN

A non-systematic review was done through a search on the following databases: MEDLINE, EMBASE, Global Health, The Cochrane Library (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Cochrane Methodology Register), Health Technology Assessment Database and Web of Science, using the medical subject heading (MeSH) term "endometriosis" (MeSH Unique ID: D004715) in combination with "diagnostic imaging" (MeSH Unique ID Q000000981) and "consensus" (MeSH Unique ID D032921). The information extracted from the articles of interest, written in English and published from inception of the above-mentioned databases until May 2021, was graded by the level of evidence using the American College of Chest Physicians (ACCP) classification system. The recommendations for a structured reporting of ultrasound findings were developed through multiple cycles of literature analysis and expert discussion following the Delphi method.

RESULTS

The ISGE recommends the adoption of the terms, definitions and methods proposed by the International Deep Endometriosis Analysis (IDEA) Group for ultrasound assessment of patients with suspected or known endometriosis (grade 1C), since this is the most comprehensive and systematic concept currently available. This paper provides the ISGE structured reporting template for presenting quantitative and qualitative information upon the IDEA consensus-based sonographic assessment of the uterus, adnexa, anterior and posterior compartment. The #Enzian classification is recommended to summarize the findings in a standard fashion (grade 1B).

CONCLUSION

Mapping of pelvic endometriosis by ultrasound is accurate when trained sonographers perform the technique. Structured reporting of the lesions may improve patient counseling and treatment planning, including the organization of multidisciplinary teams and the selection of the most appropriate medical or surgical therapeutic strategy.

The role of imaging in pelvic exenteration for gynecological cancers

Pelvic exenteration (PE) is one of the most challenging gynecologic oncologic surgeries and is an overriding term for different procedures that entail radical en bloc resection of the female reproductive organs and removal of additional adjacent affected pelvic organs (bladder, rectum, anus, etc.) with concomitant surgical reconstruction to restore bodily functions. Multimodality cross-sectional imaging with MRI, PET/CT, and CT plays an integral part in treatment decision-making, not only for the appropriate patient selection but also for surveillance after surgery. The purpose of this review is to provide a brief background on pelvic exenteration in gynecologic cancers and to familiarize the reader with the critical radiological aspects in the evaluation of patients for this complex procedure. The focus of this review will be on how imaging can aid in treatment planning and guide management.

Transvaginal Sonographic Imaging and Associated Techniques for Diagnosis of Ovarian, Deep Endometriosis, and Adenomyosis: A Comprehensive Review

Imaging of endometriosis and in particular deep endometriosis (DE) is crucial in the clinical management of women facing this debilitating condition. Transvaginal sonography (TVS) is the first-line imaging method and magnetic resonance imaging (MRI) may provide supplemental information. However, the delay in diagnosis of up to 10 years and more is of concern. This problem might be overcome by simple steps using imaging with emphasis on TVS and referral to tertiary care. Finally, TVS is crucial in mapping extent and location of disease in planning surgical therapy and counseling women regarding various therapeutic options. This review presents the available data on imaging of endometriosis with a focus on TVS and MRI for DE, adenomyosis, and ovarian endometriomas including endometriomas in pregnancy as well as the use of "soft markers." The review presents an approach that is in accordance with the International Deep Endometriosis Analysis (IDEA) group consensus statement.

The Noninvasive Diagnostic Value of MRN for CIDP: A Research from Qualitative to Quantitative

STUDY DESIGN

We examined the chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients and non-CIDP patients who have similar symptoms and difficult to differential diagnosis with CIDP by magnetic resonance neurography to find the difference among them.

OBJECTIVE

To investigate the differential diagnostic value of magnetic resonance neurography (MRN) for CIDP and other peripheral neuropathies.

SUMMARY OF BACKGROUND DATA

Thirty-two consecutive patients with CIDP and 22 non-CIDP patients with symptoms similar to CIDP and difficult to be discriminate were recruited and imaged as a control group between May 2017 and May 2019.

METHODS

In this prospective study, the brachial plexus and lumbosacral plexus of 32 CIDP patients and 22 non-CIDP patients were examined by MRN. The clinical features and the nerve roots cross-sectional area (CSA) of the brachial plexus and lumbosacral plexus were measured.

RESULTS

The CSA of nerve roots of CIDP, Charcot-Marie-Tooth disease type-1 and polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes syndrome patients were all shown extensive by MRN. The sensitivity of MRN in diagnosing CIDP was 81.25% (26/32), the specificity was 68.18% (15/22), the positive predictive value was 78.79% (26/33), the negative predictive value was 71.43% (15/21), the accuracy was 75.93% (40/54), the misdiagnosis rate was 24.07% (13/54), and the kappa value was 0.498. Receiver operating characteristic analysis showed higher diagnostic accuracy for CIDP with the CSA of the lumbosacral plexus (area under the curve [AUC] = 0.762) and that of the brachial plexus (AUC = 0.762), and the combined of both examinations did not improve the diagnostic efficacy compared with either (AUC = 0.769).

CONCLUSIONS

The nerve roots of CIDP, Charcot-Marie-Tooth disease type-1, and polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes syndrome were difficult to distinguish by MRN. Atypical CIDP patients had less nerve root injury compared with typical CIDP patients. MRN of either the brachial plexus or the lumbosacral plexus had a high diagnostic accuracy for CIDP, and it is not necessary to perform both parts of the examination.

LEVEL OF EVIDENCE

2.

A Novel Approach for Imaging of Thoracic Outlet Syndrome Using Contrast-Enhanced Magnetic Resonance Angiography (CE-MRA), Short Inversion Time Inversion Recovery Sampling Perfection with Application-Optimized Contrasts Using Different Flip Angle Evolutions (T2-STIR-SPACE), and Volumetric Interpolated Breath-Hold Examination (VIBE)

Background

The aim of this study was to introduce a novel method combining contrast-enhanced magnetic resonance angiography (CE-MRA), short inversion time inversion recovery sampling perfection with application-optimized contrasts using different flip angle evolutions (T2-STIR-SPACE) and volumetric interpolated breath-hold examination (VIBE) sequences in the assessment of thoracic outlet syndrome (TOS).

Material/Methods

CE-MRA, T2-STIR-SPACE, and VIBE techniques were employed to evaluate neurovascular bundles in 27 patients clinically suspected of TOS. Images were evaluated to determine the cause of neurovascular bundle compression. Surgical exploration was performed in patients with abnormal magnetic resonance imaging (MRI) results.

Results

Twenty patients were found to be abnormal: 6 cases showed only neurogenic TOS and the correlates included infraclavicular hemangiomas (n=1) and transverse cervical artery (n=5). Arterial-neurogenic TOS was found in 4 cases, including subclavian lymph node metastasis from breast cancer (n=3) and schwannoma (n=1). Arterial-venous-neurogenic TOS was found in 1 subject, and the correlates included a fibrous band from the cervical rib and elongated C7 transverse process. In this case, the subclavian artery/vein was compressed dynamically. Venous–neurogenic TOS was noted in one subject. Nine patients were considered as post-traumatic TOS, including brachial plexus edema (n=3), the brachial plexus rupture (n=2), peri-brachial plexus effusion (n=3), and stenosis of the SCA (n=1). In the remaining 7 patients, MRI did not detect abnormalities.

Conclusions

TOS can be evaluated by CE-MRA, T2-STIR-SPACE, and VIBE during a single examination, with a reduced contrast material dose. This imaging modality performs well in showing the anatomical structure of the neurovascular bundle and the cause of the compression.

Structured Ultrasound and Magnetic Resonance Imaging Reports for Patients with Suspected Endometriosis: Guide for Imagers and Clinicians

In this article we propose a structured imaging report applied to ultrasound and magnetic resonance imaging in patients with suspected endometriosis.

MR imaging of endometriosis: Spectrum of disease

Endometriosis is a common gynecological disorder defined by the presence of endometrial tissue outside the uterus. It is the most common cause of chronic pelvic pain and typically affects the ovaries, uterine ligaments, peritoneum, tubes, rectovaginal septum and bladder. It may, however, be found at various extrapelvic sites, including the perineum, liver, pancreas, lung or even the central nervous system, and in such cases, diagnosis may be quite challenging. Even though definitive diagnosis requires laparoscopy, preoperative identification of endometriosis is important not only to differentiate it from other diseases with similar clinical presentations but also, for accurate presurgical mapping, since complete removal of all endometriotic foci is critical for the effective treatment of the patient's symptoms. Ultrasound is performed initially, but magnetic resonance imaging (MRI) is increasingly being used, particularly when sonographic findings are unclear, when deep pelvic endometriosis is suspected or when surgery is planned, as it provides better contrast resolution and a larger field of view compared to ultrasound. In this article, we will discuss distinctive MRI appearances of endometriotic foci and we will review common and uncommon locations of endometriosis within the body, in an attempt to familiarize radiologists with its wide spectrum of manifestations.

Iodine and freeze-drying enhanced high-resolution MicroCT imaging for reconstructing 3D intraneural topography of human peripheral nerve fascicles

BACKGROUND

The precise annotation and accurate identification of the topography of fascicles to the end organs are prerequisites for studying human peripheral nerves.

NEW METHOD

In this study, we present a feasible imaging method that acquires 3D high-resolution (HR) topography of peripheral nerve fascicles using an iodine and freeze-drying (IFD) micro-computed tomography (microCT) method to greatly increase the contrast of fascicle images.

RESULTS

The enhanced microCT imaging method can facilitate the reconstruction of high-contrast HR fascicle images, fascicle segmentation and extraction, feature analysis, and the tracing of fascicle topography to end organs, which define fascicle functions.

COMPARISON WITH EXISTING METHODS

The complex intraneural aggregation and distribution of fascicles is typically assessed using histological techniques or MR imaging to acquire coarse axial three-dimensional (3D) maps. However, the disadvantages of histological techniques (static, axial manual registration, and data instability) and MR imaging (low-resolution) limit these applications in reconstructing the topography of nerve fascicles.

CONCLUSIONS

Thus, enhanced microCT is a new technique for acquiring 3D intraneural topography of the human peripheral nerve fascicles both to improve our understanding of neurobiological principles and to guide accurate repair in the clinic. Additionally, 3D microstructure data can be used as a biofabrication model, which in turn can be used to fabricate scaffolds to repair long nerve gaps.

[Imaging of the lumbosacral plexus : Diagnostics and treatment planning with high-resolution procedures]

BACKGROUND

Technical advances in magnetic resonance (MR) and ultrasound-based neurography nowadays facilitate the radiological assessment of the lumbosacral plexus.

OBJECTIVE

Anatomy and imaging of the lumbosacral plexus and diagnostics of the most common pathologies.

MATERIAL AND METHODS

Description of the clinically feasible combination of magnetic resonance imaging (MRI) and ultrasound diagnostics, case-based illustration of imaging techniques and individual advantages of MRI and ultrasound-based diagnostics for various pathologies of the lumbosacral plexus and its peripheral nerves.

RESULTS

High-resolution ultrasound-based neurography (HRUS) is particularly valuable for the assessment of superficial structures of the lumbosacral plexus. Depending on the examiner's experience, anatomical variations of the sciatic nerve (e. g. relevant in piriformis syndrome) as well as more subtle variations, for example as seen in neuritis, can be sonographically depicted and assessed. The use of MRI enables the diagnostic evaluation of more deeply located nerve structures, such as the pudendal and the femoral nerves. Modern MRI techniques, such as peripheral nerve tractography allow three-dimensional depiction of the spatial relationship between nerves and local tumors or traumatic alterations. This can be beneficial for further therapy planning.

CONCLUSION

The anatomy and pathology of the lumbosacral plexus can be reliably imaged by the meaningful combination of MRI and ultrasound-based high resolution neurography.