MRI Appearance Research Articles

RE-VISITING BIOPSIES FOR SUSPECTED CNS LYMPHOMAS: TO BIOPSY OR NOT TO BIOPSY?

Abstract AIMS It is a common practice to get a histological diagnosis before treatment of suspected CNS (central nervous system) lymphoma. Should CNS lesions be routinely biopsied in patients with background systemic lymphoma? METHOD A 10-year retrospective review of biopsy-proven CNS lymphoma was conducted. Data was analyzed using SPSS for Windows, version 25 (SPSS, Inc., Chicago, Illinois, USA), and a p-value < 0.05 was considered significant for the appropriate test statistic. RESULTS Patients with background systemic lymphoma whose brain MRI appearances were in favour of lymphoma after MDT discussion all had histologically-proven lymphoma after brain biopsy. Pre-biopsy MDT diagnosis was congruent with post-biopsy histology in 87.6% of cranial lesions (p-value 0.003) and 40% of spinal lymphomas (p-value 0.002). Secondary CNS lymphoma was seen in 21.2%. Stereotactic brain biopsy was the most common biopsy technique for cranial lesions (79.8%). Histology was Diffuse B Cell Lymphoma in 93% of cases. The mean Ki67 percentage for cranial lymphomas was higher than that of spine (p-value 0.028) The complication rate for cranial biopsy was 8.9%. Transient motor deficits (4.4%) and post-operative haematoma (2.2%) were the most common. The 24-hour post-brain biopsy mortality rate was 1.1%, while overall 30-day post-op mortality rate was 4.4%. The mean percentage of Ki67 was higher among patients who had complications (p-value 0.001). CONCLUSION In a setting of properly constituted neurooncology MDT, a sub-set of patients with suspected brain lymphoma and background systemic lymphoma might not require brain biopsy. KEY WORDS Lymphoma, Brain, Spine, Biopsy, Complication

Osteochondroma of the Distal Tibia in an Adolescent: A Case Report

A 17-year-old male presented with a painful left ankle that had been worsening over the preceding 1 year. Clinical and radiographic inspection revealed marked bowing with a deformation of the fibula secondary to the laterally outgrowing bone lesion from the distal tibia proximal to the growth plate. MRI appearance suggestive of an osteochondroma of the lower extremity of the left tibia with signs of degeneration, It is surrounded by a cartilaginous cap, thickened in places, measuring 22 mm in maximum thickness. Although the radiographic characteristics of the lesion were indicative of osteochondroma, a typically asymptomatic and benign tumor that is usually identified as an incidental finding, the large size and symptoms associated with the lesion described in this article make it rather unusual. In this particular case, excessive bony outgrowth, pain, joint malposition, necessitated surgical intervention. The patient was successfully treated with resection of the tumor, after which gradual restoration of the alignment of the distal leg ensued without the need for fibular osteotomy. After more than 1 year of postoperative follow-up, neither radiographic nor clinical evidence of recurrence had been observed and the patient displayed a pain-free range of ankle motion without any physical limitations.

Magnetic Resonance Imaging appearance of regenerative peripheral nerve interface

PurposeTo describe the MRI appearance of Regenerative peripheral nerve interface (RPNI) and the potential association between the MR appearance and RPNI revision. Material and methodsA retrospective assessment was undertaken of the MR appearance of RPNIs performed at our institution between 1/1/2010- 7/29/2023 with clinical correlation. Results14 patients (8 males, 6 females, age range 31-80 years, median age- 51 years) with technically adequate MRI of RPNIs were included in this study including 5 patients with below knee amputation (BKA) with 5 tibial and 4 CPN RPNI, 8 patients with above knee amputations (AKA) with sciatic RPNIs and one patient following forequarter amputation with a brachial plexus RPNI. Two patients had undergone revision RPNI surgery x3 (AKA-sciatic nerve) for a total of 6 RPNI revisions. On T1 weighted sequences, all RPNIs were isointense to muscle and blended with the surrounding scar and muscle tissues while on T2 weighted sequences, all RPNIs were hyperintense in signal compared to muscle. All but one RPNI underwent post contrast enhancement in variable patterns. No statistically significant difference in MR appearance was found between RPNIs with or without a following RPNI revision surgery. ConclusionRPNI on MRI typically have a bright and intermediate signal on T2 and T1 weighted sequences accordingly, and typically undergo postcontrast enhancement in variable patterns without a statistically significant difference between cases with and without a following RPNI revision. Enhancement of RPNI should not be misconstrued as pathological.

The imaging appearances of stapical footplate fistula related to inner ear malformation

Objective: To summarize the HRCT and MRI appearances of stapical footplate fistula related to inner ear malformation (SFF-Re-IEM). Methods: The HRCT and MRI materials of 48 cases (53 ears) SFF-Re-IEM were retrospectively analyzed. Among them, 25 SFF-Re-IEM ears were confirmed by surgery. Their CT and MRI findings including associated IEM type, internal auditory canal (IAC) malformation, tympanic fluid, its density and signal features, and accompanied labyrinthitis were recorded. Results: Among 48 cases (53 ears) with SFF-Re-IEM, 17 ears with incomplete partition type Ⅰ, accounting for 32.1%, 13 ears with common cavity for 24.5%, 13 ears with cochlear aplasia for 24.5%, 7 ears with cochlear dysplasia Ⅱ for 13.2%, and 3 ears with Mondini for 5.7%,were found respectively. 94.3% of them were associated with a defect or dysplasia in the found of the IAC. They were divided into 4 types according to the intact of the stapical footplate and accompanied CSF otorrhea: 22 ears were diagnosed as the stapical footplate leaking, of them, 2 ears might come from the stapical footplate bony defect, 6 ears were from the stapical footplate hernia. 1 ear belonged to the peristapical footplate leaking. 30 ears with the isolated the stapical footplate hernia were another found. The bony defect in 2 ears with the stapical footplate bony defect were not presented on CT and MRI.The focal bony defect of the affected stapical footplate of 36 ears with the stapical footplate hernia were demonstrated, which presented the hemispherical protruding into the tympana, the soft-tissue density on CT, and CSF-like signal on the MR heaved-T2WI images. Among 22 ears with the stapical footplate leaking, their imaging appearances varied from the different amount of the leaking CSF. Besides the focal bony defects of the affected stapical footplates, there were much more CSF-like density or signal in the ipsilateral tympanic cavity in 17 affected ears connecting with the vestibule through the defect area. In the CSF leaking ears with less CSF leaking in 5 ears, the CSF-like cysts like SFH were shown on the stapical footplate defect area, but their outer edges were irregular, and the CSF-like signal scattering in the tympanic cavity did not connect with the protruding cysts at the stapical area. Conclusion: The variable appearances of the SFF-Re-IEM ears based on the different subtypes are its characteristic HRCT and MRI appearances. This is helpful for the SFF-Re-IEM diagnosing to grasp its imaging features.

Muscle Healing in Sports Injuries: MRI Findings and Proposed Classification Based on a Single Institutional Experience and Clinical Observation.

MRI plays a crucial role in assessment of patients with muscle injuries. The healing process of these injuries has been studied in depth from the pathophysiologic and histologic points of view and divided into destruction, repair, and remodeling phases, but the MRI findings of these phases have not been fully described, to our knowledge. On the basis of results from 310 MRI studies, including both basal and follow-up studies, in 128 athletes with muscle tears including their clinical evolution, the authors review MRI findings in muscle healing and propose a practical imaging classification based on morphology and signal intensity that correlates with histologic changes. The proposed phases, which can overlap, are destruction (phase 1), showing myoconnective tissue discontinuity and featherlike edema; repair (phase 2), showing filling in of the connective tissue gaps by a hypertrophic immature scar; and remodeling (phase 3), showing scar maturation and regression of the edema. A final healed stage can be identified with MRI, which is characterized by persistence of a slight fusiform thickening of the connective tissue. This information can be obtained from a truncated MRI protocol with three acquisitions, preferably performed with a 3-T magnet. During MRI follow-up of muscle injuries, other important features to be assessed are changes in muscle edema and specific warning signs, such as persistent intermuscular edema, new connective tear, and scar rupture. An understanding of the MRI appearance of normal and abnormal muscle healing and warning signs, along with cooperation with a multidisciplinary team, enable optimization of return to play for the injured athlete. ©RSNA, 2024 See the invited commentary by Flores in this issue.

Ex vivo evaluation of the soft tissue components of the equine stifle using 3 Tesla magnetic resonance imaging under flexion, extension, and loading.

High-field MRI of the equine stifle provides high-resolution information about soft tissues that is useful in the diagnosis of stifle lameness. The aim of this prospective anatomic study was to describe the appearance, position, size, and shape of the equine femorotibial ligaments, meniscal ligaments, and menisci using 3 Tesla MRI under extended, extended-loaded, and flexed conditions. Additionally, histologic examination of the collateral and cruciate ligaments (CLs) of a single stifle was performed to compare with MRI images. In extension, mild variations in MRI signal intensity were apparent in the CLs, and the cranial had two distinct longitudinal regions indicating two ligament bundles. Flexion had minor effects on CL signal intensity and altered the tibial angles of attachment. Histology indicated that both CLs were comprised of two fiber bundles. The collateral ligaments were the same low-signal intensity. The medial collateral ligament had a smaller cross-sectional area than the lateral, and flexion increased the length of the medial collateral ligament and the cross-sectional area of the lateral. Low loads in extension did not affect the MRI appearance of stifle soft tissues. Flexion of the stifle impacted cruciate ligament insertion angles and the size and shape of collateral ligaments. This study provides support for the use of MRI to understand the anatomy and function of stifle ligaments.

Cardiac sarcoidosis and neurosarcoidosis - multidisciplinary approach for diagnosis.

The current review aims to highlight the role of multidisciplinary approach in the diagnosis of patients with cardiac and neurosarcoidosis. Multidisciplinary approach integrates the available clinical information, imaging and histopathological results aiming to reach a definite or at least provisional diagnosis and allow appropriate management. Multidisciplinary approach is the reference standard for diagnosis of interstitial lung disease and should be strongly considered in complex clinical conditions such as cardiac sarcoidosis (CS) and neurosarcoidosis. Histopathological confirmation of noncaseating granulomatous inflammation provides a definite diagnosis of sarcoidosis involving any organ. However, a provisional high confidence or even definite clinical diagnosis can be reached using multidisciplinary evaluation of all available evidence. The diagnosis of cardiac sarcoidosis and neurosarcoidosis requires the integration of different expertise based on the current diagnostic criteria sets. Identifying typical or at least compatible patterns on advanced imaging modalities (CMR and Fluro-Deoxy-Glucose Positron Emission Tomography (FDG-PET)) seems key for the diagnosis of CS, while a confident diagnosis of extra-cardiac disease supports an at least provisional diagnosis. Similarly, in neurosarcoidosis integrating compatible MRI appearances and cerebrospinal fluid results in patients with systemic sarcoidosis allows an at least provisional diagnosis. Exclusion of alternative differential diagnoses is crucial and requires high clinical suspicion, imaging review expertise and appropriate tests performance. There have been considerable advances in the diagnostic approach of patients with cardiac and neurosarcoidosis. Multidisciplinary approach for both diagnosis and management is required to reach a confident clinical diagnosis and should be applied when possible.

Reasons for Discordance between 68Ga-PSMA-PET and Magnetic Resonance Imaging in Men with Metastatic Prostate Cancer.

PSMA PET has emerged as a "gold standard" imaging modality for assessing prostate cancer metastases. However, it is not universally available, and this limits its impact. In contrast, whole-body MRI is much more widely available but misses more lesions. This study aims to improve the interpretation of whole-body MRI by comparing false negative scans retrospectively to PSMA PET. This study was a retrospective sub-analysis of a prospectively collected database of patients who participated in a clinical trial of PSMA PET/MRI comparing PSMA PET and whole-body MRI from 2018-2021. Subjects whose separately read PSMA PET and MRI diagnostic reports showed discrepancies ("false negative" MRI cases) were selected for sub-analysis. The cases were reviewed by the same attending radiologist who originally read the scans. The radiologist noted specific features on MRI indicating metastatic disease that were initially missed. Of 263 cases, 38 (14%) met the inclusion criteria and were reviewed. Six classes of mpMRI false negatives were identified: anatomically normal (18, 47%), atypical MRI appearance (6, 16%), mischaracterization (1, 3%), undercall (6, 16%), obscured (4, 11%), and no abnormality on MRI (3, 8%). Considering that the atypical and undercalled cases could have been adjusted in retrospect, and that 4 additional cases had positive lesions to the same extent and 11 further cases had disease confined to the pelvis, only 11 (4%) of the original 263 would have had disease outside of a conventional radiation treatment plan. Notably, almost 50% of the cases, including most lymph node metastases, were anatomically normal using standard criteria. This suggests that current anatomic criteria for evaluating prostate cancer lymph node metastases are not ideal, and there is a need for improved criteria. In addition, 32% of cases involved some element of human interpretive error, and, therefore, improving reader training may lead to more accurate results.

Breast Hemangiomas: Imaging Features With Histopathology Correlation.

Breast hemangiomas are rare benign vascular lesions. In a previously performed review of approximately 10,000 breast surgical pathology results, roughly 0.15% (15/~10 000) were hemangiomas. Hemangiomas are more frequent in women and have a documented age distribution of 1.5 to 82 years. They are most often subcutaneous or subdermal and anterior to the anterior mammary fascia but may rarely be seen in the pectoralis muscles or chest wall. On imaging, breast hemangiomas typically present as oval or round masses, often measuring less than 2.5 cm, with circumscribed or mostly circumscribed, focally microlobulated margins, equal or high density on mammography, and variable echogenicity on US. Calcifications, including phleboliths, can be seen. Color Doppler US often shows hypovascularity or avascularity. MRI appearance can vary, although hemangiomas are generally T2 hyperintense and T1 hypointense with variable enhancement. Pathologic findings vary by subtype, which include perilobular, capillary, cavernous, and venous hemangiomas. If core biopsy pathology results are benign, without atypia, and concordant with imaging and clinical findings, surgical excision is not routinely indicated. Because of histopathologic overlap with well-differentiated or low-grade angiosarcomas, surgical excision may be necessary for definitive diagnosis. Findings that are more common with angiosarcomas include size greater than 2 cm, hypervascularity on Doppler US, irregular shape, and invasive growth pattern.

Intracranial meningiomas at a tertiary hospital: Spectrum of MRI findings with histopathologic correlation.

Intracranial meningiomas consist of a heterogenous group of histological subtypes, some of which are rare. Data that may play an important role in neurosurgical decision-making regarding the incidence and MRI features of these histological subtypes in the South African population groups, are lacking. This study aimed to assess the spectrum of MRI findings and histological subtypes of meningiomas in the South African context, with the goal of improving the paucity of literature on the topic. A retrospective review of the MRI features of 41 cases of histologically confirmed intracranial meningiomas was performed at a tertiary hospital level. Imaging features were audited and correlated with histological subtypes during statistical analysis. Eleven different histological subtypes of meningioma were encountered. World Health Organization (WHO) Grade I meningothelial meningiomas were the most common histological subgroup. Overall, meningiomas were found to be predominantly isointense to grey matter on T1-weighted imaging, irrespective of the histological subtype, with greater signal variability on T2-weighted imaging. Morphologies of specific subtypes are in keeping with the literature. Analysis of this series of intracranial meningiomas did not demonstrate statistically significant differences in MRI features between histological subtypes to allow for accurate preoperative prediction of meningioma subtype or WHO grade. This highlights the importance of definitive histopathological diagnosis rather than over-reliance on presumed benign imaging features. This original research article discusses the impact of histological subtype on the MRI appearance of intracranial meningiomas, with the aim to improve the paucity of literature on the subject in the context of the South African population.

Halka Şekilli Lateral Ventrikül Nodüllerinin Konvansiyonel ve Diffüzyon MR Görüntüleme Özellikleri

Objective: The aim of this study is to evaluate the conventional and diffusion MRI findings of ring-shaped lateral ventricular nodules (RSLVN) along with clinical features.
 Methods: MR images of all patients who underwent contrast-enhanced brain MRI between 2019 and 2023 were retrospectively evaluated. The number, shape, maximal diameter, and signal intensity of RSLVNs on T1-weighted (T1W), T2-weighted (T2W), fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted imaging (DWI), and contrast-enhancement status were evaluated. Apparent diffusion coefficient (ADC) values and normalized ADC ratios of nodules were also determined. If follow-up MRIs were performed, morphological changes of RSLVNs were evaluated. 
 Results: RSLVN was observed in fifteen (0.51%) of 2920 patients. Multiple RSLVNs were observed in five patients and therefore a total of 23 RSLVNs were identified in fifteen patients. Nodules were located on the roof of the lateral ventricle in eight nodules (34.8%), in the frontal horn in twelve nodules (52.2%), and in the septum pellucidum in three. 6 of 23 RSLVNs (26.1%) were larger than 1 cm. All RSLVNs were isointense on T1W and T2W, while hyperintense on FLAIR. On DWI, 20 of 23 RSLVNs had isointense signal and the remaining 3 lesions were hyperintense. The mean ADC value and nADC ratio were 1.42 ± 0.29 x 10-3mm2 and 1.87 ± 0.31, respectively.
 Conclusion: RSLVNs may be more frequent than previously reported. Their uniform MRI appearance and typical localizations are distinctive, and they can reach relatively large sizes. Morphological stability during follow-up and the ADC values of these lesions suggest a possible benign nature.

Rotator cuff tear patterns: MRI appearance and its surgical relevance.

A new perspective on rotator cuff anatomy has allowed a better understanding of the patterns of the different rotator cuff tears. It is essential for radiologists to be aware of these different patterns of tears and to understand how they might influence treatment and surgical approach. Our objective is to review the arthroscopy correlated magnetic resonance imaging appearance of the different types of rotator cuff tears based on current anatomical concepts.Critical relevance statement Knowledge of the characteristics of rotator cuff tears improves our communication with the surgeon and can also make it easier for the radiologist to prepare a report that guides therapeutic conduct and serves as a prognosis for the patient.Key points• There is no universally accepted classification for RC tears.• New patterns such as delamination or myotendinous junction tears have been defined.• The most difficult feature to assess in full thickness tears on MRI is the pattern.• Fatty infiltration of the RC tendons is crucial in the prognosis and outcome.• The radiological report is an effective way of communication with the surgeon.

Analysis of the initial orbital MRI in aquaporin-4 antibody-positive optic neuritis (AQP4-ON): lesion location and lesion length can be predictive of visual prognosis.

Despite mounting evidence indicating that aquaporin-4 antibody-positive optic neuritis (AQP4-ON) presents a less favorable prognosis than other types of optic neuritis, there exists substantial heterogeneity in the prognostic outcomes within the AQP4-ON cohort. Considering the persistent debate over the role of MRI in assessing the prognosis of optic neuritis, we aim to investigate the correlation between the MRI appearance and long-term visual prognosis in AQP4-ON patients. We retrospectively reviewed the ophthalmological and imaging data of AQP4-ON patients admitted to our Neuro-ophthalmology Department from January 2015 to March 2018, with consecutive follow-up visits for a minimum of 3years. A total of 51 AQP4-ON patients (59 eyes) meeting the criteria were enrolled in this research. After assessing the initial orbital MR images of each patient at the first onset, we observed the involvement of the canalicular segment (p < 0.001), intracranial segment (p = 0.004), optic chiasm (p = 0.009), and the presence of LEON (p = 0.002) were significantly different between recovery group and impairment group. For quantitative measurement, the length of the lesions is significantly higher in the impairment group (20.1 ± 9.3mm) than in the recovery group (12.5 ± 5.3mm) (p = 0.001). AQP4-ON patients with involvement of canalicular, intracranial segment and optic chiasm of the optic nerve, and the longer range of lesions threaten worse vision prognoses. Timely MR examination during the initial acute phase can not only exclude the intracranial or orbital mass lesions but also indicate visual prognosis in the long term.

Evolution of radiation-induced temporal lobe injury after intensity-modulated radiation therapy in nasopharyngeal carcinoma: a large cohort retrospective study

BackgroundPrevious studies have demonstrated conflicting findings regarding the initial MRI patterns of radiotherapy-induced temporal lobe injury (RTLI) and the evolution of different RTLI patterns. The aim of this study was to evaluate the initial MRI pattern and evolution of RTLI in patients with nasopharyngeal carcinoma (NPC) by means of a large cohort study.MethodsData of patients with RTLI were retrospectively collected from two hospitals between January 2011 and December 2021. The injured lobes were categorized into three patterns based on initial MRI patterns: isolated white matter lesions (WMLs), isolated contrast-enhanced lesions (CELs), and combined WMLs and CELs. The latency period, MRI appearances, and temporal changes in WMLs and CELs were evaluated.ResultsA total of 913 RTLI patients with 1092 injured lobes were included in this study. The numbers of isolated WMLs, isolated CELs, and combined WMLs and CELs identified at the first MRI detection were 7 (0.6%), 172 (15.8%), and 913 (83.6%), respectively. The evolution of bilateral RTLI was different in the same patient, and that of unilateral RTLI combined with WMLs and CELs also may occur asynchronously. The time intervals from the initial MRI detection of isolated WMLs, isolated CELs, combined WMLs and CELs to the last negative MRI scan were 8.6, 8.9 and 11.0 months, respectively. A significant difference was observed in the time intervals between the three patterns (H = 14.287, P = 0.001). And the time interval was identified as an independent factor influencing the initial MRI pattern of RTLI after Poisson regression (P = 0.002).ConclusionBoth WMLs and CELs could be the initial and only MRI abnormalities in patients with RTLI. This study is of great significance in accurately diagnosing RTLI early and providing timely treatment options. Additionally, it provides clinical evidence for guidelines on NPC, emphasizing the importance of regular follow-up of NPC patients.

MRI and CT Appearances in Various Cardiac Tumours.

While primary cardiac malignancies are infrequent, the heart often serves as a site for metastases. Myxomas are recognized as among the most prevalent primary benign tumours globally, while sarcomas represent the most common malignant primary tumours. The diverse range of potential clinical presentations depends on factors such as location, size, and the aggressiveness of the disease. The majority of diagnoses rely on medical imaging, making it crucial to familiarize oneself with their distinctive characteristics. When a cardiac mass is suspected, MRIof the heart has emerged as the preferred diagnostic method, surpassing previous techniques. CTis a valuable tool for assessing cardiac morphology and improving electrocardiography gating by providing enhanced details. This article conducts a comprehensive review of the MRI and CT characteristics of both primary and secondary cardiac malignancies, emphasizing crucial distinctions and common diagnostic pitfalls. Despite their rarity, cardiac masses continue to hold significance in the realm of cardio-oncology. Furthermore, this article explores conditions such as thrombus, Lambl's excrescences, and pericardial cysts, which can mimic tumours. Multimodal imaging has played a pivotal role in identifying the origin of cardiac masses in numerous cases, particularly when combined with the clinical context. This article offers an in-depth examination of the frequency, clinical indicators, imaging, diagnostic procedures, available treatments, and prognoses related to cardiac masses.

Primary central nervous system lymphoma.

Primary central nervous system lymphoma (PCNSL) is a rare type of non-Hodgkin lymphoma (NHL) manifesting in the brain, spinal cord, cerebrospinal fluid and/or eyes, in the absence of systemic manifestations. With an increasing incidence and a 30% 5-year overall survival if promptly treated, timely diagnosis and subsequent treatment is paramount. The typical MRI appearance for PCNSL is a solitary or multiple T2-hypointense, homogeneous gadolinium-enhancing lesion with restricted diffusion. Dexamethasone treatment might compromise and delay the diagnosis. Hallmark of treatment is induction with intravenous high-dose methotrexate consisting polychemotherapy followed by consolidation treatment. Consolidation treatment consists of either whole brain radiotherapy (WBRT) or autologous stem cell transplantation (ASCT). Given the (cognitive) side effects of WBRT, ASCT is increasingly being used as the first choice of treatment.

Predicting the WHO Grading of Pediatric Brain Tumors Based on Their MRI Appearance: A Retrospective Study.

The treatment of central nervous system (CNS) tumors constitutes a significant part of a pediatric neurosurgeon's workload. The classification of such neoplasms spans many entities. These include low- and high-grade lesions, with bothoccurring in the population of patients under 18 years of age. Magnetic resonance imaging serves as the imaging method of choice for neoplastic lesions of the brain. Through its different modalities, such as T1, T2, T1 C+,apparent diffusion coefficient (ADC), diffusion-weighted imaging (DWI), susceptibility-weighted imaging(SWI), fluid-attenuated inversion recovery(FLAIR), etc., it allows the medical team to plan the therapeutic process accordingly while also possibly suggesting the specific tumor subtype prior to obtaining a definitive histological diagnosis. We conducted a retrospective study spanning 32 children treated surgically for brain tumors between July 2021 and January 2023 who had a precise histological diagnosis determined by using the 2021 WHO Classification of Tumors of the Central Nervous System. We divided them into two groups (high-grade and low-grade tumors, i.e., WHO grades 1 and 2, and grades 3 and 4, respectively) and analyzed their demographic data and preoperative MRI results. This was done using the following criteria: sub or supratentorial location of the tumor; lesion is circumscribed or infiltrating; solid, cystic, or mixed solid and cystic character of the tumor; number of compartments in cystic lesions; signal intensity (hypo-, iso-, hyperintensitysequences: T1, T2, T1 C+); presence of restricted diffusion; the largest diameter of the solid component and/or the largest diameter of the largest cyst in the transverse section. Then, we examined the results to find any correlation between the lesions' morphologies and their final assigned degree of malignancy. We found that the only radiological criteria correlating with the final WHO grade of the tumor were an infiltrative pattern of growth (25% of low-grade lesions, 75% of high-grade; p = 0.006) and the presence of a cystic component in the tumor (in 68.75% of low-grade tumors and 43.75% of high-grade tumors; p = 0.041). The only other feature close to attaining statistical significance was diffusion restriction (33.3% of low-grade tumors, 66.7% high-grade; p = 0.055). Older children tended to present with tumors of lower degrees of malignancy, and there was a predominance of female patients (21 female, 11 male).

Evaluation of Presumptive Normal Feline Tonsils with Low-Field Magnetic Resonance Imaging: A Preliminary Retrospective Study.

Palatine tonsils are lymphoid organs, whose anatomic localization gives them a role against antigens entering the body during feeding and breathing. In human medicine, MRI is used to investigate tonsillar diseases. In veterinary medicine, a recent study on healthy dogs described the MRI appearance of canine palatine tonsils, with no available reports about feline ones. Due to the similarities between animals and humans, and based on the study on canine tonsils, the authors aimed to evaluate the feasibility of low-field MRI to detect and describe presumed normal features of feline palatine tonsils, assessing the finding's reproducibility. Low-field MRI of the heads of 14 cats was reviewed, and qualitative findings (visualization, shape, margins, signal intensity, and pattern) and size of each tonsil were recorded. Each observer recorded 71% of the expected tonsils. Most of them were classified as oval, ill-defined, and hyperintense structures with both homogeneous and heterogeneous signal patterns; the overall agreement was considered good. Low-field MRI is potentially a useful imaging modality to visualize palatine tonsils in cats, and their normal appearance has been described for the first time. The authors recommend the evaluation of tonsils in the transverse plane and consider the most accurate estimation of the short axis.

Ultrasound Guided Cryoablation of Morton’s Neuroma: Case Series Including Post-Ablation MRI Appearances

Category: Midfoot/Forefoot; Other Introduction/Purpose: Morton’s neuroma (MN) is a very common compressive neuropathy of the interdigital nerve. Non- operative management is recommended initially and many therapies have been described. Cryoablation has shown promising results, however there are limited published studies in the literature. The purpose of this study was to assess the safety and efficacy of Cryoablation in patients with MN. A secondary aim was to evaluate post-procedure MRI appearances. Methods: A retrospective analysis was completed for 24 MN treated between June 2021 and September 2022. All patients had refractory MN symptoms after previous US guided steroid and LA injection within the previous year. Three patients also had refractory symptoms after prior alcohol ablation. Cryoablation was performed as a single outpatient procedure under continuous US monitoring and local anesthesia with 1 cycle for average of 2 minutes. Telephone follow up by radiology department with a 0–10 visual analogue scale (VAS) score was performed at 6 weeks and 3 months post-ablation. The patients were also encouraged to submit patient reported outcomes to a British Foot and Ankle Society (BOFAS) online scoring database as facilitated by the surgical team. Post-ablation MRI was performed to evaluate for post-procedure appearances at various intervals between 3 to 14 months. Results: 24 MN were treated. The mean size of MN treated was 12.3mm. Technical success was 100% and all patients tolerated the procedure well under local anesthesia. Mean pre-procedure VAS pain score was 8, which reduced to 1 at 6 weeks, and 2 at 3 months follow up in the treated MN. There is high patient satisfaction with 20 cases (83%) very satisfied. Four cases had various persistent symptoms and would want to have it done again (17%). Post-ablation MRI showed various bone and soft tissue changes in the ablation zone. There were two cases of fibrosis in the intermetatarsal space and one residual neuroma observed on MRI, although the patients were asymptomatic in the ablation site. No complications occurred e.g. infection, fracture or thermal injury. Conclusion: In this small series, ultrasound guided Cryoablation was deemed safe and effective treatment for MN. Clinical advantages of the procedure are good patient tolerance, single outpatient procedure, high patient satisfaction and reduced risk of scarring or residual neuroma. Further controlled prospective studies would be beneficial.

Sonography and MRI Appearance of Proximal Long Head Biceps Tendon

Sonography and MRI Appearance of Proximal Long Head Biceps Tendon