Meniscal and Cartilage Changes on Serial MRI After Medial Opening-Wedge High Tibial Osteotomy

Background: Assessments of the effects of realignment using opening-wedge high tibial osteotomy (OWHTO) on the medial, lateral, and patellofemoral compartments have been limited to cartilage evaluations. Purpose/Hypothesis: The purpose was to evaluate the effects of OWHTO on the meniscus and cartilage of each compartment as a cooperative unit (meniscochondral unit) using serial magnetic resonance imaging (MRI). It was hypothesized that (1) favorable changes in the meniscochondral unit would occur in the medial compartment and (2) that changes in the patellofemoral and lateral compartments would be negligible. Study Design: Case series; Level of evidence, 4. Methods: Included were 36 knees that underwent OWHTO from March 2014 to February 2016 and had postoperative serial MRI. The MRI was performed at 19.9 ± 7.4 and 52.3 ± 8.3 months postoperatively, and the cartilage and meniscal changes were evaluated by highlighting the regions of interest. We evaluated the T2 relaxation times of each cartilage and meniscal area, the cross-sectional area of the menisci, and the extrusion of the medial meniscus (MM). The meniscochondral unit was assessed using subgroup analyses according to the status of the MM. Results: Significant decreases were seen in T2 relaxation times in the medial femoral condyle (MFC) ( P < .001) and medial tibial plateau (MTP) ( P = .050), and significant increases were seen in the lateral femoral condyle (LFC) ( P = .036). The change was more prominent in the MFC compared with the MTP and LFC ( P = .003). No significant changes were observed in the lateral tibial plateau, patella, or trochlear groove. The area of the lateral meniscus (body and posterior horn) was decreased compared with preoperative MRI ( P < .001 for both). The extent of MM extrusion decreased between the preoperative, first follow-up, and second follow-up MRIs ( P < .001). Conclusion: OWHTO affected the medial compartment positively, the lateral compartment negatively, and the patellofemoral compartment negligibly. The effects were more prominent and consistent in the medial than in the lateral compartment.

Syrinx reduction due to spontaneous spinal cord tear: demonstration on 3 T MRI and review of the literature

A holocord syringomyelia due to Chiari 1.5 malformation (CM) in a 12-year-old girl was serially imaged with 3 T MRI over 4 years. The serial MRI showed reduction in size of the syrinx, without any surgical intervention or CM improvement, but rather due to spontaneous spinal cord tear. The tear was clearly demonstrated by evidence of flow signal across the tear between syrinx and subarachnoid space at the upper thoracic level. The tear showed spontaneous closure at follow-up. A medullary tear has been described in the adult population as one of the putative causes of spontaneous syringomyelia reduction, but its clear demonstration with modern high-resolution MRI has not been reported in the paediatric population. Moreover, this is the first reported case of syrinx reduction due to spontaneous fissuration in a paediatric patient.

Defining clinically significant tumor size in vestibular schwannoma to inform timing of microsurgery during wait-and-scan management: moving beyond minimum detectable growth

OBJECTIVE Detection of vestibular schwannoma (VS) growth during observation leads to definitive treatment at most centers globally. Although ≥ 2 mm represents an established benchmark of tumor growth on serial MRI studies, 2 mm of linear tumor growth is unlikely to significantly alter microsurgical outcomes. The objective of the current work was to ascertain where the magnitude of change in clinical outcome is the greatest based on size. METHODS A single-institution retrospective review of a consecutive series of patients with sporadic VS who underwent microsurgical resection between January 2000 and May 2020 was performed. Preoperative tumor size cutpoints were defined in 1-mm increments and used to identify optimal size thresholds for three primary outcomes: 1) the ability to achieve gross-total resection (GTR); 2) maintenance of normal House-Brackmann (HB) grade I facial nerve function; and 3) preservation of serviceable hearing (American Academy of Otolaryngology–Head and Neck Surgery class A/B). Optimal size thresholds were obtained by maximizing c-indices from logistic regression models. RESULTS Of 603 patients meeting inclusion criteria, 502 (83%) had tumors with cerebellopontine angle (CPA) extension. CPA tumor size was significantly associated with achieving GTR, postoperative HB grade I facial nerve function, and maintenance of serviceable hearing (all p < 0.001). The optimal tumor size threshold to distinguish between GTR and less than GTR was 17 mm of CPA extension (c-index 0.73). In the immediate postoperative period, the size threshold between HB grade I and HB grade > I was 17 mm of CPA extension (c-index 0.65). At the most recent evaluation, the size threshold between HB grade I and HB grade > I was 23 mm (c-index 0.68) and between class A/B and C/D hearing was 18 mm (c-index 0.68). Tumors within 3 mm of the 17-mm CPA threshold displayed similarly strong c-indices. Among purely intracanalicular tumors, linear size was not found to portend worse outcomes for all measures. CONCLUSIONS The probability of incurring less optimal microsurgical outcomes begins to significantly increase at 14–20 mm of CPA extension. Although many factors ultimately influence decision-making, when considering timing of microsurgical resection, using a size threshold range as depicted in this study offers an evidence-based approach that moves beyond reflexively recommending treatment for all tumors after detecting ≥ 2 mm of tumor growth on serial MRI studies.

Rapid brain atrophy after COVID-19 encephalitis;Disintegrata Furiosa!

Objectives: We had a patient with COVID-19 encephalitis who demonstrated striking brain atrophy on 3 MRI scans 60 days apart. We aimed to quantify the volume loss and brain atrophy. This is the first report that quantifies brain atrophy with COVID encephalitis.Methods: A 75 year old partially vaccinated man with COVID encephalitis underwent 3 serial MRI scans. Manual volumetry using PACS software was used to average and quantify brain atrophy between the three scans.Results: In 60 days, our patient had approximately 11.52 % (117 ml) of forebrain atrophy, which corresponded to 78 years of accelerated aging. Cerebellar atrophy of 6.2% (7.7 cc) was also noted. Discussion: We have demonstrated striking brain atrophy with COVID encephalitis. Brain involvement and atrophy or connectome disruptions might contribute to post COVID cognitive impairment. Serial MRI scans after COVID-19 and volumetric analysis may detect post COVID brain atrophy as a cause of cognitive dysfunction.

Rapid brain atrophy after COVID-19 encephalitis; Disintegrata Furiosa!

Objectives: We had a patient with COVID-19 encephalitis who demonstrated striking brain atrophy on 3 MRI scans 60 days apart. We aimed to quantify the volume loss and brain atrophy. This is the first report that quantifies brain atrophy with COVID encephalitis.Methods: A 75 year old partially vaccinated man with COVID encephalitis underwent 3 serial MRI scans. Manual volumetry using PACS software was used to average and quantify brain atrophy between the three scans.Results: In 60 days, our patient had approximately 11.52 % (117 ml) of forebrain atrophy, which corresponded to 78 years of accelerated aging. Cerebellar atrophy of 6.2% (7.7 cc) was also noted. Discussion: We have demonstrated striking brain atrophy with COVID encephalitis. Brain involvement and atrophy or connectome disruptions might contribute to post COVID cognitive impairment. Serial MRI scans after COVID-19 and volumetric analysis may detect post COVID brain atrophy as a cause of cognitive dysfunction.

Clinical and Radiologic Features, Pathology, and Treatment of Baló Concentric Sclerosis

Objective:To describe clinical, radiological and pathological features of patients with Baló’s concentric sclerosis (BCS) and assess overlap between BCS and other central nervous system inflammatory demyelinating diseases.Methods:Retrospective review of BCS cases from US and Australian tertiary care centers.Results:We identified 40 BCS cases with 38 available MRIs. Solitary MRI lesions were present in 26% (10/38). We saw >1 active concurrent BCS lesion in 45% (17/38). A third (13/38) had multiple sclerosis-suggestive lesions on the index MRI, of which 10 fulfilled Barkhof criteria. In patients with serial MRI performed within one month of the index MRI, lesions expanded radially with sequentially increased numbers of T2 hyperintense rings 52% (14/27). Initially non-enhancing or centrally enhancing lesions subsequently developed single or multiple enhancing rings (41%; 9/22) and incomplete enhancing rings (14%; 3/22). Discordance between rings as they appear on ADC, DWI, and gadolinium-enhanced imaging was observed in 67% (22/33). AQP4-IgG (n=26) and MOG-IgG (n=21) were negative in all patients with serum available. Clinical response to steroid treatment was seen in 46% (13/28). A monophasic clinical course was present in 56% (18/32) at last follow-up (median 27.5 months; range 3-100 months). The initial attack was fatal in 10% (4/40). Median time from symptom onset to death was 23 days (range 19-49 days). All 17 patients with pathology available demonstrated typical findings of multiple sclerosis. Patients with active demyelinating lesions all demonstrated oligodendrocytopathy (pattern III).Conclusions:BCS may be a distinct subtype of multiple sclerosis characterized by pattern III immunopathology.

Nonoperative management of enlarging syringomyelia in clinically stable patients after decompression of Chiari malformation type I

OBJECTIVE The authors aimed to describe the natural history and optimal management of persistent syringomyelia after suboccipital craniectomy for Chiari malformation type I (CM-I). METHODS A cohort of all patients who presented to a tertiary pediatric hospital with newly diagnosed CM-I between 2009 and 2017 was identified. Patients with persistent or worsened syringomyelia were identified on the basis of a retrospective review of medical records and imaging studies. The management of these patients and their clinical courses were then described. RESULTS A total of 153 children with CM-I and syringomyelia were evaluated between 2009 and 2017. Of these, 115 (68.8%) patients underwent surgical intervention: 40 patients underwent posterior fossa decompression (PFD) alone, 43 underwent PFD with duraplasty, and 32 underwent PFD with duraplasty and fourth ventricle stent placement. Eleven (7.19%) patients had increased syringomyelia on subsequent postoperative imaging. Three of these patients underwent revision surgery because of worsening scoliosis or pain, 2 of whom were lost to follow-up, and 4 were managed nonoperatively with close surveillance and serial MRI evaluations. The syringes decreased in size in 3 patients and resolved completely in 1 patient. CONCLUSIONS Persistent or worsened syringomyelia after CM-I decompression is uncommon. In the absence of symptoms, nonoperative management with close observation is safe for patients with persistent syrinx.

The Use of Serial Non EPI DWI MRI Scans to Determine the Growth of Cholesteatoma

Introduction It is an established practice to use non-EPI DWI MRI scans to detect the presence of cholesteatoma post operatively. In the present era of Covid-19 where routine surgery to remove cholesteatoma has been suspended resulting in potentially unprecedented demands on the service, a review of serial MRI scans performed over a 7 year period was undertaken to determine the rate of growth of cholesteatoma. Materials and Methods A retrospective longitudinal study identified 24 middle ear cholesteatomas in 17 patients with serial non-EPI DWI MRI scans (having excluded those having surgical intervention between scans) for a median period of 33 months (range of 6-91 months). Cholesteatomas were measured by the first author and by the consultant radiologist. Results Of 24 cholesteatomas, 1 resolved completely, 5 reduced, 6 stayed the same size, 4 grew slowly and 8 grew significantly. Conclusion Non-EPI DWI MRI scans to determine cholesteatoma growth in asymptomatic ears is useful in triaging patients in the Covid-19 era.