Rethinking Thrombolysis in Cerebral Infarction 2b: Which Thrombolysis in Cerebral Infarction Scales Best Define Near Complete Recanalization in the Modern Thrombectomy Era?

BACKGROUND AND PURPOSE: Within the thrombolysis in cerebral infarction (TICI) classification, TICI 2b has been historically considered successful recanalization. Recent studies have suggested that TICI 3 and a proposed TICI 2c should be separately reported from TICI 2b, in both the original (>66% reperfusion) and modified (>50% reperfusion) definitions, because of differences in clinical outcomes with greater reperfusion. The purpose of this study was to evaluate differences in early neurological improvement and independence at 90 days using the original TICI, modified TICI, and modified TICI with 2c scales. METHODS: A retrospective review of 129 consecutive patients with middle cerebral artery, M1 segment or intracranial internal carotid artery occlusions. Patient angiograms were graded by 2 experienced readers by percentage recanalization. This was then categorized into original TICI, modified TICI (mTICI), and mTICI with TICI 2c (mTICI 2c) grading scales. Comparison of baseline demographics, early neurological improvement, and independence at 90 days was performed. RESULTS: A significant difference in early neurological improvement was observed between 2b and 3 (P=0.032), as well as between 2b and 2c (P=0.028) under the mTICI 2c grading scale. Similarly, a significant difference in functional independence was observed between 2b and 3 (P=0.037), as well as between 2b and 2c (P=0.047) under the mTICI 2c scale. The difference in early neurological improvement or functional independence between 2b and 3 for the original TICI and mTICI scales was not significant. When combining the 2c and 3 groups under the mTICI 2c scale, there were significant differences between 2b and 2c/3 in regards to both early neurological improvement (P=0.011) and independence (P=0.018). CONCLUSIONS: Using a TICI grading system that includes an additional category beyond TICI 2b allows for refined prediction of early neurological improvement and functional independence.

Varicella Zoster Associated Vasculopathy and Retinitis with Natalizumab Use in Multiple Sclerosis.

Natalizumab (Tysabri®, NTZ) is a monoclonal autoantibody approved for treatment of relapsing-remitting multiple sclerosis. NTZ inhibits leukocyte migration across the blood-brain barrier, preventing autoreactive cells from inciting an inflammatory immune response. This immunosuppression is highly efficacious in attenuating the risk of relapse of disease, but has been associated with opportunistic central nervous system (CNS) infections, most notably progressive multifocal leukoencephalopathy. Varicella-zoster and herpes simplex viruses have also been associated with NTZ, inciting a spectrum of disease, including encephalitis, meningitis, and acute retinal necrosis. While rare, these infections can result in devastating outcomes even when promptly identified and treated.   We present a case of combined CNS varicella zoster vasculitis and acute retinal necrosis in a 57-year-old woman maintained on monthly Natalizumab therapy, who presented with headache and visual field deficits.

Use of Large Language Models to Predict Neuroimaging.

PURPOSE: Large language models (LLMs) have demonstrated a level of competency within the medical field. The aim of this study was to explore the ability of LLMs to predict the best neuroradiologic imaging modality given specific clinical presentations. In addition, the authors seek to determine if LLMs can outperform an experienced neuroradiologist in this regard. METHODS: ChatGPT and Glass AI, a health care-based LLM by Glass Health, were used. ChatGPT was prompted to rank the three best neuroimaging modalities while taking the best responses from Glass AI and the neuroradiologist. The responses were compared with the ACR Appropriateness Criteria for 147 conditions. Clinical scenarios were passed into each LLM twice to account for stochasticity. Each output was scored out of 3 on the basis of the criteria. Partial scores were given for nonspecific answers. RESULTS: ChatGPT and Glass AI scored 1.75 and 1.83, respectively, with no statistically significant difference. The neuroradiologist scored 2.20, significantly outperforming both LLMs. ChatGPT was also found to be the more inconsistent of the two LLMs, with the score difference between both outputs being statistically significant. Additionally, scores between different ranks output by ChatGPT were statistically significant. CONCLUSIONS: LLMs perform well in selecting appropriate neuroradiologic imaging procedures when prompted with specific clinical scenarios. ChatGPT performed the same as Glass AI, suggesting that with medical text training, ChatGPT could significantly improve its function in this application. LLMs did not outperform an experienced neuroradiologist, indicating the need for continued improvement in the medical context.

The evaluation of the swallow tail sign in patients with parkinsonism and gait disorders.

BACKGROUND: Swallow tail sign (STS), which represents nigrosome-1 in the substantia nigra on 3 Tesla (T) susceptibility-weighted imaging (SWI), has attracted attention as a promising magnetic resonance imaging (MRI) biomarker for idiopathic Parkinson's disease (iPD). Some reports have shown high sensitivity and specificity-both above 94%-for distinguishing iPD from healthy controls. However, abnormal STS has been observed in many neurodegenerative parkinsonisms and even in multiple sclerosis. METHODS: All patients with parkinsonism who had 3 T MRI were included in a retrospective chart review from a single movement disorders clinic. All subjects were evaluated by a single movement disorder specialist, using Movement Disorders Society diagnostic criteria and American Academy of Neurology consensus guidelines for diagnoses. All MRIs were interpreted by a single neuroradiologist who was blinded to the diagnosis. RESULTS: Twenty patients were included in the study. Twelve had abnormal STS: iPD (n = 2), probable multiple system atrophy (n = 3), vascular parkinsonism (n = 1), psychogenic gait disorder (n = 1), neuroleptic parkinsonism (n = 2), cervical dystonia (n = 1), static encephalopathy (n = 1) and gait disorder of unknown etiology (n = 1). Eight had normal STS: iPD (n = 1), probable progressive supranuclear palsy (n = 1), vascular parkinsonism (n = 2), transient parkinsonism of unknown etiology (n = 2), valproic acid induced parkinsonism (n = 1), and essential tremor with parkinsonism (n = 1). 123I-Ioflupane SPECT dopamine transporter (DaT) scan results were available on seven subjects; four subjects had incongruency between DaT and MRI. CONCLUSION: Our results suggest that the abnormal STS is not, in isolation, a reliable biomarker of idiopathic Parkinson's disease.

Long-term outcomes of anterior cruciate ligament reconstruction surgery: 2020 OREF clinical research award paper.

ACL injuries place the knee at risk for post-traumatic osteoarthritis (PTOA) despite surgical anterior cruciate ligament (ACL) reconstruction. One parameter thought to affect PTOA risk is the initial graft tension. This randomized controlled trial (RCT) was designed to compare outcomes between two graft tensioning protocols that bracket the range commonly used. At 7 years postsurgery, we determined that most outcomes between the two tension groups were not significantly different, that they were inferior to an uninjured matched control group, and that PTOA was progressing in both groups relative to controls. The trial database was also leveraged to gain insight into mechanisms of PTOA following ACL injury. We determined that the inflammatory response at the time of injury undermines one of the joint's lubricating mechanisms. We learned that patients continue to protect their surgical knee 5 years postinjury compared to controls during a jump-pivot activity. We also established that presurgical knee function and mental health were correlated with symptomatic PTOA at 7 years, that there were specific anatomical factors associated with poor outcomes, and that there were no changes in outcomes due to tunnel widening in patients receiving hamstring tendon autografts. We also validated a magnetic resonance imaging technique to noninvasively assess graft strength. In conclusion, the RCT determined that initial graft tensioning does not have a major influence on 7-year outcomes. Therefore, surgeons can reconstruct the ACL using a graft tensioning protocol that is within the window of the two graft tensioning techniques evaluated in this RCT.

Diffusion-weighted MRI of peripheral zone prostate cancer: comparison of tumor apparent diffusion coefficient with Gleason score and percentage of tumor on core biopsy.

OBJECTIVE: The objective of our study was to determine the relationship between the apparent diffusion coefficient (ADC) value on diffusion-weighted imaging (DWI) and Gleason score of prostate cancer and percentage of tumor involvement on prostate core biopsy. MATERIALS AND METHODS: We performed a retrospective study of 57 patients with biopsy-proven prostate cancer who underwent endorectal MRI with DWI between July 2007 and March 2008. Regions of interest (ROIs) were drawn on ADC maps at sites of visible tumor on DW images and ADC maps. A hierarchic mixed linear model was used to compare the ADC value of prostate cancer with the Gleason score and the percentage of tumor on core biopsy. RESULTS: Eighty-one sites of biopsy-proven prostate cancer were visible on DW images and ADC maps. The least-squares mean ADC for disease with a Gleason score of 6 was 0.860 x 10(-3) mm(2)/s (standard error of the mean [SEM], 0.036); Gleason score of 7, 0.702 x 10(-3) mm(2)/s (SEM, 0.030); Gleason score of 8, 0.672 x 10(-3) mm(2)/s (SEM, 0.057); and Gleason score of 9, 0.686 x 10(-3) mm(2)/s (SEM, 0.067). Differences between the mean ADC values for a prostate tumor with a Gleason score of 6 and one with a Gleason score of 7 (p = 0.0096) and for a prostate tumor with a Gleason score of 6 and one with a Gleason score of 8 (p = 0.0460) were significant. Comparison between the ADC and percentage of tumor on core biopsy showed a mean ADC decrease of 0.006 (range, 0.004-0.008 x 10(-3) mm(2)/s) for every 1% increase in tumor in the core biopsy specimen. CONCLUSION: DWI may help differentiate between low-risk (Gleason score, 6) and intermediate-risk (Gleason score, 7) prostate cancer and between low-risk (Gleason score, 6) and high-risk (Gleason score > 7) prostate cancer. There is an inverse relationship between the ADC and the percentage of tumor involvement on prostate core biopsies.

Acute retrobulbar optic neuritis and macular detachment associated with morning glory optic disc anomaly.

A 31-year-old woman with morning glory optic disc anomaly (MGDA) developed acute retrobulbar optic neuritis and a bullous macular detachment. MRI demonstrated truncation of the perineural space of the affected optic nerve as well as focal optic nerve enhancement. Optical coherence tomography (OCT) showed retinoschisis associated with the macular detachment. The MRI and OCT findings support the vitreous as the source of the subretinal fluid. This is the first reported case of optic neuritis in MGDA.

Imaging signs of posterior glenohumeral instability.

OBJECTIVE: The purpose of this article is to review mechanisms of injury leading to posterior glenohumeral instability and the correlated imaging findings on CT and MRI. CONCLUSION: In patients with suspected posterior glenohumeral instability, imaging of the affected shoulder can show abnormalities of the bone, labrum, and joint capsule. Accurate detection and characterization of these lesions aid in both diagnosis and management.

Endonasal ethmoidectomy and bifrontal craniotomy with craniofacial approach for resection of frontoethmoidal osteoma causing tension pneumocephalus.

Tension pneumocephalus is an unusual, potentially life-threatening complication of frontal fossa tumors. We present an uncommon case of a frontoethmoidal osteoma causing a tension pneumocephalus and neurological deterioration prompting a combined endonasal ethmoidectomy and bifrontal craniotomy with craniofacial approach for resection. A 68-year-old man presented with a 1-week history of worsening headache, slowness of speech, and increasing confusion. Standard computed tomography scan revealed a marked tension pneumocephalus with ventricular air and 1-cm midline shift to the right. Further studies showed a calcified left ethmoid mass and a left anterior cranial-base defect. A team composed of neurosurgery and otolaryngology performed a combined endonasal ethmoidectomy and bifrontal craniotomy with craniofacial approach to resect a large frontoethmoid bony tumor. No abscess or mucocele was identified. The skull base defect was repaired with the aid of a transnasal endoscopy, a titanium mesh, and a pedunculated pericranial flap. Postoperatively, the pneumocephalus and the patient's symptoms completely resolved. Pathology was consistent with a benign osteoma. This is an uncommon case of a frontoethmoidal osteoma associated with tension pneumocephalus. Recognition of this entity and timely diagnosis and treatment, consisting of an endonasal ethmoidectomy and a bifrontal craniotomy with craniofacial approach, may prevent potential life-threatening complications.

Voice recognition dictation: radiologist as transcriptionist.

Continuous voice recognition dictation systems for radiology reporting provide a viable alternative to conventional transcription services with the promise of shorter report turnaround times and increased cost savings. While these benefits may be realized in academic institutions, it is unclear how voice recognition dictation impacts the private practice radiologist who is now faced with the additional task of transcription. In this article, we compare conventional transcription services with a commercially available voice recognition system with the following results: 1) Reports dictated with voice recognition took 50% longer to dictate despite being 24% shorter than those conventionally transcribed, 2) There were 5.1 errors per case, and 90% of all voice recognition dictations contained errors prior to report signoff while 10% of transcribed reports contained errors. 3). After signoff, 35% of VR reports still had errors. Additionally, cost savings using voice recognition systems in non-academic settings may not be realized. Based on average radiologist and transcription salaries, the additional time spent dictating with voice recognition costs an additional $6.10 per case or $76,250.00 yearly. The opportunity costs may be higher. Informally surveyed, all radiologists expressed dissatisfaction with voice recognition with feelings of frustration, and increased fatigue. In summary, in non-academic settings, utilizing radiologists as transcriptionists results in more error ridden radiology reports and increased costs compared with conventional transcription services.

Perfusion abnormalities in subchondral bone associated with marrow edema, osteoarthritis, and avascular necrosis.

Bone marrow edema is seen in osteoarthritis, avascular necrosis, and other clinical conditions including the bone marrow edema syndrome. Bone marrow edema is associated with bone pain and may be related to the pathophysiology of osteoarthritis. Our hypothesis is that bone marrow edema is associated with a reduction in perfusion in subchondral bone, which contributes to focal and segmental bone necrosis and cartilage breakdown. We further hypothesize that altered fluid dynamics in subchondral bone comprise part of the physicochemical environment to which osteocytes are highly sensitive and alter their cytokine expression profile in response to changes in fluid flow, pressure, and oxygen gradients. We have used contrast-enhanced magnetic resonance imaging with Gd-DTPA to characterize changes in subchondral bone perfusion in two relevant and related models-the Dunkin-Hartley guinea pig model of osteoarthritis and human bone marrow edema associated with osteoarthritis and avascular necrosis. Pharmacokinetic modeling was used to extract dynamic parameters of perfusion. Representative time-intensity curves are derived, which characterize normal bone and bone with marrow edema. Dynamic contrast-enhanced magnetic resonance imaging may be a useful tool for the early diagnosis of bone perfusion abnormalities and may be used to characterize marrow edema associated with a number of clinical conditions. This technique may also shed light on the pathophysiology of subchondral perfusion in osteoarthritis and avascular necrosis.

MRI of cerebral microhemorrhages.

OBJECTIVE: The purpose of this pictorial essay is to discuss the differential diagnosis of cerebral microhemorrhages on T2*-weighted gradient-echo MRI. CONCLUSION: Cerebral amyloid angiopathy and chronic systemic hypertension are the two most common causes of cerebral microhemorrhages. Less common causes include diffuse axonal injury, cerebral embolism, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, multiple cavernous malformations, vasculitis, hemorrhagic micrometastasis, radiation vasculopathy, and Parry-Romberg syndrome.

The meniscal roots: gross anatomic correlation with 3-T MRI findings.

OBJECTIVE: The purpose of this article is to highlight the normal anatomic features of the meniscal roots on photographs of dissected cadaveric knee specimens and 3-T MR images. CONCLUSION: The meniscal roots, which are critical attachment sites of the medial and lateral menisci to the central tibial plateau, are well-visualized on intermediate-weighted, turbo spin-echo 3-T MRI and can be identified in proximity to the tibial insertions of the anterior and posterior cruciate ligaments.

Quantification of meniscal volume by segmentation of 3T magnetic resonance images.

Meniscal injuries place the knee at risk for early osteoarthritis (OA) because they disrupt their load-bearing capabilities. Partial resection is routinely performed to alleviate symptomatic meniscal tears. While the removal of meniscal tissue may not be the only factor associated with partial meniscectomy outcome, the amount removed certainly contributes to functional loss. It is unknown, however, whether there is a critical amount of meniscal tissue that can be removed without diminishing the structure's chondroprotective role. In order to examine the existence of such a threshold, it is necessary to accurately quantify meniscal volume both before and after partial meniscectomy to determine the amount of meniscal tissue removed. Therefore, our goal was to develop and validate an MR-based method for assessing meniscal volume. The specific aims were: (1) to evaluate the feasibility of the MR-based segmentation method; (2) to determine the method's reliability for repeated measurements; and (3) to validate its accuracy in situ. MR images were obtained on a 3T magnet, and each scan was segmented using a biplanar approach. The MR-based volumes for each specimen were compared to those measured by water displacement. The results indicate that the biplanar approach of measuring meniscal volumes is accurate and reliable. The calculated volumes of the menisci were within 5% of the true values, the coefficients of variation were 4%, and the intraclass correlation coefficients were greater than 0.96. These data demonstrate that this method could be used to measure the amount of meniscal tissue excised during partial meniscectomy to within 125.7 mm(3).

Effect of Matching or Overconstraining Knee Laxity During Anterior Cruciate Ligament Reconstruction on Knee Osteoarthritis and Clinical Outcomes: A Randomized Controlled Trial With 84-Month Follow-up.

BACKGROUND: The "initial graft tension" applied at the time of graft fixation during anterior cruciate ligament (ACL) reconstruction surgery modulates joint contact mechanics, which in turn may promote posttraumatic osteoarthritis (OA). PURPOSE/HYPOTHESES: The study objectives were to compare clinical, functional, patient-reported, and OA imaging outcomes between 2 different initial laxity-based graft tension cohorts and a matched uninjured control group as well as to evaluate the effects of laxity-based graft tension on OA development at 84-month follow-up. The 2 laxity-based tension protocols were (1) to restore normal anteroposterior (AP) laxity at the time of surgery relative to the contralateral uninjured knee (low-tension group) or (2) to overconstrain AP laxity by 2 mm relative to the contralateral uninjured knee (high-tension group). The hypotheses were that (1) the high-tension group would have improved outcomes and decreased OA compared with the low-tension group after 84 months, and (2) the outcomes for the high-tension group would be equivalent to those for an age-, sex-, race-, and activity-matched group of control participants with uninjured knees. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Patients had their ACLs reconstructed with either a bone-patellar tendon-bone or 4-stranded hamstring autograft, and outcomes were compared with a matched control group. Outcomes were evaluated preoperatively and at 60 and 84 months postoperatively and included clinical (KT-1000 arthrometer AP laxity measurement and International Knee Documentation Committee [IKDC] examination score), functional (1-legged hop for distance and knee extensor torque), patient-reported (Knee injury and Osteoarthritis Outcome Score [KOOS], Short Form-36 [SF-36], and patient satisfaction survey), and OA imaging (measurement of joint space width [JSW], Osteoarthritis Research Society International [OARSI] radiographic score, and Whole-Organ Magnetic Resonance Imaging Score [WORMS]) components. Repeated-measures analyses of variance were used to evaluate differences in outcomes between the treatment groups and the control group. RESULTS: There were significant differences between the 2 tension groups in 1 of 5 KOOS subscales (sports and recreation; P = .04) and 2 of 8 SF-36 subscales (vitality, mental health; P < .04) at 84 and 60 months, respectively. Both tension groups scored significantly worse than the control group in the IKDC examination (P < .001), 1-legged hop (P ≤ .017), KOOS quality of life and symptoms subscales (P < .03), and OARSI radiographic score (P ≤ .02) at 84 months. The low-tension group performed significantly worse than the control group on the KOOS pain subscale (P = .03), SF-36 general health and social functioning (P < .04), OARSI radiographic score (P < .001), and WORMS (P = .001), while the high-tension group had statistically different results than the control group in AP knee laxity (P < .001), radiographic JSW (P = .003), and OARSI radiographic score (P = .02) as well as significantly more subsequent knee injuries (P = .02) at 84 months. CONCLUSION: The results do not support the hypotheses that the high-tension group would have improved outcomes when compared with the low-tension group after 84 months of healing or that the outcomes for the high-tension group would be equivalent to those for the matched control group. While there were minor differences in patient-reported outcomes between the 2 laxity-based tension groups, all other outcomes were similar. REGISTRATION: NCT00434837.