Precise Image-level Localization of Intracranial Hemorrhage on Head CT Scans with Deep Learning Models Trained on Study-level Labels.

"Just Accepted" papers have undergone full peer review and have been accepted for publication in Radiology: Artificial Intelligence. This article will undergo copyediting, layout, and proof review before it is published in its final version. Please note that during production of the final copyedited article, errors may be discovered which could affect the content. Purpose To develop a highly generalizable weakly supervised model to automatically detect and localize image- level intracranial hemorrhage (ICH) using study-level labels. Materials and Methods In this retrospective study, the proposed model was pretrained on the image-level RSNA dataset and fine-tuned on a local dataset using attention-based bidirectional long-short-term memory networks. This local training dataset included 10,699 noncontrast head CT scans from 7469 patients with ICH study-level labels extracted from radiology reports. Model performance was compared with that of two senior neuroradiologists on 100 random test scans using the McNemar test, and its generalizability was evaluated on an external independent dataset. Results The model achieved a positive predictive value (PPV) of 85.7% (95% CI: [84.0%, 87.4%]) and an AUC of 0.96 (95% CI: [0.96, 0.97]) on the held-out local test set (n = 7243, 3721 female) and 89.3% (95% CI: [87.8%, 90.7%]) and 0.96 (95% CI: [0.96, 0.97]), respectively, on the external test set (n = 491, 178 female). For 100 randomly selected samples, the model achieved performance on par with two neuroradiologists, but with a significantly faster (P < .05) diagnostic time of 5.04 seconds per scan (versus 86 seconds and 22.2 seconds for the two neuroradiologists, respectively). The model's attention weights and heatmaps visually aligned with neuroradiologists' interpretations. Conclusion The proposed model demonstrated high generalizability and high PPVs, offering a valuable tool for expedited ICH detection and prioritization while reducing false-positive interruptions in radiologists' workflows. ©RSNA, 2024.

Predictors of salvage therapy for parasagittal meningiomas treated with primary surgery, radiosurgery, or surgery plus adjuvant radiotherapy.

OBJECTIVE: Parasagittal meningiomas (PM) are treated with primary microsurgery, radiosurgery (SRS), or surgery with adjuvant radiation. We investigated predictors of tumor progression requiring salvage surgery or radiation treatment. We sought to determine whether primary treatment modality, or radiologic, histologic, and clinical variables were associated with tumor progression requiring salvage treatment. METHODS: Retrospective study of 109 consecutive patients with PMs treated with primary surgery, radiation (RT), or surgery plus adjuvant RT (2000-2017) and minimum 5 years follow-up. Patient, radiologic, histologic, and treatment data were analyzed using standard statistical methods. RESULTS: Median follow up was 8.5 years. Primary treatment for PM was surgery in 76 patients, radiation in 16 patients, and surgery plus adjuvant radiation in 17 patients. Forty percent of parasagittal meningiomas in our cohort required some form of salvage treatment. On univariate analysis, brain invasion (OR: 6.93, p < 0.01), WHO grade 2/3 (OR: 4.54, p < 0.01), peritumoral edema (OR: 2.81, p = 0.01), sagittal sinus invasion (OR: 6.36, p < 0.01), sagittal sinus occlusion (OR: 4.86, p < 0.01), and non-spherical shape (OR: 3.89, p < 0.01) were significantly associated with receiving salvage treatment. On multivariate analysis, superior sagittal sinus invasion (OR: 8.22, p = 0.01) and WHO grade 2&3 (OR: 7.58, p < 0.01) were independently associated with receiving salvage treatment. There was no difference in time to salvage therapy (p = 0.11) or time to progression (p = 0.43) between patients receiving primary surgery alone, RT alone, or surgery plus adjuvant RT. Patients who had initial surgery were more likely to have peritumoral edema on preoperative imaging (p = 0.01). Median tumor volume was 19.0 cm3 in patients receiving primary surgery, 5.3 cm3 for RT, and 24.4 cm3 for surgery plus adjuvant RT (p < 0.01). CONCLUSION: Superior sagittal sinus invasion and WHO grade 2/3 are independently associated with PM progression requiring salvage therapy regardless of extent of resection or primary treatment modality. Parasagittal meningiomas have a high rate of recurrence with 80.0% of patients with WHO grade 2/3 tumors with sinus invasion requiring salvage treatment whereas only 13.6% of the WHO grade 1 tumors without sinus invasion required salvage treatment. This information is useful when counseling patients about disease management and setting expectations.

Cranial Nerve Palsies in the Setting of Arachnoid Cysts: A Case Series and Literature Review.

BACKGROUND: Arachnoid cysts (ACs) are benign lesions typically believed to not cause neurologic defects in the adult population and are most often found incidentally on imaging. We describe 2 patients with ACs potentially leading to isolated cranial nerve (CN) dysfunction. METHODS: We describe 2 patients, 1 with a fourth nerve palsy and the other with a sixth nerve palsy found to have ACs on MRI brain imaging in locations that potentially caused a compressive CN palsy. We review previous literature of ACs presenting with CN III, IV, or VI palsy. RESULTS: Patient 1 was a 62-year-old man who presented with a 22-year history of diplopia with strabismus examination consistent with a congenital CN IV palsy. Despite multiple surgeries, his CN IV palsy insidiously worsened. An AC in the posterior fossa with mass effect on the quadrigeminal plate and asymmetric atrophy of the right superior oblique was identified on imaging. Patient 2 was an 80-year-old man who presented with an 18-year history of diplopia and was found to have a left esotropia and abduction deficit consistent with complete CN VI palsy. An AC in the left cavernous sinus was identified on imaging. He underwent strabismus surgery with satisfactory resolution of diplopia. We identified a total of 18 previously published cases: 8 reports of CN III palsy, 4 reports of CN IV palsy, and 6 reports of CN VI palsy. Patient ages ranged from 1 to 67 with a median of 34.5. In 16/18 (89%) cases, the diagnosis of ACs was made within 1 year of symptom onset. Surgical removal of the AC was successful in resolving diplopia in 7/12 (58%) cases. In no case was strabismus surgery performed as primary treatment. CONCLUSIONS: Although ACs are typically congenital asymptomatic lesions, we present a case series of 2 patients with ACs in anatomic locations that potentially caused chronic, progressive, isolated CN palsies leading to strabismus. Our literature review revealed that most published cases detailing this clinical scenario resulted in neurosurgical fenestration of ACs with mixed results. Our cases represent 2 patients with AC-associated CN palsy treated with strabismus surgery.

Monkeypox-Associated Central Nervous System Disease: A Case Series and Review.

OBJECTIVE: Monkeypox virus (MPXV) disease has been declared a public health emergency by the World Health Organization, creating an urgent need for neurologists to be able to recognize, diagnosis, and treat MPXV-associated neurologic disease. METHODS: Three cases of MPXV-associated central nervous system (CNS) disease occurring during the 2022 outbreak, and their associated imaging findings are presented, with 2 cases previously published in a limited capacity in a public health bulletin. RESULTS: Three previously healthy immunocompetent gay men in their 30s developed a febrile illness followed by progressive neurologic symptoms with presence of a vesiculopustular rash. MPXV nucleic acid was detected by polymerase chain reaction (PCR) from skin lesions of 2 patients, with the third patient having indeterminate testing but an epidemiologic link to a confirmed MPXV disease case. Cerebrospinal fluid demonstrated a lymphocytic pleocytosis, elevated protein, and negative MPXV-specific PCR. In 2 patients, magnetic resonance imaging of the brain and spine demonstrated partially enhancing, longitudinally extensive central spinal cord lesions with multifocal subcortical, basal ganglia, thalamic, cerebellar, and/or brainstem lesions. The third patient had thalamic and basal ganglia lesions. All patients received 14 days of tecovirimat, and 2 patients also received multiple forms of immunotherapy, including intravenous immunoglobulin, pulsed high-dose steroids, plasmapheresis, and/or rituximab. Good neurologic recovery was observed in all cases. INTERPRETATION: MPXV can be associated with CNS disease. It is unclear whether this is from a parainfectious immune-mediated injury or direct CNS viral invasion. ANN NEUROL 2023;93:893-905.

Case Report: Anterior Spinal Cord Ischemia Following Embolization of Cerebellar Arteriovenous Malformation: An Illustrative Case and Review of Spinal Cord Vascular Anatomy.

Spinal cord ischemia (SCI) is a rare entity with high mortality and morbidity which can arise from causes such as atherosclerosis, aortic dissection or aneurysm, thromboembolic events or systemic hypotension, and is a potential complication of spinal surgery. Published literature contains very few reports of SCI as a complication of intracranial interventions, highlighting the uncommon nature of SCI in these circumstances. We report the occurrence of anterior SCI in a 69-year-old patient following successful embolization of a cerebellar arteriovenous malformation (AVM), marked by upper extremity weakness, lower extremity paraplegia, loss of bladder and bowel control, and hypercapnic respiratory failure requiring mechanical ventilation. Magnetic resonance imaging (MRI) demonstrated upper cervical diffusion restriction and T2/STIR hyperintensity. Unusually, SCI occurred in this case without intraprocedural catheter wedging or obvious flow limitation, prolonged procedure time, hypercoagulable state, or general hypotension. We review previous cases in the literature as well as spinal cord vascular anatomy, and discuss the possible etiologies of this complication. Spinal cord ischemia could be a very rare complication of neuroendovascular procedures even in the absence of warning signs and should be carefully evaluated in patients with suspected neurologic symptoms after such procedures.

Radiology Education of Physician Extenders: What Role Should Radiologists Play?

As physician extenders (PEs) enter the medical community in large numbers, they have an increasing impact on imaging utilization and imaging-based procedures. Physician assistants (PAs) and nurse practitioners (NPs) have an advanced level of education and some practice autonomously. However, PA and NP programs are not required to provide any basic radiology education. For PEs who did receive basic radiology education during their graduate program, the curriculum is nonstandard and there is a wide variation. PEs working in primary care and nonradiology specialties place imaging orders, review report findings, and answer patient questions. Other PEs working within radiology practices operate as liaisons with patients in diagnostic radiology or perform an increasing number of interventional procedures. Basic radiology education in formal PE certificate programs as well as on-the-job education about radiology may benefit patients, radiologists, and the health-care system. What role, if any, should the radiologist assume for educating PE students and practicing PAs and NPs? This review analyzes the benefits and drawbacks of radiologists educating PEs.

Endovascular correction of an infantile intracranial venous outflow obstruction.

The authors report on the case of a 7-year-old boy who presented with a reduced level of activity, macrocephaly, prominent scalp veins, and decreased left-sided visual acuity. Imaging workup demonstrated generalized cerebral volume loss, bilateral chronic subdural hematomas, absent left sigmoid sinus, hypoplastic left transverse sinus, and severe focal weblike stenosis of the right sigmoid sinus. Right sigmoid sinus angioplasty and stent insertion was performed, with an immediate reduction in the transduced intracranial venous pressure gradient across the stenosis (from 22 to 3 mm Hg). Postprocedural diminution of prominent scalp and forehead veins and spinal venous collateral vessels was followed by a progressive improvement in visual acuity and physical activity over a 1-year follow-up period, supporting the efficacy of angioplasty and stent insertion in intracranial venous outflow obstruction. There are multiple potential causes of intracranial venous hypertension in children. Development of dural sinus stenosis in infancy may be one such cause, mimicking the clinical presentation of other causes such as vein of Galen malformations. This condition can be ameliorated by early endovascular revascularization.

Blood pressure reduction, decreased diffusion on MRI, and outcomes after intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Decreased diffusion (DD) consistent with acute ischemia may be detected on MRI after acute intracerebral hemorrhage (ICH), but its risk factors and impact on functional outcomes are not well-defined. We tested the hypotheses that DD after ICH is related to acute blood pressure (BP) reduction and lower hemoglobin and presages worse functional outcomes. METHODS: Patients who underwent MRI were prospectively evaluated for DD by certified neuroradiologists blinded to outcomes. Hemoglobin and BP data were obtained via electronic queries. Outcomes were obtained at 14 days and 3 months with the modified Rankin Scale, a functional scale scored from 0 (no symptoms) to 6 (dead). We used logistic regression for dependence or death (modified Rankin Scale score 4-6). RESULTS: DD distinct from the hematoma was found on MRI in 39 of 95 patients (41%). DD was associated with greater BP reductions from baseline and a higher risk of dependence or death at 3 months (odds ratio, 4.8; 95% confidence interval, 1.7-13.9; P=0.004) after correction for ICH score (1.8 per point; 95% confidence interval, 1.2-3.1; P=0.01). Lower hemoglobin was associated with worse ICH score, larger hematoma volume, and worse outcomes, but not DD. CONCLUSIONS: DD is common after ICH, associated with greater acute BP reductions, and associated with disability and death at 3 months in multivariate analysis. The potential benefits of acute BP reduction to reduce hematoma growth may be limited by DD. The prevention and treatment of cerebral ischemia manifested as DD are potential methods to improve outcomes.

Endovascular treatment of a bilateral dural carotid-cavernous fistula using an unusual unilateral approach through the basilar plexus.

BACKGROUND: Indirect carotid-cavernous fistulae are dural arteriovenous shunts between dural branches of the internal and/or external carotid arteries and the cavernous sinuses. METHODS: We present an uncommon case of bilateral dural carotid-cavernous fistula with aggressive angioarchitectural features that was successfully treated with bilateral coil embolization using an unusual unilateral transvenous approach through the basilar plexus. CONCLUSIONS: This route should be considered for similar cases, and also for unilateral fistulae when the ipsilateral petrosal sinus cannot be accessed.

Will CT ordering practices change if we educate residents about the potential effects of radiation exposure? Experience at a large academic medical center.

RATIONALE AND OBJECTIVES: The aim of this study was to determine if educating residents about the potential effects of radiation exposure from computed tomographic (CT) imaging alters ordering patterns. This study also explored whether referring physicians are interested in radiation education and was an initial effort to address their CT ordering behavior. MATERIALS AND METHODS: Two to four months after a radiologist's lecture on the potential effects of radiation exposure related to CT scans, urology and orthopedic residents were surveyed regarding the number and types of CT scans they ordered, the use of alternative imaging modalities, and whether they used the lecture information to educate patients. RESULTS: Twenty-one resident lecture attendants completed the survey. The number of CT scans ordered after the lecture stayed constant for 90% (19 of 21) and decreased for 10% (two of 21). The types of CT scans ordered changed after the lecture for 14% (three of 21). Thirty-three percent (seven of 21) reported increases in alternative imaging after the lecture, including 24% (five of 21) reporting increases in magnetic resonance imaging and 19% (four of 21) reporting increases in ultrasound. Patients directed questions about radiation exposure to 57% (12 of 21); 38% (eight of 21) used the lecture information to educate patients. Referring physicians were interested in the topic, and afterward, other physician groups requested radiation education lectures. CONCLUSIONS: Most clinicians did not change their CT scan ordering after receiving education about radiation from a radiologist. Radiation education allowed clinicians to discuss CT benefits and risks with their patients and to choose appropriate CT protocols. Referring physician groups are interested in this topic, and radiologists should be encouraged to give radiation lectures to them.

Reversal of diffusion restriction after embolization of dural arteriovenous fistula: case report.

BACKGROUND AND IMPORTANCE: We report a rare case of diffusion restriction caused by venous hypertension resulting from a dural arteriovenous fistula (DAVF) that completely reversed after successful embolization. CLINICAL PRESENTATION: A 54-year-old man presented with symptoms secondary to a DAVF. Magnetic resonance imaging (MRI) revealed left parieto-temporo-occipital diffusion restriction. The angiogram revealed a Cognard type III left lateral tentorial DAVF resulting in severe venous hypertension. Transarterial Onyx embolization was performed, resulting in angiographic cure of the fistula with normalization of the venous drainage in the left parieto-temporo-occipital region. A follow-up MRI examination performed 4 weeks after the embolization revealed resolution of the previously seen area of restricted diffusion. CONCLUSION: It is important to consider the possibility of diffusion restriction reversal, because misdiagnosis or the false assumption that irreversible cerebral infarction has occurred may inappropriately alter or delay the treatment of these aggressive lesions.

Frequency and diagnostic utility of intralabyrinthine FLAIR hyperintensity in the evaluation of internal auditory canal and inner ear pathology.

RATIONALE AND OBJECTIVES: Fluid-attenuated inversion recovery (FLAIR) imaging can detect elevated protein levels in fluid that may be difficult or impossible to detect with T1- or T2-weighted imaging. The purpose of this study is to evaluate the frequency and asses the diagnostic utility of abnormal FLAIR signal in various types of inner ear and internal auditory canal (IAC) pathology. MATERIALS AND METHODS: A retrospective review of medical records and magnetic resonance images from 187 consecutive patients who underwent imaging of the temporal bones for possible inner ear or IAC pathology over a 1-year period were reviewed for abnormal increased FLAIR signal, increased intrinsic T1 signal, abnormal enhancement after gadolinium administration, and the presence of a mass lesion within the cerebellopontine angle, IAC, or inner ear. Reviewers were blinded to clinical diagnosis. RESULTS: Twenty-five of 32 (78%) patients with schwannomas restricted to the IAC and cerebellopontine angle demonstrated associated increased FLAIR signal within the ipsilateral inner ear structures. The sensitivity, specificity, positive predictive value, and negative predictive value of inner ear FLAIR hyperintensity for a schwannoma were 80%, 95%, 78%, and 95%, respectively. Inner ear FLAIR hyperintensity was also seen in cases of intracochlear hemorrhage, labyrinthitis, and labyrinthitis ossificans, but these conditions did not occur with sufficient frequency in our study population to determine statistical significance. CONCLUSION: Identification of inner ear FLAIR hyperintensity can alert the radiologist to scrutinize pre- and post-gadolinium T1-weighted images and T2-weighted images for subtle IAC and inner ear abnormalities. Although enhancement after the administration of gadolinium contrast media is the gold standard for detection of schwannoma, inner ear FLAIR hyperintensity may be a helpful diagnostic adjunct for vestibular schwannoma. This may be particularly helpful when gadolinium was not administered and the T2-weighted images are equivocal, especially when dedicated thin-section imaging of the IACs and temporal bones was not performed.

The use of the "puffed-cheek" computed tomography technique to confirm the diagnosis of pneumoparotitis.

Pneumoparotitis is a rare etiology of symptomatic parotid gland enlargement that is often misdiagnosed clinically. Pneumoparotitis results from air refluxing into the parotid ductal system via an incompetent Stensen duct orifice. We report a protracted case of pneumoparotitis evaluated with the "puffed-cheek" computed tomography technique to help confirm the diagnosis.

Autologous non-myeloablative haemopoietic stem cell transplantation in relapsing-remitting multiple sclerosis: a phase I/II study.

BACKGROUND: Autologous non-myeloablative haemopoietic stem cell transplantation is a method to deliver intense immune suppression. We evaluated the safety and clinical outcome of autologous non-myeloablative haemopoietic stem cell transplantation in patients with relapsing-remitting multiple sclerosis (MS) who had not responded to treatment with interferon beta. METHODS: Eligible patients had relapsing-remitting MS, attended Northwestern Memorial Hospital, and despite treatment with interferon beta had had two corticosteroid-treated relapses within the previous 12 months, or one relapse and gadolinium-enhancing lesions seen on MRI and separate from the relapse. Peripheral blood haemopoietic stem cells were mobilised with 2 g per m2 cyclophosphamide and 10 microg per kg per day filgrastim. The conditioning regimen for the haemopoietic stem cells was 200 mg per kg cyclophosphamide and either 20 mg alemtuzumab or 6 mg per kg rabbit antithymocyte globulin. Primary outcomes were progression-free survival and reversal of neurological disability at 3 years post-transplantation. We also sought to investigate the safety and tolerability of autologous non-myeloablative haemopoietic stem cell transplantation. FINDINGS: Between January, 2003, and February, 2005, 21 patients were treated. Engraftment of white blood cells and platelets was on median day 9 (range day 8-11) and patients were discharged from hospital on mean day 11 (range day 8-13). One patient had diarrhoea due to Clostridium difficile and two patients had dermatomal zoster. Two of the 17 patients receiving alemtuzumab developed late immune thrombocytopenic purpura that remitted with standard therapy. 17 of 21 patients (81%) improved by at least 1 point on the Kurtzke expanded disability status scale (EDSS), and five patients (24%) relapsed but achieved remission after further immunosuppression. After a mean of 37 months (range 24-48 months), all patients were free from progression (no deterioration in EDSS score), and 16 were free of relapses. Significant improvements were noted in neurological disability, as determined by EDSS score (p<0.0001), neurological rating scale score (p=0.0001), paced auditory serial addition test (p=0.014), 25-foot walk (p<0.0001), and quality of life, as measured with the short form-36 (SF-36) questionnaire (p<0.0001). INTERPRETATION: Non-myeloablative autologous haemopoietic stem cell transplantation in patients with relapsing-remitting MS reverses neurological deficits, but these results need to be confirmed in a randomised trial.