Imaging Errors in Distinguishing Pituitary Adenomas From Other Sellar Lesions.

BACKGROUND: Pituitary adenomas and nonadenomatous lesions in the sellar region may be difficult to distinguish by imaging yet that distinction is critical in guiding management. The nature of the diagnostic errors in this setting has not been well documented. METHODS: Two neurosurgeons and 2 neuroradiologists of differing experience levels viewed deidentified MRIs of 18 nonadenomatous sellar lesions and 21 adenomas. They recorded their diagnoses, the imaging features they used to make those diagnoses, and their confidence in making those diagnoses. RESULTS: Among the 18 nonadenoma cases, 11 (61%) were incorrectly diagnosed as adenoma by at least 1 reader, including Rathke cleft cyst, plasmacytoma, aneurysm, craniopharyngioma, chordoma, Langerhans cell histiocytosis, metastasis, and undifferentiated sinonasal carcinoma. Among the 21 adenoma cases, 8 (38%) were incorrectly diagnosed by at least 1 reader as craniopharyngioma, Rathke cleft cyst, sinonasal carcinoma, hemangioblastoma, and pituitary hyperplasia. Incorrect imaging diagnoses were made with high confidence in 13% of readings. Avoidable errors among the nonadenomatous cases occurred when readers failed to appreciate that the lesion was separate from the pituitary gland. Unavoidable errors in those cases occurred when the lesions were so large that the pituitary gland had been obliterated or the imaging features of a nonadenomatous lesion resembled those of a cystic pituitary adenoma. Avoidable errors in misdiagnosis of adenomas as nonadenomas occurred when readers failed to appreciate features highly characteristic of adenomas. An unavoidable error occurred because a cystic adenoma had features correctly associated with craniopharyngioma. CONCLUSIONS: Errors in imaging differentiation of pituitary adenoma from nonadenomatous lesions occurred often and sometimes with high confidence among a small sample of neurosurgeons and neuroradiologists. In the misdiagnosis of nonadenomatous lesions as adenomas, errors occurred largely from failure to appreciate a separate pituitary gland, but unavoidable errors occurred when large lesions had obliterated this distinguishing feature. In the misdiagnosis of adenomas as nonadenomatous lesions, avoidable errors occurred because readers failed to recognize imaging features more characteristic of adenomas and because cystic adenomas share features with craniopharyngiomas and Rathke cleft cysts. Awareness of these errors should lead to improved management of sellar lesions.

Safety and diagnostic efficacy of gadoteridol for magnetic resonance imaging of the brain and spine in children 2 years of age and younger.

BACKGROUND: Neonates and young children require efficacious magnetic resonance imaging (MRI) examinations but are potentially more susceptible to the short- and long-term adverse effects of gadolinium-based contrast agents due to the immaturity of their body functions. OBJECTIVE: To evaluate the acute safety and diagnostic efficacy of gadoteridol (ProHance) for contrast-enhanced MRI of the central nervous system (CNS) in children ≤2 years of age. MATERIALS AND METHODS: One hundred twenty-five children ≤2 years old (including 57 children <6 months old) who underwent contrast-enhanced MRI of the CNS with gadoteridol at 0.1 mmol/kg body weight were retrospectively enrolled at five imaging centers. Safety data were assessed for acute/subacute adverse events in the 48 h following gadoteridol administration and, when available, vital signs, electrocardiogram (ECG) and clinical laboratory values obtained from blood samples taken from 48 h before until 48 h following the MRI exam. The efficacy of gadoteridol-enhanced MRI compared to unenhanced MRI for disease diagnosis was evaluated prospectively by three blinded, unaffiliated readers. RESULTS: Thirteen changes of laboratory values (11 mild, 1 moderate, 1 unspecified) were reported as adverse events in 7 (5.6%) patients. A relationship to gadoteridol was deemed possible though doubtful for two of these adverse events in two patients (1.6%). There were no clinical adverse events, no serious adverse events and no clinically meaningful changes in vital signs or ECG recordings. Accurate differentiation of tumor from non-neoplastic disease, and exact matching of specific MRI-determined diagnoses with on-site final diagnoses, was achieved in significantly more patients by each reader following the evaluation of combined pre- and post-contrast images compared to pre-contrast images alone (84.6-88.0% vs. 70.9-76.9%; P≤0.006 and 67.5-79.5% vs. 47.0-66.7%; P≤0.011, respectively). CONCLUSION: Gadoteridol at 0.1 mmol/kg body weight is safe, well tolerated and effective for contrast-enhanced MRI of the CNS in children ≤2 years of age.

Catastrophic Allergic Fungal Sinusitis: A Report of Two Cases.

BACKGROUND: Allergic fungal rhinosinusitis (AFRS) is a common condition in which sinusitis develops as an IgE-mediated response to common sinonasal fungal organisms. If that response leads to blockage of sinus ostia, bone expansion and erosion by expansive cysts containing dense inspissated debris may occur with the potential for critical neurovascular compression including damage to the anterior visual pathway. METHODS: Review of clinical and imaging features of 2 patients who sustained catastrophic clinical outcomes. RESULTS: The first patient had pansinusitis with massive mucocele-like cysts expanding the sphenoid sinus and cranial base and causing compression of the anterior visual pathway that led to persistent severe vision loss despite extensive sinus surgery. The second patient developed sphenoethmoidal expansion with a marked inflammatory response and presumed conversion to invasive fungal sinusitis that caused anterior visual pathway vision loss, bilateral ocular motor palsies from extension into the cavernous sinuses, and death from a large middle cerebral artery stroke. CONCLUSIONS: Although AFRS is most often benign and treatable, it may rarely produce catastrophic outcomes, especially if the sphenoid sinus is involved. Irreversible vision loss may occur from compression, and ocular motor palsies and death from conversion to invasive fungal disease. Close ophthalmologic and imaging monitoring is necessary in patients with expanded sinuses, and prophylactic sinus surgery may be indicated in certain cases.

Diagnostic Approach to Intrinsic Abnormality of Spinal Cord Signal Intensity.

Intramedullary cord hyperintensity at T2-weighted MRI is a common imaging feature of disease in the spinal cord, but it is nonspecific. Radiologists play a valuable role in helping narrow the differential diagnosis by integrating patient history and laboratory test results with key imaging characteristics. The authors present an algorithmic approach to evaluating intrinsic abnormality of spinal cord signal intensity (SI), which incorporates clinical evaluation results, time of onset (acute vs nonacute), cord expansion, and pattern of T2 SI abnormality. This diagnostic approach provides a practical framework to aid both trainees and practicing radiologists in workup of myelopathy.©RSNA, 2019.

Magnetic resonance imaging in patients with cardiac implanted electronic devices: focus on contraindications to magnetic resonance imaging protocols.

AIMS: Magnetic resonance imaging (MRI) has been reported to be safe in patients with cardiac implantable electronic devices (CIED) provided a specific protocol is followed. The objective of this study was to assess whether this is also true for patients excluded from published protocols. METHODS AND RESULTS: A total of 160 MRIs were obtained in 142 consecutive patients with CIEDs [106 patients had an implantable cardioverter defibrillator (ICD) and 36 had a pacemaker implanted] using an adapted, pre-specified protocol. A cardiac MRI was performed in 95 patients, and a spinal/brain MRI was performed in 47 patients. Forty-six patients (32%) had either abandoned leads (n = 10), and/or were pacemaker dependent with an implanted ICD (n = 19), had recently implanted CIEDs (n = 1), and/or had a CIED device with battery depletion (n = 2), and/or a component of the CIED was recalled or on advisory (n = 32). No major complications occurred. Some device parameters changed slightly, but significantly, right after or at 1-week post-MRI without requiring any reprogramming. In one patient with an ICD on advisory, the pacing rate changed inexplicably during one of his two MRIs from 90 to 50 b.p.m. CONCLUSION: Using a pre-specified protocol, cardiac and non-cardiac MRIs were performed in CIED patients with pacemaker dependency, abandoned leads, or depleted batteries without occurrence of major adverse events. Patients with devices on advisory need to be monitored carefully during MRI, especially if they are pacemaker dependent.

Reassessing the Anatomic Origin of the Juvenile Nasopharyngeal Angiofibroma.

OBJECTIVE: A modern imaging review is necessary to further define the anatomic origin of the juvenile nasopharyngeal angiofibroma. METHODS: After institutional review board approval, a search from January 1998 to January 2013 yielded 33 male patients (aged 10-23 years) with pathologically proven juvenile nasopharyngeal angiofibroma lesions, as well as pretreatment computed tomography/magnetic resonance imaging. Juvenile nasopharyngeal angiofibroma involvement was assessed in the following regions: sphenopalatine foramen, pterygopalatine fossa, vidian canal, nasopharynx, nasal cavity, sphenoid sinus, choana, pterygomaxillary fissure/masticator space, orbit, and sphenoid bone. RESULTS: The choana and nasopharynx were involved in all 33 patients. In contrast, only 22 lesions involved the pterygopalatine fossa, 24 lesions involved the sphenopalatine foramen, and 28 lesions involved the vidian canal. CONCLUSIONS: Our results suggest that the juvenile nasopharyngeal angiofibroma origin is in the region of the choana and nasopharynx rather than the sphenopalatine foramen or pterygopalatine fossa.

The current role of diagnostic imaging in the preoperative workup for refractory neonatal brachial plexus palsy.

INTRODUCTION: Despite recent improvements in perinatal care, the incidence of neonatal brachial plexus palsy (NBPP) remains relatively common. CT myelography is currently considered to be the optimal imaging modality for evaluating nerve root integrity. Recent improvements in MRI techniques have made it an attractive alternative to evaluate nerve root avulsions (preganglionic injuries). AIM: We demonstrate the utility of MRI for the evaluation of normal and avulsed spinal nerve roots. We also show the utility of ultrasound in providing useful preoperative evaluation of the postganglionic brachial plexus in patients with NBPP.

Hypoxic-Ischemic Encephalopathy With Clinical and Imaging Abnormalities Limited to Occipital Lobe.

BACKGROUND: The vulnerable brain areas in hypoxic-ischemic encephalopathy (HIE) following systemic hypotension are typically the neocortex, deep cerebral gray nuclei, hippocampus, cerebellum, and the parieto-occipital arterial border zone region. The visual cortex is not commonly recognized as a target in this setting. METHODS: Single-institution review from 2007 to 2015 of patients who suffered cortical visual loss as an isolated clinical manifestation following systemic hypotension and whose brain imaging showed abnormalities limited to the occipital lobe. RESULTS: Nine patients met inclusion criteria. Visual loss at outset ranged from hand movements to 20/20, but all patients had homonymous field loss at best. In 1 patient, imaging was initially normal but 4 months later showed encephalomalacia. In 2 patients, imaging was initially subtle enough to be recognized as abnormal only when radiologists were advised that cortical visual loss was present. CONCLUSIONS: The occipital lobe may be an isolated target in HIE with cortical visual loss as the only clinical manifestation. Imaging performed in the acute period may appear normal or disclose abnormalities subtle enough to be overlooked. Radiologists informed of the clinical manifestations may be more attune to these abnormalities, which will become more apparent months later when occipital volume loss develops.

Utility of ultrasound in noninvasive preoperative workup of neonatal brachial plexus palsy.

BACKGROUND: Ultrasound has been utilized in the evaluation of compressive and traumatic peripheral nerve pathology. OBJECTIVE: To determine whether US can provide comprehensive evaluation of the post-ganglionic brachial plexus in the setting of neonatal brachial plexus palsy and whether this information can be used to guide preoperative nerve reconstruction strategies. MATERIALS AND METHODS: In this retrospective cohort study, preoperative brachial plexus ultrasonography was performed in 52 children with neonatal brachial plexus palsy who were being considered for surgery. The 33 children who had surgery compose the patient cohort. The presence and location of post-ganglionic neuromas were evaluated by US and compared to the surgical findings. US evaluation of shoulder muscle atrophy was conducted as an indirect way to assess the integrity of nerves. Finally, we correlated glenohumeral joint laxity to surgical and clinical management. RESULTS: Ultrasound correctly identified 21 of 25 cases of upper trunk and middle trunk neuroma involvement (84% sensitivity for each). It was 68% sensitive and 40% specific in detection of lower trunk involvement. US identified shoulder muscle atrophy in 11 of 21 children evaluated; 8 of these 11 went on to nerve transfer procedures based upon the imaging findings. US identified 3 cases of shoulder joint laxity of the 13 children evaluated. All 3 cases were referred for orthopedic evaluation, with 1 child undergoing shoulder surgery and another requiring casting. CONCLUSION: Ultrasound can provide useful preoperative evaluation of the post-ganglionic brachial plexus in children with neonatal brachial plexus palsy.

Inborn errors of metabolism: combining clinical and radiologic clues to solve the mystery.

OBJECTIVE: Inborn errors of metabolism in children can be challenging to interpret because of the similarity of their appearances on imaging. There are important clues to the diagnosis based on clinical history, head circumference (e.g., macrocephaly), geographic distribution of lesions (e.g., subcortical vs deep white matter or frontal vs parietooccipital), and other imaging features (e.g., contrast enhancement, calcification, cysts, and cortical dysplasia). CONCLUSION: In this article, we present an algorithm-based approach to diagnosing pediatric metabolic disease with a discussion of key imaging features.

Lateral geniculate lesions causing reversible blindness in a pre-eclamptic patient with a variant of posterior reversible encephalopathy syndrome.

Bilateral lateral geniculate nucleus (LGN) injury is a rare cause of vision loss. We describe a patient with pre-eclampsia who developed profound but reversible bilateral vision loss, bilateral serous retinal detachments, and magnetic resonance imaging signs of a variant of posterior reversible encephalopathy syndrome (PRES) that affected both LGNs and spared the retrogeniculate pathways. We provide evidence that the visual loss was not from the chorioretinal lesions but from the LGN lesions. The concurrence of PRES and lesions attributed to choroidal hypoperfusion provides support for the notion that vasoconstriction also underlies the pathogenesis of PRES.

Adaptive statistical iterative reconstruction: reducing dose while preserving image quality in the pediatric head CT examination.

BACKGROUND: Over the last decade there has been escalating concern regarding the increasing radiation exposure stemming from CT exams, particularly in children. Adaptive statistical iterative reconstruction (ASIR) is a relatively new and promising tool to reduce radiation dose while preserving image quality. While encouraging results have been found in adult head and chest and body imaging, validation of this technique in pediatric population is limited. OBJECTIVE: The objective of our study was to retrospectively compare the image quality and radiation dose of pediatric head CT examinations obtained with ASIR compared to pediatric head CT examinations without ASIR in a large patient population. MATERIALS AND METHODS: Retrospective analysis was performed on 82 pediatric head CT examinations. This group included 33 pediatric head CT examinations obtained with ASIR and 49 pediatric head CT examinations without ASIR. Computed tomography dose index (CTDIvol) was recorded on all examinations. Quantitative analysis consisted of standardized measurement of attenuation and the standard deviation at the bilateral centrum semiovale and cerebellar white matter to evaluate objective noise. Qualitative analysis consisted of independent assessment by two radiologists in a blinded manner of gray-white differentiation, sharpness and overall diagnostic quality. RESULTS: The average CTDIvol value of the ASIR group was 21.8 mGy (SD = 4.0) while the average CTDIvol for the non-ASIR group was 29.7 mGy (SD = 13.8), reflecting a statistically significant reduction in CTDIvol in the ASIR group (P < 0.01). There were statistically significant reductions in CTDI for the 3- to 12-year-old ASIR group as compared to the 3- to 12-year-old non-ASIR group (21.5 mGy vs. 30.0 mGy; P = 0.004) as well as statistically significant reductions in CTDI for the >12-year-old ASIR group as compared to the >12-year-old non-ASIR group (29.7 mGy vs. 49.9 mGy; P = 0.0002). Quantitative analysis revealed no significant difference in the homogeneity of variance in the ASIR group compared to the non-ASIR group. Radiologist assessment of gray-white differentiation, sharpness and overall diagnostic quality in ASIR examinations was not substantially different compared to non-ASIR examinations. CONCLUSION: The use of ASIR in pediatric head CT examinations allows for a 28% CTDIvol reduction in the 3- to 12-year-old age group and a 48% reduction in the >12-year-old age group without substantially affecting image quality.

Subretinal abscess causing restricted diffusion on magnetic resonance imaging.

BACKGROUND: Restricted diffusion of water molecules on diffusion-weighted magnetic resonance imaging most commonly associated with acute stroke, has also been described in brain abscess. It has been reported in only one case of sub-retinal abscess. METHODS: Review of two cases. RESULTS: Two cases of visual loss from subretinal abscess had restricted diffusion in the region of the abscess. In the first case, DWI revealed restricted diffusion in a white mass visible in the posterior retina. In the second case, restricted diffusion was present in an anterior retinal mass invisible by ophthalmoscopy and ultrasound. In combination of restricted diffusion in the cerebrum consistent with septic emboli, these imaging abnormalities allowed earlier treatment that either preserved vision or prevented enucleation.

Restricted diffusion of the superior and inferior ophthalmic veins in cavernous sinus thrombosis.

Two previous reports have described restricted diffusion in thrombosed superior ophthalmic veins (SOVs) in patients with cavernous sinus thrombosis (CST). We report a patient who displayed restricted diffusion in both the SOV and inferior ophthalmic vein in CST consequent to a masticator space abscess. The orbital vascular imaging findings added support to the cavernous sinus findings in making the diagnosis of CST. Diffusion-weighted imaging of the orbit is a valuable asset in this setting.

Sonographically guided lumbar puncture in pediatric patients.

Our aim with this study was to develop a user-friendly method for pediatric sonographically guided lumbar punctures so that we can visualize intrathecal anatomy, confirm intrathecal injection at the time of injection, and, most importantly, avoid ionizing radiation to a child's already radiosensitive pelvis. Sonographically guided lumbar puncture was prospectively performed in children aged 7 weeks to 16 years. All attempts (n = 9) were successful. We were able to identify relevant anatomy (including the conus in children 10 years and younger), confirm intrathecal injection, visualize intrathecal hematoma, and avoid radiation. Sonography is a promising modality for image-guided lumbar punctures without radiation in children.

Single Ventricle Reconstruction III: Brain Connectome and Neurodevelopmental Outcomes: Design, Recruitment, and Technical Challenges of a Multicenter, Observational Neuroimaging Study.

Patients with hypoplastic left heart syndrome who have been palliated with the Fontan procedure are at risk for adverse neurodevelopmental outcomes, lower quality of life, and reduced employability. We describe the methods (including quality assurance and quality control protocols) and challenges of a multi-center observational ancillary study, SVRIII (Single Ventricle Reconstruction Trial) Brain Connectome. Our original goal was to obtain advanced neuroimaging (Diffusion Tensor Imaging and Resting-BOLD) in 140 SVR III participants and 100 healthy controls for brain connectome analyses. Linear regression and mediation statistical methods will be used to analyze associations of brain connectome measures with neurocognitive measures and clinical risk factors. Initial recruitment challenges occurred that were related to difficulties with: (1) coordinating brain MRI for participants already undergoing extensive testing in the parent study, and (2) recruiting healthy control subjects. The COVID-19 pandemic negatively affected enrollment late in the study. Enrollment challenges were addressed by: (1) adding additional study sites, (2) increasing the frequency of meetings with site coordinators, and (3) developing additional healthy control recruitment strategies, including using research registries and advertising the study to community-based groups. Technical challenges that emerged early in the study were related to the acquisition, harmonization, and transfer of neuroimages. These hurdles were successfully overcome with protocol modifications and frequent site visits that involved human and synthetic phantoms.

Single Ventricle Reconstruction III: Brain Connectome and Neurodevelopmental Outcomes: Design, Recruitment, and Technical Challenges of a Multicenter, Observational Neuroimaging Study.

Patients with hypoplastic left heart syndrome who have been palliated with the Fontan procedure are at risk for adverse neurodevelopmental outcomes, lower quality of life, and reduced employability. We describe the methods (including quality assurance and quality control protocols) and challenges of a multi-center observational ancillary study, SVRIII (Single Ventricle Reconstruction Trial) Brain Connectome. Our original goal was to obtain advanced neuroimaging (Diffusion Tensor Imaging and Resting-BOLD) in 140 SVR III participants and 100 healthy controls for brain connectome analyses. Linear regression and mediation statistical methods will be used to analyze associations of brain connectome measures with neurocognitive measures and clinical risk factors. Initial recruitment challenges occurred related to difficulties with: 1) coordinating brain MRI for participants already undergoing extensive testing in the parent study, and 2) recruiting healthy control subjects. The COVID-19 pandemic negatively affected enrollment late in the study. Enrollment challenges were addressed by 1) adding additional study sites, 2) increasing the frequency of meetings with site coordinators and 3) developing additional healthy control recruitment strategies, including using research registries and advertising the study to community-based groups. Technical challenges that emerged early in the study were related to the acquisition, harmonization, and transfer of neuroimages. These hurdles were successfully overcome with protocol modifications and frequent site visits that involved human and synthetic phantoms. Trial registration number: ClinicalTrials.gov Registration Number: NCT02692443.

Homonymous hemianopia from infarction of the optic tract and lateral geniculate nucleus in deep cerebral venous thrombosis.

A 20-year-old man developed right homonymous hemianopia, hemiparesis, and hemisensory loss from deep cerebral venous thrombosis in the setting of high altitude. Approximately 3 months later, brain MRI showed encephalomalacia of the left optic tract and lateral geniculate nucleus, as well as signal abnormalities of the internal capsule and posterolateral thalamus. Homonymous hemianopia has previously been described in 1 case after deep cerebral venous thrombosis but without detailed neuroimaging features.

Impact of ultraviolet-absorbing 2-hydroxy-4-quaternaryammoniumalkoxy benzophenone motif on photodegradation of disulfoton: a case study.

Pesticide deposits post-treatment and before diffusing inside the plants are exposed to sunlight. Many of them degrade into a variety of photoproducts that may be harmful to living beings through accidental ingestion. The addition of ultraviolet light absorbers to the pesticide formulations is an attractive strategy to prevent photodegradation of the pesticides. Water-soluble quaternary ammonium ultraviolet light absorbers (QAUVAs) were synthesized from 2,4-dihydroxy benzophenones (BP-1) and their structures were confirmed by 1H NMR, 13C NMR, UV, and FTIR. A cost-saving approach for the photoprotection of disulfoton insecticide using these QAUVAs is presented. All the four QAUVAs exhibit excellent UV screening effect. The insecticide disulfoton was recovered in much higher amounts (22.27 ~ 25.64% higher than control) when it was irradiated in the presence of QAUVAs in comparison with the amount of recovery of pesticide exposed in absence of them.