The Impact of Gadolinium Deposition on Radiology Practice: An International Survey of Radiologists.

RATIONALE AND OBJECTIVES: Brain deposition of gadolinium following the administration of gadolinium-based contrast agents (GBCAs) was initially reported in 2014. Gadolinium deposition is now recognized as a dose-dependent consequence of exposure. The potential clinical implications are not yet understood. The purpose of this study was to determine radiologists' reporting practices in response to gadolinium deposition. MATERIALS AND METHODS: An electronic survey querying radiologists' practices regarding gadolinium deposition was distributed by Radiopaedia.org from November-December 2015. RESULTS: Our study sample included 94 total respondents (50% academic; 27% private practice; 23% hybrid) from 30 different countries (USA 18%). Fifty-seven (62%) radiologists had observed brain gadolinium deposition on MRI brain studies howerver more than half of these (30 of 57) reported detecting dentate T1 shortening only rarely (<1/month). Among respondents, 58% (52 of 89) do not or would not include the finding in the radiology report; only 12 (13%) report the finding in the impression of their reports. The most common reason for not reporting gadolinium deposition was the risk of provoking unnecessary patient anxiety (29%, 20 of 70). Recent data on gadolinium deposition has led to a reported practice change in 24 of 87 (28%) of respondents. CONCLUSION: Recognition of, and attitudes toward, brain gadolinium deposition were inconsistent in this worldwide sample. Most surveyed radiologists do not routinely report dentate T1shortening as a marker of gadolinium deposition. Fear of provoking patient/clinician anxiety and an incomplete understanding of the implications of gadolinium deposition contribute to inconsistencies in reporting.

PRES and Epilepsy: A Potential Long-Term Consequence of a "Reversible" Syndrome.

Epilepsy is very rarely attributed to posterior reversible encephalopathy syndrome (PRES). We report the case of a previously healthy 21-year-old who developed epilepsy with mesial temporal sclerosis following an episode of PRES related to a complicated Cesarean delivery. Neuroimaging at the time of PRES and 3 months after revealed the development of unilateral hippocampal volume loss following resolution of acute PRES-related brain edema. We discuss the incidence and importance of "non-reversible" sequelae of PRES and their implications for patient care.

Analysis of the Relationship between the Location of the Anterior Ethmoid Artery and Keros Classification.

Objective We sought to identify a relationship between skull base height and anterior ethmoid artery (AEA) anatomy. Study Design Retrospective radiologic chart review. Setting University of Arkansas for Medical Sciences. Subjects Patients seen in a tertiary rhinology clinic between September 2014 and October 2015. Methods Review of 101 maxillofacial computed tomography scans with institutional review board approval. Skull base height and AEA locations were measured on each side. Prevalence of the AEA outside of the skull base and distance of the AEA from skull base were calculated and compared with Keros classification using χ2 testing. Comparisons of skull base height between sexes and age and distance between skull base and the AEA among Keros 2 and Keros 3 patients were made using an unpaired, 2-tailed t test. Results The AEA was located below the skull base in 25.7% of cases and more often in Keros type 3 (55%) than in Keros type 2 (29.5%) or Keros type 1 (0%) ( P < .05). Male patients were significantly more likely to have a greater average skull base height (5.25 vs 4.28 mm) and to have AEAs below the skull base (38.4% vs 14.8%). In addition, the distance of the AEA from the skull base was significantly higher in Keros type 3 patients compared with Keros type 2 patients (4.55 vs 3.42 mm, P = .001). Conclusions Variations in the AEA pathway occur more in male patients and those with higher Keros classifications. The distance between the variant AEA and the skull base increases with higher Keros classification. Keros classification can yield insight to the location of the AEA.

Predictors of poor outcome in patients with posterior reversible encephalopathy syndrome.

PURPOSE: Posterior reversible encephalopathy syndrome (PRES) is an acute neurotoxic syndrome that, although characteristically reversible, can be fatal or result in long-term disability in a subset of patients. Our aim was to identify factors associated with poor discharge outcome in PRES patients. MATERIALS AND METHODS: We retrospectively reviewed the clinical and radiological records of all patients with PRES admitted at our tertiary care medical center from 2007 to 2014. They were divided based their modified Rankin Score at discharge and compared for their baseline variables, clinical, laboratory and imaging features. Poor outcome was defined by a modified Rankin scale 2-6 and was subdivided based on the primary mechanism that led to poor outcome. RESULTS: Out of 100 PRES subjects, 36% had poor discharge outcomes. Factors associated with poor outcomes on univariate analysis were history of diabetes mellitus, coma, high Charlson comorbidity index, post-transplantation, autoimmune condition, lack of systolic or diastolic hypertension, elevated blood urea nitrogen and involvement of the corpus callosum. On multivariate analysis, only prior diabetes mellitus odd ratio (OR) = 6.8 (95% CI 1.1-42.1, p = 0.04), corpus callosum involvement (OR = 11.7; 95% CI 2.4-57.4, p = 0.00) were associated with poor outcome. Poor outcome also correlated with increased length of hospital stay (OR = 7.9; 95% CI 1.3-49.7, p = 0.03). CONCLUSION: Large prospective studies incorporating serial blood glucose values and advanced imaging studies are required to validate these findings.

Root Cause Analysis: An Examination of Odontogenic Origins of Acute Maxillary Sinusitis in Both Immunocompetent & Immunocompromised Patients.

BACKGROUND AND PURPOSE: Dental and periodontal diseases represent important but often overlooked causes of acute sinusitis. Our goal was to examine the prevalence of potential odontogenic sources of acute maxillary sinusitis according to immune status and their associations with sinusitis. MATERIALS AND METHODS: A retrospective review of maxillofacial computed tomography studies from 2013 to 2014 was performed. Each maxillary sinus and its ipsilateral dentition were evaluated for findings of acute sinusitis and dental/periodontal disease. RESULTS: Eighty-four patients (24 immunocompetent, 60 immunocompromised) had 171 maxillary sinuses that met inclusion criteria for acute maxillary sinusitis. Inspection of dentition revealed oroantral fistula in 1%, periapical lucencies in 16%, and projecting tooth root(s) in 71% of cases. Immunocompromised patients were more likely to have bilateral sinusitis than immunocompetent patients (67% vs 33%, P = 0.005). A paired case-control analysis in a subset of patients with unilateral maxillary sinusitis (n = 39) showed a higher prevalence of periapical lucency in association with sinuses that had an air fluid level-29% of sinuses with a fluid level had periapical lucency compared with 12% without sinus fluid (P = 0.033). CONCLUSIONS: Potential odontogenic sources of acute maxillary sinusitis are highly prevalent in both immunocompetent and immunocompromised patients, although the 2 patient populations demonstrate no difference in the prevalence of these potential odontogenic sources. Periapical lucencies were found to be associated with an ipsilateral sinus fluid level. Increased awareness of the importance of dental and periodontal diseases as key components of maxillofacial computed tomography interpretation would facilitate a more appropriate and timely treatment.

Characterization of Thyroid Nodules by 4-Dimensional Computed Tomography: Initial Experience.

OBJECTIVE: We aimed to evaluate the use of 4-dimensional computed tomography (4DCT) for characterization of thyroid nodules. METHODS: Our study drew from 100 consecutive patients with primary hyperparathyroidism who underwent 4D parathyroid CT imaging for adenoma localization. Included subjects had tissue sampling of a thyroid nodule within 3 months of 4DCT. RESULTS: Twenty subjects (18 women and 2 men) had thyroid nodules that were pathologically confirmed. Precontrast nodule attenuation was significantly lower in malignant nodules when compared with benign nodules (36 vs 61 HU, P = 0.05). Arterial phase and delayed phase nodule attenuations were not significantly different in malignant and benign nodules (128 vs 144 HU, P = 0.7; 74 vs 98 HU, P = 0.3). CONCLUSIONS: Our initial experience with a small group of patients was unable to support the use of 4DCT for characterizing thyroid nodules; however, precontrast nodule attenuation was significantly lower in malignant nodules when compared with benign nodules.

Predictors of intensive care unit utilization in patients with posterior reversible encephalopathy syndrome.

Posterior reversible encephalopathy syndrome (PRES) is an acute neurological syndrome that requires prompt, aggressive management to improve outcomes. Our aim was to identify factors that would necessitate care in the intensive care unit (ICU) in patients with PRES and the outcomes on discharge following ICU stay. We retrospectively reviewed the medical records and radiological data of adult PRES patients admitted to our tertiary care medical center. We dichotomized them into two groups based on their need for ICU care and compared their clinical, laboratory, imaging characteristics and discharge outcomes. Outcomes were defined using the modified Rankin Score (mRS) and Glasgow Outcome Score (GOS) on discharge. Out of 100 patients, 67 % required admission to the ICU. On univariate analysis, factors associated with ICU admission were atrial fibrillation (19.4 vs 0 %; p ≤ 0.05), encephalopathy from PRES (89.6 vs 66.7 %; p < 0.05), low Glasgow Coma Score (GCS) (11 ± 4 vs 14 ± 2; p = 0.01) and cortical involvement on imaging (89.6 vs 72.7 %, p = 0.03). On multivariate logistic regression analysis, encephalopathy (odds ratio 10.22; 95 % CI (1.14-91.55; p = 0.04) was the sole predictor of ICU utilization. This correlated with a GCS <12 (odds ratio 5.53; 95 % CI (1.05-29.22; p = 0.04). Despite worse functional outcomes following ICU care based on mRS (2.3 ± 2.1 vs 1.3 ± 1.4, p = 0.02) and GOS (3.9 ± 1.3 vs 4.6 ± 0.7, p ≤ 0.05), only a borderline increase in mortality was observed (10.4 vs 0 %, p = 0.05). The presence of PRES-related encephalopathy might aid in prompt identification of patients who require ICU care.

Posterior Reversible Encephalopathy Syndrome: A Comparative Study of Pediatric Versus Adult Patients.

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is an acute neurotoxic syndrome that, although characteristically reversible, can result in long-term disability. Our aim was to identify the clinical and radiological factors that are unique to children with PRES compared with adults with the syndrome in a single center. METHODS: We retrospectively reviewed the clinical and radiological records of all patients with PRES admitted at a tertiary care medical center from 2007 to 2014. All patients who met the clinical and radiological criteria for PRES were dichotomized into children (less than 18 years) and adults (18 years or older) based on their age groups, and comparison of their baseline variables, clinical, laboratory, and imaging features was performed. RESULTS: During this study period, 19 pediatric patients and 100 adult patients with PRES were identified. On univariate analysis, factors significantly associated with pediatric patients with the syndrome were multiorgan failure (84.2% vs 50%, P = 0.006), temporal lobe involvement (63.3% vs 39%, P = 0.04), restricted diffusion (42.1% vs 18%, P = 0.02), and less likelihood of cerebellar involvement (21.1% vs 57%, P = 0.004). On bivariate logistic regression analysis, all these factors remained significantly associated with pediatric PRES; multiorgan failure (odds ratio: 5.80, 95% confidence interval: 1.45 to 29.41, P = 0.03), temporal lobe involvement (odds ratio: 5.08, 95% confidence interval: 1.17 to 22.17, P = 0.03), restricted diffusion (odds ratio: 2.48, 95% confidence interval: 1.61 to 10.10, P = 0.02), and less likely to have cerebellar involvement (odds ratio: 0.08, 95% confidence interval: 0.002 to 0.39, P = 0.002). CONCLUSIONS: Factors unique to PRES in children compared with adults include a greater propensity with multi-organ failure, involvement of the temporal lobe, and restricted diffusion on imaging.

Predictors of seizures in patients with posterior reversible encephalopathy syndrome.

PURPOSE: Although seizures are common in patients with posterior reversible encephalopathy syndrome (PRES), epilepsy is rare. Our objective was to identify predictors and impact of seizures in patients with PRES. METHODS: A retrospective review of the clinical and radiological parameters of all patients diagnosed with PRES from 2007 to 2014 was performed. Patients were divided into two groups based on the occurrence of PRES-related seizures at presentation or during their hospital course. Univariate and multivariate analyses were performed to determine factors associated with the occurrence of PRES-related seizures. RESULTS: Of 100 patients, 70% experienced at least one seizure from PRES. On univariate analysis, the factors associated with seizures were the following: high Charlson comorbidity index (4.16±2.89 vs. 2.87±2.20, p=0.03), systemic malignancy (41.4% vs. 16.7%, p=0.02), occipital lobe involvement (97.1% vs. 83.3%, p=0.02), more lobes involved (4.6±1.48 vs. 3.9±1.32, p=0.03) but less likely in patients with visual disturbances (15.7% vs. 46.7%, p=0.005), and facial droop (12.9% vs. 16.7%, p=0.002). On multivariate analysis, only occipital lobe involvement was significantly (odds ratio: 9.63, 95% CI: 1.45-64.10, p=0.02) associated with the occurrence of PRES-related seizures. Despite the occurrence of seizures, they were less likely to require a nursing home placement upon hospital discharge (odds ratio: 0.17, 95% CI: 0.03-0.91, p=0.04). CONCLUSION: We conclude that seizures are common in patients with occipital lobe involvement from PRES.

Seronegative neuromyelitis optica presenting with life-threatening respiratory failure.

CONTEXT: Dyspnea has rarely been reported as a presenting symptom in patients with neuromyelitis optica (NMO). We report an unusual case of NMO relapse presenting with rapidly progressive respiratory failure and briefly discuss the possible pathophysiological mechanisms of this potential life-threatening complication of NMO. FINDINGS: The 58-year-old woman with a history of bilateral optic neuritis presented to the emergency department with rapidly worsening dyspnea. Cervical spine magnetic resonance imaging showed extensive abnormal signal with involvement of the medulla oblongata. Since in our patient chest radiography failed to disclose a diaphragmatic palsy that is commonly observed in patients with phrenic nerve involvement, this acute manifestation of the disease may be attributed to brainstem involvement instead of cervical myelitis. CONCLUSION/CLINICAL RELEVANCE: Clinicians should be aware of this atypical presentation of NMO, which needs to be promptly recognized and aggressively treated.

Preoperative 4D CT Localization of Nonlocalizing Parathyroid Adenomas by Ultrasound and SPECT-CT.

OBJECTIVE: To evaluate 4-dimensional (4D) computed tomography (CT) for the localization of parathyroid adenomas previously considered nonlocalizing on ultrasound and single-photon emission CT with CT scanning (SPECT-CT). To measure radiation exposure associated with 4D-CT and compared it with SPECT-CT. STUDY DESIGN: Case series with chart review. SETTING: University tertiary hospital. SUBJECTS AND METHODS: Nineteen adults with primary hyperparathyroidism who underwent preoperative 4D CT from November 2013 through July 2014 after nonlocalizing preoperative ultrasound and technetium-99m SPECT-CT scans. Sensitivity, specificity, predictive values, and accuracy of 4D CT were evaluated. RESULTS: Nineteen patients (16 women and 3 men) were included with a mean age of 66 years (range, 39-80 years). Mean preoperative parathyroid hormone level was 108.5 pg/mL (range, 59.3-220.9 pg/mL), and mean weight of the excised gland was 350 mg (range, 83-797 mg). 4D CT sensitivity and specificity for localization to the patient's correct side of the neck were 84.2% and 81.8%, respectively; accuracy was 82.9%. The sensitivity for localizing adenomas to the correct quadrant was 76.5% and 91.5%, respectively; accuracy was 88.2%. 4D CT radiation exposure was significantly less than the radiation associated with SPECT-CT (13.8 vs 18.4 mSv, P = 0.04). CONCLUSION: 4D CT localizes parathyroid adenomas with relatively high sensitivity and specificity and allows for the localization of some adenomas not observed on other sestamibi-based scans. 4D CT was also associated with less radiation exposure when compared with SPECT-CT based on our study protocol. 4D CT may be considered as first- or second-line imaging for localizing parathyroid adenomas in the setting of primary hyperparathyroidism.

Using Social Media to Share Your Radiology Research: How Effective Is a Blog Post?

PURPOSE: The aim of this study was to compare the volume of individuals who viewed online versions of research articles in 2 peer-reviewed radiology journals and a radiology blog promoted by social media. METHODS: The authors performed a retrospective study comparing online analytic logs of research articles in the American Journal of Neuroradiology (AJNR) and the American Journal of Roentgenology (AJR) and a blog posting on Radiopaedia.org from April 2013 to September 2014. All 3 articles addressed the topic of reporting incidental thyroid nodules detected on CT and MRI. The total page views for the research articles and the blog article were compared, and trends in page views were observed. Factors potentially affecting trends were an AJNR podcast and promotion of the blog article on the social media platforms Facebook, Tumblr, and Twitter to followers of Radiopaedia.org in February 2014 and August 2014. RESULTS: The total numbers of page views during the study period were 2,421 for the AJNR article and 3,064 for the AJR article. The Radiopaedia.org blog received 32,675 page views, which was 13.6 and 10.7 times greater than AJNR and AJR page views, respectively, and 6.0 times greater than both journal articles combined. Months with activity above average for the blog and the AJNR article coincided with promotion by Radiopaedia.org on social media. CONCLUSIONS: Dissemination of scientific material on a radiology blog promoted on social media can substantially augment the reach of more traditional publication venues. Although peer-reviewed publication remains the most widely accepted measure of academic productivity, researchers in radiology should not ignore opportunities for increasing the impact of research findings via social media.

Features of infratentorial-predominant posterior reversible encephalopathy syndrome.

Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic process that typically occurs in the setting of immune dysregulation. In contrast to the characteristic pattern involving parieto-occipital and posterior frontal regions, predominant involvement of the infratentorial brain occurs in a minority of PRES patients. We examined six patients with infratentorial predominant posterior reversible encephalopathy syndrome (IPPRES) relative to those with typical PRES in terms of clinical factors of toxicity and outcomes. We review the current understanding of PRES pathophysiology. An institutional database of PRES patients was created through an IRB-approved search of the electronic record from 2007 to 2012. MR images were reviewed and classified by two neuro radiologists. Clinical data including laboratory data, blood pressure, and discharge outcome were collected through review of existing electronic medical records. Characteristics of the two groups were compared. Six cases among 80 PRES patients displayed an atypical distribution of signal abnormality predominantly involving the infratentorial brain. In IPPRES patients, signal abnormalities within the supratentorial brain, when present, showed a predominantly central distribution rather than the typical peripheral distribution. IPPRES patients showed higher rates of extreme hypertension, renal dysfunction, abnormal serum calcium, and abnormal serum magnesium relative to typical PRES patients. Outcomes were similar between the two groups. In our small series, IPPRES differs from typical PRES patients not only in the distribution of imaging abnormalities but also in rates of extreme hypertension and several laboratory indices. Despite these differences, clinical outcome in the IPPRES group was similar to that of typical PRES.

Longitudinally extensive transverse myelitis in systemic lupus erythematosus: case report and review of the literature.

OBJECTIVE: To report a case of longitudinally extensive transverse myelitis (LETM), a rare but disabling condition defined as a lesion of the spinal cord that extends over four or more vertebrae on MRI, in association with systemic lupus erythematosus (SLE). METHODS: We present a rare case of LETM involving the cervical and thoracic spinal cord in a patient with SLE and review the existing literature on the association of lupus-associated myelitis. RESULTS: LETM is included within the diagnostic criteria for Neuromyelitis Optica (NMO), but is also known to be associated with a wide range of auto-immune diseases. Only 37 cases of LETM in patients with SLE have been previously described. We performed an updated review on epidemiology, pathophysiology, clinical features, diagnosis, management, and prognosis of LETM in the setting of SLE. CONCLUSION: Due to the generally poor prognosis of LETM in SLE patients, prompt diagnosis and treatment is of critical importance for a positive clinical outcome. We provide a comprehensive perspective of past and current literature in order to aid diagnosis and management of this rare phenomenon.

Lithium toxicity and PRES: a novel association.

We report two cases of posterior reversible encephalopathy syndrome (PRES) occurring in association with supra-therapeutic serum lithium levels. Although the neurologic manifestations of lithium toxicity are well known, this is, to our knowledge, the first report describing a link between lithium toxicity and PRES. We discuss the current understanding of the pathogenesis of PRES and suggest mechanisms by which lithium may play a role in its development.