The 100 most-cited and 100 most-mentioned COVID-19-related radiological articles: a comparative bibliometric analysis.

OBJECTIVES: This study aimed to identify the 100 most-cited and 100 most-mentioned coronavirus disease-2019 (COVID-19)-related radiological articles and compare their characteristics. MATERIALS AND METHODS: We searched the Web of Science and Altmetric.com using the search terms "COVID," "COVID-19," "Coronavirus," "SARS-CoV-2," "nCoV," and "pandemic" to identify the most-cited and most-mentioned COVID-19-related articles. We identified the top 100 most-cited and 100 most-mentioned articles in the field of radiology, regardless of their publication journal. We extracted the information from the listed articles and compared the characteristics between the most-cited and most-mentioned. RESULTS: Thirty (30%) articles were featured in the lists of the most-cited and most-mentioned articles. The comparison of the 100 most-cited and most-mentioned articles on each list showed that the most frequently cited articles were published in November 2020 and before (p < .001), originated from China (p < .001), covered the topic of diagnosis of COVID-19 (p < .001), and were related to the subspecialty of pulmonary imaging (p < .001); the most frequently mentioned articles were published in December 2020 and after (p < .001), originated from the USA (p < .001), covered the topic of diagnosis of sequelae of COVID-19 (p = .013) and post-vaccination complications (p < .001), and were related to the subspecialties of cardiac imaging (p < .001) and neuroradiology (p < .013). CONCLUSION: Significant differences were observed in publication date, country of origin, topic, and subspecialty of scientific knowledge related to COVID-19 in the field of radiology, between citation and public dissemination. CLINICAL RELEVANCE STATEMENT: This bibliometric analysis compares the 100 most-cited and 100 most-mentioned COVID-19-related radiologic articles, aiming to provide valuable insights into the patterns of knowledge dissemination during the pandemic era. KEY POINTS: • Thirty articles were featured on the lists of the 100 most-cited and 100 most-mentioned COVID-19-related articles. • The 70 unique most-cited articles more frequently originated from China (48.6%), while the unique most-mentioned articles more frequently originated from the USA (51.4%) (p < 0.001). • The 70 unique most-mentioned articles were more frequently related to cardiac imaging (25.7% vs.0%, p < 0.001) and neuroradiology (15.7% vs. 1.4%, p < 0.005) compared to the unique most-mentioned articles.

Changes in radiomic and radiologic features in meningiomas after radiation therapy.

OBJECTIVES: This study evaluated the radiologic and radiomic features extracted from magnetic resonance imaging (MRI) in meningioma after radiation therapy and investigated the impact of radiation therapy in treating meningioma based on routine brain MRI. METHODS: Observation (n = 100) and radiation therapy (n = 62) patients with meningioma who underwent MRI were randomly divided (7:3 ratio) into training (n = 118) and validation (n = 44) groups. Radiologic findings were analyzed. Radiomic features (filter types: original, square, logarithm, exponential, wavelet; feature types: first order, texture, shape) were extracted from the MRI. The most significant radiomic features were selected and applied to quantify the imaging phenotype using random forest machine learning algorithms. Area under the curve (AUC), sensitivity, and specificity for predicting both the training and validation sets were computed with multiple-hypothesis correction. RESULTS: The radiologic difference in the maximum area and diameter of meningiomas between two groups was statistically significant. The tumor decreased in the treatment group. A total of 241 series and 1691 radiomic features were extracted from the training set. In univariate analysis, 24 radiomic features were significantly different (P < 0.05) between both groups. Best subsets were one original, three first-order, and six wavelet-based features, with an AUC of 0.87, showing significant differences (P < 0.05) in multivariate analysis. When applying the model, AUC was 0.76 and 0.79 for the training and validation set, respectively. CONCLUSION: In meningioma cases, better size reduction can be expected after radiation treatment. The radiomic model using MRI showed significant changes in radiomic features after radiation treatment.

Computed tomography findings of thyroid hemiagenesis: differentiation from hemithyroidectomy.

OBJECTIVES: Thyroid hemiagenesis is a rare congenital anomaly characterized by the lack of development of one thyroid lobe. The purpose of this study was to evaluate computed tomography (CT) findings of thyroid hemiagenesis and to establish useful CT criteria for differentiating thyroid hemiagenesis from the hemithyroidectomy state. METHODS: The CT images of 11 patients with thyroid hemiagenesis were retrospectively reviewed and compared with those of 100 (49 left and 51 right) patients in a hemithyroidectomy state. Image analysis was performed according to the following CT parameters: (a) side of thyroid hemiagenesis, (b) edge of the medial end of the remnant thyroid gland, (c) location of the medial end of the remnant thyroid gland, expressed as the angle of the medial end and (d) any other thyroid abnormality observed during the initial examination. RESULTS: The missing lobe occurred more often in the left than in the right lobe (72.7% vs. 27.3%) as well as concomitant isthmus agenesis (100% vs. 37.5%). The sharp edge of the medial end of the remnant thyroid gland was more common in thyroid hemiagenesis (64%) than in hemithyroidectomy (26%) (P = 0.0153). In left thyroid hemiagenesis, the angle of the medial end (63%) was more frequently > + 30° than in hemithyroidectomy (0%) (P < 0.0001). Two patients presented with hypothyroidism; the remaining nine showed a normal thyroid function. The associated thyroid diseases were autoimmune thyroiditis (n = 1) and papillary thyroid carcinoma (n = 1). CONCLUSIONS: The sharp edge of the medial end of the remnant thyroid gland and an angle of > + 30° for the medial end in cases wherein the left lobe is absent are useful CT features for distinguishing thyroid hemiagenesis from hemithyroidectomy.

Lymphangitis Carcinomatosa in Neck Soft Tissue: Computed Tomography Findings With Emphasis on Differentiation From Cellulitis.

OBJECTIVE: Lymphangitis carcinomatosa (LC) is a rare form of metastasis. The purposes of this study were to evaluate computed tomography (CT) findings associated with LC in neck soft tissue and to determine those that were useful in distinguishing LC from cellulitis. METHODS: Contrast-enhanced CT images of 26 patients with pathologically confirmed LC (n = 5) and clinically proven cellulitis (n = 21) were reviewed retrospectively. The following CT findings were evaluated and compared between the 2 groups: subcutaneous fat infiltration, enlargement of muscle, thick irregular enhancement of the superficial cervical fascia, grouping of micronodules, focal intramuscular enhancement, localized fluid collection, and nodular skin thickening. RESULTS: Thick irregular enhancement of the superficial cervical fascia (80.0% vs 0%, P < 0.0005), grouping of micronodules (60.0% vs 0%, P < 0.005), and focal intramuscular enhancement (60.0% vs 4.8%, P < 0.05) were significantly more frequent in LC than in cellulitis. Other findings did not show statistical significance between both groups. CONCLUSIONS: When soft tissue swelling is present in the neck with either thick irregular enhancement of the superficial cervical fascia, grouping of micronodules, or focal intramuscular enhancement, the possibility of LC should be considered especially in patients with underlying malignancy.

A comprehensive analysis of self-corrected publications in the imaging literature.

BACKGROUND: The characteristics of self-corrected publications have not been fully evaluated. PURPOSE: To evaluate the annual number and characteristics of self-corrected publications in the imaging literature within the last 20 years. MATERIAL AND METHODS: We searched MEDLINE (via PubMed) using the following keyword: ("Published Erratum" [Publication Type] OR "Corrected and Republished Article" [Publication Type]) in the imaging literature to identify all self-corrected publications in which initial versions of articles were published during 1999-2018. Extracted data included: date of publication of the original version; date of correction notification; the time interval between initial publication and correction; journal name; journal impact factor (IF); type of articles; number of authors; country of origin; and location of errors. Journals were divided into four quartiles (Q1-Q4) based on their IF. RESULTS: A total of 1071 self-corrected publications were identified, representing 0.30% of all papers published in the imaging literature. Trend analysis showed exponential growth of the number and rate of self-corrected publications during 1999-2018. The median (range) time interval from initial publication to correction was 120 days (0-7755 days). The rate of self-corrected publications in Q4 journals (0.17%) was significantly lower than those in Q1 (0.35%, P<0.0001), Q2 (0.26%, P=0.0007), and Q3 (0.30%, P<0.0001) journals. Additionally, 80.8% of self-corrected publications were original articles, 29.2% were from the USA, and 30.7% were corrected for author information (name, affiliation, and email address). CONCLUSION: Self-corrected publications in the imaging literature have increased exponentially during 1999-2018 and author information was the most common location of error correction.

Changes in computed tomography perfusion parameters and maximum contrast enhancement in patients having hydrocephalus with a ventriculoperitoneal shunt: a pilot study.

BACKGROUND: Acute hydrocephalus may decrease cerebral perfusion by increasing intracranial pressure. Computed tomography perfusion (CTP) has become a significant adjunct in evaluating regional and global cerebral blood flow (CBF). PURPOSE: To investigate the changes in cerebral perfusion parameters and maximum contrast enhancement (MCE) in patients with hydrocephalus with ventriculoperitoneal shunt (VPS). MATERIAL AND METHODS: We performed brain CTP in 45 patients, including those with subarachnoid hemorrhage (SAH)-induced hydrocephalus with VPS (n = 14, G1), hydrocephalus (not related to SAH) with VPS (n = 11, G2), SAH-induced hydrocephalus without VPS (n = 10, G3), and hydrocephalus (not related to SAH) without VPS (n = 10, G4). We measured the cerebral perfusion in the frontal white matter (FWM), centrum semiovale, basal ganglia (BG), and eight cortical lesions of interest and compared the differences in CTP parameters among the groups. RESULTS: Between the four groups, cerebral blood volume and MCE in the left FWM and CBF in the right FWM increased significantly in G1 and G2 who underwent VP shunt compared to G3 and G4, whereas perfusion significantly reduced in G3 and G4 who did not undergo VP shunt compared to G1 and G2. MCE in the left BG significantly increased in G2 and decreased in G3 and G4. SAH-induced hydrocephalus showed a lower perfusion than hydrocephalus (not related to SAH) in FWM. CONCLUSIONS: Perfusion changes in patients with hydrocephalus after VP shunt were seen in the FWM and BG, which appears to be the result of the hydrocephalus reducing brain perfusion in the deep part of the brain. We concluded that SAH slows brain perfusion recovery.

Surgical exposure of the vertebral artery for endovascular access in a hybrid operating room.

PURPOSE: Endovascular procedures are a desirable treatment option for neurovascular lesions in posterior circulation. However, endovascular access occasionally fails due to tortuosity of the proximal vertebral artery (VA), aortic arch, and/or VA ostium stenosis. We aimed to describe the creation of endovascular access via surgical exposure of the VA in a hybrid operating room to overcome anatomical difficulties hampering distal access to the VA through the transfemoral or transradial approach. METHODS: We present six patients with seven posterior circulation lesions in whom distal access via the conventional approach to the VA was impossible. Surgical exposure of the VA was performed to provide endovascular access to these patients. Radiographic characteristics, operative techniques, and outcomes were reviewed. RESULTS: Surgical exposure of the VA was performed in six patients with cerebral aneurysm (n = 4) and symptomatic stenosis of the VA ostium (n = 3). There were four female and two male patients, aged 73-82 years. Surgical exposure was usually performed beyond the tortuous segments of the VA. After endovascular access was provided, coil embolization was performed for cerebral aneurysms and/or balloon angioplasty and stenting was performed to treat the VA ostium stenosis. All puncture sites were closed by direct suture using a 7-0 Prolene suture. All procedures were completed without adverse events. CONCLUSION: Endovascular access via surgical exposure of the VA is a feasible and safe alternative for patients in whom the femoral or radial route does not allow the navigation and stabilization of the guiding catheter into the proximal segment of the VA.

256-row multislice CT angiography in the postoperative evaluation of cerebral aneurysms treated with titanium clips: using three-dimensional rotational angiography as the standard of reference.

OBJECTIVE: To assess the diagnostic accuracy of 256-row multislice computed tomographic angiography (CTA) compared with three-dimensional rotational angiography (3DRA) in the postoperative evaluation of cerebral aneurysms treated with titanium clips. METHODS: A total of 128 patients (42 men, 86 women; mean age, 57.6 years) with 143 cerebral aneurysms treated using titanium clips underwent both CTA and 3DRA. Two reviewers retrospectively evaluated the following parameters on CTA and 3DRA: (1) residual/recurrent aneurysm (absent or present), (2) patency of parent artery (patent or occluded/severe stenotic (> 70%)), and (3) patency of adjacent branch (patent or occluded/absent). RESULTS: A total of 24 residual/recurrent aneurysms were detected by 3DRA. The sensitivity, specificity, and accuracy of CTA for the detection of residual/recurrent aneurysms were 83.3%, 100%, and 97.2% for reviewer 1 and 79.2%, 100%, and 96.5% for reviewer 2, respectively. The sensitivity, specificity, and accuracy of CTA for the evaluation of patency of parent artery were 100%, 100%, and 100%, respectively, for both reviewers. The sensitivity, specificity, and accuracy of CTA for evaluation of the patency of adjacent branch were 85.1%, 100%, and 92.3% for reviewer 1 and 82.4%, 100%, and 90.9% for reviewer 2, respectively. CONCLUSION: A 256-row multislice CTA is a valuable non-invasive tool for assessment of cerebral aneurysms treated with titanium clips. KEY POINTS: • A 256-row multislice CTA is an accurate imaging technique for the postoperative assessment of cerebral aneurysms treated with titanium clips. • Sensitivity of CTA for the detection of residual/recurrent aneurysms was 79-83% compared with 3DRA. • CTA is still limited in detecting residual/recurrent aneurysms of < 2 mm and small adjacent branches.

The value of CT, MRI, and PET-CT in detecting retropharyngeal lymph node metastasis of head and neck squamous cell carcinoma.

BACKGROUND: The diagnostic accuracies of the imaging studies should be clearly acknowledged in managing head and neck cancer patients; however, the accuracies of preoperative imaging studies in detecting retropharyngeal lymph node (RPLN) metastasis are still not clarified. This study was to evaluate diagnostic accuracies of computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET-CT) in detecting RPLN metastasis of head and neck squamous cell carcinomas. METHODS: For 123 patients who had performed RPLN dissection during the surgery of their squamous cell carcinoma of the head and neck, preoperative CT, MRI, and/or PET-CT were reviewed for RPLN metastasis in a blinded fashion by one experienced radiologist. Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of each imaging modality were assessed, by comparing with the histopathologic findings of the resected RPLNs that served as the standard of reference. RESULTS: RPLNs were pathologically positive for metastasis in 43 of the 123 patients (35%). Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy in detecting metastasis to RPLN were 65, 94, 85, 83, and 84% for CT; 74, 94, 87, 87 and 87% for MRI; 83, 93, 89, 89 and 89% for PET-CT, respectively. When all the three imaging modalities were considered together (n = 74), they offered sensitivity of 90%, specificity of 91%, positive predictive value of 87%, negative predictive value of 93%, and accuracy of 91%. CONCLUSIONS: The preoperative imaging studies offered relatively high specificity rates, but rather low sensitivity rates. The three imaging modalities altogether increased diagnostic accuracies, which highlights the potential of the three studies when used altogether can minimize missed diagnoses of RPLN metastasis.

Top-cited articles versus top Altmetric articles in nuclear medicine: a comparative bibliometric analysis.

BACKGROUND: The impact of any scientific article has traditionally been measured by the number of citations received. More recently, alternative metrics (altmetrics) reflect the digital dissemination of knowledge across the online mediasphere. PURPOSE: To evaluate and compare the characteristics of top-cited articles with those of top Altmetric articles related to nuclear medicine (NM). MATERIAL AND METHODS: We performed a search of the Web of Science and Altmetric databases using 114 search terms to identify the 50 top-cited and 50 top Altmetric articles, respectively, in the field of NM. We then compared the following characteristics of the selected articles: publication type; journal category; country of origin; year of publication; topic; imaging modality; and accessibility. Chi-square tests were performed for statistical analysis. RESULTS: There were no overlaps between the 50 top-cited and 50 top Altmetric articles. In general, compared to the leading Altmetric articles in this field, the cited articles were: more frequently review works published in NM and radiology journals (76% vs. 13%, P = 0.000); published in or before 2005 (84% vs. 0%, P = 0.000); the majority were related to oncology (56% vs. 44%, P = 0.000); and originated from the Netherlands (12% vs. 0%, P = 0.000). Compared to the top-cited articles, the leading Altmetric articles were: more frequently original articles published in other clinical field journals (54% vs. 0%, P = 0.000); primarily published between 2016 and 2018 (70% vs. 0%, P = 0.000); focused on neurology (50% vs. 22%, P = 0.000); and originated from the UK (18% vs. 2%, P = 0.000). CONCLUSION: Citation counts and Altmetric scores represent unique perspectives for evaluating the impact of NM research.

Intra-parotid lymph node metastasis in patients with non-cutaneous head and neck cancers: clinical and imaging features for differentiation from simultaneous parotid primary tumor.

BACKGROUND: Although uncommon, intra-parotid lymph node (IPLN) metastasis should be considered in the differential diagnosis of parotid masses in patients with head and neck cancers. PURPOSE: To compare the clinical and imaging features of IPLN metastases from head and neck cancers and simultaneous parotid primary tumors. MATERIAL AND METHODS: A retrospective review of 2199 patients with non-parotid head and neck cancers revealed 63 patients who also underwent parotidectomy during curative resection of head and neck cancer. After exclusion of direct extension to the parotid gland from adjacent primary tumors (n = 12) and IPLN metastases from skin cancer (n = 5), the final study group was composed of 46 patients, including 26 (1.2%) with 33 IPLN metastases and 20 (0.9%) with 24 simultaneous parotid primary tumors. We compared clinical features of patients (sex, age, site of primary tumor, histologic type, history of prior treatment for malignancy, TNM stages, side of parotid lesion, multiplicity, and metastasis in ipsilateral cervical LNs) and the CT (location in parotid gland, maximum dimension, margins, and central necrosis or cystic change) and 18F-FDG PET/CT (maximum standardized uptake value) findings. RESULTS: Ipsilateral level II LN metastasis was more frequent in the IPLN metastasis group than in the simultaneous parotid primary tumor group (73.1% vs. 35.0%, P < 0.05). Imaging features such as location in parotid gland, maximum dimension, margins, central necrosis or cystic change, and maximum standardized uptake value showed no significant differences between the two groups. CONCLUSION: CT and PET/CT findings of IPLN metastasis are indistinguishable from simultaneous parotid primary tumor in patients with head and neck cancers.

Diagnostic performance of CT, MRI, and their combined use for the assessment of the direct cranial or intracranial extension of malignant head and neck tumors.

BACKGROUND: Preoperative radiological evaluation of the cranial or intracranial extension of malignant head and neck tumors is critical in the planning of curative surgery. PURPOSE: To assess the diagnostic accuracy of computed tomography (CT) combined with magnetic resonance imaging (MRI), compared to CT or MRI alone in diagnosing the direct cranial or intracranial extension of malignant head and neck tumors, using histopathologic results as the reference standard. MATERIAL AND METHODS: CT and MRI images in 41 patients with malignant head and neck tumors abutting the skull were retrospectively reviewed. The images were evaluated for the presence or absence of skull invasion (erosion/destruction of the skull), dural invasion (nodular dural enhancement), and brain invasion (enhancing brain lesion with or without brain swelling/edema). The results of the CT alone, MRI alone, and CT combined with MRI were compared with the histopathologic findings. RESULTS: Of the 41 patients studied, ten had no invasion, eight had skull invasion, 17 had dural invasion, and six had brain invasion by tumor. The sensitivity/specificity/accuracy of CT alone, MRI alone, and CT combined with MRI for diagnosing intracranial extension were 78.0%/100%/94.5%, 85.4%/80.5%/93.9%, and 95.1%/100%/98.8%, respectively. The sensitivity of CT combined with MRI was significantly higher than those of CT alone ( P = 0.0156) and MRI alone ( P = 0.0313). CONCLUSION: CT combined with MRI is a more sensitive tool for the diagnosis of the direct cranial or intracranial extension of malignant head and neck tumors than CT alone and MRI alone.

Detection of loco-regional recurrence in malignant head and neck tumors: a comparison of CT, MRI, and FDG PET-CT.

BACKGROUND: The early and accurate detection of local or regional recurrence of head and neck tumor is critically important. PURPOSE: To compare the diagnostic accuracy of contrast-enhanced computed tomography (CT), contrast-enhanced magnetic resonance imaging (MRI), and fluorodeoxyglucose (FDG) positron emission tomography (PET)-CT, alone and in combination, in detecting the locoregional recurrence of malignant head and neck tumor. MATERIAL AND METHODS: A total of 93 patients with loco-regional recurrence of malignant head and neck tumors underwent CT, MRI, and PET-CT within 30 days before surgery. CT, MRI, and PET-CT for each patient were retrospectively reviewed to determine the presence of recurrent tumors in the primary site on a patient-by-patient basis and that of regional lymph nodes on a level-by-level basis. The diagnostic accuracy of CT, MRI, and PET-CT, alone and combined, were accessed with the postoperative histopathological findings or with 12-month follow-up results as the standard of reference. RESULTS: The sensitivity/specificity/and accuracy of CT, MRI, and PET-CT for the detection of primary site recurrence was 89.9/85.7/89.3%, 94.9/85.7/93.6%, and 97.5/92.9/96.8%, respectively. The sensitivity/specificity/accuracy of CT, MRI, and PET-CT for the detection of nodal recurrence was 66.3/99.4/92.4%, 74.7/99.4/94.2%, and 85.5/94.9/93.0%, respectively. MRI + PET-CT achieved the best performance in the receiver operating characteristics curve analysis (Az value = 0.958 for primary site recurrence and 0.929 for nodal recurrence). CONCLUSION: MRI + PET-CT offered the highest diagnostic performance in the detection of loco-regional recurrence of malignant head and neck tumor, compared with CT, MRI, PET-CT, and other combinations including CT.

The 100 top-cited articles focused on magnetic resonance: a bibliometric analysis.

BACKGROUND: The number of citations that an article has received can be used to evaluate its impact on a particular research area. PURPOSE: The aim of this study was to identify and characterize the 100 top-cited articles focused on magnetic resonance (MR). MATERIAL AND METHODS: We determined the 100 top-cited articles on MR via the Scopus database, using the search term. The following information was recorded for each article: year of publication; journal title; impact factor of journal; number of citations; number of annual citations; authorship; department; institution; country; type of article; topic; MR protocol; and disease. RESULTS: The number of citations for the 100 top-cited articles was in the range of 898-5679 (median = 1342.5) and the number of annual citations was in the range of 19.7-372.4 (median = 60.9). The 100 top-cited articles were published in 46 journals, led by Magnetic Resonance in Medicine (n = 13). The majority of articles were published in 1990-1999 (n = 53), originated in the United States (n = 69), were original articles (n = 81), and dealt with the clinical application of MR (n = 57). The Department of Radiology, Massachusetts General Hospital (n = 5) was the leading institution. The majority of articles did not use any specific protocol (n = 51) and was not associated with any specific disease (n = 56). CONCLUSION: Our study presents a detailed list and analysis of the 100 top-cited articles on MR, which provides an insight into historical development in this field.

A hybrid operating room for combined surgical and endovascular procedures for cerebrovascular diseases: a clinical experience at a single centre.

Purpose: To describe our experiences with a fully equipped high-end digital subtraction angiography (DSA) system within a hybrid operating room (OR). Material and methods: A single-plane DSA system with 3-dimensional rotational angiography (3DRA), cone-beam computed tomography, and real-time navigation software was used in our hybrid OR. Between April 2014 and January 2018, 191 sessions of neurovascular procedures were performed in our hybrid OR. After the retrospective review of all cases, the procedures were categorised into five subcategorical procedures according to the dominance of surgical and/or endovascular procedures: intraoperative angiographic evaluation, combined endovascular and surgical procedure, complementary rescue procedure during intervention and surgery, surgical approach for interventional procedure, and frameless stereotaxic operation. Results: Intraoperative angiography revealed unsatisfactory clipping of intracranial aneurysms in 6 (13.6%) patients and remnant AVMs in 1 (16.7%) patient, which were determined as complete surgical outcome via indocyanine green videoangiography. Four cases of blood blister aneurysms and a ruptured posterior inferior cerebellar artery aneurysm were treated using bypass surgery and endovascular trapping. Eight cases of ruptured aneurysm with intracranial haemorrhage (ICH) were treated by partial embolisation and surgical clipping. Two (5.4%) of the 37 cases of pre-mature rupture during clipping were secured by endovascular coil embolisation. In 1 (0.8%) complicated case of 103 intra-arterial (IA) thrombectomy procedures, emergency surgical embolectomy with bypass surgery was performed. Direct puncture of the common carotid artery or vertebral artery was performed to achieve interventional access to treat aneurysm or recanalise vessel occlusions in 7 cases. In 27 cases of ICH, frameless stereotaxic haematoma aspiration was performed using XperGuide® system. All procedures were performed in single sessions without any procedural complications. Conclusion: Hybrid OR with a fully equipped DSA system could provide safe and precise treatment for neurovascular diseases. Hybrid procedures for neurovascular diseases in hybrid OR are a promising new trend.

Quantitative analysis of cochlear signal intensity on three-dimensional and contrast-enhanced fluid-attenuated inversion recovery images in patients with Meniere's disease: Correlation with the pure tone audiometry test.

PURPOSE: The purpose of this study was to correlate the quantitative analysis of cochlear signal intensity (SI) on 3-dimensional fluid-attenuated inversion recovery (3D-FLAIR) and contrast-enhanced (CE) 3D-FLAIR images with results of the pure tone audiometry (PTA) test in patients with Meniere's disease (MD). MATERIALS AND METHODS: Over a 3-year period, 123 patients with MD underwent 3-Tesla (3 T) temporal magnetic resonance imaging (MRI), including 3D-FLAIR and CE-FLAIR sequences. The SI of membranous labyrinth of the cochlea in both ears of each patient was measured by drawing a region of interest (ROI) with a seed growing technique. The correlation between measured cochlear SIs on 3D-FLAIR and CE-FLAIR images, contrast enhancement index (CEI), and contrast enhancement ratio (CER) and clinical findings and pre- and post-treatment PTA results were assessed. RESULTS: Cochlear signal ratios of symptomatic ears on 3D-FLAIR and CE-FLAIR images were significantly higher than those of asymptomatic ears (P < 0.001). The area under the curve, from the receiver operating characteristic curve of cochlear SIs on 3D-FLAIR and CE-FLAIR images for discrimination between symptomatic and asymptomatic ears, was 0.729 and 0.728, respectively. Cochlear SIs on 3D-FLAIR and CE-FLAIR images were significantly correlated with patients' sex (P < 0.05 and P < 0.01, respectively), symptomatic ear (both P < 0.0001), and pre-treatment PTA (P < 0.0001 and P < 0.005, respectively), but were not significantly correlated with patients' age, post-treatment PTA or hearing threshold level at 0.5, 1.0, 2.0, or 4.0 kHz. CONCLUSION: Quantitative analysis of cochlear SI on 3D-FLAIR and CE-FLAIR images may be a helpful diagnostic adjunct for MD, but may be of little value in predicting the prognosis of MD.

The blind pushing technique for peripherally inserted central catheter placement through brachial vein puncture.

OBJECTIVE: The objective of this study was to conduct a prospective clinical trial evaluating the technical feasibility and short-term clinical outcome of the blind pushing technique for placement of pretrimmed peripherally inserted central catheters (PICCs) through brachial vein access. METHODS: Patients requiring PICC placement at any of the three participating institutions were prospectively enrolled between January and December 2016. The review boards of all participating institutions approved this study, and informed consent was obtained from all patients. PICC placement was performed using the blind pushing technique and primary brachial vein access. The following data were collected from unified case report forms: access vein, obstacles during PICC advancement, procedure time, and postprocedural complications. RESULTS: During the 12-month study period, 1380 PICCs were placed in 1043 patients. Of these, 1092 PICCs placed in 837 patients were enrolled, with 834 PICCs (76%) and 258 PICCs (34%) placed through brachial vein and nonbrachial vein access, respectively. In both arms, obstacles were most commonly noted in the subclavian veins (n = 220) and axillary veins (n = 94). Successful puncture of the access vein was achieved at first try in 1028 PICCs (94%). The technical success rate was 99%, with 1055 PICCs (97%) placed within 120 seconds of procedure time and 1088 PICCs (99%) having the tip located at the ideal position. Follow-up Doppler ultrasound detected catheter-associated upper extremity deep venous thrombosis (UEDVT) for 18 PICCs in 16 patients and late symptomatic UEDVT for 16 PICCs in 16 patients (3.1%). Catheter-associated UEDVT was noted for 28 PICCs (82%) and 6 PICCs (18%) placed through brachial vein and nonbrachial vein access, respectively. The incidence of obstacles and the procedure time (<120 seconds) differed significantly between brachial vein and nonbrachial vein access (P = .001). There was no statistically significant difference between brachial vein and nonbrachial vein access in the incidence of UEDVT (odds ratio, 0.68; 95% confidence interval, 0.59-3.52; P = .22). CONCLUSIONS: The placement of pretrimmed PICCs by the blind pushing technique and primary brachial vein access is technically feasible and may represent an alternative to the conventional PICC placement technique, having low incidences of UEDVT and other complications, with no significant difference in outcomes between brachial vein and nonbrachial vein access.

The most downloaded and most cited articles in radiology journals: a comparative bibliometric analysis.

OBJECTIVES: To evaluate and compare the characteristics of the most downloaded and most cited articles in radiology journals. METHODS: We selected 41 radiology journals that provided lists of both the most downloaded and most cited articles on their websites, and identified the 596 most downloaded articles and 596 most cited articles. We compared the following characteristics of the most downloaded and most cited articles: year of publication, journal title, department of the first author, country of origin, publication type, radiologic subspecialty, radiologic technique and accessibility. RESULTS: Compared to the most cited articles, the most downloaded articles were more frequently review articles (36.1% vs 17.1%, p < 0.05), case reports (5.9% vs 3.2%, p < 0.05), guidelines/consensus statements (5.4% vs 2.7%, p < 0.05), editorials/commentaries (3.7% vs 0.7%, p < 0.05) and pictorial essays (2.0% vs 0.2%, p < 0.05). Compared to the most cited articles, the most downloaded articles more frequently originated from the UK (8.7% vs 5.0%, p < 0.05) and were more frequently free-access articles (46.0% vs 39.4%, p < 0.05). CONCLUSION: Educational and free-access articles are more frequent among the most downloaded articles. KEY POINTS: • There was only small overlap between the most downloaded and most cited articles. • Educational articles were more frequent among the most downloaded articles. • Free-access articles are more frequent among the most downloaded articles.

Transcervical access via direct neck exposure for neurointerventional procedures in the hybrid angiosuite.

PURPOSE: A complicated course of the femoral route for neurointervention can prevent approaching the target. Thus, we determined whether transcervical access in the hybrid angiosuite is applicable and beneficial in real practice. METHODS: From January 2014 to March 2017, this approach was used in 17 of 453 (3.75%) cases: 11 cerebral aneurysms (4 ruptured, 7 unruptured), 4 acute occlusions of the large cerebral artery, 1 proximal internal carotid artery (ICA) stenosis, and 1 direct carotid cavernous fistula (CCF). RESULTS: All patients were elderly (mean age, 78.1 years). The main cause was severe tortuosity of the supra-aortic course or the supra-aortic and infra-aortic courses (eight and five cases, respectively), orifice disturbance (three cases), and femoral occlusion (one case). Through neck dissection, 6-8Fr guiding catheters were placed via subcutaneous tunneling to enhance device stability and support. All cerebral aneurysms were embolized (eight complete and three neck remnants) using the combination of several additional devices. Mechanical stent retrieval with an 8Fr balloon guiding catheter was successfully achieved in a few runs (mean, 2 times; range, 1-3) within the proper time window (mean skin to puncture, 17 ± 4 min; puncture to recanalization, 25 ± 4 min). Each stent was satisfactorily deployed in the proximal ICA and direct CCF without catheter kick-back. All puncture sites were closed through direct suturing without complications. CONCLUSIONS: In the hybrid angiosuite, transcervical access via direct neck exposure is feasible in terms of device profile and support when the femoral route has an unfavorable anatomy.

Intraobserver and Interobserver Variability in Ultrasound Measurements of Thyroid Nodules.

OBJECTIVES: The purpose of this study was to assess the intraobserver and interobserver variability in ultrasound (US) measurements of thyroid nodules. METHODS: We performed a prospective study of the US examinations of 73 patients with 122 thyroid nodules greater than 5 mm in size. Ultrasound measurements in 4 dimensions (anteroposterior, transverse, longitudinal, and maximum diameters) and measurement of the estimated volume (using the ellipsoid formula) of each thyroid nodule were performed twice by 2 independent radiologists (A and B, with 10 years and 6 months of experience, respectively). The intraobserver and interobserver variability in measurements of thyroid nodules was assessed by a Bland-Altman analysis of agreement. The absolute values for intraobserver and interobserver variability were compared by a paired t test. RESULTS: The 95% intraobserver and interobserver limits of agreement for the anteroposterior, transverse, longitudinal, and maximum diameters and estimated volume of thyroid nodules were ±18.2%, ± 14.3%, and ±21.0%; ± 17.2%%, ± 17.3%, and 18.2%; ± 14.6%, ± 15.5%, and ±22.3%; ± 13.8%, ± 15.5%, and ±19.6%; and ±30.2%, ± 27.7%, and ±44.1%, respectively. The absolute values for intraobserver variability were lower than those for interobserver variability for all measurements. CONCLUSIONS: There was considerable intraobserver and interobserver variability in US measurement of thyroid nodules, which must be taken into account during follow-up US examinations of patients with thyroid nodules.