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Leiomyosarcoma (LMS) is a smooth muscle-derived malignant mesenchymal tumour. Primary LMS arising from the ovarian vein is uncommon. A 51-year-old female presented with left loin pain and was diagnosed with a LMS arising from the gonadal vein. The patient refused any treatment. Early detection and timely diagnosis of retroperitoneal masses will improve the prognosis and survival rate in these patients. CT imaging plays an important role in diagnosis. Contribution: Retroperitoneal leiomyosarcoma of vascular origin is a rare entity. CT plays crucial role in diagnosing them by demonstrating the extent of the tumor along the gonadal vein. Early detection and timely diagnosis of retroperitoneal masses will improve the prognosis and survival rate in these patients.

Thyroid isthmus lesions are generally small sized and can be solid or cystic. Discerning isthmic origin of a large nodule, especially if purely cystic, can become a diagnostic challenge because of thin thyroid tissue in it. We report a case of a 68-year-old male patient who had 6 weeks history of non- inflammatory central neck swelling associated with recent dysphagia, for which he underwent ultrasound and computed tomography (CT) scan examinations. Colloid nodules usually do not require further attention. Despite being commonest and benign thyroid nodules, they may require treatment if causing pressure symptoms. Its imaging characteristics can be variable, but they usually exhibit comet tail artifacts on ultrasound. In equivocal cases, claw sign on CT scan is diagnostic to confirm the site. Radiologists have a principle role to rule out other differentials of cystic neck lesions by careful examination of imaging features. In our case, CT scan allowed to rule out primary differential of thyroglossal cyst and guided clinicians for specific management plan.

Background: Mechanical thrombectomy (MT) is an effective treatment for acute cerebral large vessel occlusion (LVO). Complete recanalization of vessels in a single procedure is defined as the first-pass effect (FPE) and is associated with good prognosis. In this study, angiographic clot protruding sign termed the "claw sign," was examined as candidate preoperative imaging factor for predicting the FPE. Methods: We retrospectively analyzed data from 91 consecutive patients treated for acute LVO in the anterior circulation by MT between January 2014 and December 2019. The claw sign was defined as a thrombus that protruded proximally by more than half of the diameter of the parent artery. Radiological findings such as claw sign, clinical and etiological features, and outcomes were compared between groups with and without successful FPE. Multivariate analysis was conducted to evaluate perioperative factors associated with FPE. Results: FPE was achieved in 26 of 91 (28.6%) patients and the claw sign was observed in 34 of 91 (37.4%) patients. The claw sign was significantly more frequent in the successful FPE group than in the failed FPE group (53.8% vs. 30.8%; P = 0.040). After the multivariate analysis, the claw sign was the only pretreatment parameter that could predict FPE (odds ratio, 2.67; 95% confidence interval, 1.01--7.06; P = 0.047). Conclusion: The claw sign is an angiographic imaging factor that might predict FPE after MT for anterior circulation acute ischemic stroke. [ABSTRACT FROM AUTHOR]

Background: Mechanical thrombectomy (MT) is an effective treatment for acute cerebral large vessel occlusion (LVO). Complete recanalization of vessels in a single procedure is defined as the first-pass effect (FPE) and is associated with good prognosis. In this study, angiographic clot protruding sign termed the "claw sign," was examined as candidate preoperative imaging factor for predicting the FPE. Methods: We retrospectively analyzed data from 91 consecutive patients treated for acute LVO in the anterior circulation by MT between January 2014 and December 2019. The claw sign was defined as a thrombus that protruded proximally by more than half of the diameter of the parent artery. Radiological findings such as claw sign, clinical and etiological features, and outcomes were compared between groups with and without successful FPE. Multivariate analysis was conducted to evaluate perioperative factors associated with FPE. Results: FPE was achieved in 26 of 91 (28.6%) patients and the claw sign was observed in 34 of 91 (37.4%) patients. The claw sign was significantly more frequent in the successful FPE group than in the failed FPE group (53.8% vs. 30.8%; P = 0.040). After the multivariate analysis, the claw sign was the only pretreatment parameter that could predict FPE (odds ratio, 2.67; 95% confidence interval, 1.01-7.06; P = 0.047). Conclusion: The claw sign is an angiographic imaging factor that might predict FPE after MT for anterior circulation acute ischemic stroke. [ABSTRACT FROM AUTHOR]

Background: The claw sign is advocated as a discriminant of renal versus non-renal origin of tumours. The accuracy of the claw sign on magnetic resonance imaging (MRI) is unknown and is potentially hindered by the inferior spatial resolution and the larger tumour sizes at presentation in developing countries. Objectives: To define and evaluate the claw sign in differentiating renal from non-renal retroperitoneal masses in children undergoing MRI. Methods: A definition of the claw sign was proposed. Magnetic resonance imaging studies, clinical and laboratory records of 53 children were reviewed to test the diagnostic accuracy, inter- and intra-observer reliability. Three tumour–mass interface characteristics, inherent to the claw sign, were tested: (1) a smooth tapering kidney edge blending continuously with the tumour, (2) absence of infolding of the kidney and (3) an obtuse superficial angle. Results: The sensitivity, specificity, negative predictive value and positive predictive values of the claw sign were 97%, 74%, 83% and 94%. The Cohen’s kappa values for intra-rater reliability were 0.72 (95% confidence interval 0.54–0.86) for the first reader and 0.83 (0.66–1.00) for the second reader. The Cohen’s kappa values for inter-rater reliability were 0.67 (0.50–0.85) and 0.65 (0.44–0.86) for the second reading respectively (p 0.0001). Conclusion: The three tumour–mass interface characteristics investigated are all important characteristics of the claw sign. Intra- and inter-rater reliability is moderate to strong for all characteristics and overall impression of the claw sign. The claw sign is therefore sensitive in the accurate placement of an intra-renal mass but lacks specificity.

Background: The claw sign is advocated as a discriminant of renal versus non-renal origin of tumours. The accuracy of the claw sign on magnetic resonance imaging (MRI) is unknown and is potentially hindered by the inferior spatial resolution and the larger tumour sizes at presentation in developing countries. Objectives: To define and evaluate the claw sign in differentiating renal from non-renal retroperitoneal masses in children undergoing MRI. Methods: A definition of the claw sign was proposed. Magnetic resonance imaging studies, clinical and laboratory records of 53 children were reviewed to test the diagnostic accuracy, inter- and intra-observer reliability. Three tumour-mass interface characteristics, inherent to the claw sign, were tested: (1) a smooth tapering kidney edge blending continuously with the tumour, (2) absence of infolding of the kidney and (3) an obtuse superficial angle. Results: The sensitivity, specificity, negative predictive value and positive predictive values of the claw sign were 97%, 74%, 83% and 94%. The Cohen's kappa values for intra-rater reliability were 0.72 (95% confidence interval 0.54-0.86) for the first reader and 0.83 (0.66-1.00) for the second reader. The Cohen's kappa values for inter-rater reliability were 0.67 (0.50-0.85) and 0.65 (0.44-0.86) for the second reading respectively (p < 0.0001). Conclusion: The three tumour-mass interface characteristics investigated are all important characteristics of the claw sign. Intra- and inter-rater reliability is moderate to strong for all characteristics and overall impression of the claw sign. The claw sign is therefore sensitive in the accurate placement of an intra-renal mass but lacks specificity. [ABSTRACT FROM AUTHOR]

Background: Mechanical thrombectomy (MT) is an effective treatment for acute cerebral large vessel occlusion (LVO). Complete recanalization of vessels in a single procedure is defined as the first-pass effect (FPE) and is associated with good prognosis. In this study, angiographic clot protruding sign termed the "claw sign," was examined as candidate preoperative imaging factor for predicting the FPE., Methods: We retrospectively analyzed data from 91 consecutive patients treated for acute LVO in the anterior circulation by MT between January 2014 and December 2019. The claw sign was defined as a thrombus that protruded proximally by more than half of the diameter of the parent artery. Radiological findings such as claw sign, clinical and etiological features, and outcomes were compared between groups with and without successful FPE. Multivariate analysis was conducted to evaluate perioperative factors associated with FPE., Results: FPE was achieved in 26 of 91 (28.6%) patients and the claw sign was observed in 34 of 91 (37.4%) patients. The claw sign was significantly more frequent in the successful FPE group than in the failed FPE group (53.8% vs. 30.8%; P = 0.040). After the multivariate analysis, the claw sign was the only pretreatment parameter that could predict FPE (odds ratio, 2.67; 95% confidence interval, 1.01-7.06; P = 0.047)., Conclusion: The claw sign is an angiographic imaging factor that might predict FPE after MT for anterior circulation acute ischemic stroke., Competing Interests: There are no conflicts of interest., (Copyright: © 2022 Surgical Neurology International.)

Background: The claw sign is advocated as a discriminant of renal versus non-renal origin of tumours. The accuracy of the claw sign on magnetic resonance imaging (MRI) is unknown and is potentially hindered by the inferior spatial resolution and the larger tumour sizes at presentation in developing countries., Objectives: To define and evaluate the claw sign in differentiating renal from non-renal retroperitoneal masses in children undergoing MRI., Methods: A definition of the claw sign was proposed. Magnetic resonance imaging studies, clinical and laboratory records of 53 children were reviewed to test the diagnostic accuracy, inter- and intra-observer reliability. Three tumour-mass interface characteristics, inherent to the claw sign, were tested: (1) a smooth tapering kidney edge blending continuously with the tumour, (2) absence of infolding of the kidney and (3) an obtuse superficial angle., Results: The sensitivity, specificity, negative predictive value and positive predictive values of the claw sign were 97%, 74%, 83% and 94%. The Cohen's kappa values for intra-rater reliability were 0.72 (95% confidence interval 0.54-0.86) for the first reader and 0.83 (0.66-1.00) for the second reader. The Cohen's kappa values for inter-rater reliability were 0.67 (0.50-0.85) and 0.65 (0.44-0.86) for the second reading respectively ( p < 0.0001)., Conclusion: The three tumour-mass interface characteristics investigated are all important characteristics of the claw sign. Intra- and inter-rater reliability is moderate to strong for all characteristics and overall impression of the claw sign. The claw sign is therefore sensitive in the accurate placement of an intra-renal mass but lacks specificity., Competing Interests: The authors declare that they have no financial or personal relationships that may have inappropriately influenced them in writing this research article., (© 2021. The Authors.)

The article describes the claw sign seen on a radiological image when a lesion arises within a preexisting organ and expands towards the surface of the organ, thinning the parenchyma between it and the surface. The sign can be useful in determining whether a lesion arises adjacent to or within an organ. The claw sign can be seen throughout the body and in intussusception.

Background: In 1988, Modic and his colleagues described changes in the subchondral bone marrow of the vertebral plates in patients with degenerative disease or other pathologies, which were observed in the nuclear magnetic resonance (NMR) of the spine and were subdivided into three patterns of signal changes, called Modic type I, Modic type II and Modic type III. The main differential diagnosis of the Modic I changes of the vertebral plates due to degenerative disease in spine NMR, is infection in its early stages. In their study in 2014, Patel and collaborators, using a protocol and the concept of diffusion in spine MRI, were able to demonstrate that by means of the "claw sing", a degenerative disease with Modic type I changes, can be differentiated from an infection in early stages. In this series of cases, the algorithm used by Patel et al. was implemented., Methods: The clinical records of patients who consulted the emergency department for lumbar pain without clear etiology, between January 1, 2017 and December 31, 2017, were analyzed. Due to axial lumbar pain, subjects were hospitalized and studies were ordered, including contrasted MRI of the lumbosacral spine. Then, with laboratory tests and MRI findings of Modic type I changes, it was not possible to differentiate between degenerative disease vs. spondylodiscitis. Therefore, the algorithm used in the study by Patel and collaborators was applied., Results: There were 13 patients identified with lumbar or dorsal pain over 3 months of evolution, with nonspecific symptoms; 5 patients (38.46%) reported arterial hypertension, 4 patients (30.77%) diabetes mellitus, and 4 patients (30.77%) chronic kidney disease stage V in management with hemodialysis, 3 patients (23.08%) presented immunosuppressive conditions and 3 patients (23.08%) had a history of spinal surgery with instrumentation. All the patients were hospitalized and a lumbosacral and thoracic spine simple MRI was performed with Modic type I changes to perform contrast-enhanced MRI with diffusion and ADC. From the 13 cases studied for low back pain, there were 7 patients (53.85%) with confirmed findings of Modic type I changes due to degenerative disease for presenting claw sign in spinal MRI diffusion and 6 patients (46.15%) Modic type changes I due to infection in the absence of a claw sign in the column MRI diffusion., Conclusions: Spinal column MRI with diffusion is useful to differentiate patients with type I changes due to degenerative disease with positive claw sign; of patients with type I changes due to infection with absent claw sign. In addition, in patients with compromised renal function, column MRI with diffusion without contrast could be a diagnostic alternative, since it does not require contrast media to confirm infection., Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare.