Deep CNN-Based Static Modeling of Soft Robots Utilizing Absolute Nodal Coordinate Formulation.

Soft continuum robots, inspired by the adaptability and agility of natural soft-bodied organisms like octopuses and elephant trunks, present a frontier in robotics research. However, exploiting their full potential necessitates precise modeling and control for specific motion and manipulation tasks. This study introduces an innovative approach using Deep Convolutional Neural Networks (CNN) for the inverse quasi-static modeling of these robots within the Absolute Nodal Coordinate Formulation (ANCF) framework. The ANCF effectively represents the complex non-linear behavior of soft continuum robots, while the CNN-based models are optimized for computational efficiency and precision. This combination is crucial for addressing the complex inverse statics problems associated with ANCF-modeled robots. Extensive numerical experiments were conducted to assess the performance of these Deep CNN-based models, demonstrating their suitability for real-time simulation and control in statics modeling. Additionally, this study includes a detailed cross-validation experiment to identify the most effective model architecture, taking into account factors such as the number of layers, activation functions, and unit configurations. The results highlight the significant benefits of integrating Deep CNN with ANCF models, paving the way for advanced statics modeling in soft continuum robotics.

Preoperative Determination of Depth of Invasion in Oral Cavity Squamous Cell Carcinoma by Standard Cross-Sectional Imaging With Computed Tomography and Positron Emission Tomography/Computed Tomography.

Background Depth of invasion (DOI) is a known indicator of metastatic potential in oral cavity squamous cell carcinoma (SCC). Our purpose was to investigate the accuracy of preoperative determination of DOI in oral cavity SCC by computed tomography (CT) and positron emission tomography/computed tomography (PET/CT). Methodology A retrospective study was performed using consecutive patients with histologically proven oral cavity SCC presenting to our otorhinolaryngology department between January 2014 and July 2019 who underwent preoperative contrast-enhanced CT and/or PET/CT. Pathological assessment of DOI was determined by a review of pathology reports. The degree of DOI determined by radiographic studies was correlated to pathology results. Results A total of 79 patients were screened of whom appropriate radiographic studies were available for 63 patients. The mean DOI by pathological assessment was 12.3 ± 9.1 mm. CT and PET/CT determined depth both correlated with pathological DOI (r = 0.710; p < 0.001, r = 0.798; p < 0.001). No significant correlation was seen for CT-determined depth (r = 0.136; p = 0.709) or PET-determined depth (r = 0.234; p = 0.707) with pathologically confirmed superficial tumors (<5 mm). For patients with pathological tumor depth >10 mm, CT and PET determined depth both correlated with pathological depth (r = 0.577; p = 0.002, r = 0.668; p = 0.001). The sensitivity and specificity of CT and PET for the identification of deep invasion were 88.2% and 41.7% and 52.9% and 50%, respectively. Conclusions DOI measurement is feasible with routine preoperative CT and PET/CT images and is comparable to pathological measurement in patients with oral cavity SCC.

Erratum to "Late magnetic resonance imaging findings in trauma-induced central diabetes insipidus: Case report and review of literature" [Radiology Case Reports 16 (2021) 1514-1517].

[This corrects the article DOI: 10.1016/j.radcr.2021.03.048.].

Autoincudotomy as an uncommon etiology of conductive hearing loss: Case report and review of literature.

Ossicular pathology is a recognized etiology of conductive hearing loss. Ossicular pathology includes 2 main categories, that is, ossicular chain fixation and ossicular discontinuity. Ossicular discontinuity can be congenital or acquired. Auto-incudotomy is an uncommon form of acquired ossicular discontinuity that usually occurs as a sequel of spontaneous expulsion of cholesteatoma. Typically, it manifests with conductive hearing loss without evidence of cholesteatoma. In this report, we presented CT imaging finding of a 34-year-old male with tympanic membrane perforation and defective long process of the incus (auto-incudotomy) with minimal middle ear granulation tissue and adhesions, sequela of cholesteatoma. Radiologists should pay attention for evaluation of ossicles especially in patients presented with conductive hearing loss.

Cross-sectional imaging evaluation of atypical and uncommon extra-nodal head and neck Non-Hodgkin lymphoma: Case series.

Extra-nodal Non-Hodgkin lymphoma (ENHL) of the head and neck is not uncommon and has variable clinical and imaging presentations. It represents about 25% of extra-nodal lymphomas. In addition, lymphoma is the third most common malignancy of the head and neck just after squamous cell carcinoma (SCC) and salivary gland neoplasms. Unlike SCC, ENHL usually presents as a well-defined mass in the oral cavity, along the pharyngeal mucosa, sinonasal cavity, orbit, and other different neck spaces. One of the common presentations of ENHL is the glandular type which can arise within the salivary or thyroid glands as marginal zone non-Hodgkin lymphoma. ENHL can infiltrate the bone resembling high grade osseous malignancies. Rarely, ENHL can present as perineural spread without definitive mass and manifest clinically with several neuropathies. In this case series, we presented different imaging features and presentation of ENHL of the head and neck. The knowledge of various presentations of ENHL of the head and neck can help early diagnosis and prompt management of these patients' population.

Effect of Percutaneous Inferior Sympathetic Ganglion Block on Medium-Sized Intracranial Artery Diameters on Cerebral Angiography.

BACKGROUND: Some data suggest a vasodilatory effect of sympathetic blockade in patients with aneurysmal subarachnoid hemorrhage, but the effect on medium-sized intracranial arteries remains unclear. We report the results of serial cerebral angiography to study the cerebral vasodilatory effects of percutaneous inferior sympathetic ganglion block in 2 patients. METHODS: Serial ipsilateral intracranial angiograms were obtained before and after percutaneous inferior sympathetic ganglion block and were imported to a DICOM reader, Horos Open-Source Medical Image Viewer (version 3.3.6). The percent change of arterial diameter was calculated in the intracranial internal carotid artery (ICA), middle carotid artery (MCA), and anterior cerebral artery (ACA). We assessed the interobserver reliability using the Bland-Altman method. RESULTS: In Patient 1, there was an average increase in diameter of intracranial ICA and MCA at 1 minute, 5 minutes, and 10 minutes, with a relative decrease in the diameter of the ACA. In Patient 2, there was an average relative increase in diameter of intracranial ICA and MCA at 1 minute, 5 minutes, 10 minutes, 20 minutes, and 30 minutes, with a relative increase in diameter at 5 minutes, 10 minutes, and 30 minutes in the ACA. The Bland-Altman coefficient of variation was -5.35 (range -0.44 to 0.28) with all the data points within the 98% upper and lower limits of acceptance. CONCLUSIONS: We observed vasodilation in medium-sized intracranial arteries ipsilateral to the percutaneous inferior sympathetic ganglion block as early as 1 minute post treatment and persisting for at least until 30 minutes post blockade.

Hemorrhagic stroke: Uncommon complication of diabetic ketoacidosis in pediatric patients.

Diabetic ketoacidosis (DKA) is a well-known complication of type 1 diabetes mellitus. Diabetic ketoacidosis predisposes patients into devastating neurological complications. The most common neurologic complication is cerebral edema. Stroke either ischemic or hemorrhagic are uncommon complications of DKA with worse patient's outcome. Hemorrhagic stroke can manifest as subarachnoid or intraparenchymal hemorrhage. We present a 14-year-girl presented with DKA and complicated with both subarachnoid and intraparenchymal hemorrhages. Owing to early diagnosis and prompt treatment the patient had good outcome.

Atypical and uncommon presentation of sarcoidosis with long segment involvement of the pharynx and larynx: Case report and review of literature.

Pharynx/Larynx is an uncommon site of involvement of sarcoidosis. Isolated pharyngo-laryngeal sarcoidosis is extremely rare as most of the cases are part from multiorgan and systemic sarcoidosis. Pharyngo-laryngeal sarcoidosis is usually asymptomatic which could be attributed to its rare incidence as many cases pass unnoticed. Symptomatic cases usually present with hoarseness of voice. As the disease progress, the patient can present with progressive dysphagia to solid and liquid with globus sensation. We described an atypical involvement of almost the whole length of the pharynx with extension into the larynx in a 51-year-old woman who presented with progressive dysphagia. To the best of our knowledge, this is the first report to describe the imaging features of sarcoidosis involvement of the pharynx and larynx.

Superior mesenteric artery thrombosis and small bowel necrosis: An uncommon thromboembolic manifestation in COVID-19 pneumonia.

Thromboembolism is a recognized complication in patients with COVID-19 infection. It is believed that coagulopathy results secondary to severe inflammatory response syndrome with release of cytokines, viral activation of coagulation cascade or viral related vasculitis. Both arterial and venous thromboembolic complications have been described, however venous thromboembolic complications are much far common. We present an uncommon thromboembolic complication of the superior mesenteric artery in a 49-year-old male with COVID-19 pneumonia. The patient also developed segmental infarct of his renal transplant. Patients with SARS-COV-2 infection should be closely evaluated and monitored for the development of thromboembolic complications. Prompt evaluation with CT angiography of suspected thromboembolism could help early diagnosis and treatment which can reflect better patients' outcomes.

Solitary fibrous tumors: Clinical and imaging features from head to toe.

Solitary fibrous tumors (SFTs) are rare fibroblastic mesenchymal tumors that are usually benign with variable malignant potential. They can develop in any organ due to their spindle cell origin. The exact etiology of solitary fibrous tumors is unknown. The majority of SFTs are benign with 10-30% of them exhibiting aggressive and malignant features. The aggressiveness of this type of tumor is not associated with its histological features, which makes surgical resection the treatment of choice. We will review the clinical and radiological features and possible differential diagnoses of SFTs according to their anatomical sites following the World Health Organization 2020 classification.

Identification of novel missense mutation in a patient with an asymptomatic para-aortic paraganglioma.

A 31-year-old Caucasian woman underwent a standard workup as a potential kidney transplant donor. Kidney donor protocol CT showed a left para-aortic hypervascular mass suspicious for a paraganglioma. Biochemical workup revealed elevated urinary catecholamines, supporting this suspicion. The patient underwent surgical resection with histopathological evaluation that confirmed the diagnosis. Endocrine evaluation 2 years later revealed a family history of a cousin with a history of pheochromocytoma as a teenager. A genetic panel identified a missense mutation in succinate dehydrogenase C (c.202T>C; p.Ser68Pro), which was described as a variant of unknown significance. In silico analysis suggested that it may be a deleterious mutation. We concluded that this mutation may be pathogenic, considering these supporting pieces of evidence and her early-onset paraganglioma. This report highlights the importance of genetic screening in patients with paragangliomas/pheochromocytomas, since many cases are familial. Additionally, it underscores the importance of evaluating and documenting cases of variants of unknown significance.

Clinical utility of fetal echocardiography: an Egyptian center experience.

BACKGROUND: The impact of early diagnosis of fetal cardiac abnormalities on the postnatal outcome has been controversial in literature. We aimed to evaluate the role of fetal echocardiography (FE) as a diagnostic tool for early detection and proper management of fetal cardiac abnormalities, study the indications of referral and detect the perinatal outcome in our institution. RESULTS: This is a cross-sectional observational and descriptive study that included one hundred and one singleton pregnant women (101 fetuses) who were referred for FE over a period of one year. Indications for referral and perinatal risk factors were documented. FE and postnatal transthoracic echocardiography were done. Fetal cardiac abnormalities were detected in 46.5% of cases. Congenital heart defects (CHDs) in 34.6%, fetal arrythmias in 9.9%, cardiomyopathy in 2.9% and cardiac mass (Rhabdomyoma) in 1% (combined structural and rhythm abnormalities were observed in two fetuses). Of the CHDs, complex heart lesions were diagnosed in 57.1%, common atrioventricular canal in 28.6% and conotrunchal anomalies in 14.3%. Of the ten cases with fetal arrythmias, five fetuses had tachyarrhythmias, four had ectopics and one fetus had congenital heart block in association with maternal lupus. The indications for referral were abnormal obstetric ultrasound (52.5%), maternal medical illnesses (23.8%), multiple neonatal deaths (13.9%) and positive family history of CHD (10.9%). The number of fetuses with cardiac abnormalities was significantly higher than those without cardiac abnormalities in mothers not exposed to perinatal risk factors (p = 0.009) and was statistically lower in mothers exposed to perinatal risk factors (p = 0.005). FE showed 100% accuracy in diagnosing complex lesions, common atrio-ventricular canals, cono-truncal anomalies, cardiac masses and fetal arrhythmias. It missed two cases of tiny muscular ventricular septal defects and one case of aortic coarctation. Cases of fetal supraventricular tachycardia were successfully treated in-utero. CONCLUSIONS: CHDs exist in fetuses with no underlying perinatal risk factors. FE can accurately diagnose most of the cardiac anomalies though few errors remain challenging (aortic coarctation). It also offers a good chance for successful early life-saving management of some types of fetal arrhythmia.

Reliability of Magnetic Resonance Spectroscopy and Positron Emission Tomography Computed Tomography in Differentiating Metastatic Brain Tumor Recurrence from Radiation Necrosis.

BACKGROUND: Clinical and/or neuroimaging changes after whole-brain radiation therapy (WBRT) or stereotactic radiosurgery (SRS) for metastatic brain tumor(s) present the clinical dilemma of differentiating tumor recurrence from radiation necrosis. Several imaging modalities attempt to answer this clinical question, including magnetic resonance spectroscopy (MRS) and positron emission tomography (PET) computed tomography (CT). We evaluated our experience regarding the ability of MRS and PET CT to differentiate tumor recurrence from radiation necrosis in patients who have received WBRT or SRS. METHODS: We retrospectively reviewed records of 242 patients with previous WBRT or SRS to identify those who had MRS and/or PET CT to differentiate tumor recurrence from radiation necrosis. Patients were sorted into true-positive, false-positive, false-negative, and true-negative groups on the basis of imaging interpretation and clinical course combined with surgical pathology results or reaction to nonsurgical treatments including SRS, dexamethasone, or observation. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were then calculated. RESULTS: Of 25 patients presenting such diagnostic questions, 19 were evaluated with MRS and 13 with PET CT. MRS sensitivity was 100%, specificity was 50%, and accuracy was 81.8%, whereas PET CT sensitivity was 36.4%, specificity was 66.7%, and accuracy was 42.9%. CONCLUSIONS: MRS has better accuracy than PET CT and a high negative predictive value, therefore making it more useful in distinguishing recurrent tumor from radiation necrosis. We encourage correlation with symptoms at imaging to aid in clinical decision making.

Late magnetic resonance imaging findings in trauma-induced central diabetes insipidus: Case report and review of literature.

We presented the late magnetic resonance imaging characteristics in a 47-year-old male who diagnosed with a permanent trauma-induced diabetes insipidus. The patient developed polyuria following a deceleration injury which has been diagnosed as central diabetes insipidus based on the water deprivation test. Computed tomography or magnetic resonance evaluation of the pituitary gland is usually normal in such cases. Therefore, negative imaging studies do not exclude the diagnosis. However, MRI is more sensitive and can depict subtle injuries of the hypothalamus-pituitary axis in acute and late phases. The late MR imaging findings are not well established. To the best of our knowledge, this will be the first report to describe the late MR imaging features in a permanent case of trauma-induced diabetes insipidus.

Multi-parametric magnetic resonance imaging evaluation of cerebral amyloid angiopathy related inflammation: Case series and review of literature.

Cerebral amyloid angiopathy related inflammation is a rare disorder in the spectrum of cerebral amyloid angiopathy which is characterized by vascular and/or perivascular inflammation related to Aß deposits. Clinically, the patient typically presents with acute to subacute encephalitis-like symptoms with focal neurological deficits, rapidly cognitive decline, and/or seizures. Typical magnetic resonance imaging findings include asymmetric mass-like non-enhancing white matter hyperintensity with scattered microhemorrhages. Additionally, in these cases diffusion weighted imaging, perfusion weighted imaging and magnetic resonance spectroscopy help to exclude neoplastic processes and could determine the correct diagnosis.

Ligament of Treitz: Anatomy, Relevance of Radiologic Findings, and Radiologic-Pathologic Correlation.

OBJECTIVE. The objective of this article is to discuss the anatomy, embryonic origin, normal variants, and various attachments of the ligament of Treitz. We also describe the pathologic processes that develop along the ligament of Treitz and the role of cross-sectional imaging in identifying these conditions. CONCLUSION. The ligament of Treitz, also known as the suspensory ligament of the duodenum, is an important anatomic landmark in the abdomen. It is essential that radiologists understand the anatomic attachments, normal variants, and various pathologic conditions involving the ligament of Treitz as well as the role of cross-sectional imaging in the assessment of these conditions.

A review of anatomy, pathology, and disease spread in the perisplenic region.

The perisplenic region is a complex anatomical area involving multiple peritoneal and subperitoneal structures, which influence the presentation and behavior of various pathologic processes. This review is a comprehensive resource for perisplenic anatomy and pathology with associated clinical presentations and imaging findings. Understanding the pathophysiologic intricacies of the perisplenic region assists the radiologist in building a helpful differential diagnosis and recognizing predictable disease patterns.

Magnetic resonance imaging criteria of immune checkpoint inhibitor-induced hypophysitis.

Autoimmune hypophysitis is a rare complication of immune checkpoint inhibitors. Immune checkpoint inhibitors have been used for advanced stages of melanoma, renal cell carcinoma, and lung cancer. Multiple endocrinopathies, among them hypophysitis, could result as a reverse event from this therapy. MRI is the imaging modality of choice and usually demonstrates pituitary gland hypertrophy, irregular thickening of the pituitary infundibulum, and diffuse enhancement. We present a case of stage IV metastatic renal cell carcinoma complicated with hypophysitis secondary to combined nivolumab and ipilimumab therapy.