Distinct Imaging Features Research Articles

Hypertrophic olivary degeneration following head injury: a case report

BackgroundHypertrophic olivary degeneration (HOD) is a unique type of neuronal degeneration presenting as hypertrophy, in contrast to atrophy as seen in most cases. It presents with classical characteristic clinical features due to involvement of dentate-rubral-olivary pathway, also described as triangle of Guillain and Mollaret formed in midbrain, pons and cerebellum. It can be idiopathic or secondary to infarction, bleeding, tumours, trauma or demyelination. However, the mechanism is still unclear. Herein, we present a case of HOD that had developed after post-traumatic pontine and midbrain haemorrhagic contusion.Case presentationA young male patient presented with progressively increasing tremors of both hands, inability to walk and multiple cranial nerve palsy. Magnetic resonance imaging demonstrated bilateral inferior olivary nucleus enlargement and signal changes seen as T2 and T2-FLAIR hyperintensities and non-enhancing T1 iso-intensities. Based on these features, diagnosis of HOD was made. Patient was kept on conservative management and his condition improved.ConclusionsHypertrophic olivary degeneration is a unique neuronal degeneration with typical clinical manifestations and distinct imaging features. Proper and early recognition and multidisciplinary treatment approach can result in the best outcomes for the patient.

Prognostic implications of distinctive imaging characteristics in primary intracranial germ cell tumors: A retrospective analysis

PurposePrimary central nervous system (CNS) germ cell tumors (GCTs) are rare brain tumors that encompass two subtypes: germinomas and non-germinomatous germ cell tumors (NGGCTs), NGGCTs have less favorable outcome and require multi-modality treatment. Biopsy is recommended for disease diagnosis, the specimen may not adequately reflect the entire tumor. This study aimed to assess distinct imaging characteristics to differentiate between GCT subgroups and to identify possible initial image and subgroup features that influence survival. MethodThis retrospective study, conducted from January 2006 to March 2023, analyzed patient data and MRI findings of primary CNS GCTs. It evaluated tumor characteristics including cysts, seeding, multifocality, and hemorrhage. Tumor volumes and apparent diffusion coefficient (ADC) values of both tumoral and normal-appearing contralateral white matter were measured. These factors were correlated with overall and 5-year survival rates. ResultsThis study included 51 participants with CGTs, comprising 19 germinoma and 32 NGGCTs cases. GCTs with hemorrhage had worse overall (P = 0.03) and 5-year (P = 0.01) survival rates. No survival difference between germinoma and non-hemorrhagic NGGCT. NGGCTs were more likely to bleed (P < 0.001) than germ cell tumor, especially those with choriocarcinoma or yolk sac tumor components (P = 0.001). The ADC ratios of germinomas were significantly lower than those of NGGCTs (P = 0.03 for whole tumor; P < 0.01 or solid part), The ADC ratios of choriocarcinoma were also lower than mixed tumor (P = 0.01; P = 0.02). ConclusionHemorrhage indicates worse prognosis. Intratumoral hemorrhage and ADC ratios differentiate germinoma from NGGCTs. Larger cohorts and advanced MR techniques are needed for future study.

Iris freckle: a distinct entity

PurposeTo report distinctive clinical and imaging features of iris freckles to differentiate them from iris nevi.DesignRetrospective observational study.Subjects53 patients (277 freckles) with incidental iris freckles and 102 patients (104 nevi)...

Distinct CT imaging features of new liver metastases from primary genitourinary cancers.

To apply natural language processing (NLP) to a large volume of structured radiology reports in the investigation of CT imaging features of new liver metastases from primary genitourinary cancers. In this retrospective study, a previously reported NLP model was applied to consecutive structured CT reports from 2016 to 2022 to predict those patients with primary genitourinary cancer who developed liver metastasis. Pathology or imaging follow-up served as the reference standard for validating NLP predictions. Subsequently, diagnostic CTs of the identified patients were qualitatively assessed by two radiologists, whereby several imaging features of new liver metastasis were assessed. Proportions of the assessed imaging features were compared between primary genitourinary cancers using the Chi-square or Fisher's exact test. In 112 patients (mean age = 72years; 83 males), the majority of new liver metastases were hypovascular (73.2%), well defined (76.6%), homogenous (66.9%), and without necrotic/cystic component (73.2%). There was a higher proportion of iso- to hyperdense liver metastases for primary kidney cancer vs other primary genitourinary cancers (42.5% in kidney cancer; 2.3% in ureter/bladder cancer, 8% in prostate cancer, and 0% in testicular cancer; p < 0.05) and a higher proportion of new liver metastases with ill-defined margin for primary prostate cancer vs other primary genitourinary cancers (44.0% in prostate cancer, 15.0% in kidney cancer, 18.6% in ureter/bladder cancer, and 25.0% in testicular cancer; p < 0.05). New liver metastases from primary genitourinary cancers tend to be hypovascular and show several distinct imaging features between different primary genitourinary cancers.

Ultrasound evaluation of portal venous gas and its mimics.

Portal venous gas on abdominal ultrasound classically represents an indirect indicator of bowel ischemia, a critical condition which poses a high patient mortality and therefore warrants emergent corrective action. While the classic appearance of portal venous gas on ultrasound is well-described in the literature, the characteristic descriptors are nonspecific and may actually represent other less emergent mimics. Therefore, while radiologists should remain vigilant for the detection of findings corresponding to portal venous gas, they should also be aware of similar-appearing entities in order to provide the most accurate diagnosis. This pictorial essay will open with imaging examples of true portal venous gas attributable to bowel ischemia and describe the classic features which should alert radiologists to this specific diagnosis. Subsequently, this pictorial essay will provide imaging examples of other various other clinical entities which on ultrasound may share similar imaging characteristics. An important objective of this pictorial essay is to highlight distinguishing imaging features along with specific clinical circumstances for each pathological entity which can direct radiologists into identifying the correct diagnosis.

Exploring the Terrain: An Investigation into Deep Learning-Based Fusion Strategies for Integrating Infrared and Visible Imagery

Infrared and visible image fusion technologies influence distinct image features acquired from distinct sensors, preserving complementary information from input images throughout the process of fusion, and utilizing redundant data to enhance the quality of the resulting fused image. Recently, deep learning methods (DL) have been employed by numerous researchers to investigate image fusion, revealing that the application of DL significantly enhances the efficiency of the model and the quality of fusion outcomes. Nevertheless, it is very important to note that DL can be implemented in various branches, and currently, a comprehensive investigation of deep learning-based methods in image fusion is in process.The paper aims to provide an exhaustive review of the evolution of image fusion algorithms grounded in deep learning over the years. Precisely, this paper undertakes a particular exploration of the fusion techniques applied to infrared and visible images through deep learning methodologies. The investigation includes a qualitative and quantitative comparison of extant fusion algorithms using established quality indicators, along with a thorough discussion of diverse fusion approaches. The current research status concerning infrared and visible image fusion is presented, with a forward-looking perspective on potential future directions. This research makes an effort to contribute valuable insights into various image fusion methods developed in recent years, thereby laying a solid foundation for subsequent research goings-on in this domain.

Abstract 7564: DNA methylation profiling identifies two distinct groups of oligosarcoma, IDH-mutant with distinct genetic alterations and clinical outcomes

Abstract DNA methylation has been extensively adopted for the classification of brain tumors and is endorsed by current neuropathology guidelines. Recently, oligosarcoma, IDH-mutant has been characterized as a distinct group of IDH mutant gliomas by DNA methylation classification. However, emerging studies revealed the variety in this group. Here, we employed DNA methylation-based t-SNE analysis to characterize oligosarcomas identified by the dkfz brain tumor classifier (v12.5). Thereby, we uncovered that oligosarcomas were segregated into two distinct groups, namely, subgroup A and subgroup B, which were further validated by genetic alterations and clinical outcomes. Next-generation Sequencing revealed subtype A tumors enriched with chr 1p/19q co-deletion, chr 6q loss, CDKN2A/B homogeneous deletion, TERT promoter mutation, and NF1 mutation, while subtype B tumors showed chr7 gaining and TP53 mutation. RNA sequencing and gene set enrichment analysis (GSEA) revealed that neuronal-tumor interaction and muscular progression pathways were more enriched in subtype A tumors. In contrast, subtype B tumors showed enrichment for angiogenesis and mTOR pathways. Additionally, inter-chromosomal fusion genes were more frequently found in subtype A tumors. Clinically, patients with subgroup A oligosarcomas manifested poorer survival and distinct imaging features in magnetic resonance imaging (MRI) compared to those with subgroup B. Collectively, we provided more cases of oligosarcoma, IDH-mutant, confirming the existence of this newly identified group, and revealed the subgroups harboring different genetic alterations and suffering different prognoses, providing new evidence for the molecular pathology in diffuse glioma. Citation Format: Kenan Zhang, Lingyu Liu, Xing Liu, Tao Jiang. DNA methylation profiling identifies two distinct groups of oligosarcoma, IDH-mutant with distinct genetic alterations and clinical outcomes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7564.

Many Faces of Diencephalic-Mesencephalic Junction Dysplasia Syndrome with GSX2 and PCDH12 Variants

Introduction: Diencephalic-mesencephalic junction dysplasia syndrome is a rare neurogenetic disorder reported to be caused by variants in several genes. Phenotypic presentation is characterized by clinical findings including developmental delay, hypotonia, spasticity, and dyskinetic movements in combination with distinctive imaging features on brain magnetic resonance imaging (MRI). Methods: Whole exome sequencing was conducted to unveil the molecular etiology of patients presenting with neurological manifestations from two unrelated families. Results: To the best of our knowledge, here we report the third family affected with diencephalic-mesencephalic junction dysplasia caused by a novel variant in GSX2 and two siblings with a PCDH12 variant exhibiting a less severe phenotype. The siblings with a PCDH12 variant were positioned at the milder end of the phenotypic spectrum. Although both exhibited a clinical phenotype resembling cerebral palsy, one showed partial fusion of the hypothalamus and mesencephalon, whereas MRI was unremarkable in the other. Biallelic GSX2 variants have been implicated in basal ganglia agenesis, and similarly, our patients had basal ganglia hypoplasia along with hypothalamic-mesencephalic fusion. Conclusion: Identifying variants associated with the syndrome in different genes will contribute to genotype-phenotype correlation.

Noninvasive Stratification of Colon Cancer by Multiplex PET Imaging.

The current approach for molecular subtyping of colon cancer relies on gene expression profiling, which is invasive and has limited ability to reveal dynamics and spatial heterogeneity. Molecular imaging techniques, such as PET, present a noninvasive alternative for visualizing biological information from tumors. However, the factors influencing PET imaging phenotype, the suitable PET radiotracers for differentiating tumor subtypes, and the relationship between PET phenotypes and tumor genotype or gene expression-based subtyping remain unknown. In this study, we conducted 126 PET scans using four different metabolic PET tracers, [18F]fluorodeoxy-D-glucose ([18F]FDG), O-(2-[18F]fluoroethyl)-l-tyrosine ([18F]FET), 3'-deoxy-3'-[18F]fluorothymidine ([18F]FLT), and [11C]acetate ([11C]ACE), using a spectrum of five preclinical colon cancer models with varying genetics (BMT, AKPN, AK, AKPT, KPN), at three sites (subcutaneous, orthograft, autochthonous) and at two tumor stages (primary vs. metastatic). The results demonstrate that imaging signatures are influenced by genotype, tumor environment, and stage. PET imaging signatures exhibited significant heterogeneity, with each cancer model displaying distinct radiotracer profiles. Oncogenic Kras and Apc loss showed the most distinctive imaging features, with [18F]FLT and [18F]FET being particularly effective, respectively. The tissue environment notably impacted [18F]FDG uptake, and in a metastatic model, [18F]FET demonstrated higher uptake. By examining factors contributing to PET-imaging phenotype, this study establishes the feasibility of noninvasive molecular stratification using multiplex radiotracer PET. It lays the foundation for further exploration of PET-based subtyping in human cancer, thereby facilitating noninvasive molecular diagnosis.

Clinical Characteristics of Adrenal Hemangioma.

Adrenal hemangioma (AH) is a rare, benign adrenal tumor often detected incidentally by imaging. This retrospective study aimed to investigate the clinical characteristics of AH, including clinical and diagnostic imaging features, to improve the recognition and understanding of AH. We retrospectively analyzed the medical records of patients diagnosed with AH at Peking Union Medical College Hospital between 2008 and 2022. Clinical manifestations, adrenal hormone levels, imaging findings, treatment approaches, and pathological results were collected and analyzed. Of the 7140 adrenal tumor patients, 40 (0.56%) had AH confirmed postoperatively. The mean age at diagnosis was 53.9 years, with a female predominance. Most (70%) were asymptomatic and diagnosed incidentally. Misdiagnosis before surgery was common, most frequently as pheochromocytoma. Imaging characteristics, especially enhanced computed tomography, revealed distinct features based on tumor size. Surgery was the main treatment, with laparoscopic adrenalectomy preferred. This study elucidates the clinical characteristics of AH, including demographics, diagnostic challenges, and imaging features. AH often presents incidentally and is frequently misdiagnosed preoperatively. Recognizing distinct imaging characteristics and appropriate surgical management can enable accurate diagnosis and optimal treatment.

IMAGING AND CLINICAL FEATURES OF PULSATILE POLYPOIDAL CHOROIDAL VASCULOPATHY.

To investigate the imaging and clinical features of polypoidal choroidal vasculopathy (PCV) with pulsation. The PCV eyes were classified into pulsatile and nonpulsatile PCV groups according to the pulsation on indocyanine green angiography. Imaging features including the dye filling time of the polyp and clinical features were compared. A total of 75 eyes were classified into the pulsatile PCV (30 eyes) and the nonpulsatile PCV (45 eyes) groups. The initial filling time and complete filling time of the polyp of the pulsatile PCV group (2.59 ± 0.93 and 8.33 ± 3.42 seconds) were shorter than those of the nonpulsatile PCV group (4.11 ± 1.87 and 10.63 ± 3.81 seconds, P < 0.001 and P = 0.010, respectively). The pigment epithelial detachment height of the pulsatile PCV group (414.90 ± 377.15 µ m) was greater than that of the nonpulsatile PCV group (247.81 ± 164.07 µ m, P = 0.030). The pulsatile PCV group showed a higher prevalence of subretinal hemorrhage (43.33%) after intravitreal injection than the nonpulsatile PCV group (13.95%, P = 0.005) during 12 months. The mean number of injections during 12 months of the pulsatile PCV group (5.48 ± 1.46) was greater than that of the nonpulsatile PCV group (4.09 ± 1.21, P < 0.001). Eyes with pulsatile PCV showed shorter filling time of the polyp, greater pigment epithelial detachment height, higher prevalence of subretinal hemorrhage, and more intravitreal injection numbers during 12 months. These might suggest that PCV has distinct imaging and clinical features according to the polyp pulsation.

Radiological Diagnosis of Pulmonary Aspergillosis.

Imaging plays an important role in the various forms of Aspergillus-related pulmonary disease. Depending on the immune status of the patient, three forms are described with distinct imaging characteristics: invasive aspergillosis affecting severely immunocompromised patients, chronic pulmonary aspergillosis affecting less severely immunocompromised patients but suffering from a pre-existing structural lung disease, and allergic bronchopulmonary aspergillosis related to respiratory exposure to Aspergillus species in patients with asthma and cystic fibrosis. Computed tomography (CT) has been demonstrated more sensitive and specific than chest radiographs and its use has largely contributed to the diagnosis, follow-up, and evaluation of treatment in each condition. In the last few decades, CT has also been described in the specific context of cystic fibrosis. In this particular clinical setting, magnetic resonance imaging and the recent developments in artificial intelligence have shown promising results.

Distinctive Imaging Characteristics of Retinal and Cerebral Vessels between Central and Branch Retinal Vein Occlusion by MRI and AI-Based Image Analyzer

Retinal vessels have been good predictive and prognostic imaging biomarkers for systemic or eye diseases. Numerous studies have shown that the two retinal vein occlusion entities may correlate with cardiovascular and cerebrovascular events or primary open-angle glaucoma. This study aims to investigate if there is a disparity in the correlations between branch RVO (BRVO) and central RVO (CRVO) with systemic disorders or POAG, thus explaining the pathogenic difference between BRVO and CRVO. This retrospective case-control study enrolled 59 RVO subjects (118 eyes), including 25 CRVO and 34 BRVO subjects, who received routine eye and brain MRI examinations. The geometric characteristics of the caliber of the retinal and cerebral blood vessels and the optic nerve subarachnoid space width (ONSASW) were measured. Multivariable logistic regression analysis showed that ONSASW at 3 mm behind the globe (p = 0.044) and the relative retinal venular calibers (p = 0.031) were independent risk factors for the CRVO-affected eyes group in comparison with the BRVO-affected eyes group after adjusting for age, duration of hypertension, BMI, and IOP. In the CRVO-affected eyes, narrower relative retinal arteriolar calibers (p = 0.041) and wider relative venular calibers (p = 0.011) were independent risk factors compared with the CRVO-contralateral normal eyes when adjusting for IOP. We concluded that BRVO may be more associated with cerebrovascular diseases, and CRVO may be correlated with primary angle glaucoma. The geometric characteristics difference between the retinal and cerebrovascular may explain the pathological difference between CRVO and BRVO.

Musculoskeletal involvement in neglected tropical diseases: a comprehensive review.

Neglected tropical diseases (NTDs) encompass a group of diseases predominantly found in tropical regions, with origins dating back to their inclusion in the United Nations Millennium Development Goals in 2000. This initiative aimed to raise awareness and global funding to combat these diseases, which thrive in areas with limited sanitation, healthcare, and education. NTDs are caused by various pathogens such as bacteria, fungi, parasites, and viruses and affect over two billion individuals in resource-poor communities, leading to preventable deaths and devastating consequences. While the musculoskeletal system is only occasionally affected, the resulting chronic disabilities prevent individuals from working, posing a significant socioeconomic burden in this region of the world. Some NTDs exhibit distinct imaging features, and radiologists need to be aware of these characteristics to facilitate early treatment. In this review, we delve into musculoskeletal NTDs, focusing on clinical features and imaging findings, differential diagnosis, and clinical management.

Identification of CT Features to Differentiate Pulmonary Sarcoma from Carcinoma.

Background Primary lung sarcoma (PLS) differs in management protocols and prognosis from the more common primary lung carcinoma (PLC). It becomes imperative to raise a high index of suspicion on radiological and pathological features. Purpose The aim of this study is to highlight the variable imaging appearances of PLS compared with PLC, which impacts radiologic - pathologic correlation. Materials and Methods A retrospective observational study of 68 patients with biopsy-proven lung tumors who underwent baseline imaging at our tertiary care cancer hospital was conducted between January 2018 and March 2022. The patient details and imaging parameters of the mass on contrast-enhanced computed tomography (CECT) were recorded and analyzed for patients with PLS and compared with PLC. Follow-up imaging was available in 9/12 PLS and 52/56 PLC patients. Results Among 12 patients with PLS, 5 patients had synovial sarcoma on histopathology. PLS was seen in patients with a mean age of 40.8 years; the mass showed a mean size of 13.2 cm, lower lobe (75%), parahilar (75%), hilar involvement (41.7%), oval shape (41.7%), circumscribed (25%) or lobulated (75%) margins, lower mean postcontrast attenuation of 57.3 HU, fissural extension (50%), calcification (50%), and no organ metastasis other than to the lung. PLC (56 patients) was seen in the elderly with a mean age of 54.8 years; the mass showed a mean size of 5.7 cm, irregular shape (83.9%), spiculated margins (73.2%), higher mean postcontrast attenuation (77.3 HU), chest wall infiltration (30.4%), and distant metastasis (58.9%) at baseline imaging. A statistically significant difference ( p < 0.05) was seen between sarcoma and carcinoma in the mean age, size, site, shape, margins, postcontrast attenuation, presence of calcifications, fissural extension, and distant metastasis. Conclusion The distinct imaging features of sarcoma help in differentiating it from carcinoma. This can also be used to corroborate with histopathology to achieve concordance and guide clinicians on further approach.

Imaging of musculoskeletal tuberculosis.

Tuberculosis (TB) represents a major public health problem worldwide. Any tissue may be infected. Involvement of the musculoskeletal (MSK) system account for 1-3% of all tuberculous infections. MSK TB may manifest as tuberculous spondylitis, arthritis, osteomyelitis, and soft tissue infections. Although TB spondylitis may present with distinctive imaging features compared to pyogenic infections of the spine, the imaging semiology of extra-spinal TB infections is mostly nonspecific and may mimic other lesions. TB infections should therefore always be considered in the differential diagnosis, particularly in immunocompromised patients. The aim of this article is to review the imaging features of spinal and extra-spinal MSK TB. Magnetic resonance imaging is considered the modality of choice to make the diagnosis and to evaluate the extent of the disease.

Multiple Myeloma Patient with Secondary Liver and Tongue Involvement, Complicated by COVID-19-Induced ARDS: An Autopsy Case Report and Literature Review

Background. Liver involvement secondary to multiple myeloma is a rare and uncommon radiologic finding. Such extraosseous secondary lesions as well as tongue involvement require pathohistological confirmation to prevent misdiagnosis. Clinical and laboratory diagnostics are challenging in patients with COVID-19 and underlying multiple myeloma and its secondary lesions, leading to difficulties in treatment and outcomes.&#x0D; Case Report. A 64-year-old male patient, not vaccinated against COVID-19, with a history of multiple myeloma presented with symptoms of headache, fatigue, dyspnea, cough, and fever. The patient’s medical history was intricate, involving cholecystectomy and a diagnosis of multiple myeloma, which was subsequently treated with chemotherapy and radiation therapy. Additionally, uncommon liver and tongue involvement secondary to multiple myeloma was found. Upon admission, the patient’s peripheral oxygen saturation was 90%, accompanied by increasing shortness of breath and a respiratory rate of 26 breaths per minute. A positive COVID-19 test was recorded. A lung computed tomography revealed bilateral multifocal areas of ground-glass opacity and consolidation, encompassing the entire pulmonary regions, corresponding to CO-RADS 6. The patient was admitted to the intensive care unit. Despite initiating oxygen support and symptomatic therapy, the patient’s death occurred. Autopsy confirmed the development of severe acute respiratory distress syndrome and bilateral hemorrhagic pneumonia, with multiple myeloma as a contributing factor.&#x0D; Conclusions. This case report highlighted the rare occurrence of secondary liver involvement in multiple myeloma, characterized by nodules with distinct imaging features. It underscored the importance of identifying coexisting lesions, such as tongue involvement, and the diagnostic challenges they pose. Additionally, the case emphasized the need for comprehensive clinical assessment in patients with concurrent COVID-19 and underlying multiple myeloma, as it may lead to the development of acute respiratory distress syndrome.

Clinical and non-contrast computed tomography characteristics and disease development in patients with benign pulmonary subsolid nodules with a solid component ≤ 5 mm

ObjectivesTo evaluate the clinical and non-contrast computed tomography (CT) features of patients with benign pulmonary subsolid nodules (SSNs) with a solid component ≤ 5 mm and their development trends via follow-up CT.MethodsWe retrospectively collected 436 data from patients who had SSNs with a solid component ≤ 5 mm, including 69 with absorbable benign SSNs (AB-SSNs), 70 with nonabsorbable benign SSNs (NB-SSNs), and 297 with malignant SSNs (M-SSNs). Models 1, 2, and 3 for distinguishing the different types of SSNs were then developed and validated.ResultsPatients with AB-SSNs were younger and exhibited respiratory symptoms more frequently than those with M-SSNs. The frequency of nodules detected during follow-up CT was in the following order: AB-SSNs > NB-SSNs > M-SSNs. NB-SSNs were smaller than M-SSNs, and ill-defined margins were more frequent in AB-SSNs than in NB-SSNs and M-SSNs. Benign SSNs exhibited irregular shape, target sign, and lower CT values more frequently compared to M-SSNs, whereas the latter demonstrated bubble lucency more commonly compared to the former. Furthermore, AB-SSNs showed more thickened interlobular septa and satellite lesions than M-SSNs and M-SSNs had more pleural retraction than AB-SSNs (all p < 0.017). The three models had AUCs ranging 0.748–0.920 and 0.790–0.912 in the training and external validation cohorts, respectively. A follow-up CT showed nodule progression in four benign SSNs.ConclusionsThe three SSN types have different clinical and imaging characteristics, with some benign SSNs progressing to resemble malignancy.Critical relevance statementA good understanding of the imaging features and development trends of benign SSNs may help reduce unnecessary follow-up or interventions. This retrospective study explores the CT characteristics of benign SSNs with a solid component ≤ 5 mm by comparing AB-SSNs, NB-SSNs, and M-SSNs and delineates their development trends via follow-up CT.Key points1. Different subsolid nodule types exhibit distinct clinical and imaging features.2. A miniscule number of benign subsolid nodules can progress to resemble malignancy.3. Knowing the clinical and imaging features and development trends of benign subsolid nodules can improve management.Graphical

SECEC Didier Patte Prize 2023: the ABC classification of posterior shoulder instability

BackgroundThe ABC classification has recently been proposed as a comprehensive classification system for posterior shoulder instability (PSI). The purpose of this study was to analyze the comprehensiveness as well as inter- and intra-rater reliability of the ABC classification. MethodsIn a prospective study all consecutive patients presenting with unidirectional PSI from June 2019 to June 2021 were included. No patients were excluded, leaving a consecutive series of 100 cases in 91 patients. All recorded clinical and imaging data was used to create anonymized clinical case vignettes, which were evaluated twice according to the ABC classification at the end of the recruitment period in random sequential order by four independent raters, two experienced shoulder surgeons and two orthopedic residents in order to analyze the comprehensiveness as well as inter- and intra-rater reliability of the ABC classification for posterior shoulder instability and to describe differences in characteristics among subtypes. Group A was defined as first-time singular posterior shoulder instability event less than 3 months in the past regardless of etiology and is further subdivided in Type 1 and Type 2 depending on the occurrence of a subluxation (A1) or dislocation (A2). Group B comprises recurrent dynamic PSI regardless of time since onset and is further subdivided by the cause of instability in functional (B1) and structural (B2) dynamic PSI. Group C includes chronic static PSI with posterior humeral decentering that can either be constitutional (C1) or acquired (C2). ResultsNone of the cases was deemed unsuitable to be classified based on the proposed system by the observers. After consensus agreement between the two experts 16 cases were attributed to group A (A1: 8, A2: 8), 64 to group B (B1: 33, B2: 31), and 20 to group C (C1: 11, C2: 9). The expert raters agreed in 99% and 96% of the cases on the classification subtypes during the first and second rating (ICC: 0.998 and ICC: 0.99). The intraobserver reliability was excellent for both raters. The beginners reached the same conclusion as the consensus agreement in 94% (ICC: 0.99) and 89% of the cases (ICC: 0.97) during the first round and 94% each (ICC: 0.97) during the second round. The intraobserver reliability was excellent for both beginners. Overall, discrepancies between raters were found between groups B1 and B2 (n=14), B2 and C2 (n=4), B1 and C1 (n=1), as well as A1 and B2 (n=1). In general, each subtype shows distinctive clinical and imaging characteristics that facilitate the diagnosis. ConclusionThe presented ABC classification for PSI is a comprehensive classification with a high reliability and reproducibility. However, a gradual transition and potential progression between the subtypes of PSI must be considered. The reliable distinction between different subtypes of PSI based on etiology and pathomechanism provides a standardized basis for future investigations on treatment recommendation.

Image Intrinsic-Based Unsupervised Monocular Depth Estimation in Endoscopy.

Unsupervised monocular depth estimation plays a vital role for endoscopy-based minimally invasive surgery (MIS). However, it remains challenging due to the distinctive imaging characteristics of endoscopy which disrupt the assumption of photometric consistency, a foundation relied upon by conventional methods. Distinct from recent approaches taking image pre-processing strategy, this paper introduces a pioneering solution through intrinsic image decomposition (IID) theory. Specifically, we propose a novel end-to-end intrinsic-based unsupervised monocular depth learning framework that is comprised of an image intrinsic decomposition module and a synthesis reconstruction module. This framework seamlessly integrates IID with unsupervised monocular depth estimation, and dedicated losses are meticulously designed to offer robust supervision for network training based on this novel integration. Noteworthy, we rely on the favorable property of the resulting albedo map of IID to circumvent the challenging images characteristics instead of pre-processing the input frames. The proposed method is extensively validated on SCARED and Hamlyn datasets, and better results are obtained than state-of-the-art techniques. Beside, its generalization ability and the effectiveness of the proposed components are also validated. This innovative method has the potential to elevate the quality of 3D reconstruction in monocular endoscopy, thereby enhancing the accuracy and robustness of augmented reality navigation technology in MIS. Our code will be available at: https://github.com/bobo909/IID-SfmLearner.