Anatomical Variations Research Articles

S4003 Cystic Duct Take Off From the Right Main Hepatic Duct: Case of an Interesting Anatomic Variant

S4003 Cystic Duct Take Off From the Right Main Hepatic Duct: Case of an Interesting Anatomic Variant

Sinonasal Plasmablastic Lymphoma: A Systematic Review

Abstract Objective Plasmablastic lymphoma (PBL) is a type of non-Hodgkin's B-cell lymphoma associated with human immunodeficiency virus and Epstein–Barr virus, commonly located in the oral cavity or gastrointestinal tract. Sinonasal involvement is rare, and there is no consensus on treatment. Data Sources Peer-reviewed published articles served as data sources. Review Methods A systematic review was conducted of the PubMed database for all cases of sinonasal PBL between 1978 and 2023 with the phrase “plasmablastic lymphoma.” Studies not written in English and that did not separate individual cases of sinonasal PBL from aggregated data were excluded. Age, sex, immune status, treatment, and outcomes were collected. Conclusion PBL is a rare malignancy in the sinonasal region usually treated with chemotherapy. It most commonly occurs in immunocompromised adults but has also been diagnosed in immunocompromised children and in immunocompetent adults. It is aggressive and has a poor prognosis. Implications for Practice PBL is a recently described entity with few cases of the sinonasal anatomic variant in the literature. Sinonasal PBL was most frequently treated with chemotherapy alone, closely followed by chemoradiation. The most common chemotherapy regimen utilized in the literature is cyclophosphamide, doxorubicin, oncovin/vincristine, and prednisone, which is also the most common chemotherapy regimen in nonsinonasal PBL. A second commonly used regimen is cyclophosphamide, vincristine/oncovin, doxorubicin/adriamycin, and dexamethasone. However, no treatment has emerged as superior to others with regard to survival. Further data are needed to better understand this rare disease.

Pitfalls in Interpretive Applications of Artificial Intelligence in Radiology.

Interpretive artificial intelligence (AI) tools are poised to change the future of radiology. However, certain pitfalls may pose particular challenges for optimal AI interpretative performance. These include anatomic variants, age-related changes, postoperative changes, medical devices, image artifacts, lack of integration of prior and concurrent imaging examinations and clinical information, and the satisfaction-of-search effect. Model training and development should account for such pitfalls to minimize errors and optimize interpretation accuracy. More broadly, AI algorithms should be exposed to diverse and complex training datasets to yield a holistic interpretation that considers all relevant information beyond the individual examination. Successful clinical deployment of AI tools will require that radiologist end users recognize these pitfalls and other limitations of the available models. Furthermore, developers should incorporate explainable AI techniques (e.g., heat maps) into their tools, to improve radiologists' understanding of model outputs and to enable radiologists to provide feedback for guiding continuous learning and iterative refinement. In this article, we provide an overview of common pitfalls that radiologists may encounter when using interpretive AI products in daily practice. We present how such pitfalls lead to AI errors and offer potential strategies that AI developers may use for their mitigation.

Assessing the impact of fetal-type posterior cerebral artery variations on cerebral hemodynamics

The circle of Willis (CoW) is a critical, arterial structure that ensures balanced, cerebral-blood supply. The fetal-type posterior cerebral artery (f-PCA) is a CoW variant that can significantly affect hemodynamics and elevate the risk of cerebrovascular diseases. This study used computational fluid dynamics simulations and a patient-specific, three-dimensional model to evaluate the hemodynamic effects of the f-PCA variants on cerebral-blood flow and key hemodynamic indices—such as time-averaged wall-shear stress (TAWSS), oscillatory shear index (OSI), pulsatility index, and resistive index. The fetal ratio (FR) is defined as the ratio of the diameter of the posterior communicating artery (PCoA) to that of the first segment (P1) of the PCA. Our findings indicate that as the FR increases, the contribution of the basilar artery to the second segment (P2) of PCA decreases significantly. Specifically, the flow rate through ipsilateral P1 decreased by 40.0% for FR = 1 and 70.9% for FR = 2, with the internal carotid artery (ICA) compensating for this reduction. Moreover, variations in f-PCA led to significant increases in TAWSS and OSI in key arterial segments (including the ipsilateral P1, PCoA, and the anterior communicating artery), which are associated with a higher risk of aneurysm initiation and growth. Under conditions of unilateral stenosis in the ipsilateral ICA, f-PCA models exhibit a more complex and pronounced impact on blood flow than models without f-PCA, emphasizing the need for detailed hemodynamic assessments in clinical evaluations and preoperative planning to mitigate the risks associated with CoW anatomical variations.

Do Anatomical Variations of Sphenoid Sinus Influence Sella Exposure and Residual Disease in Pituitary Surgery? - A Study in an Indian Population.

Introduction Endoscopic transsphenoidal surgery (ETS) is the standard practice in pituitary surgeries. The sellar exposure becomes the main factor which determines the residual disease in ETS. Not many studies can be found in the literature on the influence of anatomical variations of the sphenoid on intraoperative sella exposure. Objective The aim of the current study is to ascertain whether sphenoid sinus variations play a role in sellar exposure and residual tumor volume. Methods This is a prospective study conducted in a south Indian tertiary care center between June 2020 to June 2022, with 21 study participants who were scheduled to have ETS. The relation of preoperative computed tomography (CT) and magnetic resonance imaging (MRI) parameters with the intraoperative area of sellar exposure and residual tumor volume was evaluated. Results Sphenoid sinus dimensions, like presellar width (mean = 1.89 ± 0.51 cm), maximum width (mean = 2.94 ± 1.09 cm), presellar depth (mean = 1.14 ± 0.55 cm), suprasellar depth (mean = 1.08 ± 0.24 cm), infrasellar depth (mean = 2.36 ± 0.92 cm), presellar height (mean = 2.22 ± 0.47 cm), or the 9 internal carotid artery (ICA)-related measures, did not have any correlation with the mean intraoperative area of sellar exposure (0.57 ± 0.28 cm 2 ). Also, the adequacy of sellar exposure did not relate to the residual tumor. Preoperative tumor volume was found to be higher (20.2 [55.3-13.2] cm 3 ) in patients with residual tumor compared with those with no residual tumor (5.9 [6.8-5.2] cm 3 ). Tumor extension had a significant association with the residual tumor volume. Conclusion According to the present study, anatomical variations of the sphenoid sinus do not influence the adequacy of sellar exposure. Further studies need to be undertaken concerning residual tumor volume as well as preoperative tumor volume and extension.

Strategies for prevention and treatment of vascular and nerve injuries in mandibular anterior implant surgery

Important anatomical structures such as mandibular incisive canal, tongue foramen, and mouth floor vessels may be damaged during implant surgery in the mandibular anterior region, which may lead to mouth floor hematoma, asphyxia, pain, paresthesia and other symptoms. In severe cases, this can be life-threatening. The insufficient alveolar bone space and the anatomical variation of blood vessels and nerves in the mandibular anterior region increase the risk of blood vessel and nerve injury during implant surgery. In case of vascular injury, airway control and hemostasis should be performed, and in case of nerve injury, implant removal and early medical treatment should be performed. To avoid vascular and nerve injury during implant surgery in the mandibular anterior region, it is necessary to be familiar with the anatomical structure, take cone-beam computed tomography, design properly before surgery, and use digital technology during surgery to achieve accurate implant placement. This article summarizes the anatomical structure of the mandibular anterior region, discusses the prevention strategies of vascular and nerve injuries in this region, and discusses the treatment methods after the occurrence of vascular and nerve injuries, to provide clinical reference.

A Rare Case of Carpal Tunnel Syndrome with Bifid Median Nerve and Palmaris Profundus Muscle

Summary: Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy. We report an extremely rare case of CTS associated with a bifid median nerve and palmaris profundus muscle. A 68-year-old man presented with numbness and pain in the right hand. Intraoperatively, a bifid median nerve was identified, with the ulnar branch severely compressed by the palmaris profundus muscle. The muscle was resected, leading to symptom resolution. Anatomical variations of the median nerve and anomalous muscles should be considered in CTS. Preoperative imaging and open carpal tunnel release are recommended to identify and address such variations.

Recurrent Ischemic Strokes Due to Anatomic Variation of the Hyoid Bone and Thyroid Cartilage.

Recurrent Ischemic Strokes Due to Anatomic Variation of the Hyoid Bone and Thyroid Cartilage.

Non-Surgical Endodontic Management of Teeth with Aberrant Anatomy: A Case Series

The root canal therapy aims to remove the necrotic and vital pulp tissue remnants from the root canal to treat the periradicular inflammation. The knowledge of the tooth anatomy is essential to ensure a successful treatment. However, the deviation of the tooth anatomy complicates the diagnostic and treatment processes. Effective management of such complexities requires a tailored approach, utilizing detailed imaging and precise endodontic techniques to achieve successful outcomes and restore patient function and comfort. This case series presents the endodontic management of three different anatomic variations of permanent teeth that include taurodontism in the mandibular molar, two rooted mandibular canine and dilacerated maxillary central incisor and underscores the importance of personalized treatment planning and advanced diagnostic tools in managing complex dental anomalies.

Asian Pacific Society of Cardiology Consensus Statements on the Use of Percutaneous Coronary Intervention on Stenosis of the Left Main Coronary Artery

Stenosis of the left main coronary artery (LM stenosis) is associated with significant mortality and morbidity due to the large area of affected myocardium. Evidence on the use of percutaneous coronary intervention (PCI) for the treatment of LM stenosis is growing. However, the role of Western guidelines on patients in the Asian-Pacific region is unclear due to anatomical variations, substantial heterogeneity in healthcare resources and infrastructure, and the lack of consensus on the optimal management of LM stenosis in the Asia-Pacific region. Hence, an Asian Pacific Society of Cardiology (APSC) working group developed consensus recommendations on the use of PCI in the management of LM stenosis in the Asia-Pacific region. The APSC expert panel reviewed and appraised the available evidence using the Grading of Recommendations Assessment, Development, and Evaluation system. Consensus recommendations were developed and put to an online vote. Consensus was reached when 80% of votes for a given recommendation were in support of ‘agree’ or ‘neutral’. The resulting 12 statements provide guidance for clinical practitioners in the region on the use of PCI in the treatment of patients with LM stenosis.

Can lung anatomy predict the development of COVID-19 pneumonia in RT-PCR positive cases?

Purpose: The objective of this study was to investigate the relationship between Coronavirus disease 2019 (COVID-19) pneumonia and anatomical characteristics, including tracheobronchial and fissure variations, right/left main bronchus angle, carina angle, and large airway diameter, in patients who tested positive for the virus via reverse transcription-polymerase chain reaction (RT-PCR) at the outset of the pandemic. Materials and Methods: This cross-sectional study included 165 cases with positive RT-PCR tests who were admitted between March and June 2020 and subsequently scanned with thin-section unenhanced chest computed tomography (CT). They were divided into two groups according to the presence of pneumonia based on the chest CT images. Results: In our study, a total of 165 cases were analyzed, pneumonia was found in 35 of 76 (46.05%) female patients and 51 of 89 (57.30%) male patients. COVID-19 pneumonia was observed in older age groups. Anatomical variations and the presence of incomplete fissures were statistically higher in the pneumonia-positive group, while the difference was not statistically significant for accessory fissures. Mean tracheal area and right main bronchus angle were statistically higher in the pneumonia-positive group compared to the negative patients. The right lung was more involved than the left in terms of both zonal and total lung involvement. When the presence of comorbidity was assessed, 59 patients (35.75%) were found to have comorbidity. Hypertension, diabetes mellitus and cardiovascular disease were significantly higher among comorbidities in the pneumonia-positive group. The regression model showed that hypertension was associated with a 3.75-fold increase in COVID-19 pneumonia in test positive cases. Conclusion: Anatomical lung variations and incomplete fissures were observed more frequently in the COVID-19 pneumonia cases, independent of other comorbidities. We believe that there are anatomical variables that can be used to identify those predisposed to pneumonia in RT-PCR test positive cases.

Anatomical Variations in Keystone Area in Nepalese Noses: A Descriptive Cross-sectional Study

Introduction: The keystone area, a crucial part of the nasal dorsum that maintains its structural stability, is known to have anatomical variations. This study aimed to evaluate these anatomical variations in Nepalese noses. Methods: This was an observational, analytical study done at a tertiary center after taking ethical approval {208(6-11)E2-077/078}. Thirty-one cadaveric noses consisting of 26 males and five females aged 24 to 70 years were dissected. The shape of the caudal margin and the overlap pattern of the nasal bone over upper lateral cartilage were assessed. The proportion of overlap was calculated. The lengths of the lateral and dorsal keystone and dorsal quadrangular cartilage were measured. Results: The most common shape of the nasal bone caudal margin was curvilinear 15 (48.39%) followed by paramedian retractions 8 (25.81%). Elongated midline was the least commonly seen in 1 (3.23%) female only. The length of the dorsal keystone ranged from 1-12 mm (mean 6.97 ± 2.57) whilst the lateral keystone measured 1-4 mm (mean 2.22± 1.20). The dorsal quadrangular cartilage measured 21 – 39 mm ( mean 29.77± 4.6). The mean overlap proportion was 23.82± 7.33 (11 – 40) %.Conclusions: Anatomical variations in the structural components of the keystone area in Nepalese was seen in this study.

Computer modeling and validation testing for glenoid component rotation and optimal glenoid screw angles for reverse shoulder arthroplasty in an Asian population

PurposeGood initial fixation of glenoid component for reverse total shoulder arthroplasty (RTSA) relies on component placement and screw purchase in the scapula bone. This is especially difficult in an Asian population with small glenoid geometry. Optimal glenoid component roll angle and screw angulation to achieve the longest screws for best fixation has not been defined in the current literature.MethodsComputer 3D modelling of 133 scapulas with RTSA performed were analyzed to determine patient specific optimal glenoid roll angle (GRA) for the longest bi-cortical screws attainable. The cranial-caudal angle (CCA), anterior-posterior angle (APA) and lengths for the superior and inferior screws were measured. Validation testing using calculated average (CA) angles and rounded average (RA) angles to the nearest 5 degree were recomputed for each case to determine the bi-cortical screw lengths achievable. The CA and RA screw lengths were compared against patient specific modelling using paired-sample t-tests.ResultsAverage GRA was − 1.6°, almost perpendicular to the long axis of the glenoid and achieves an average bi-cortical screw length of 51.3 mm and 45.5 mm for the superior and inferior screws respectively. The CCA and APA were 9.1° cranial and 6.5° posterior for the superior screw and screw angulation of 11.2° caudal and 0.7° anterior for the inferior screw. Validation testing shows statistically shorter screw lengths in the CA and RA models compared to patient specific modelling (p < 0.01).ConclusionValidation testing with average angles for GRA, CCA and APA demonstrates strong patient heterogeneity and anatomical variation. Despite this, screw lengths attainable in the RA group were > 38 mm with good safety profile. Surgeons may consider the additional use of navigation-assisted, or 3D printed patient specific instrumentation to optimize baseplate and screw configuration for RTSA.

Features of vascular anatomy in pancreaticoduodenal resection

In about 55–79% of patients, the vascular anatomy of the hepatic-pancreaticoduodenal area is characterized by a typical structure. In the rest of patients, the vascular and, primarily, arterial anatomy may vary due to both different variants of branches and additional arteries. Undoubtedly, this creates difficulties in surgical planning and performing pancreaticoduodenal resection. Vascular anatomic variations may contribute to increased intraoperative blood loss, postoperative complications, changes in the course and volume of surgery, and increased duration of hospital stay after surgery. Modern diagnostic methods, CT angiography in particular, facilitate the process of surgical planning and reduce the risk of unforeseen situations related to ligation or damage of arterial vessels, which are to be preserved during operations. In this work, we carry out a review of publications on the topography of arterial vessels in the area of pancreaticoduodenal resection. The issues related to anatomical variations in both trunk and pancreatic vessels are considered. Special attention is paid to the possible influence of variations in the vascular network structure on the course and volume of surgery, as well as the risk of intraoperative and postoperative complications.

Intra-Atrial Course of Right Coronary Artery: Rare Anatomical Variants Are Becoming More Common with Modern Cardiac CT Scanners

Coronary artery anomalies, which range from benign variations to potentially malignant conditions, are increasingly being identified due to advancements in coronary computed tomography (CT) imaging. This case report highlights a 51-year-old male patient who was diagnosed with an intra-atrial course of the right coronary artery while undergoing evaluation for symptoms suggestive of angina. The detection of this rare anatomical variant was facilitated by modern cardiac CT technology. Following diagnosis, the patient was thoroughly reassured and educated about his condition. He was advised to avoid excessive physical exertion and was given guidance on lifestyle modifications to manage his symptoms effectively. It is crucial for healthcare providers to be aware of such anomalies, especially when planning surgical interventions or invasive procedures, to prevent potentially catastrophic outcomes.

Supervised deep learning-based synthetic computed tomography from kilovoltage cone-beam computed tomography images for adaptive radiation therapy in head and neck cancer.

To generate and investigate a supervised deep learning algorithm for creating synthetic computed tomography (sCT) images from kilovoltage cone-beam computed tomography (kV-CBCT) images for adaptive radiation therapy (ART) in head and neck cancer (HNC). This study generated the supervised U-Net deep learning model using 3,491 image pairs from planning computed tomography (pCT) and kV-CBCT datasets obtained from 40 HNC patients. The dataset was split into 80% for training and 20% for testing. The evaluation of the sCT images compared to pCT images focused on three aspects: Hounsfield units accuracy, assessed using mean absolute error (MAE) and root mean square error (RMSE); image quality, evaluated using the peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM) between sCT and pCT images; and dosimetric accuracy, encompassing 3D gamma passing rates for dose distribution and percentage dose difference. MAE, RMSE, PSNR, and SSIM showed improvements from their initial values of 53.15 ± 40.09, 153.99 ± 79.78, 47.91 ± 4.98 dB, and 0.97 ± 0.02 to 41.47 ± 30.59, 130.39 ± 78.06, 49.93 ± 6.00 dB, and 0.98 ± 0.02, respectively. Regarding dose evaluation, 3D gamma passing rates for dose distribution within sCT images under 2%/2 mm, 3%/2 mm, and 3%/3 mm criteria, yielded passing rates of 92.1% ± 3.8%, 93.8% ± 3.0%, and 96.9% ± 2.0%, respectively. The sCT images exhibited minor variations in the percentage dose distribution of the investigated target and structure volumes. However, it is worth noting that the sCT images exhibited anatomical variations when compared to the pCT images. These findings highlight the potential of the supervised U-Net deep learningmodel in generating kV-CBCT-based sCT images for ART in patients with HNC.

Sex differences in transradial access failure in ST segment elevation myocardial infarction.

Transradial access (TRA) is now the default access site for PPCI, but technically is a more challenging approach mostly due to anatomic challenges connected to the RA. To assess the differences according to sex in radial artery (RA) access site characteristics during primary percutaneous coronary intervention (PPCI) for ST segment elevation myocardial infarction (STEMI). All 5092 consecutive STEMI patients from our center in the period from March 2011 until December 2017 were examined. The right proximal radial was the "intention-to-treat" access in all patients. Preprocedural RA angiography was performed in all patients. Clinical and procedure characteristics, type of radial anatomy variants, need to use another arterial access sites (the primary endpoint for this study), and procedure time were analyzed by sex. Using logistic regression, we selected predictors of radial crossover. Access site bleeding complications and vascular complications were also recorded. The STEMI population in this period included 1326 females and 3766 male patients. Females were older (65 ± 11 years) than males (59 ± 11 years, p < 0.0001). Among standard risk factors, hypertension and diabetes mellitus were more common in women and smoking less common. RA anomalies were more frequent in the females (8.8% vs. 6.5%, p < 0.0001), with complex RA loop and tortuous RA twice as frequent in women. Failure of TRA access as the initially chosen site occurred in 4.6% (61) of females versus 2.5% (97) of male STEMI patients (p = 0.0003). The most common subsequent access site was right ulnar access in both groups (57 and 61% respectively). Access site bleeding complications were more common in women 4.4% versus 3.2%, mirrored in hematomas with EASY score III to V. Clinical RA spasm (RAS) was significantly more frequent in females (5.7% vs. 2.2%, p < 0.0001). Multiple regression analysis identified 5 independent predictors for TRA access crossover: previous TRA, anomalous RA, RAS, along with female sex and diabetes. Female sex is a significant predictor of more complex TRA in STEMI. Understanding sex differences and predictors for TRA crossover will strengthen the use of different procedural modalities that can help in preserving a successful wrist access in female STEMI patients.

Morphometric evaluation of suprascapular notch and superior angle of the scapula using three-dimensional computed tomography in the Indian population

BackgroundAmong the various aspects of scapular anatomy, the suprascapular notch has gained attention as its anatomical variation is a predisposing factor for compression of the suprascapular nerve in this region, potentially impacting orthopedic surgery. This study aims to investigate the morphology of suprascapular notch (SSN) and its variation with age and sexual dimorphism. It also seeks to classify and correlate the superior angle of the scapula with the SSN in the Indian population. MethodsA retrospective analysis of 360 computed tomography scans of scapulae of 180 adults was conducted. The morphology of SSN was classified according to Rengachary's classification (types I-VI), and the maximum depth (MD) and maximum width (MW) of SSN were measured. The superior angle of the scapula was classified based on morphological characteristics. ResultsType I SSN was the most prevalent, suggesting lower susceptibility to suprascapular nerve entrapment. Males had significantly greater MD than females. Identical types of SSN and superior angles on both sides of the scapula were statistically significant, though variations on each side were also observed. There was no significant difference in age. The superior angle of the scapula was classified into four types: Hilly, mountain peak, crescent, and chimney, with the hilly type being the most common. No correlation was found between SSN and the superior angle. ConclusionThese findings may provide a comprehensive understanding necessary for accurate diagnoses of related abnormalities and for performing safe and effective endoscopic and open surgical procedures in the suprascapular region.

Botulinum toxin-related blepharoptosis in emergency department admissions

The use of Botulinum Toxin Type A (BoNT-A) has become prevalent not only for therapeutic purposes but also for cosmetic applications. Among healthcare professionals, there has been an increase in BoNT-A administration within familial or friend circles. This rise has corresponded with a notable increase in cases of unilateral blepharoptosis presenting in emergency department admissions. This trend may be attributed to insufficient knowledge and experience regarding the proper dosing of BoNT-A, inadequate understanding of facial anatomy, or anatomical variations of the supraorbital foramen or neurovascular pedicle. While BoNT-A administration for reducing facial wrinkles may appear straightforward for a healthcare professional, a thorough understanding of anatomy and the causes and treatment of blepharoptosis is essential.

PERMANENT MANDIBULAR CANINE WITH TWO ROOTS AND TWO CANALS

Mandibular canines are documented as frequently having one root and one canal in most cases, although around 15% may have two canals and two roots. Thus, anatomic variation exists therefore knowledge and keen observation during root canal can help to identify the less frequent variation morphology of tooth and play a pivotal role in the success of root canal treatment. This case report discusses a mandibular canine with two roots and two canals.