Anatomical variations of posterior inferior cerebellar artery (PICA) on digital subtraction angiography (DSA)

Introduction: The posterior inferior cerebellar artery (PICA) often exhibits anatomical variations at the craniovertebral junction. Few studies investigated variations of the posterior inferior cerebellar artery, and the prevalence of other variations has not been reported. The study aimed to identify variations of the posterior inferior cerebral artery using cerebral Digital Subtraction Angiography (DSA). Method: 50 patients underwent 64-slice cerebral Digital Subtraction Angiography. Four types of variations were observed. Results: Out of a total of 50 patients, 23 (46%) were males and 27 (54%) females (all age groups). Our study has shown the utility of the 2 sequences - fluoroscopy and cine. All 2 sequences have their significance in evaluating anatomical variations in PICA. Only 20% of the 50 patients had all the posterior inferior cerebellar artery without anatomical variations. Anatomic variations commonly involve the distal segment of the vertebral artery (VA). Most of them are seen arising from the C1, C2, and both C1 and C2 origins. Anatomic variations involve arising from the C1 origin in 9 patients, C2 origin in 11 patients, C1 & C2 origin in 8 patients, and other variations observed in 12 patients. Conclusion: Variations of the posterior inferior cerebellar artery can be easily evaluated by cerebral Digital Subtraction Angiography (CDSA). Recognizing and reporting them at cerebral CDSA may be clinically important. Surgeons should be mindful of this variation during operations.

Vertebral Anatomic Variations in Thoroughbred Racehorses in Trinidad

Reports of the occurrence of lumbar vertebrae variants in horses in Trinidad are rare in the literatures. Parts of the skeletons of two horses of unknown age and sex that died in a horse farm in Trinidad and Tobago were brought to the Anatomy laboratory. It was reported that specimens of fused left transverse processes of the 5th and 6th lumbar vertebrae and a blunted left transverse process of the 6th lumbar vertebra in thoroughbred racehorses in Trinidad.

Anatomic Variation of the Lateral Sinus in Patients With Idiopathic Intracranial Hypertension: Delineation With Black-Blood Contrast-Enhanced MRI

Objectives: The purpose of this study was to describe the peculiar anatomic variations in the lateral sinus and analyze the patterns of cerebrospinal fluid (CSF) drainage by using high-resolution (HR) black-blood (BB) contrast-enhanced magnetic resonance imaging (MRI) in patients with idiopathic intracranial hypertension (IIH).Methods: Total 33 IIH patients who were found cerebral venous sinus stenosis (CVSS) by MR venography (MRV) were enrolled in this study. HR-BB contrast-enhanced MRI was used to assess the features of anatomical variations in transverse sinus and sigmoid sinus. The development of bilateral sinuses was firstly evaluated, including unilateral hypoplasia with contralateral dominance or bilateral balanced development. Then, four kinds of anatomical variations were eventually recorded, including circumscribed stenosis, arachnoid granulation (AG), fibrous septum (FS), and brain herniation (BH) into dural venous sinus (DVS).Results: Bilateral venous drainage dysfunction was found in 30(90.9%) patients, whereas only 3(9.1%) patients presented unilateral venous drainage dysfunction. There was no difference in clinical symptoms between the two groups. The most common case is hypoplasia in unilateral sinus combined with anatomic variation in the contralateral dominant transverse sinus such as AG and BH into DVS. Total of 52 anatomic variations were finally found in bilateral sinuses in 33 enrolled patients, including 19(36.5%)AGs, 12(23.1%)FS, 7(13.5%) BH into DVS and 14(26.9%) circumscribed stenoses. Moreover, 41(62.1%) lateral sinuses showed enhancement in T1-weight-enhanced MRI.Conclusions: Patients with CVSS almost had CSF outflow disorders, whatever bilateral equalization or unilateral hypoplasia with contralateral dominance. Four types of main anatomic variations, including circumscribed stenosis, AG, FS, and BH into DVS, caused venous reflux obstruction by elevating the intracranial press (ICP).

DISTRIBUTION OF ANATOMIC VARIATIONS OF THE NOSE AND PARANASAL SINUSES IN KASHMIRI POPULATION BY COMPUTED TOMOGRAPHY SCAN ANALYSIS.

Background: Knowledge of anatomy constitutes an integral part of the total management of patients with sinonasal diseases. The aim of this study was to obtain the prevalence of sinonasal anatomic variations in the Kashmiri population and to understand their importance and impact on the disease process, as well as their influence on surgical management and outcome. Materials and Methods: This study is a prospective review of retrospectively performed normal computed tomography (CT) scans of the nose and paranasal sinuses in the adult Kashmiri population at SMHS Hospital. The scans were reviewed by two independent observers. Results: The most common anatomic variation after excluding agger nasi cells were pneumatized Crista Galli, which was seen in 69% of the scans. However, the least common variation seen in this series was Pneumatized inferior turbinate, which was encountered in 1.1 % of the cases. Conclusion: A wide range of regional differences in the prevalence of each anatomic variation exists. Understanding the preoperative CT scan is substantially important because it is the roadmap for the sinus surgeon. Detection of anatomic variations is vital for surgical planning and the prevention of complications.

Development of a fully automatic deep learning system for L3 selection and body composition assessment on computed tomography

As sarcopenia research has been gaining emphasis, the need for quantification of abdominal muscle on computed tomography (CT) is increasing. Thus, a fully automated system to select L3 slice and segment muscle in an end-to-end manner is demanded. We aimed to develop a deep learning model (DLM) to select the L3 slice with consideration of anatomic variations and to segment cross-sectional areas (CSAs) of abdominal muscle and fat. Our DLM, named L3SEG-net, was composed of a YOLOv3-based algorithm for selecting the L3 slice and a fully convolutional network (FCN)-based algorithm for segmentation. The YOLOv3-based algorithm was developed via supervised learning using a training dataset (n = 922), and the FCN-based algorithm was transferred from prior work. Our L3SEG-net was validated with internal (n = 496) and external validation (n = 586) datasets. Ground truth L3 level CT slice and anatomic variation were identified by a board-certified radiologist. L3 slice selection accuracy was evaluated by the distance difference between ground truths and DLM-derived results. Technical success for L3 slice selection was defined when the distance difference was < 10 mm. Overall segmentation accuracy was evaluated by CSA error and DSC value. The influence of anatomic variations on DLM performance was evaluated. In the internal and external validation datasets, the accuracy of automatic L3 slice selection was high, with mean distance differences of 3.7 ± 8.4 mm and 4.1 ± 8.3 mm, respectively, and with technical success rates of 93.1% and 92.3%, respectively. However, in the subgroup analysis of anatomic variations, the L3 slice selection accuracy decreased, with distance differences of 12.4 ± 15.4 mm and 12.1 ± 14.6 mm, respectively, and with technical success rates of 67.2% and 67.9%, respectively. The overall segmentation accuracy of abdominal muscle areas was excellent regardless of anatomic variation, with CSA errors of 1.38–3.10 cm2. A fully automatic system was developed for the selection of an exact axial CT slice at the L3 vertebral level and the segmentation of abdominal muscle areas.

Anatomical Variations of Celiac Trunk and Its Branching Pattern with Special Reference to Surgical Implications in Mysore Based Population

BACKGROUND Celiac trunk (CT) is the first major abdominal branch of the aorta. Anatomic variations and accessory vessels have been reported with variable percentages. We report here a particularly rare variant involving absence of the celiac trunk in association with trifurcation of the common hepatic artery (CHA). The purpose of this study was to report the pattern of the celiac trunk and its anatomic variations in a sample of Mysore population. METHODS Celiac trunk dissection was performed in 10 fresh cadavers and 50 cases of contrast enhanced computed tomography (CECT) images of Mysore based subjects at JSS Medical College and Hospital aged 18 years and above were included. Celiac trunk variations, length, diameter, accessory vessels, and vertebral level of origin were described. RESULTS The branching pattern of coeliac trunk was observed in 60 cases (37 males, 23 females) by dissection and CECT scan method. Type I was found in 48 cases (80 %), Type I form 2a was found in 2 cases (3.3 %). Type II form 1 in 6 cases (10 %). Type III was observed in 1 case and in another case left hepatic artery (LHA) arising from coeliac trunk, Type VII was found in 2 cases (3.3 %). The length and diameter of coeliac trunk were analysed using descriptive statistics and mean ± SD for length was 1.8 ± 0.4 and diameter 0.5 ± 0.2 respectively. CONCLUSIONS Awareness of CT variations is important in surgical resection, transplantation, and interventional radiology procedure. KEY WORDS Celiac Trunk, Variations, Morphometry, Contrast Enhanced Computed Tomography Scan Method