This medical illustration and diagnostic image set presents the ZJUSAH classification for Pontine Brainstem Hemorrhage (PBH). Panel A displays four schematic cross-sections of the pons outlining the classification types. Type 0 shows a hematoma restricted to the fourth ventricle or cistern. Type 1 illustrates unilateral involvement. Types 2 and 3 describe midline-spanning hematomas, further divided into subtypes (A: ventral, B: dorsal, C: central) based on their position relative to dashed lines dividing the ventral-dorsal diameter. Panel B demonstrates the application of this anatomical classification on an axial non-contrast CT head scan. It illustrates an estimation method for determining brainstem quarter-borderlines: a green line marks the ventral-dorsal midline; yellow tangent lines follow the ventrolateral edges; and red lines bisect the resulting angles to define the left and right 1/4 borderlines. This system is designed to improve prognostic accuracy and guide stereotactic surgical planning by characterizing the hematoma's spatial distribution within critical brainstem structures.

This composite educational image illustrates the classification of middle tentorial notch meningiomas (TNM) into three subtypes: T2a, T2b, and T2c. Section A provides schematic diagrams and T1-weighted axial, coronal, and sagittal MRI scans with gadolinium contrast, highlighting the growth patterns. Type T2a (Infratentorial Type) is shown with a tumor base at the middle tentorial notch extending inferiorly into the internal auditory canal (IAC) and posterior cranial fossa. Type T2b (Supratentorial Type) demonstrates a tumor mass growing superiorly from the tentorium into the middle cranial fossa, often involving Meckel’s cavity, without infratentorial extension. Type T2c (Supra-infratentorial Type) displays a bi-directional growth pattern, with the tumor mass extending both above and below the tentorium, involving the middle and posterior cranial fossae as well as the midline structures. Section B includes a summary table detailing the tumor base at the middle tentorial notch for all types and listing their respective primary extension sites and case frequencies. This resource serves for preoperative surgical planning and neurosurgical classification.

This orthopaedic anatomical diagram illustrates the Chiron classification (2004) for femoral head fractures, shown across five categorized types (Type I to Type V). Each type is presented using a dry bone model of the proximal femur from two perspectives: a lateral/oblique view and a frontal view of the femoral head. Fracture lines are demarcated by solid black lines to indicate the morphology and size of the fracture fragments. Type I displays small osteochondral fragments at the superior-lateral aspect. Type II shows a 1/4 head fragment on the anterior-superior surface. Type III demonstrates a 1/3 head fragment extending from superior to posterior. Type IV depicts a vertical fracture dividing approximately 1/2 of the femoral head. Type V illustrates cranial cartilage impaction with multiple intersecting lines across the superior articular surface. The classification is clinically relevant for orthopedic surgeons and residents for determining the severity of femoral head trauma and informing surgical decisions, such as fragment fixation versus excision based on size and location.

This medical illustration presents the Yotsuyanagi classification system for cauliflower ear (auricular hematoma/deformity of the pinna), categorized into two primary types based on the preservation of the auricular outline. Type 1 deformities maintain a relatively normal external ear outline and are subdivided into four categories: 1A (localized deformity within the concha), 1B (involvement extending from the antihelix to the helix), 1C (generalized deformity affecting the entire internal ear architecture), and 1D (deformity associated with skin defects or scarring). Type 2 deformities, highlighted in the orange box, represent more severe stages where the overall auricular outline is significantly altered. Type 2A displays moderate structural integrity where a distorted but recognizable ear shape remains. Type 2B shows poor structural integrity with severe distortion and loss of the characteristic anatomical outline. This diagram is an educational resource for plastic surgery and sports medicine to grade the severity of chronic auricular trauma commonly seen in contact sports like judo or wrestling.

This clinical photograph displays a right-sided mastoidectomy dissection, focusing on the identification of Macewen’s suprameatal triangle. The image depicts the temporal bone cortex with initial surgical incisions. An orange arrow indicates the first straight cut made along the temporal line, which serves as the superior boundary of the attack triangle. A green arrow identifies a second cut made perpendicular to the first, positioned immediately posterior to the posterior ear canal wall. The surgical site exhibits characteristic yellowish-white bone texture with moist, reflective surfaces from irrigation. The defined triangular area serves as a critical anatomical landmark for ENT residents and surgeons to safely begin bone drilling and subsequent mastoid antrum identification. This pedagogical image illustrates the initial steps of otological surgery, emphasizing the importance of establishing accurate landmarks to avoid injury to deeper structures such as the middle cranial fossa dura or the facial nerve.

This educational resource features two reformatted computed tomography (CT) images of the human skull base and temporal bone region, highlighting key landmarks for mastoid morphometry. Image (a) is an oblique axial CT scan demonstrating 'mastoid depth.' It identifies the Henle suprameatal spine (hs) as a bony landmark on the lateral mastoid surface and illustrates the shortest distance (white arrow) to the sigmoid sinus (ss). This measurement is crucial for surgical planning in mastoidectomies to avoid vascular injury. Image (b) is a coronal reformatted CT scan showing 'mastoid length' (ml). A vertical double-headed white arrow measures the distance between the superior boundary, the tegmen tympani (the roof of the middle ear and mastoid antrum), and the inferior boundary, the mastoid tip. These diagnostic images serve as a teaching tool for radiological anatomy, specifically focusing on the spatial relationships between surgical landmarks and critical neurovascular structures within the mastoid process of the temporal bone.

This historical anatomical diagram illustrates a lateral view of the temporal bone, specifically demonstrating a mastoidectomy procedure. The diagram depicts the mastoid process (P.m.) after a surgical opening has been created to expose the mastoid antrum (A.m.). Key landmarks include the external auditory meatus (M.a.e.) located inferior to the antrum, the zygomatic process (P.zyg.) extending anteriorly, and the glenoid fossa (F.g.l.) which accommodates the mandibular condyle. Posterior to the surgical site, the foramen of the mastoid vein (F.m.) is visible. The illustration highlights the orientation of the surgical access point, situated superior to the ear canal and inferior to the temporal line, which serves as a traditional landmark for accessing the middle ear air cell system. This technical drawing is pedagogically significant for understanding the early development of otologic surgical techniques and the spatial relationships within the mastoid portion of the temporal bone.

Diagnostic axial Cone Beam Computed Tomography (CBCT) scans of the right temporal bone, focused on the mastoid region at the anatomical level of the head of the malleus (HM). The images illustrate the morphology of Körner's septum (KS), a persistent petrosquamosal suture that acts as a surgical landmark within the mastoid antrum. Image (a) demonstrates a 'complete' Körner's septum, characterized by a continuous, well-defined bony lamina (indicated by white arrowheads) that extends posterior to the head of the malleus, effectively compartmentalizing the mastoid air cells into superficial (squamous) and deep (petrous) portions. Image (b) shows an 'incomplete' Körner's septum, where the bony lamina is fragmented or less extensive, lacking full division of the mastoid cellularity. These radiological findings are clinically significant for otologic surgeons, particularly during mastoidectomy, as the presence of a complete septum can mimic the medial wall of the antrum and potentially obscure deeper anatomical structures like the lateral semicircular canal or the facial nerve.