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Gastrointestinal tract and salivary glands
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
With the imaging couch horizontal the C-arm is moved into the vertical position. The patient is supine and positioned central on the imaging couch with the patient’s head positioned near the head of the couch. The patient’s head is raised on a small non-opaque pad, with the orbitomeatal line and median sagittal plane perpendicular to the imaging couch. Prior to injection the image receptor is positioned immediately over the face and the patient positioned, using the imaging couch table top movement controls, so that the area of interest is within the centre of the imaging field. Fine adjustment of the patient’s position is undertaken taken using pulsed fluoroscopy, with the beam collimated to the area of interest and applying last image hold. Static images or cine images of the filling phase are acquired according to local protocol to demonstrate filling of the ducts and emptying.
Discussions (D)
Published in Terence R. Anthoney, Neuroanatomy and the Neurologic Exam, 2017
Unfortunately, some authors use other anatomical lines and planes for aligning the head from a lateral view, without giving their angular relationship to any of the three standard planes already described. Five examples are the canthorneatal line (presumably identical to the orbitomeatal line, though this is not always stated: e.g., “parallel to the line between the eye and the ear canal,” k&s, p. 268), the tragocanthal line (presumably the mid-point of the tragus is used, though this is not always stated: e. g., Potter, 1971, p. x), the nasomeatal line (e.g., “joins the tip of the nose with the center of the acoustic meatus,” Takahashi, 1983, p. 41), the supraorbitomeatal line (e.g., “a line from the supraorbital ridge to the external auditory meatus,” DeArmond, Fusco, and Dewey, 1976, p. v3), and the “base of the skull” (e.g., Ramsey, 1977, p. 2).
Neurological Investigations
Published in John Greene, Ian Bone, Understanding Neurology a problem-orientated approach, 2007
The path from collimator to detector establishes a single ‘beam’ passing though a patient’s tissues. During the scan the computer takes brief readings from all detectors. In the earlier scanners both collimator and detector rotated around the patient whereas in modern third and fourth generation units the detectors are fixed with only the X-ray source moving. Computer processing with multiple beams and detectors completely encircling the head allows absorption values for blocks of tissue (voxels) to be established. Reconstruction of this by twodimensional display (pixels) results in the eventual CT appearance (13). Slices studied can be varied in thickness (1–10 mm) and can be rendered parallel to the orbitomeatal line (a reference line drawn through the orbit and ear), to allow anatomical interpretation and reproducibility for repeated studies. ‘High definition’ (1–2 mm) scans give greater anatomical detail, take longer to acquire, and are reserved for examination of specific sites (orbit, Circle of Willis, pituitary). Alteration of window level will change the contrast appearance and allow more detailed assessment of bony structures or help visualize subtle differences in tissue contrast, such as with an acute cerebral infarct.
Outcomes of the Baha Attract System combined with auricle reconstruction in mandarin speaking patients with bilateral microtia-atresia
Published in Acta Oto-Laryngologica, 2019
Xinmiao Fan, Yu Chen, Xiaomin Niu, Yibei Wang, Yue Fan, Xiaowei Chen
The implantation procedure in both subsets of patients began by using a Baha Attract indicator to mark the location of the implant in the postaural region. Preferably, the implant site was 7.0 cm from ear canal and at an angle to the orbitomeatal line. A C-shaped incision marking was made about 1.5 cm anterior, marking the anterior edge of the magnet, and the thicknesses of soft tissue at the implant site and at the anterior and posterior edges of the magnet were measured. An incision was made with a thin intact periosteum below, resulting in an elevated flap for accommodation of the implant magnet template. To properly orient the implant, the periosteum was marked with methylene blue dye, followed by a cruciate incision on the periosteum at the marked implant site and elevation with a detacher.
Unilateral chronic subdural hematoma due to spontaneous intracranial hypotension: a report of four cases
Published in British Journal of Neurosurgery, 2020
Yoshinari Osada, Ichiyo Shibahara, Atsuhiro Nakagawa, Hiroyuki Sakata, Kuniyasu Niizuma, Ryuta Saito, Masayuki Kanamori, Miki Fujimura, Shinsuke Suzuki, Teiji Tominaga
Cranial asymmetry was calculated as reported by Akhaddar et al.15 For calculation, an axial CT section located approximately 6 cm above the orbitomeatal line was used. For cranial convexity, an angle comprising the midline and a line contacting the inner table on either side of the anterior cranium was calculated. Cranial convexity was considered asymmetric if the difference between the angles was >2°.15,16 The angles of cranial convexity are illustrated in Figures 1(E), 2(E), 3(F), and 4(D). None of the patients exhibited symmetric cranial morphology.
Normative orbital measurements in an Australian cohort on computed tomography
Published in Orbit, 2023
Khizar Rana, Valerie Juniat, Wen Yong, Sandy Patel, Dinesh Selva
Axial CT orbit scans 0.6 mm thick were obtained at 0.4 mm intervals on a Siemens Somatom Force CT (SIEMENS, Germany). The axial scans were obtained at an angle of 10–15 degrees relative to the orbitomeatal line. Coronal reconstructions were performed perpendicular to the axial plane. Quasi-sagittal reconstructions were made parallel to the orbital axis passing through the centre of the inferior rectus. Patients were asked to maintain a forward gaze to prevent asymmetric extraocular muscle contraction. A window width of 360 HU and a centre of 60 HU was used.