Navicular bone location in radiographs and solar scintigrams

The anatomical location of the navicular bone region in the solar projection scintigram has not been clearly established and it is often not possible to define the navicular bone in solar projection bone phase scintigrams. This is due to the relatively poor anatomical detail of scintigrams. In contrast, skeletal radiology has high spatial and contrast resolutions and skeletal structures can be well defined, however radiology does not provide the functional information that scintigraphy does. Techniques using quantitative analysis of scintigrams, particularly the navicular bone region in the solar scintigram, seem to be becoming more popular. For these techniques to be reliable, correct positioning of regions of interest or profiles is essential, and this requires accurate location of anatomical structures. Superimposition of the proximal interphalangeal joint region on the navicular bone region in the solar projection scintigram is a recognised problem when evaluating the palmar regions of the foot for abnormal areas of radiopharmaceutical uptake, and this superimposition could result in incorrect interpretation of the radiopharmaceutical uptake in a navicular bone region of interest. It was hypothesised that landmarks in the solar projection scintigram could be used to locate the navicular bone region and that there would be the least superimposition of the proximal interphalangeal joint region on the navicular bone region when the interphalangeal joints were flexed. Measurements were taken from radiographs of specimen horse legs to determine if the navicular bone moved relative to the distal phalanx when the leg position was changed. Using both specimen horse legs and live horses radiographs were examined to investigate the navicular bone position relative to landmarks on the distal phalanx. Radiographs of specimen horse legs were taken with the legs positioned in maximum interphalangeal joint flexion, maximum interphalangeal joint extension and a fixed angle (50º), and the degree of overlap of the proximal interphalangeal joint region and the navicular bone region was measured. Leg positioning did not change the position of the navicular bone relative to the distal phalanx in a dorsal to palmar plane. Very little variation existed between individuals in: the ratio of the distance from the dorsodistal margin of the distal phalanx to the dorsal margin of the navicular bone (P3-Navicular) compared to the dorsopalmar length of the navicular bone (Navicular length), the ratio between the maximum lateral width (P3 width) of the distal phalanx and P3-Navicular, and the ratio between P3 width and the maximum lateral width of the navicular bone (Navicular width). In contrast, large variation existed in the ratio of the distance from the palmar aspect of the palmar processes to the palmar aspect of the navicular bone (Navicular-PP), compared to Navicular length. Positioning the pastern in maximum flexion resulted in the least overlap of the proximal interphalangeal joint and navicular regions. It is recommended that the phalanges are flexed and the sole is placed flat on a raised horizontal gamma camera when the solar projection is acquired. The measurement ratios of the distal phalanx and the navicular bone were applied to a solar projection scintigram to predict navicular bone position and position a navicular bone region of interest using anatomical landmarks that could be distinctly identified in the scintigram

Imagerie par résonance magnétique de l'ostéoarthrose métacarpo-phalangienne équine : évaluation des paramètres non-cartilagineux

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Sintesi delle Pubblicazioni : Anni 1988 - 1995

Repertorio delle pubblicazioni scientifiche negli anni dal 1988 al 1995 dei docenti e ricercatori della Facoltà di Medicina Veterinaria. Digitalizzazione effettuata nel 2018 a cura della Biblioteca di Veterinaria "Ercolani". La digitalizzazione è stata autorizzata da Clueb, editrice della pubblicazione cartacea

Characterization of alar ligament on 3.0T MRI: a cross-sectional study in IIUM Medical Centre, Kuantan

INTRODUCTION: The main purpose of the study is to compare the normal anatomy of alar ligament on MRI between male and female. The specific objectives are to assess the prevalence of alar ligament visualized on MRI, to describe its characteristics in term of its course, shape and signal homogeneity and to find differences in alar ligament signal intensity between male and female. This study also aims to determine the association between the heights of respondents with alar ligament signal intensity and dimensions. MATERIALS & METHODS: 50 healthy volunteers were studied on 3.0T MR scanner Siemens Magnetom Spectra using 2-mm proton density, T2 and fat-suppression sequences. Alar ligament is depicted in 3 planes and the visualization and variability of the ligament courses, shapes and signal intensity characteristics were determined. The alar ligament dimensions were also measured. RESULTS: Alar ligament was best depicted in coronal plane, followed by sagittal and axial planes. The orientations were laterally ascending in most of the subjects (60%), predominantly oval in shaped (54%) and 67% showed inhomogenous signal. No significant difference of alar ligament signal intensity between male and female respondents. No significant association was found between the heights of the respondents with alar ligament signal intensity and dimensions. CONCLUSION: Employing a 3.0T MR scanner, the alar ligament is best portrayed on coronal plane, followed by sagittal and axial planes. However, tremendous variability of alar ligament as depicted in our data shows that caution needs to be exercised when evaluating alar ligament, especially during circumstances of injury

Case series of breast fillers and how things may go wrong: radiology point of view

INTRODUCTION: Breast augmentation is a procedure opted by women to overcome sagging breast due to breastfeeding or aging as well as small breast size. Recent years have shown the emergence of a variety of injectable materials on market as breast fillers. These injectable breast fillers have swiftly gained popularity among women, considering the minimal invasiveness of the procedure, nullifying the need for terrifying surgery. Little do they know that the procedure may pose detrimental complications, while visualization of breast parenchyma infiltrated by these fillers is also deemed substandard; posing diagnostic challenges. We present a case series of three patients with prior history of hyaluronic acid and collagen breast injections. REPORT: The first patient is a 37-year-old lady who presented to casualty with worsening shortness of breath, non-productive cough, central chest pain; associated with fever and chills for 2-weeks duration. The second patient is a 34-year-old lady who complained of cough, fever and haemoptysis; associated with shortness of breath for 1-week duration. CT in these cases revealed non thrombotic wedge-shaped peripheral air-space densities. The third patient is a 37‐year‐old female with right breast pain, swelling and redness for 2- weeks duration. Previous collagen breast injection performed 1 year ago had impeded sonographic visualization of the breast parenchyma. MRI breasts showed multiple non- enhancing round and oval shaped lesions exhibiting fat intensity. CONCLUSION: Radiologists should be familiar with the potential risks and hazards as well as limitations of imaging posed by breast fillers such that MRI is required as problem-solving tool