Biomedical subjects

Marcel O Philipp

Publications and source records attributed to Marcel O Philipp.

8 recordsLinked to original sources

PubMed2004

The effect of varying low-dose protocols on perceived image quality in multidetector CT in a rabbit model of acute appendicitis.

The aim of this study was to evaluate the value of multidetector CT (MD-CT) with low-dose protocols in the diagnosis of acute appendicitis in a rabbit model. Ten New Zealand white rabbits underwent ligation of the appendix. MD-CT (Siemens Somatom Plus 4 Volume Zoom) was performed using three low-dose protocols: 80 kV/70 mAs; 80 kV/50 mAs; and 80 kV/20 mAs. Axial and coronal reformations were performed. Three experienced radiologists evaluated the images using a four-grade score: (1) excellent; (2) good; (3) moderate; and (4) not sufficient. Diagnosis was confirmed histopathologically. The overall score for the 80 kV/70 mAs was 1, for the 80 kV/50 mAs protocol 1.3, and the 80 kV/20 mAs protocol reached an overall score of 2. The coronal reformations reached with 1.1 (80 kV/70 mAs), 1.2 (80 kV/50 mAs), and 1.4 (80 kV/20 mAs) had a slightly better median score than the axial reconstructions. In cases of inconclusive ultrasound and clinical presentation, the use of MD-CT can be considered when evaluating children for suspected appendicitis.

Acute Disease↗

PubMed2004

Imaging of the scrotum in children.

Clinical examination of the scrotum is difficult due to the small size of the testes and the epididymis in infants and young children, and eliciting patients' history is challenging. Therefore imaging of the scrotum in childhood bears great importance. Ultrasound is the standard imaging technique of choice providing the clinicians with a definitive diagnosis in most cases. However, in conditions of testicular torsion and epididymoorchitis--the most common differential diagnosis of scrotal pain--ultrasound findings can be inconclusive and further evaluation is required. Since there is a large overlap between paediatric and adult pathology, differences from adults in anatomy and pathology must be considered when evaluating the paediatric scrotum.

Child↗

PubMed2004

Asymmetric closure of ischiopubic synchondrosis in pediatric patients: correlation with foot dominance.

OBJECTIVE: The enlarged ischiopubic synchondrosis is a well-known anatomic structure; however, little is known about its physiology. In early childhood, enlargement of this synchondrosis occurs bilaterally, whereas before complete ossification, it is frequently found unilaterally. In most children, the unilateral enlarged ischiopubic synchondrosis is observed in the left hemipelvis, a finding that was hitherto unexplained. During common athletic activities, increased ground reaction forces are exerted on the weight-bearing nondominant limb, which in up to 87% of the general population is the left leg. The asymmetric exertion of these forces may explain the distinct closure sequence of this temporary joint. The purpose of this study was to correlate unilateral enlarged ischiopubic synchondrosis with foot dominance. MATERIALS AND METHODS: The study cohort comprised 32 children who had undergone unenhanced radiography, CT, or MRI for reasons other than bone disorders and who presented with enlarged ischiopubic synchondroses. In these children, the distribution of enlarged ischiopubic synchondrosis and foot dominance were evaluated either retrospectively (n = 11) or prospectively (n = 21). RESULTS: In this cohort, 78% of patients were right-footed and 22% were left-footed. Nine of the 32 children presented with unilateral enlarged ischiopubic synchondrosis (left, seven [78%] of nine; right, two [22%] of nine). All children with enlarged left ischiopubic synchondrosis were right-footed, and all children with enlarged right ischiopubic synchondrosis were left-footed. CONCLUSION: Unilateral enlarged ischiopubic synchondrosis is closely correlated with foot dominance. The asymmetric ossification pattern of the ischiopubic synchondrosis indicates delayed ossification of this anatomic structure due to asymmetrically applied mechanical forces to the nondominant limb.

Adolescent↗

PubMed2003

Three-dimensional volume rendering of multidetector-row CT data: applicable for emergency radiology.

Multidetector-row computed tomography (MD-CT) not only creates new opportunities but also challenges for medical imaging. Isotropic imaging allows in-depth views into anatomy and disease but the concomitant dramatic increase of image data requires new approaches to visualize, analyze and store CT data. The common diagnostic reviewing process slice by slice becomes more and more time consuming as the number of slice increases, while on the other hand CT volume data sets could be used for three-dimensional visualization. These techniques allow for comprehensive interpretation of extent of fracture, amount of dislocation and fragmentation in a three-dimensional highly detailed setting. Further more, using minimal invasive techniques like CT angiography, new opportunities for fast emergency room patient's work up arise. But the most common application is still trauma of the musculoskeletal system as well as face and head. The following is a brief review of recent literature on volume rendering technique and some exemplary applications for the emergency room.

Angiography↗

PubMed2003

Four-channel multidetector CT in facial fractures: do we need 2 x 0.5 mm collimation?

OBJECTIVE: Our aim was to optimize acquisition protocols and multiplanar reformation algorithms for the evaluation of facial fractures using multidetector CT (MDCT) and to determine whether 2 x 0.5 mm collimation is necessary. MATERIALS AND METHODS: A cadaveric head with artificial blunt facial trauma was examined using a four-channel MDCT scanner. The influence of acquisition parameters (collimation, 2 x 0.5 mm, 4 x 1 mm, 4 x 2.5 mm; tube current, 120 mAs, 90 mAs, 60 mAs), image reconstruction algorithms (standard vs ultra-high-resolution modes; reconstructed slice thicknesses, 0.5 mm, 1 mm, 3 mm; increment, 0.3 mm, 0.6 mm, 1.5 mm), and reformation algorithms (slice thicknesses, 0.5 mm, 1 mm, 3 mm; overlap, 0.5 mm, 1 mm, 3 mm) on detectability of facial fractures in multiplanar reformations with MDCT was analyzed. RESULTS: Fracture detection was significantly higher with thin multiplanar reformations (0.5 and 0.5 mm, 1 and 0.5 mm, and 1 and 1 mm) (p < or = 0.014) acquired with 2 x 0.5 mm collimation (p < or = 0.046) in ultra-high-resolution mode (p < 0.0005) with 120 mAs (p < or = 0.025). Interobserver variability showed very good agreement (kappa > or = 0.942). Non-ultra-high-resolution mode, lower milliampere-seconds, and thick multiplanar reformations (3 and 0.5 mm, 3 and 1 mm, and 3 and 0.5 mm) showed significantly decreased fracture detectability. CONCLUSION: Although thin multiplanar reformations obtained from thin collimation (2 x 0.5 mm) are statistically superior for the detection of subtle fractures, 4 x 1 mm collimation is sufficient for routine diagnostic evaluation. Ultra-high-resolution mode with 120 mAs is mandatory for detection of clinically relevant fractures.

Aged↗

PubMed2003

[Diagnostic management of nipple discharge].

Nipple discharge may be a symptom of a variety of diseases. The importance of nipple discharge is its possible association with breast carcinoma. Not only the precise clinical evaluation but also particularly imaging evaluation by mammography, ultrasound, galactography or MR-galactography is necessary to establish the exact diagnosis and plan proper treatment. Depending on the underlying pathology--most commonly intraductal papilloma, fibrocystic changes or breast carcinoma--the optimal therapeutic regimen, such as single lactiferous duct excision on the one end and modified radical mastectomy on the other end of the spectra may be chosen.

Breast Cyst↗

PubMed2002

Vertebral metastases: assessment with apparent diffusion coefficient.

The authors evaluated the apparent diffusion coefficient (ADC) in the assessment of vertebral metastases and acute vertebral compression fractures in 22 patients with known or suspected vertebral metastases. On the basis of significantly (P <.03) different ADCs, vertebral metastases (0.69 x 10(-3) mm2/sec) and pathologic compression fractures (0.65 x 10(-3) mm2/sec) can be safely distinguished from vertebral bodies (1.66 x 10(-3) mm2/sec) and benign compression fractures (1.62 x 10(-3) mm2/sec). Thus, the use of ADCs may increase the specificity of magnetic resonance imaging in these patients.

Echo-Planar Imaging↗

PubMed2002

[Good cell culture practice--implementation of a relational cell culture database].

The claim for cell culture to provide validable in vitro models for biomedical research postulates evasion of possible fatal record keeping errors. A prototype of a relational computer database for IBM-compatible personal computers using Microsoft(r) Windows 95/98/2000 and NT for administration of cell culture data has been developed using Microsoft(r) Access 98 (Microsoft Corporation, Redmond, USA), -Access Basic, -Visual Basic and Structured Query Language (SQL) (IBM Corporation, Armonk, USA), and was tested successfully. The modular software application manages the many aspects of cell culture laboratory record keeping like detailed information on tissue donor, primary cell isolation/cell line origin, immunohistochemical/molecular biological characterisation, cell countings at passaging/subcultivation/cell aliquotation and cryopreservation. One main feature is a collection of all methods performed at our cell culture laboratory, where linked tables and files store specific informations. Entries into the database are checked via validation rules for correctness to avoid mistakes. The developed prototype has been demonstrated to be an adaptable, reliable tool for improving quality of information storage according to Good Scientific Practice (GSP), Good Cell Culture Practice (GCCP) and general ISO certification trends.

Animals↗