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Fulltext Brain death: rapid evaluation using computerized radionuclide cerebral flow study

Paramsothy M, Ong GSY, Wong BH, Loh TG, Delilkan AE

Med J Malaysia, 1986 Sep;41(3):189-97.

Demonstration of arrested intracerebral blood flow is the ultimate evidence of brain death. Computerized radionuclide cerebral flow study was done on 18 patients diagnosed clinically as brain dead. Correlation was made with clinical neurophysiological and EEG findings. The criteria for diagnosis of arrested intracerebral perfusion using radionuclide flow study were: non-visualization of blood flow activity in the intracranial arteries during the arterial phase, diffused cerebral activity during the capillary phase and non-filling of venous sinuses during the venous phase; visualization of typical 'hot nasal' activity; the time activity curve over the cerebral hemispheres lacks a bolus effect and instead shows a delayed gradual rise of activity. These features are pathognomonic of brain tamponade.
Arrested intracranial circulation was seen in 16 patients (ten had electrocerebral silence; one had extremely abnormal EEG with small voltage activity and five had no EEG done). In the remaining two patients, some cerebral blood flow was demonstrated (one had no definite cerebral activity and the other had diffused EEG activity).
Radionuclide cerebral flow study is a very sensitive, accurate, safe, simple, rapid and non-invasive modality in confirming brain death and is especially useful in patients on "brain-protection" regime, in hypothermia or in certain metabolic states where diagnosis based on clinical and EEG criteria is difficult. EEG need not be a required procedure once brain death is established by the demonstration of arrested intracranial circulation.

Matched MeSH terms: Image Processing, Computer-Assisted

Racial variations in the extent of tooth root translucency in ageing individuals

Whittaker DK, Bakri MM

Arch Oral Biol, 1996 Jan;41(1):15-9.

PMID: 8833585

One hundred and ninety-eight single-rooted teeth from individuals aged 21-90 yr of Caucasian, Malay, Chinese Malay and Indian Malay origin were studied. Single or serial longitudinal sections of extracted teeth were cut following dye imbibition of patent dentinal tubules. The extent of sclerosis of apical dentinal tubules was assessed and correlated with the age of the individual. Correlation with age was higher in the Caucasian than the Malay races and within the Malaysian racial groups correlation with age was highest in the Malays and lowest in the Chinese. It is concluded that factors other than age may be important in the formation of sclerotic apical dentine in teeth of different racial origin. The effect of racial origin should be considered when using sclerosis as a means of age determination in forensic cases.

Matched MeSH terms: Image Processing, Computer-Assisted

Microcalcification clustering parameters in breast disease: a morphometric analysis of radiographs of excision specimens

Ng KH, Looi LM, Bradley DA

Br J Radiol, 1996 Apr;69(820):326-34.

PMID: 8665132

X-ray microradiography of surgically excised breast specimens offers the possibility of morphological characterization of calcifications. When combined with digital imaging techniques there exists added potential for obtaining valuable basic quantitative morphometric information regarding differences between microcalcifications in tissues exhibiting evidence of fibrocystic change, benign and malignant tumours. A total of 157 excised breast specimens from 84 patients were microradiographed using a Softex Super Soft X-ray unit and Kodak AA high resolution industrial film. A Quantimet 570C image analysis system was used to digitize and analyse the microradiographs. Of the 157 microradiographs, 51 (from 30 patients) revealed microcalcification clusters. The existence of significant differences between the three identified categories of tissue were indicated by clustering parameters. These included the number of particles per cluster, area of clusters, maximum distance to nearest neighbour, and geometric mean distance to nearest neighbour. The distribution pattern index (DPI), another of the clustering parameters used in this study, has been observed to be a particularly powerful discriminator. The value for fibrocystic change was found to be significantly smaller (0.514) than that for benign tumour (0.796) whilst that for benign tumour was observed to be significantly larger than that for malignant tumour (0.604) at a p-value of less than 0.05 (Kruskal-Wallis one-way analysis of variance).

Matched MeSH terms: Image Processing, Computer-Assisted

Denture microlabeling technique

Ibrahim WM

J Prosthet Dent, 1996 Jul;76(1):104.

PMID: 8814640

Matched MeSH terms: Image Processing, Computer-Assisted

Analysis of fliC variation among clinical isolates of Burkholderia cepacia

Winstanley C, Hales BA, Morgan JAW, Gallagher MJ, Puthucheary SD, CISSé MF, et al.

J Med Microbiol, 1999 Jul;48(7):657-662.

PMID: 10403416 DOI: 10.1099/00222615-48-7-657

PCR and restriction fragment length polymorphism (RFLP) typing of flagellin genes (fliC) from 57 clinical isolates of Burkholderia cepacia indicated that only type 11 flagellins were present. Twenty-two isolates previously identified as the epidemic UK cystic fibrosis strain were indistinguishable by this method, as were 11 isolates from a pseudo-outbreak in Senegal. Other clinical isolates, including 19 from disparate sources in Malaysia, were separated into nine fliC RFLP groups, exhibiting a large degree of divergence. When isolates were indistinguishable by fliC genotyping, their similarity was confirmed by whole genome macro-restriction analysis with pulsed-field gel electrophoresis following XbaI digestion. The variation in fliC sequences of B. cepacia was far greater than that with B. pseudomallei, supporting the view that 'B. cepacia', as currently defined, may comprise several different genomic species.

Matched MeSH terms: Image Processing, Computer-Assisted

Evaluation of groundwater and soil pollution in a landfill area using electrical resistivity imaging survey

Ahmed AM, Sulaiman WN

Environ Manage, 2001 Nov;28(5):655-63.

PMID: 11568845

Landfills are sources of groundwater and soil pollution due to the production of leachate and its migration through refuse. This study was conducted in order to determine the extent of groundwater and soil pollution within and around the landfill of Seri Petaling located in the State of Selangor, Malaysia. The condition of nearby surface water was also determined. An electrical resistivity imaging survey was used to investigate the leachate production within the landfill. Groundwater geochemistry was carried out and chemical analysis of water samples was conducted upstream and downstream of the landfill. Surface water was also analyzed in order to determine its quality. Soil chemical analysis was performed on soil samples taken from different locations within and around the landfill in the vadose zone (unsaturated zone) and below the water table (in the soil saturated zone). The resistivity image along line L-L1 indicated the presence of large zones of decomposed waste bodies saturated with highly conducting leachate. Analysis of trace elements indicated their presence in very low concentrations and did not reflect any sign of heavy metal pollution of ground and surface water or of soil. Major ions represented by Na, K, and Cl were found in anomalous concentrations in the groundwater of the downstream bore hole, where they are 99.1%, 99.2%, and 99.4%, respectively, higher compared to the upstream bore hole. Electrical conductivity (EC) was also found in anomalous concentration downstream. Ca and Mg ions represent the water hardness (which is comparatively high downstream). There is a general trend of pollution towards the downstream area. Sulfates (SO4) and nitrates (NO3) are found in the area in low concentrations, even below the WHO standards for drinking water, but are significantly higher in the surface water compared to the groundwater. Phosphate (PO4) and nitrite (NO2), although present in low levels, are significantly higher at the downstream. There is no significant difference in the amount of fluoride (F) in the different locations. In the soil vadose zone, heavy metals were found to be in their typical normal ranges and within the background concentrations. Soil exchangeable bases were significantly higher in the soil saturated zone compared to the vadose zone, and no significant difference was obtained in the levels of inorganic pollutants. With the exception of Cd, the concentration ranges of all trace elements (Cu, Zn, Cr, Pb, and Ni) of Seri Petaling landfill soils were below the upper limits of baseline concentrations published from different sources.

Matched MeSH terms: Image Processing, Computer-Assisted

Preoperative high resolution CT and MR imaging in cochlear implantation

Abdullah A, Mahmud MR, Maimunah A, Zulfiqar MA, Saim L, Mazlan R

Ann Acad Med Singap, 2003 Jul;32(4):442-5.

PMID: 12968546

INTRODUCTION: Accurate preoperative imaging of the temporal bone in patients receiving cochlear implants is important. High resolution computed tomography (HRCT) and magnetic resonance (MR) imaging are the 2 preoperative imaging modalities that provide critical information on abnormalities of the otic capsule, pneumatisation of the mastoid, middle ear abnormalities, cochlear ducts patency and presence of cochlear nerve.

MATERIALS AND METHODS: The HRCT and MR imaging in 46 cochlear implant patients in our department were reviewed.

RESULTS: Majority of our patients [34 patients (73.9%)] showed normal HRCT of the temporal bone; 5 (10.9%) patients had labyrinthitis ossificans, 2 (4.3%) had Mondini's abnormality and 2 (4.3%) had middle ear effusion. One patient each had high jugular bulb, hypoplasia of the internal auditory canal and single cochlear cavity, respectively.

CONCLUSION: The above findings contribute significantly to our surgical decisions regarding candidacy for surgery, side selection and surgical technique in cochlear implantation.

Matched MeSH terms: Image Processing, Computer-Assisted/methods*

Aberrant expression of acute-phase reactant proteins in sera and breast lesions of patients with malignant and benign breast tumors

Doustjalali SR, Yusof R, Yip CH, Looi LM, Pillay B, Hashim OH

Electrophoresis, 2004 Jul;25(14):2392-401.

PMID: 15274022

We have analyzed unfractionated sera of newly diagnosed patients (n=10) with breast carcinoma (BC), prior to treatment, and patients (n=5) with fibrocystic disease of the breast (FDB) by two-dimensional gel electrophoresis (2-DE) and silver staining. The patients' 2-DE serum protein profiles obtained were then subjected to image analysis and compared to similar data generated from sera of normal healthy female controls (n=10) of the same range of age. The relative expression of alpha1-antichymotrypsin (ACT), clusterin, and complement factor B was significantly higher in all BC patients as compared to normal controls. However, the expression of alpha1-antitrypsin (AAT) in BC patients was apparently lower than that of the controls. Similar differential expression of ACT was detected in the FDB patients. The aberrant expression of the serum acute-phase proteins of patients with BC and FDB was confirmed by competitive enzyme-linked immunosorbent assay (ELISA). Similar altered proteins expression was also observed from immunohistochemical studies of malignant (n=5) and benign (n=5) breast lesions of the respective patients performed using antisera to the aberrantly expressed proteins. However, the malignant breast lesions were instead positively stained for AAT. The differential expression of the serum proteins was apparently abrogated when a six-month follow-up study was performed on nine of the BC patients subsequent to treatment.

Matched MeSH terms: Image Processing, Computer-Assisted

Cross-sectional morphology and minimum canal wall widths in C-shaped roots of mandibular molars

Chai WL, Thong YL

J Endod, 2004 Jul;30(7):509-12.

PMID: 15220648

The cross-sectional canal morphology and minimum widths of buccal and lingual canal walls were studied in 20 mandibular molars with C-shaped roots and canal orifices. The roots were mounted in clear resin blocks and sectioned transversely at 1-mm intervals. A total of 154 cross-sections were evaluated with an image analyzer. Twelve different longitudinal canal configurations were identified. The most prevalent were types 1-2 and 1-2-1 with each type occurring in four roots. Evaluation of the cross-sectional morphology showed that the configurations were complete "C" (27%), incomplete C (64%), and non-C (9%). The mean value for the minimum width of the lingual canal wall was 0.58 +/- 0.21 mm and the buccal wall was 0.96 +/- 0.26 mm. This suggests that there is a higher risk of root perforation at the thinner lingual walls of C-shaped canals during shaping and post canal preparation procedures. Both buccal and lingual canal walls were frequently narrower at mesial locations.

Matched MeSH terms: Image Processing, Computer-Assisted

Image signal-to-noise ratio estimation using the autoregressive model

Sim KS, Kamel NS

Scanning, 2004 7 31;26(3):135-9.

PMID: 15283250

In the last two decades, a variety of techniques for signal-to-noise ratio (SNR) estimation in scanning electron microscope (SEM) images have been proposed. However, these techniques can be divided into two groups: first, SNR estimators of good accuracy, but based on impractical assumptions; second, estimators based on realistic assumptions but of poor accuracy. In this paper we propose the implementation of autoregressive (AR)-model interpolation as a solution to the problem. Unlike others, the proposed technique is based on a single SEM image and offers the required accuracy and robustness in estimating SNR values.

Matched MeSH terms: Image Processing, Computer-Assisted

Granulometric analysis of spots in DNA microarray images

Latha B, Venkatesh B

Genomics Proteomics Bioinformatics, 2004 Nov;2(4):222-36.

PMID: 15901251

As the topological properties of each spot in DNA microarray images may vary from one another, we employed granulometries to understand the shape-size content contributed due to a significant intensity value within a spot. Analysis was performed on the microarray image that consisted of 240 spots by using concepts from mathematical morphology. In order to find out indices for each spot and to further classify them, we adopted morphological multiscale openings, which provided microarrays at multiple scales. Successive opened microarrays were subtracted to identify the protrusions that were smaller than the size of structuring element. Spot-wise details, in terms of probability of these observed protrusions, were computed by placing a regularly spaced grid on microarray such that each spot was centered in each grid. Based on the probability of size distribution functions of these protrusions isolated at each level, we estimated the mean size and texture index for each spot. With these characteristics, we classified the spots in a microarray image into bright and dull categories through pattern spectrum and shape-size complexity measures. These segregated spots can be compared with those of hybridization levels.

Matched MeSH terms: Image Processing, Computer-Assisted/methods

Autoregressive Wiener filtering in a scanning electron microscopy imaging system

Sim KS, Kamel NS, Chuah HT

Scanning, 2005 6 7;27(3):147-53.

PMID: 15934507

In this paper, we propose to use the autoregressive (AR)-based interpolator with Wiener filter and apply the idea to scanning electron microscope (SEM) images. The concept for combining the AR-based interpolator with Wiener filtering comes from the essential requirement of Wiener filtering for accurate and consistent estimation of the power of the noise in images prior to filter implementation. The resultant filter is called AR-Wiener filter. The proposed filter is embedded onto the frame grabber card of the scanning electron microscope (SEM) for real-time image processing. Different images are captured using SEM and used to compare the performances of the conventional Wiener and the proposed AR-Wiener technique.

Matched MeSH terms: Image Processing, Computer-Assisted

Model-based compression for 3D medical images stored in the DICOM format

Logeswaran R, Eswaran C

J Med Syst, 2006 Apr;30(2):133-8.

PMID: 16705998

Many medical examinations involve acquisition of a large series of slice images for 3D reconstruction of the organ of interest. With the paperless hospital concept and telemedicine, there is very heavy utilization of limited electronic storage and transmission bandwidth. This paper proposes model-based compression to reduce the load on such resources, as well as aid diagnosis through the 3D reconstruction of the structures of interest, for images acquired by various modalities, such as MRI, Ultrasound, CT, PET etc. and stored in the DICOM file format. An example implementation for the biliary track in MRCP images is illustrated in the paper. Significant compression gains may be derived from the proposed method, and a suitable mixture of the models and raw images would enhance the patient medical history archives as the models may be stored in the DICOM file format used in most medical archiving systems.

Matched MeSH terms: Image Processing, Computer-Assisted/methods*

Medical image compression using 3-D Hartley transform

Shyam Sunder R, Eswaran C, Sriraam N

Comput Biol Med, 2006 Sep;36(9):958-73.

PMID: 16026779

In this paper, 3-D discrete Hartley transform is applied for the compression of two medical modalities, namely, magnetic resonance images and X-ray angiograms and the performance results are compared with those of 3-D discrete cosine and Fourier transforms using the parameters such as PSNR and bit rate. It is shown that the 3-D discrete Hartley transform is better than the other two transforms for magnetic resonance brain images whereas for the X-ray angiograms, the 3-D discrete cosine transform is found to be superior.

Matched MeSH terms: Image Processing, Computer-Assisted/methods*

The hyoid bone in malay infants with cleft lip and palate

Rajion ZA, Townsend GC, Netherway DJ, Anderson PJ, Hughes T, Shuaib IL, et al.

Cleft Palate Craniofac J, 2006 Sep;43(5):532-8.

PMID: 16986987

To compare morphological and positional variations of the hyoid bone in unoperated infants with cleft lip and palate (CL/P) with those in noncleft infants.

Matched MeSH terms: Image Processing, Computer-Assisted

Dental arch shape and size in Malay schoolchildren with Class II malocclusion

Banabilh SM, Rajion ZA, Samsudin R, Singh GD

Aust Orthod J, 2006 Nov;22(2):99-103.

PMID: 17203572

To quantify and localise differences in Class I and Class II dental arches in Malay schoolchildren.

Matched MeSH terms: Image Processing, Computer-Assisted

Facial soft tissue features assessed with finite element analysis

Banabilh SM, Rajion ZA, Samsudin AR, Singh GD

Int J Orthod Milwaukee, 2006;17(4):17-20.

PMID: 17256439

Facial soft tissues are a major determinant of treatment choice. When Class I and Class II malocclusions were compared using finite-element analysis, morphologic differences were localized and quantified. This study highlights the importance of determining the timing, magnitude and direction offacial growth prior to treatment to achieve stable results.

Matched MeSH terms: Image Processing, Computer-Assisted

Use of non-invasive phase contrast magnetic resonance imaging for estimation of atrial septal defect size and morphology: a comparison with transesophageal echo

Piaw CS, Kiam OT, Rapaee A, Khoon LC, Bang LH, Ling CW, et al.

Cardiovasc Intervent Radiol, 2006 Mar-Apr;29(2):230-4.

PMID: 16252078

Transesophageal echocardiography (TEE) is a trusted method of sizing atrial septal defect (ASD) prior to percutaneous closure but is invasive, uncomfortable, and may carry a small risk of morbidity and mortality. Magnetic resonance imaging (MRI) may be useful non-invasive alternative in such patients who refuse or are unable to tolerate TEE and may provide additional information on the shape of the A0SD.

Matched MeSH terms: Image Processing, Computer-Assisted

An Asian community's perspective on facial profile attractiveness

Soh J, Chew MT, Wong HB

Community Dent Oral Epidemiol, 2007 Feb;35(1):18-24.

PMID: 17244134

To assess the facial profile preferences of laypersons in an Asian community and the influence of age, ethnic and gender on profile selection.

Matched MeSH terms: Image Processing, Computer-Assisted

Tooth size discrepancies in an orthodontic population

Othman S, Harradine N

Angle Orthod, 2007 Jul;77(4):668-74.

PMID: 17605478

To explore how many millimeters of tooth size discrepancy (TSD) are clinically significant, to determine what percentage of a representative orthodontic population has such a tooth size discrepancy, and to determine the ability of simple visual inspection to detect such a discrepancy.

Matched MeSH terms: Image Processing, Computer-Assisted

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