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Fulltext Region of Interest-Based Tamper Detection and Lossless Recovery Watermarking Scheme (ROI-DR) on Ultrasound Medical Images

Khor HL, Liew SC, Zain JM

J Digit Imaging, 2017 Jun;30(3):328-349.
PMID: 28050716 DOI: 10.1007/s10278-016-9930-9

Tampering on medical image will lead to wrong diagnosis and treatment, which is life-threatening; therefore, digital watermarking on medical image was introduced to protect medical image from tampering. Medical images are divided into region of interest (ROI) and region of non-interest (RONI). ROI is an area that has a significant impact on diagnosis, whereas RONI has less or no significance in diagnosis. This paper has proposed ROI-based tamper detection and recovery watermarking scheme (ROI-DR) that embeds ROI bit information into RONI least significant bits, which will be extracted later for authentication and recovery process. The experiment result has shown that the ROI-DR has achieved a good result in imperceptibility with peak signal-to-noise ratio (PSNR) values approximately 48 dB, it is robust against various kinds of tampering, and the tampered ROI was able to recover to its original form. Lastly, a comparative table with the previous research (TALLOR and TALLOR-RS watermarking schemes) has been derived, where these three watermarking schemes were tested under the same testing conditions and environment. The experiment result has shown that ROI-DR has achieved speed-up factors of 22.55 and 26.65 in relative to TALLOR and TALLOR-RS watermarking schemes, respectively.

Matched MeSH terms: Radiology Information Systems/standards
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: Radiology Information Systems*
Fulltext The comparative accuracy of ultrasound and mammography in the detection of breast cancer

Tan KP, Mohamad Azlan Z, Rumaisa MP, Siti Aisyah Murni MR, Radhika S, Nurismah MI, et al.

Med J Malaysia, 2014 Apr;69(2):79-85.
PMID: 25241817 MyJurnal

AIM: This study was performed to determine the accuracy of ultrasound (USG) as compared to mammography (MMG) in detecting breast cancer.

METHODS: This was a review of patients who had breast imaging and biopsy during an 18-month period. Details of patients who underwent breast biopsy were obtained from the department biopsy record books and imaging request forms. Details of breast imaging findings and histology of lesions biopsied were obtained from the hospital Integrated Radiology Information System (IRIS). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of USG and MMG were calculated with histology as the gold standard.

RESULTS: A total of 326 breast lesions were biopsied. Histology results revealed the presence of 74 breast cancers and 252 benign lesions. USG had a sensitivity of 82%, specificity of 84%, PPV = 60%, NPV = 94% and an accuracy of 84%. MMG had a sensitivity of 49%, specificity of 89%, PPV = 53%, NPV = 88% and an accuracy of 81%. A total of 161 lesions which were imaged with both modalities were analyzed to determine the significance in the differences in sensitivity and specificity between USG and MMG. Sensitivity of USG (75%) was significantly higher than sensitivity of MMG (44%) (X(2)1=6.905, p=0.014). Specificity of MMG (91%) was significantly higher than specificity of USG (79%) (X(2)1=27.114, p<0.001). Compared with MMG, the sensitivity of USG was 50% (95% CI 10%-90%) higher in women aged less than 50 years (X(2)1=0.000, p=1.000) and 27% (95% CI 19%-36%) higher in women aged 50 years and above (X(2)1=5.866, p=0.015). Compared with MMG, the sensitivity of USG was 40% (95% CI 10%-70%) higher in women with dense breasts (X(2)1=0.234, p=0.628) and 27% (95% CI 9%-46%) higher in women with non-dense breasts (X(2)1=4.585, p=0.032).

CONCLUSION: Accuracy of USG was higher compared with MMG. USG was more sensitive than MMG regardless of age group. However, MMG was more specific in those aged 50 years and older. USG was more sensitive and MMG was more specific regardless of breast density. In this study, 20% of breast cancers detected were occult on MMG and seen only on USG.

Matched MeSH terms: Radiology Information Systems
Fulltext Do we really need standards in digital image management?

Ho E

Biomed Imaging Interv J, 2008 Oct;4(4):e20.
PMID: 21611012 MyJurnal DOI: 10.2349/biij.4.1.e20

Convention dictates that standards are a necessity rather than a luxury. Standards are supposed to improve the exchange of health and image data information resulting in improved quality and efficiency of patient care. True standardisation is some time away yet, as barriers exist with evolving equipment, storage formats and even the standards themselves. The explosive growth in the size and complexity of images such as those generated by multislice computed tomography have driven the need for digital image management, created problems of storage space and costs, and created a challenge for increasing or getting an adequate speed for transmitting, accessing and retrieving the image data. The search for a suitable and practical format for storing the data without loss of information and medico-legal implications has become a necessity and a matter of 'urgency'. Existing standards are either open or proprietary and must comply with local, regional or national laws. Currently there are the Picture Archiving and Communications System (PACS); Digital Imaging and Communications in Medicine (DICOM); Health Level 7 (HL7) and Integrating the Healthcare Enterprise (IHE). Issues in digital image management can be categorised as operational, procedural, technical and administrative. Standards must stay focussed on the ultimate goal - that is, improved patient care worldwide.

Matched MeSH terms: Radiology Information Systems
Fulltext Automatic medical X-ray image classification using annotation

Zare MR, Mueen A, Seng WC

J Digit Imaging, 2014 Feb;27(1):77-89.
PMID: 24092327 DOI: 10.1007/s10278-013-9637-0

The demand for automatically classification of medical X-ray images is rising faster than ever. In this paper, an approach is presented to gain high accuracy rate for those classes of medical database with high ratio of intraclass variability and interclass similarities. The classification framework was constructed via annotation using the following three techniques: annotation by binary classification, annotation by probabilistic latent semantic analysis, and annotation using top similar images. Next, final annotation was constructed by applying ranking similarity on annotated keywords made by each technique. The final annotation keywords were then divided into three levels according to the body region, specific bone structure in body region as well as imaging direction. Different weights were given to each level of the keywords; they are then used to calculate the weightage for each category of medical images based on their ground truth annotation. The weightage computed from the generated annotation of query image was compared with the weightage of each category of medical images, and then the query image would be assigned to the category with closest weightage to the query image. The average accuracy rate reported is 87.5 %.

Matched MeSH terms: Radiology Information Systems/statistics & numerical data*
Fulltext Development of automated image stitching system for radiographic images

Samsudin S, Adwan S, Arof H, Mokhtar N, Ibrahim F

J Digit Imaging, 2013 Apr;26(2):361-70.
PMID: 22610151 DOI: 10.1007/s10278-012-9483-5

Standard X-ray images using conventional screen-film technique have a limited field of view that is insufficient to show the full bone structure of large hands on a single frame. To produce images containing the whole hand structure, digitized images from the X-ray films can be assembled using image stitching. This paper presents a new medical image stitching method that utilizes minimum average correlation energy filters to identify and merge pairs of hand X-ray medical images. The effectiveness of the proposed method is demonstrated in the experiments involving two databases which contain a total of 40 pairs of overlapping and non-overlapping hand images. The experimental results are compared with that of the normalized cross-correlation (NCC) method. It is found that the proposed method outperforms the NCC method in classifying and merging the overlapping and non-overlapping medical images. The efficacy of the proposed method is further indicated by its average execution time, which is about five times shorter than that of the other method.

Matched MeSH terms: Radiology Information Systems/organization & administration*
Cost-effective handling of digital medical images in the telemedicine environment

Choong MK, Logeswaran R, Bister M

Int J Med Inform, 2007 Sep;76(9):646-54.
PMID: 16769242

This paper concentrates on strategies for less costly handling of medical images. Aspects of digitization using conventional digital cameras, lossy compression with good diagnostic quality, and visualization through less costly monitors are discussed.

Matched MeSH terms: Radiology Information Systems/economics*
Fulltext Repeat rate analysis of lower limb radiograph for digital radiography in general radiography at Pantai Klang hospital Selangor

Nur Aishah Jusnaidi, Nurul Fadhlina Ismail

Malaysian Journal of Applied Sciences, 2020;5(2):112-116.
MyJurnal

Assessing the repeat rate is crucial to reduce unnecessary dose to the patient by identifying the major cause for repeating the x-rays exposure to the patient and apply corrective measures. To analyse the repeat rate of routine lower limb projections in direct digital radiography (DR) from general radiology department of Pantai Klang Hospital. 26 months retrospective repeated radiograph was acquired from Picture Archiving and Communication System (PACS) at Hospital Pantai Klang. The retrieved radiographs were grouped based on the reason for the i radiographs being rejected which are incorrect positioning, incorrect collimation, patient movement, incorrect exposure factors, artefact, and other reasons. Total repeated radiographs retrieved for basic lower limbs projections were 13616. Knee was the highest repeted examination and the lowest repeat rate was tibia fibula. (repeat rate: knee = 1.04%, tibia fibula = 0.57%). incorrect positioning is the major causes for repeat exposure for all examinations type, followed by incorrect collimation, other categories, centring ray error, incorrect exposure factors and artifact.

Matched MeSH terms: Radiology Information Systems
Fulltext Assessment of Extra-Cortical Bone Bridge Interface in Cemented Mega Endoprosthesis for Limb Salvage Surgery

Murugan K, Faisham WI, Zulmi W

Malays Orthop J, 2021 Mar;15(1):93-99.
PMID: 33880154 DOI: 10.5704/MOJ.2103.014

Introduction: Mega endoprosthesis replacement for resection of primary malignant bone tumour requires immediate and long-term stability, particularly in the young and active patient. Extracortical bone bridge interface (EBBI) is a technique whereby autograft is wrapped around the interface junction of bone and porous-coated implant to induce and enhance bone formation for biological incorporation. This procedure increases the mean torsional stiffness and the mean maximum torque, which eventually improves the implant's long-term survival.
Material and methods: The extracortical bone bridge interface's radiological parameter was evaluated at the prosthesis bone junction two years after surgery utilising a picture archiving and communication system (PACS). The radiograph's anteroposterior and lateral view was analysed for both thickness and length in all four cortices. The analysis was done in SPSS Version 24 using One-Way ANOVA and independent T-Test. Results were presented as mean and standard deviation and considered significant when the p-value was < 0.05.
Results: The mean average thickness was 2.2293mm (SD 1.829), and the mean average length was 31.95% (SD 24.55). We observed that the thickness and length of EBBI were superior in the young patient or patients with giant cell tumour that did not receive chemotherapy, compared to patients treated for osteosarcoma. The distal femur also had better EBBI compared to the proximal tibia. However, the final multivariable statistical analysis showed no significant difference in all variables. EBBI thickness was significantly and positively correlated with EBBI Length (p<0.001). We conclude that, for each 1mm increase in EBBI thickness, the length will increase by 0.06% on average. About 17.2% of patients out of the 29 showed no radiological evidence of EBBI.
Conclusion: From our study, there were no factors that significantly contributed to the formation and incorporation of EBBI.

Matched MeSH terms: Radiology Information Systems