SA Journal of Radiology - Volume 13, Issue 3, 2009
Volume 13, Issue 3, 2009
Author J.P. Van NiekerkSource: SA Journal of Radiology 13 (2009)More Less
The switch of SAJR to a fully online journal has been most successfully managed by Jan Lotz, editor of the journal. In his editorial of April 2008 he explained the process of readers, authors and others accessing the SAJR in this format via www.sajr.org.za. He promised that CPD would also be available for members.
Source: SA Journal of Radiology 13, pp 49 –54 (2009)More Less
Background. Radiologists analyse both standard mammographic views of a breast to confirm the presence of abnormalities and reduce false-positives. However, at present, no computer-aided diagnosis system uses ipsilateral mammograms to confirm the presence of suspicious features.
Aim. The aim of this study was to develop image-processing algorithms that can be used to match a suspicious feature from one mammographic view to the same feature in another mammographic view of the same breast. This algorithm can be incorporated into a computer-aided diagnosis package to confirm the presence of suspicious features.
Method. The algorithms were applied to 68 matched pairs of craniocaudal and mediolateral-oblique mammograms. The results of this pilot study take the form of maps of similarity. A novel method of evaluating the similarity maps is presented, using the area under the receiver operating characteristic curve (AUC) and the contrast (C) between the area of the matched region and the background of the similarity map.
Results and conclusions. The first matching algorithm (using texture measures extracted from a grey-level co-occurrence matrix (GLCM) and a Euclidean distance similarity metric) achieved an average AUC of 0.80±0.17 with an average C of 0.46±0.26. The second algorithm (using GLCMs and a mutual information similarity metric) achieved an average AUC of 0.77±0.25 with an average C of 0.50±0.42. The latter algorithm also performed remarkably well with the matching of malignant masses and achieved an average AUC of 0.96±0.05 with an average C of 0.90±0.21. In conclusion, texture analysis methods used with suitable similarity metrics allow a suspicious feature from one mammographic view to be matched with the same suspicious feature in other mammographic views of the same breast.
Incidental MDCT finding of a subclinical PDA in an adult patient with Eisenmenger syndrome : case reportSource: SA Journal of Radiology 13, pp 56 –59 (2009)More Less
Patent ductus arteriosus (PDA) comprises 5 - 10% of all congenital cardiac lesions. The incidence of PDA is 1 in 500, although most of these children are asymptomatic. The defect must persist beyond 3 months of age to be considered pathological. The male:female ratio is 1:2 unless the condition is associated with other congenital problems. Most children with PDA are asymptomatic; however, 50% of patients with a large PDA will develop pulmonary hypertension and may eventually develop Eisenmenger's syndrome if left patent.
Unusual presentation and inconclusive biopsy render fibroadenoma in two young females a diagnostic dilemma : case reportSource: SA Journal of Radiology 13, pp 62 –65 (2009)More Less
Two young, nonlactating, nulliparous women presented with acutely painful breast masses. Sonographic features showed mixed echogenic masses. Core biopsies were not diagnostic, and surgical excision revealed infarcted fibroadenomas in both cases. Although fibroadenomas are common, they do not commonly infarct, and only rarely in non-lactating or non-pregnant females. These two cases highlight the clinical and imaging characteristics of an important differential diagnosis.
Source: SA Journal of Radiology 13, pp 66 –70 (2009)More Less
Sandhoff's disease is a rare autosomal recessive disorder of sphingolipid metabolism that results from deficiency of the lysosomalenzymes, β-hexosaminidase A and B. The resultant accumulation of GM2 ganglioside within both grey matter nuclei and myelin sheaths of the white matter results in eventual severe neuronal dysfunction and neurodegeneration. Disease progression is rapid, resulting in early death. Currently, there is no curative treatment, with therapy remaining primarily supportive.
This case report is of a 13-month-old aboriginal Canadian boy who was referred for further investigations related to global developmental delay and loss of developmental milestones, at which time the diagnosis was discovered.
Author Debra MeerkotterSource: SA Journal of Radiology 13, pp 72 –74 (2009)More Less
Mammography is an established screening tool for breast cancer. Early detection of breast cancer has a significant impact on morbidity and mortality. Correct interpretation of mammograms can avoid false negatives and unnecessary biopsies in respect of benign changes. However, interpretation of mammograms can be challenging. The medial aspect of the breast is a 'blind spot' on the medio-lateral oblique view. As mammographic techniques improve, more attention is being given to imaging the medial breast, and the sternalis muscle will be revealed with increasing frequency.
Author S. AndronikouSource: SA Journal of Radiology 13 (2009)More Less