A prospective study to compare the diagnostic performance of breast elastography versus conventional breast ultrasound.

AIM: To compare the diagnostic performance of breast elastography versus conventional ultrasound in the assessment of breast lesions. MATERIALS AND METHODS: The study was approved by the hospital's institutional review board. A prospective study involving 99 consecutive women who gave informed consent were enrolled from September 2007 to March 2008. One hundred and ten breast lesions were evaluated separately by conventional ultrasound, elastography and combined conventional ultrasound with elastography. Ultrasound assessment was based on the BIRADS classification, whereas elastographic assessment was based on strain pattern and the elastographic size ratios. Histological diagnosis was used as the reference standard. The sensitivity, specificity, and accuracy of each technique were compared. RESULTS: The mean age of the patients was 46.7 years. Twenty-six lesions were malignant and 84 were benign. Sensitivity, specificity, and accuracy were 88.5, 42.9 and 53.6%, respectively, for conventional ultrasound, 100, 73.8, and 80%, respectively, for elastography, and 88.5, 78.6, and 80.9%, respectively, for combined imaging. The specificity and accuracy of elastography and combined imaging were significantly better than that of conventional ultrasound (p<0.0001), whereas there was no statistically significant difference in the sensitivity between all three groups. Two-thirds (66.7%) of sonographic false-positive lesions had benign elastogram findings, which might have been spared from biopsy. CONCLUSION: This initial experience with ultrasound breast elastography showed that it was more specific and more accurate than conventional ultrasound. Combining elastography with ultrasound improved specificity and accuracy of ultrasound and can potentially reduce unnecessary breast biopsies.

Upright stereotactic vacuum-assisted needle biopsy of suspicious breast microcalcifications.

Stereotactic core needle biopsy is a useful technique for evaluation of suspicious breast microcalcifications. The development of the 11-G vacuum-assisted biopsy system offers another method of minimally invasive biopsy carried out on a conventional mammography unit. We evaluate its usefulness, efficacy and safety in Asian women. Vacuum-assisted biopsy was carried out through the lateral approach using an add-on stereotactic device attached to a mammography unit. One hundred and five lesions were sampled in 97 patients. Excisional biopsy was subsequently Carried out for diagnosis of atypical ductal hyperplasia or carcinoma in high-risk patients. Patients with benign diagnosis underwent mammographic follow up. The technical success rate was 97%. An average of 13.5 tissue cores were retrieved for each lesion. The histopathological result obtained from mammotome was benign in 84.8% and malignant in 15.2%. The benign microcalcifications were predominantly fibrocystic change (n = 42) whereas the malignant microcalcifications included ductal carcinoma in situ (n = 15) and invasive carcinoma (n = 1). Twenty-two patients underwent subsequent open surgical biopsy but no underestimation of disease was seen. Only two patients had vasovagal syncope and three others felt unwell during the biopsy. Nine patients had small haematomas, which resolved spontaneously. Vacuum-assisted biopsy carried out on an upright stereotactic mammography unit is a safe and effective method for evaluation of suspicious microcalcifications.

Numerical modelling of biopotential field for detection of breast tumour.

Breast cancer is a disease characterised by the uncontrolled growth of abnormal cells. These cancer cells can travel through the body by way of blood or lymph nodes. Previous studies have indicated that, changes in the electrical properties of abnormal breast are more significant compared to the breast normal tissues. In the present study, a simple 2D models of breast (close to realistic), with and without artificially inserted malignant cancer were simulated, based upon electrical activity within the breast. We developed an inhomogeneous female breast model, closer to the actual, by considering a breast as a hemisphere with various layers of unequal thickness in supine condition. In order to determine the potential distribution developed due to a dipole source, isotropic homogeneous conductivity was assigned to each of these compartments and the volume conductor problem was solved using finite element method. Significant changes in the potential distribution were recoded in the malignant and normal breast regions. The surface potential decreases about 0.5%, for the small malignant region of surface area 13 mm(2) (spherical diameter=2mm). And it (surface potential) decreases about 16.4% for large malignant surface area of 615 mm(2) (spherical diameter=14 mm). Hence, the results show that, the sizes of tumours result in the reduction of surface potential and follows a fourth order polynomial equation. Thus, biofield analysis yields promising results in the detection of the breast cancer of various sizes.

US correlation for MRI-detected breast lesions in women with familial risk of breast cancer.

AIM: To examine the value of US correlation for MRI-detected breast lesions in women with familial risk of breast cancer. METHODS: From an initial dataset of 245 women with positive family history who had breast cancer surveillance involving mammography or MRI between November 1994 and February 2001, 179 subjects with follow-up data were selected. A total of 43 women with 48 MRI-detected lesions underwent further assessment with US. Histopathological correlation was available from 38 breast biopsies performed for 33 women. RESULTS: Sonographic correlates were identified in 32 (66.7%) of the 48 MRI-detected lesions, with cancer present in 11 (34.4%) of these. This compares with 1 (6.3%) cancer found in the 16 lesions without sonographic correlates. Of the 12 malignant lesions, 11 (91.7%) had sonographic correlates whereas 21 (58.3%) of the 36 benign lesions had sonographic correlates. In all 74% of breast biopsies were performed under US guidance compared with 8% under MRI guidance. The proportion of MRI- and US-correlated benign and malignant lesions undergoing US-guided biopsy were 85.7% and 90.9%, respectively. CONCLUSION: The probability of cancer was significantly higher in MRI-detected breast lesions with sonographic correlates compared with those without such correlation. The advantage of convenient biopsy under US guidance as opposed to MRI guidance highlights the value of sonographic assessment of MRI-detected breast lesions.

Breast ultrasound in women with familial risk of breast cancer.

INTRODUCTION: The aim of this study was to assess the performance and value of breast ultrasound in women with familial risk of breast cancer. MATERIALS AND METHODS: From an initial dataset of 245 women with positive family history who had breast cancer surveillance utilising mammography or magnetic resonance imaging (MRI) between November 1994 and February 2001, 179 subjects with follow-up data were selected. Eighty-four women had breast ultrasound done with histopathological correlation available from 48 breast biopsies performed in 42 women. RESULTS: The sensitivity of ultrasound, mammography and MRI was 83.3%, 53.9% and 93.3%, respectively. The specificity of ultrasound, mammography and MRI was 65.5%, 85.7% and 63.6%, respectively. Ultrasound was the imaging modality with intermediate sensitivity, specificity, negative predictive value (NPV) and cancer detection rate. The sensitivity, specificity, positive predictive value (PPV), NPV and accuracy of combined mammography and ultrasound were 92.9%, 62.5%, 52.0%, 95.2% and 71.7%, respectively. These results did not differ significantly from MRI. Almost two-thirds of the breast biopsies were performed under ultrasound guidance. CONCLUSIONS: Although breast ultrasound screening per se was not assessed in this study, extrapolation of these results to sonographic screening of high familial risk women would come at a better specificity to MRI, albeit with a 10% decrease in sensitivity but at a fraction of the cost of MRI. Ultrasound also provides the advantage of convenient imaging guidance for biopsy. Employing ultrasound following mammography would match MRI in sensitivity, specificity, PPV, NPV and accuracy, and should not be ignored in these women.

Computerized detection of breast cancer with artificial intelligence and thermograms.

This paper shows the concurrent use of thermography and artificial neural networks (ANN) for the diagnosis of breast cancer, a disease that is growing in prominence in women all over the world. It has been reported that breast thermography itself could detect breast cancer up to 10 years earlier than the conventional golden methods such as mammography, in particular in the younger patient. However, the accuracy of thermography is dependent on many factors such as the symmetry of the breasts' temperature and temperature stability. A woman's body temperature is known to be stable in certain periods after menstruation and it was found that the accuracy of thermography in women whose thermal images are taken in a suitable period (5th - 12th and 21st day of menstruation) is higher (80%) than the total population of patients (73%). The stability of the body temperature will depend on physiological state. This paper examines the use of ANN to complement the infrared heat radiating from the surface of the body with other physiological data. Four backpropagation neural networks were developed and trained using the results from the Singapore General Hospital patients' physiological data and thermographs. Owing to the inaccuracies found in thermography and the low population size gathered for this project, the networks developed could only accurately diagnose about 61.54% of the breast cancer cases. Nevertheless, the basic neural network framework has been established and it has great potential for future development of an intelligent breast cancer diagnosis system. This would be especially useful to the teenagers and young adults who are unsuitable for mammography at a young age. An intelligent breast thermography-neural network will be able to give an accurate diagnosis of breast cancer and can make a positive impact on breast disease detection.

Outcome of percutaneous nephrostomy for the management of pyonephrosis.

OBJECTIVE: The aim of this study was to evaluate the efficacy of percutaneous nephrostomy (PCN) drainage for the interim management of pyonephrosis. METHODS: Ninety-two consecutive patients [29 men, 63 women; mean age, 57 years; range, 23 to 88] who underwent PCN for the treatment of pyonephrosis from 1996 to 1999 were evaluated retrospectively. The clinical presentation, bacteriology and patient outcomes were analyzed. RESULTS: The majority [77%] of patients had underlying obstructing urinary calculi. Other causes of obstruction included strictures [9%], papillary necrosis [7%], pelvi-ureteric junction obstruction [4%] and malignant stricture [3%]. The microorganisms cultured were Escherichia coli [30%], Klebsiella [19%], Proteus [8%], Pseudomonas [5%], Enterococcus [5%], and Candida spp [5%]. The microorganisms were sensitive to gentamicin [79%], ceftriaxone [71%], cephalexin [54%], nitrofurantoin [40%], cotrimoxazole [35%], nalidixic acid [32%] and ampicillin [29%]. Only 30% of bladder urine cultures were positive for microorganisms; the addition of PCN cultures improved this yield to 58%. The antibiotic regimen was revised according to the PCN culture whenever there was a discrepancy. After PCN, 69% of patients underwent minimally invasive procedures as definitive treatment of the obstructing lesion. Only 14% of patients required open surgery. There was low procedure-related morbidity [14%] and low overall mortality [2%]. CONCLUSIONS: PCN cultures yield important bacteriological information. The procedure is associated with minimal morbidity, facilitates definitive treatment and provides therapeutic benefit.

Single centre review of radiologically-guided percutaneous nephrostomies: a report of 273 procedures.

INTRODUCTION: To evaluate the technical success and complications associated with radiologically-guided percutaneous nephrostomies (PCNs) in a single centre. MATERIALS AND METHODS: A total of 273 PCNs performed in 190 patients in our hospital over a 3-year period from January 1997 to December 1999 were retrospectively reviewed. The study population consisted of 97 males and 93 females, ranging in age from 13 to 91 years. The main indications were urinary obstruction (77.7%), pyonephrosis (18.3%) and urinary diversion (4%). Demographic variables, technical and risk factors related to the procedure, complications, effect on urine cultures and body temperature; and subsequent patient management were examined. RESULTS: The technical success rate was 99%. The 30-day mortality was 7.2%, none of which were procedure related. Haemorrhage requiring transfusion occurred in 4.3% while septicaemia affected 3.2% of patients. Drainage catheter complications included catheter dislodgement and blockage which were 11.9% and 4.1%, respectively. Thirty-one per cent of PCNs subsequently underwent ureteric stenting as the definitive treatment modality. CONCLUSION: Radiologically-guided PCN is a safe procedure with a high technical success rate.