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.

Computer-assisted navigational surgery enhances safety in dental implantology.

INTRODUCTION: Dental implants are increasingly used to restore missing dentition. These titanium implants are surgically installed in the edentulous alveolar ridge and allowed to osteointegrate with the bone during the healing phase. After osseo-integration, the implant is loaded with a prosthesis to replace the missing tooth. Conventional implant treatment planning uses study models, wax-ups and panoramic x-rays to prefabricate surgical stent to guide the preparation of the implant site. The drilling into the alveolar ridge is invariably a "blind" procedure as the part of the drill in bone is not visible. Stereotactic systems were first introduced into neurosurgery in 1986. Since then, computer-assisted navigational technology has brought major advances to neuro-, midface and orthopaedic surgeries, and more recently, to implant placement. CLINICAL FEATURE: This paper illustrates the use of real-time computer-guided navigational technology in enhancing safety in implant surgical procedures. OUTCOME AND CONCLUSION: Real-time computer-guided navigational technology enhances accuracy and precision of the surgical procedure, minimises complications and facilitates surgery in challenging anatomical locations.

Mammographic parenchymal patterns and risk of breast cancer at and after a prevalence screen in Singaporean women.

BACKGROUND: The objective of this study was to assess the effect of mammographic parenchymal patterns on risk of breast cancer detected at first screen or in the period following a negative screen. METHODS: The study utilizes a nested case-control design with 132 breast cancer patients detected at first screen (from a total of 29 193 screened) and 42 breast cancer patients detected in the period following the first screen. These patients were matched to 348 screened-negative controls. The mammograms were classified according to Tabar's classification for parenchymal pattern and statistical analysis was done by conditional logistic regression. RESULTS: The risk of breast cancer for women with Tabar pattern IV was significantly high when compared to the remaining patterns (odds ratio 2.59). Risk factors for Tabar pattern IV coincided largely with established risk factors for breast cancer. CONCLUSION: The study confirms the increased risk of breast cancer associated with Tabar pattern IV (approximately Wolfe pattern P2), in an Asian population. This pattern is associated with nulliparity and high educational status and is strongly associated with grade 3 cancers.

Screen detected breast cancer in an Asian population: pathological findings of the Singapore breast screening project.

We document the pathological characteristics of 135 cancers detected in 132 predominantly Chinese women in the Singapore breast screening project. Thirty-four (25%) screen detected tumours were in situ ductal cancers; 98 (73%) invasive, while three (2%) women with malignant fine needle aspirate smears refused further treatment. The median size of in situ cancers was 10 mm; the majority (56%) demonstrated a comedo pattern. Of the invasive tumours which had a median size of 15 mm, three (3%) were microinvasive, 75 (77%) infiltrative ductal, three (3%) invasive lobular, and the remaining 17 (17%) special types or others. Histologic grading revealed 23 (24%) grade I, 52 (53%) grade II, 19 (19%) grade III and four (4%) ungraded cases. Sixty-three (65%) of the invasive cancers were node negative, while 64% of all screen detected malignancies were Stages 0 (in situ) or I. From the pathological perspective, problems of borderline lesions, microinvasion, grade assessment and histological subtyping have to be addressed.

Clinical safety profile of sildenafil in Singaporean men with erectile dysfunction: pre-marketing experience (ASSESS-I evaluation).

Safety and tolerability of sildenafil citrate was assessed in a population subset of 60 Singaporean men with erectile dysfunction taken from the Asian Sildenafil Efficacy and Safety Study (ASSESS-I), a double-blind, placebo-controlled, flexible-dose study. The men, from two centres, with > or = 6 months' history of erectile dysfunction, were randomized to two treatment arms for 12 weeks. One group (30 patients) received sildenafil (initial dose 50 mg taken 1 h before sexual activity for the first 2 weeks, increased to 100 mg or decreased to 25 mg, according to efficacy and/or tolerability). The remaining 30 patients received a matching placebo. Incidence and type of adverse effects were evaluated at 2, 4, 8 and 12 weeks. Nine patients (30.0%) on sildenafil (33.1% in the full ASSESS-I study) and one patient (3.3%) on placebo (22.8% in the full ASSESS-I study) experienced treatment-related adverse events, the most frequent being headache in the sildenafil group (reported by five patients [16.7%]; 11.0% in the full ASSESS-I study). Flushing, visual disturbance, dizziness, insomnia, myalgia and back pain each occurred in one patient in the sildenafil group (3.3%); in the placebo group, one patient (3.3%) had headache. Importantly, the incidence of cardiovascular and respiratory system adverse events were relatively less than in the full ASSESS-I population (cardiovascular 3.3% in the present study versus 10.2% in the full ASSESS-I population; respiratory 3.3% versus 5.5%). All adverse events were transient and mild, and did not lead to treatment withdrawal. There was no effect on sitting blood pressure, heart rate or standard laboratory parameters; more importantly, there was no incidence of myocardial infarction, stroke or priapism. These results should reassure Singaporean patients and their physicians of the safety of sildenafil for erectile dysfunction.

Experience with laparoscopic cholecystectomy at the Toa Payoh Hospital.

A retrospective analysis was done of 88 cases of laparoscopic cholecystectomy performed by the first author from November 1990 to March 1992 at the Toa Payoh Hospital. There were 61 female and 27 male patients; the average age was 47.1 years. The most common presenting symptom was biliary colic (85.3%), followed by acute cholecystitis (10.2%) and gallstone pancreatitis (4.5%). In the vast majority of patients, the diagnosis was established by ultrasound (96.6%) while the remainder was diagnosed by oral cholecystography (3.4%). The operation was performed using the usual 4 puncture approach with the single-handed technique of dissection. Antibiotic prophylaxis with a broad-spectrum agent was used in all patients and there was no incidence of wound infection. A low complication rate of 4.5% was experienced--consisting of 1 case each of subcutaneous emphysema, abdominal colic, fever and bile duct injury. There was no mortality in our series. The conversion rate was 9.1% and this was due to our policy of performing laparotomy whenever the safety of laparoscopic surgery was in doubt. The mean duration of postoperative hospitalisation was 3 days and 7 days after laparoscopic and converted cholecystectomies respectively. The majority of patients (61.4%) returned to work after 2 weeks.

Adenosquamous carcinoma of the ileum--a case report.

Small bowel malignancies are very uncommon and adenosquamous carcinomas of the small intestine are extremely rare. We report the second case of an adenosquamous carcinoma of the ileum in a 77-year-old Chinese male.

Operative cholangiography.

Retrospective analysis of 174 operative cholangiograms done over a 3-year period confirms its substantial benefit when used selectively in patients with clinical criteria for common bile duct exploration. A low incidental ductal stone rate of 1.6%, together with a 3.3% false positive cholangiogram rate and a case of bile duct injury resulting from the procedure makes its routine application appear superfluous.

The use of sildenafil in patients with erectile dysfunction in relation to diabetes mellitus--a study of 1,511 patients.

Erectile dysfunction (ED) seriously impairs the quality of life. Patients with diabetes mellitus (DM) are prone to ED due to various factors, including vasculopathy, neuropathy and sex hormone abnormalities. This is a retrospective study involving 1,511 patients taking sildenafil. Patients with DM have significantly more comorbidities like hypertension and ischaemic heart disease. They are also more likely to be on medications which may affect erectile function, including various antihypertensive drugs. 77.9% of patients with DM reported success with sildenafil, as compared to 86.5% of patients without DM. A significant number of patients with DM require a higher dose of sildenafil as compared to those without DM.

Erectile dysfunction in Singapore men: presentation, diagnosis, treatment and results.

Three hundred and thirteen new cases were seen in more than two years at the Sexual Dysfunction Clinic at the Division of Urology, Toa Payoh Hospital (TPH). Patients were assessed by history, clinical examination, psychological evaluation, hormonal and biochemical tests; special investigations such as monitoring of nocturnal penile tumescence, cavernosography, selective pudendal arteriography and tests of neurological function were performed where indicated. Two hundred and twenty-seven patients (72.5%) had impotence due to organic causes while 86 patients (27.5%) were found to have psychogenic impotence. Diabetes mellitus and vascular disease account for the large proportion of organic impotence (81%). Patients with psychogenic impotence responded fairly well to psychosexual therapy and drug treatment in certain cases. Forty-four patients underwent medical therapy which consisted mainly of pharmacologically induced penile erections by the use of papaverine, phentolamine or prostaglandin E-1; 21 patients (48%) who were on self-injection therapy became non-compliant subsequently. One hundred and fourteen andropausal patients with low testosterone levels received hormonal replacement. Thirty-one patients underwent surgery--stripping and ligation of the deep dorsal vein of the penis (13 patients), microsurgical arterial revascularisation (two patients) and penile prosthetic implantation (16 patients). Our success rates for the operations were 54%, 100% and 88% respectively.

Non-consensual double reading in the Singapore Breast Screening Project: benefits and limitations.

INTRODUCTION: The aims of this study were to assess the efficacy of non-consensual double reading (against single reading) in the Singapore Breast Screening Project (SBSP) and to compare the benefits (increase in cancer detection) and limitations (increase in recall and biopsy) with published data. MATERIALS AND METHODS: The data from the SBSP was retrospectively analysed and the recommendations of the first and second readers were evaluated separately with regards to rate of recall, biopsy and cancer detection. The mean second screener contribution (MSSC) was also calculated for double reading. RESULTS: In the SBSP, double reading detected 7 additional cancers (5.2% of cancers detected) compared with single reading and the MSCC was 5.5%. Double reading also resulted in 632 additional recalls, with a decrease in the positive predictive value (PPV) of cancer in the recalled women from 8.2% for single reading to 6.1% for double reading. An additional 30 biopsies were performed with double reading which represented a small decrease in PPV (41% compared to 42.9% for single reading). CONCLUSION: In the SBSP, non-consensual double reading (compared to single reading) resulted in a modest increase in cancer detection (MSSC, 5.5%) with a modest decrease in PPV of recall (2.1%) and biopsy (1.9%). These findings were consistent with that of published data and non-consensual double reading is thus recommended.

Venous ligation for cavernous leak impotence--a report on 30 cases.

We report our experience with the surgical treatment of 30 patients with venous leak impotence seen at the Division of Urology, Toa Payoh Hospital, over a period from April 1991 to August 1993. The patients were assessed by history, clinical examination, hormonal evaluation and intracavernosal injection of papaverine. Confirmation of venous leak impotence was obtained by pharmaco-cavernosography in all patients; dynamic cavernosometry was performed in the later part of the series. Surgical treatment consisted of ligation and stripping of the deep dorsal vein, ligation of all its emissary and circumflex tributaries for all patients, with crural plication and suspensory ligament re-approximation in selected patients. Peroperative intracavernosal injection of papaverine was used to identify veins and to assess the adequacy of the extent of venous ligation. The mean age of the patients was 40 years. The average operative time was 2 hours. The usual period of hospitalisation was 3 days. Patients were followed up for an average period of 15.6 months. Success was defined as having adequate erections for normal coitus; the success rates at 1, 3, 6, 9 and 12 months were 76.2%, 61.9%, 52.4%, 42.9% and 38.1%, respectively.

Adrenal myelolipoma presenting with spontaneous retroperitoneal haemorrhage demonstrated on computed tomography and angiogram--a case report.

INTRODUCTION: A rare case of adrenal myelolipoma presenting with spontaneous rupture and retroperitoneal haemorrhage is described. CLINICAL PICTURE: A 51-year-old Caucasian male presented with acute onset of right loin pain. Preliminary diagnosis of haemorrhagic adrenal tumour was made on computed tomography (CT) and angiography. TREATMENT: Vascular embolisation was performed to stabilise the patient prior to definitive surgery. Tumour resection was subsequently performed. Histology confirmed ruptured adrenal myelolipoma. OUTCOME: The patient made an uneventful recovery. CONCLUSION: Ruptured adrenal myelolipoma should be considered in cases of spontaneous retroperitoneal haemorrhage. Vascular embolisation may be useful in stabilising the patient prior to definitive surgery.

Extracorporeal shockwave lithotripsy and intracorporeal lithotripsy for proximal ureteric calculi--a comparative assessment of efficacy and safety.

INTRODUCTION: Extracorporeal shockwave lithotripsy (ESWL) is the treatment modality of choice of many urologists for proximal ureteric calculi. In this study, we compared the efficacy and safety of ESWL versus ureteroscopy with holmium laser lithotripsy for the treatment of this group of stones. MATERIALS AND METHODS: Between May 1999 and October 2000, 50 patients had ESWL and another 51 patients underwent ureteroscopy with holmium laser lithotripsy for proximal ureteric calculi. The two groups were similar in age, sex ratio and stone size. ESWL was performed with the Dornier Compact lithotriptor whereas holmium laser lithotripsy was performed via retrograde ureteric access with a Wolf 7.5 Fr semirigid ureteroscope. RESULTS: Ureteroscopy with holmium laser lithotripsy was significantly better in terms of the mean procedure time (56 min in ESWL; 25 min in ureteroscopy; P < 0.001) and the 1-month stone free rate (50% in ESWL; 80% in ureteroscopy; P = 0.001). The 3-month stone free rate was also higher for ureteroscopy (78% in ESWL; 90% in ureteroscopy) but this difference was not statistically significant (P = 0.09). Minor complications of steinstrasse (6%) occurred in ESWL and proximal stone migration (8%) occurred during ureteroscopy. CONCLUSION: Ureteroscopy with holmium laser lithotripsy is a viable and safe alternative to ESWL for the management of proximal ureteric calculi.

Holmium laser lithotripsy in the management of ureteric calculi.

INTRODUCTION: To evaluate the efficacy and safety of the holmium:YAG laser in retrograde ureteroscopic laser lithotripsy of ureteric calculi. METHODS: Three hundred and twenty-five patients (256 males and 69 females) with mean age of 45 years underwent 328 retrograde ureteroscopic laser lithotripsy as the primary therapy for ureteric calculi using semirigid mini-ureteroscopes and the holmium:YAG laser (Coherent, Palo Alto, California, USA). Four consultants and three registrars performed the procedures over a period of 31 months. RESULTS: The mean largest diameter of the calculi was 8.4 mm. The mean hospital stay was 1.8 days and the mean duration for the operation was 25 minutes. One hundred and twenty-two (37%) procedures were done as day surgery cases. Complete stone-free rates after single primary treatment using only the holmium:YAG laser were 75% and 91% at 4 weeks and 12 weeks of follow-up, respectively. Including 22 (7.6%) renal units which required additional procedures, the overall stone-free rate was 97%. Seventeen cases (5.2%) needed additional extracorporeal shock wave lithotripsy (ESWL) and 5 cases (1.5%) needed an additional repeat ureteroscopy and lithotripsy for complete stone clearance. Significant complications include 1 case of ureteric perforation. CONCLUSIONS: The holmium:YAG is a safe and effective intracorporeal lithotripter when deployed in a retrograde manner in conjunction with a mini-ureteroscope.

Spectrum of abnormal mammographic findings and their predictive value for malignancy in Singaporean women from a population screening trial.

INTRODUCTION: The ability to categorise mammographic features according to their likelihood of malignancy would be valuable in the management of women with abnormal mammograms. The aim of our study was to correlate abnormal mammographic features in a screened population with their histology to identify those features which are predictive of malignancy. The study also examined the spectrum of mammographic features in an Asian population. MATERIALS AND METHOD: This prospective study involved 28,231 women who were randomly selected from a population registry and underwent two-view screening mammography without physical examination. Women with suspicious lesions were recalled for further mammographic views or to a joint assessment clinic prior to biopsy. Mammographic abnormalities and their corresponding histology were assessed. RESULTS: The spectrum of mammographic abnormalities was similar to that in Caucasian populations. The positive predictive value for malignancy was 44.1% of all biopsied cases. Mammographic features could be broadly classified into low-, moderate- and high-risk categories for malignancy. Those features which correspond to high malignancy rates (9.8% to 16.0%) include multiple abnormalities or parenchymal lesions with microcalcifications. The presence of microcalcifications was a good predictor of ductal carcinoma-in-situ (DCIS): 46% of lesions in which the microcalcifications were the sole abnormality were DCIS only. Further, 71% of cancers with any microcalcification on the mammogram had a focus of DCIS on histology. CONCLUSION: Mammographic abnormalities can be segregated into three risk groups for malignancy, and this in turn can improve the selection criteria for breast biopsy, hence reducing unnecessary intervention. Furthermore, the presence of microcalcifications denotes the presence of DCIS, and would be an important determinant of the extent of surgical excision.

Penile colour duplex ultrasonography as a screening tool for venogenic erectile dysfunction.

INTRODUCTION: Vasculogenic impotence is one of the major causes of erectile dysfunction. Cavernosometry and cavernosography is traditionally the gold standard for evaluation of venogenic impotence. However, it is invasive and there are potentially significant complications. Penile colour flow Doppler imaging (PCDI) is non-invasive and can be used to assess venous incompetence. MATERIALS AND METHODS: One hundred and sixty-eight patients were referred for PCDI assessment from March 1998 to February 2001. Forty-three of these also had cavernosogram and cavernosometry done and were included in the study. RESULTS: The sensitivity was 93.9%, the specificity was 90.0%, the accuracy was 93.0% with a negative predictive value of 81.8% and a positive predictive value of 96.9%. Kappa value of 0.81 was obtained, indicating excellent agreement between PCDI and cavernosogram and cavernometry. CONCLUSIONS: Penile colour flow Doppler imaging is accurate in the assessment of venogenic erectile dysfunction. It can replace cavernometry and cavernosogram as a screening tool. Cavernometry and cavernosogram should only be done in cases when PCDI suggests venogenic impotence, and when surgery is contemplated.

Statistical analysis of healthy and malignant breast thermography.

Analysis of thermograms has often been subjective and has resulted in inconsistency in the diagnosis of breast diseases by thermography. The aim of this paper is to study the problem of subjective interpretation of breast thermograms and hence using thermography as an adjunct tool for breast cancer diagnosis. It ws proposed that the thermograms should be taken within the recommended screening period, classified and analysed in conjunction with an artificial neural network (ANN). Qualitative interpretation of thermal images can be carried out using an active contours algorithm. The 256 x 200 pixel image can be segmented as one of the inputs to the ANN. To achieve quantitative analysis of the breast thermograms, firstly the inputs of the ANN should be determined, so that the thermograms could be successfuly classified and based on the suggested inputs.

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.