False Positive Value Research Articles

PS-039 DokuPIK – Pharmaceutical interventions: Do ward pharmacists know how to document?

BackgroundThe internet-based categorical, hierarchical documentation system for routine pharmaceutical interventions (PIs) DokuPIK is widely used especially among German ward-based pharmacists.PurposeTo conduct a survey-based study on its clinical usability.Materials and methodsOut...

MAPPING FROM SPACE – ONTOLOGY BASED MAP PRODUCTION USING SATELLITE IMAGERIES

Abstract. Determination of the maximum ability for feature extraction from satellite imageries based on ontology procedure using cartographic feature determination is the main objective of this research. Therefore, a special ontology has been developed to extract maximum volume of information available in different high resolution satellite imageries and compare them to the map information layers required in each specific scale due to unified specification for surveying and mapping. ontology seeks to provide an explicit and comprehensive classification of entities in all sphere of being. This study proposes a new method for automatic maximum map feature extraction and reconstruction of high resolution satellite images. For example, in order to extract building blocks to produce 1 : 5000 scale and smaller maps, the road networks located around the building blocks should be determined. Thus, a new building index has been developed based on concepts obtained from ontology. Building blocks have been extracted with completeness about 83 %. Then, road networks have been extracted and reconstructed to create a uniform network with less discontinuity on it. In this case, building blocks have been extracted with proper performance and the false positive value from confusion matrix was reduced by about 7 %. Results showed that vegetation cover and water features have been extracted completely (100 %) and about 71 % of limits have been extracted. Also, the proposed method in this article had the ability to produce a map with largest scale possible from any multi spectral high resolution satellite imagery equal to or smaller than 1 : 5000.

MAPPING FROM SPACE – ONTOLOGY BASED MAP PRODUCTION USING SATELLITE IMAGERIES

Abstract. Determination of the maximum ability for feature extraction from satellite imageries based on ontology procedure using cartographic feature determination is the main objective of this research. Therefore, a special ontology has been developed to extract maximum volume of information available in different high resolution satellite imageries and compare them to the map information layers required in each specific scale due to unified specification for surveying and mapping. ontology seeks to provide an explicit and comprehensive classification of entities in all sphere of being. This study proposes a new method for automatic maximum map feature extraction and reconstruction of high resolution satellite images. For example, in order to extract building blocks to produce 1 : 5000 scale and smaller maps, the road networks located around the building blocks should be determined. Thus, a new building index has been developed based on concepts obtained from ontology. Building blocks have been extracted with completeness about 83%. Then, road networks have been extracted and reconstructed to create a uniform network with less discontinuity on it. In this case, building blocks have been extracted with proper performance and the false positive value from confusion matrix was reduced by about 7%. Results showed that vegetation cover and water features have been extracted completely (100%) and about 71% of limits have been extracted. Also, the proposed method in this article had the ability to produce a map with largest scale possible from any multi spectral high resolution satellite imagery equal to or smaller than 1 : 5000.

Fine-Needle Aspiration of Thyroid Nodules with Macrocalcification

The presence of microcalcification is highly suggestive of malignancy; however, the association of macrocalcification with cancer remains unclear and controversial. The purpose of this study was to evaluate the diagnostic yield and accuracy of ultrasound (US)-guided fine-needle aspiration (FNA) of thyroid nodules with macrocalcifications and to investigate the association between macrocalcification subtype and malignancy risk. We retrospectively reviewed sonographic findings and pathologic results of thyroid nodules with macrocalcification in patients who underwent US-guided FNA in our hospital from January 2009 through December 2010. Inclusion criteria were as follows: (i) malignant or benign nodules confirmed on histologic examination of surgical specimens after US-guided FNA and (ii) nodules not histologically confirmed that were subjected to FNA at least twice and follow-up US examinations for 2 years. Thyroid nodules with macrocalcification were classified into four groups: smooth total (eggshell) calcification, smooth partial calcification, irregular calcification, and nodular calcification. The diagnostic yield of FNA for thyroid nodules with macrocalcification was determined by cytology. Sensitivity, specificity, and diagnostic accuracy of preoperative FNA cytology were calculated and compared with those of histologic examination of surgical specimens. There were 188 nodules with macrocalcification in 167 patients; of these, 95 were benign, 80 were malignant, and 13 were nondiagnostic. The diagnostic yield of FNA for thyroid nodules with macrocalcification was 93.08%. Sensitivity, specificity, positive predictive value, and negative predictive value were 98.51%, 90.91%, 95.65%, and 96.77%, respectively. The false-positive value and false-negative value were 9.09% and 1.49%, respectively. The diagnostic accuracy was 96%. There was no statistically significant difference in the association between macrocalcification subtype and malignancy risk (p > 0.05). Macrocalcification associated with thyroid nodules is not a reliable criterion for malignancy. FNA of thyroid nodules with macrocalcification had a high diagnostic yield and a reliable accuracy. Consistency between cytology and histology was almost perfect. Therefore, FNA is a good screening method for malignancy of thyroid nodules with macrocalcification.

Application of DHPLC screening TGFBR-3 gene in Chinese women with idiopathic premature ovarian failure

To evaluate clinical value of denaturing high performance liquid chromatography (DHPLC) used in detecting transforming growth factor beta receptor 3 (TGFBR-3) exons 11 and 12 polymorphism in women with idiopathic premature ovarian failure (POF). From Feb. 2009 to Dec. 2011, 110 patients with idiopathic POF undergoing treatment at Shenzhen Maternal & Child Health Institute affiliated to Southern Medical University were enrolled as POF group in this study. In the mean time, 110 women under 40 years old with normal hormonal level and menstrual cycles as control group. The exons 11 and 12 of TGFBR-3 gene polymorphism were screened by using DHPLC, and results of DNA sequencing was as golden standard. Some related indexes were calculated, such as sensitivity, specificity, false negative value, false positive value, Youden index, positive predictive value, and negative predictive value. At the same time, 20% of the tested specimens were chosen randomly and detected by DHPLC again. The value of Kappa index were calculated by comparing the results between the first and second DHPLC analysis. The exon 11 of TGFBR-3 were not identified gene polymorphism and two nucleotide polymorphisms were identified in exon 12. For 2022 T/C polymorphism, the frequencies of CC with 0.9% (1/110), TC with 22.7% (25/110), TT with 76.4% (84/110), C with 12.3% (27/220) and T with 87.7% (193/220) in POF group were significantly different from CC with 0, TC with 9.1% (10/110) and TT with 90.9% (100/110), C with 4.5% (10/220) and T with 95.5% (210/220) in control group (all P<0.05). Allelic and genotypic frequencies of 2161-75 C/T were not differed significantly between the two groups (all P>0.05). As DNA sequencing as golden standard, DHPLC showed that the sensitivity was 100%, specificity was 97.9%, Youden index was 97.9%, positive predictive value was 96.3%, negative predictive value was 100%, and Kappa index was 0.888 (P<0.05). DHPLC analysis is higher validity, reliability and practicability method in detecting TGFBR-3 polymorphism in idiopathic premature ovarian failure.

False Positive Rate of Carbon Monoxide Saturation by Pulse Oximetry of Emergency Department Patients

Symptoms of carbon monoxide (CO) poisoning are non-specific. Diagnosis requires suspicion of exposure, confirmed by measuring ambient CO levels or carboxyhemoglobin (COHb). An FDA-approved pulse oximeter (Rad-57) can measure CO saturation (S(pCO)). The device accuracy has implications for clinical decision-making. From April 1 to August 15, 2008, study personnel measured S(pCO) and documented demographic factors at time of clinical blood draw, in a convenience sample of 1,363 subjects presenting to the emergency department at Intermountain Medical Center, Murray, Utah. The technician then assayed COHb. COHb and S(pCO) values were compared by subject; false positive or negative values were defined as S(pCO) at least 3 percentage points greater or less than COHb level, reported by the manufacturer to be ± 1 SD in performance. In 1,363 subjects, 613 (45%) were male, 1,141 (84%) were light-skinned, 14 in shock, 4 with CO poisoning, and 122 (9%) met the criteria for a false positive value (range 3-19 percentage points), while 247 (18%) met the criteria for a false negative value (-13 to -3 percentage points). Risks for a false positive S(pCO) reading included being female and having a lower perfusion index. Methemoglobin, body temperature, and blood pressure also appear to influence the S(pCO) accuracy. There was variability among monitors, possibly related to technician technique, as rotation of monitors among technicians was not enforced. While the Rad-57 pulse oximeter functioned within the manufacturer's specifications, clinicians using the Rad-57 should expect some S(pCO) readings to be significantly higher or lower than COHb measurements, and should not use S(pCO) to direct triage or patient management. An elevated S(pCO) could broaden the diagnosis of CO poisoning in patients with non-specific symptoms. However, a negative S(pCO) level in patients suspected of having CO poisoning should never rule out CO poisoning, and should always be confirmed by COHb.

Multiparametric Ultrasound of the Prostate: Adding Contrast Enhanced Ultrasound to Real-Time Elastography to Detect Histopathologically Confirmed Cancer

We prospectively assessed whether a combined approach of real-time elastography and contrast enhanced ultrasound would improve prostate cancer visualization. Between June 2011 and January 2012, 100 patients with biopsy proven prostate cancer underwent preoperative transrectal multiparametric ultrasound combining real-time elastography and contrast enhanced ultrasound. After initial elastographic screening for suspicious lesions, defined as blue areas with decreased tissue strain, each lesion was allocated to the corresponding prostate sector. The target lesion was defined as the largest cancer suspicious area. Perfusion was monitored after intravenous injection of contrast agent. Target lesions were examined for hypoperfusion, normoperfusion or hyperperfusion. Imaging results were correlated with final pathological evaluation on whole mount slides after radical prostatectomy. Of 100 patients 86 were eligible for final analysis. Real-time elastography detected prostate cancer with 49% sensitivity and 73.6% specificity. Histopathology confirmed malignancy in 56 of the 86 target lesions (65.1%). Of these 56 lesions 52 (92.9%) showed suspicious perfusion, including hypoperfusion in 48.2% and hyperperfusion in 48.2%, while only 4 (7.1%) showed normal perfusion patterns (p = 0.001). The multiparametric approach decreased the false-positive value of real-time elastography alone from 34.9% to 10.3% and improved the positive predictive value of cancer detection from 65.1% to 89.7%. Perfusion patterns of prostate cancer suspicious elastographic lesions are heterogeneous. However, the combined approach of real-time elastography and contrast enhanced ultrasound in this pilot study significantly decreased false-positive results and improved the positive predictive value of correctly identifying histopathological cancer.

Diagnostic accuracy of fine-needle aspiration cytology of the breast in Japan: Report from the Working Group on the Accuracy of Breast Fine-Needle Aspiration Cytology of the Japanese Society of Clinical Cytology

The Working Group of the Japanese Society of Clinical Cytology was assembled to assess the current status of breast cytology in Japan by conducting a large-scale survey regarding the accuracy of fine-needle aspiration biopsy (FNAB) in Japan. We collected data and investigated the status of breast cytological diagnosis at 12 different cooperating facilities in Japan, and re-evaluated their false-negative and false-positive cases. Among 30,535 individuals who underwent a breast cytological examination, analyses were conducted on 10,890 individuals (35.7%) in whom cytological diagnoses were confirmed by histology. Among these patients, the cytological diagnosis had an inadequate rate of 17.7%, an indeterminate rate of 7.8%, a positive predictive value of 'malignancy suspected' cells of 92.4%, an absolute sensitivity of 76.7%, a complete sensitivity of 96.7%, a specificity of 84.3%, a positive predictive value of 'malignant' cells of 99.5%, a false-negative value of 3.31%, a false-positive value of 0.25% and an accuracy rate of 88.0%. Subsequently, 297 false-negative and 23 false-positive cases were re-evaluated and several factors were characterized (i.e. histological type, tumor size and misread points). This survey collected data from a large number of cases for breast FNAB. Based on our survey, the accuracy of FNAB in Japan was relatively high compared with the goal of assessment of diagnostic accuracy. However, there were some false-negative and false-positive cases. Improvements in accuracy resulting from the learning points in the present study will lead to more useful and reliable diagnostic tools in clinical practice.

Evaluation of the Sigmoid Notch Involvement in the Intra-Articular Distal Radius Fractures: The Efficacy of Computed Tomography Compared with Plain X-ray

BackgroundThe purpose of this study is to evaluate the efficacy of computed tomography (CT) scans compared with plain radiographs on detecting the involvement of the sigmoid notch.MethodsThis study involved 121 cases diagnosed as the intra-articular distal radius fracture and performed post-reduction CT scans. We determined the presence of the sigmoid notch involvement with both plain radiographs and CT scans and compared findings of plain radiographs with CT scans about the incidence and the pattern of injuries. And the differences of results between arbeitsgemeinschaft für osteosyntheses (AO) type C2 and C3 were compared.ResultsThe incidences of sigmoid notch involvement detected in plain radiographs were 81 cases (66.9%), whereas CT scans were 99 cases (81.9%). The sensitivity of plain radiographs compared with CT scans was 74.7%, the specificity was 68.2%, the positive predictive value was 91.4%, the negative predictive value was 37.5%, the false negative value was 25.3%, and the false positive value was 31.8%. In comparison between AO type C2 and C3, the incidence of sigmoid notch involvement was not a significant difference, but the displacement of fracture fragment showed a significant difference.ConclusionsThe intra-articular distal radius fracture usually accompanies the sigmoid notch involvement. Considering that the evaluation of sigmoid notch involvement by plain radiography often results in misinterpretation or underestimation, performing CT scan in intra-articular distal radius fracture is thought to be beneficial.

Assessment of mental disorders using the patient health questionnaire as a general screening tool in western Nigeria: A community-based study

Background:Screening at the community level will provide keys to promoting health and preventing diseases at the community level and serve as the fulcrum for timely detection and intervention. This study aims to assess the prevalence and nature of mental disorder among the general population using the patient health questionnaire (PHQ). It also compares the use of PHQ and GHQ as general screening tools for mental disorders.Materials and Methods:This community-based study is cross sectional in design. Multistage sampling technique was used to obtain a representative sample of the communities. The PHQ and GHQ-12 questionnaires were concurrently administered by health care workers that were nondoctors to screen for psychiatric symptoms.Results:A total of 758 participants took part in the study, 496 (65.4%) of the subjects had a form of psychopathology or the other using PHQ and 143 (18.9%) using GHQ questionnaire (χ2 = 20.92, P = 0.000). Three hundred and thirty one subjects (43.7%) met the criteria for Somatoform disorder but 6.0% ever treated at PHC, 269 (35.5%) for depression and 4.8% ever treated, 127 (16.8%) for panic disorder and 5.5% ever treated, while 165 (21.8%) for general anxiety and 4.8% ever treated. Predictors of psychopathology were individuals who were singles (OR = 0.64, CI = 0.49–0.93) concerns about their health (OR = 3.06, CI = 2.06–4.56), worried about finance (OR = 1.84, CI = 1.27–2.67), worried about family life (OR = 2.68, CI = 1.61–4.72), and stressed at work (OR = 1.16, CI = 1.06–1.28).Conclusion:There is a high prevalence of psychopathology at the community level in this African population and few had ever been treated. PHQ as a general screening tool has a higher false-positive value compared to GHQ when used by nondoctors. PHQ should be used as an instrument to screen for specific mental disorders rather than a general screening tool for psychiatric morbidity at the community level.

Comparison of the Accuracy of Breast Cytological Diagnosis at Seven Institutions in Southern Fukuoka Prefecture, Japan

Cytological examination is inexpensive and relatively simple to carry out and deserves utilization in breast cancer screening. We investigated the status of cytological diagnosis at seven facilities in southern Fukuoka Prefecture, Japan. We collected data on the criteria for cytological judgments and status of breast cytological diagnosis at seven different facilities in this region. Among 5693 individuals who underwent breast cytological examination, analyses were conducted on 1250 individuals (22.0%) in whom cytological diagnoses were confirmed by histological diagnoses. Among these patients, cytological diagnosis had an absolute sensitivity of 71.9%, a specificity of 76.0%, a false-negative value of 6.7% and a false-positive value of 0.08%. At three facilities with relatively large numbers of cases (>300), excluding a facility for specialized breast disease, similar trends of high complete sensitivity (94.3, 95.6 and 97.1%, respectively) and low absolute sensitivity (60.4, 74.8 and 57.2%, respectively) were found. No false-negative or false-positive cases were seen in individual facilities with relatively low numbers of cases (<150). The accuracy of cytological diagnosis at the facilities we surveyed was relatively high compared with the goals of assessment of diagnostic accuracy. However, the performance was dependent on the facility type, i.e. number of cases, staff involved and whether it was specialized or not, making the diagnosis specific for this region. We recommend that management of the accuracy of cytological diagnosis be undertaken jointly by multiple facilities to establish systems in Japan that lead to more useful diagnostic tools.

Utility of positron emission tomography scans in mantle cell lymphoma

Positron emission tomography (PET) scans are widely used in patients with lymphoma but little is known about their utility in mantle cell lymphoma (MCL). MCL patients were included from two prospective trials and one observational study at our institution. A total of 276 PET scans were performed among 52 patients. After a median follow-up of 37.5 months, the 3-year event-free survival (EFS) and overall survival (OS) were 73% (95% confidence interval [CI]: 61-85%) and 92% (95% CI 85-100%), respectively. There were 34 pretreatment PET scans, 26 interim, 28 end-of-treatment, 162 surveillance, and 26 scans at relapse or beyond. Pretreatment PETs were positive in 94%. A negative interim or end-of-therapy PET scan was not significantly associated with better EFS or OS, but no deaths were observed in patients who had a negative interim or end-of-therapy PET. Surveillance PET scans had a high false positive rate (35%) and low positive predictive value (8%). PET scans contributed to an earlier diagnosis of relapse in only two out of the 18 patients (11%) who relapsed. PET scans did not meaningfully contribute to staging or surveillance of MCL patients in this study. There was a trend toward improved survival in patients who had a negative end-of-therapy PET scan.

A risk prediction model of the incidence of occupational low back pain among mining workers

Background: Low Back Pain (LBP) is the most frequently reported musculoskeletal disorder in workers. This study was aimed to develop risk prediction model of low back pain that can be used to prevent the recurring low back pain attack. Methods: The study was case-control design based on the industrial community by using ergonomical approach. Total samples were 91 workers for cases and 91 workers for controls. Workers suffering for low back pain in the last 6 months served as cases, and those from the same age group and receiving the same amount of exposure without any symptoms of low back pain served as controls. Risk factors include socio-demographic factors, socio-ocupational factors, physical working environmental factors, non-physical environmental factors, and biomechanics factors. Receiver Operating Characreistics (ROC) was used to describe relationship between true positive value (in vertical axis) and false positive value (in horizontal axis) in order to discover a risk predictive value of LBP. Results: The determinant risk factors for low back pain (LBP) were bending work postures, waist rotation movement, manual lifting, unnatural work postures, those who had worked for more than 18 years, and irregular sport activities. By using ROC with 91.20% senstivity and 87.90% spesifi city, the calculated prediction value was 0.35. This is the cut-off point to discriminate workers with and without LBP. The risk predictors value of work-induced LBP calculated by linear equation of logistic regression varied between 0-11.25. Conclusion: The prediction model of work-induced LBP can be used for early detection of LBP to reduce the risk and prevent the recurrence of LBP.

Narrow‐band imaging for diagnosing adenoid hypertrophy in adults: A simplified grading and histologic correlation

To investigate the use of narrow-band imaging (NBI) endoscopy to detect the appearance of a light crest (LC) on the epithelial surface of the nasopharyngeal mucosa, which is suggested to be a distinctive endoscopic finding associated with the presence of adenoid hypertrophy. Cross-sectional study. A total of 79 consecutive adults with a high suspicion of malignancy underwent NBI endoscopy and nasopharyngeal biopsy to validate the diagnostic accuracy of the novel endoscopic technique. The degree of correlation between the LC grading and the histologic examinations of lymphoid hyperplasia, including the number of mucin-producing cells and lymphoid follicles, was then assessed. The appearance of an LC on NBI endoscopy correlated with the histologic evidence of lymphoid hyperplasia with a sensitivity of 92.1%, a specificity of 95.1%, a positive predictive value of 94.6%, a negative predictive value of 92.9%, a false-positive value of 4.9%, a false-negative value of 7.9%, and an accuracy of 93.7%. The screening performance of NBI endoscopy for the presence of adenoid hypertrophy is significantly superior to that of conventional endoscopy (P = .0003). The LC grading was significantly correlated with the number of mucin-producing cells and lymphoid follicles (P < .001). In NBI endoscopy, observation of an LC on the epithelial surface of the nasopharyngeal mucosa is a highly accurate predictor of the presence of adenoid hypertrophy.

Can a 15-mm Cervical Length Cutoff Discriminate between Low and High Risk of Preterm Delivery in Women with Threatened Preterm Labor?

Objectives: To investigate if a cervical length (CL) cutoff of 15 mm is relevant to use in women with threatened preterm labor. Methods: From 2006 to 2009, 146 women with singleton pregnancies were admitted with threatened preterm labor between 23 and 33+6 weeks of gestation at Copenhagen University Hospital. Transvaginal sonographic measurement of CL was carried out on admission. Outcome measures were spontaneous delivery within 48 h, within 7 days and delivery before 34 weeks according to a CL cutoff of 15 mm. Results: CL was <15 mm in 36 women (24.7%) and ≧15 mm in 110 women (75.3%). Spontaneous delivery occurred within 48 h or 7 days of presentation and before 34 weeks in 25, 38.9 and 50.0% of women with CL <15 mm and 3.6, 9.1 and 11.8% of women with CL ≧15 mm, respectively. The 15-mm CL cutoff had a sensitivity, false positive rate and negative predictive value for delivery within 48 h of 69.0, 20.3 and 96.4%, and within 7 days of 58.3, 18.1 and 90.9%. Women with CL <15 mm had odds of delivery within 7 days of 6.4 (95% CI 2.5–16.2). Conclusion: Although a 15-mm CL defines a group of women at high risk of spontaneous preterm delivery, 10 out of 110 women (9.1%) with a CL ≧15 mm deliver within 7 days.

Application of contrast-enhanced ultrasonography after radiofrequency ablation for renal cell carcinoma: is it sufficient for assessment of therapeutic response?

To assess the efficacy of contrast-enhanced ultrasonography (CEUS) with Sonovue in the evaluation of therapeutic response to radiofrequency ablation (RFA) of renal cell carcinoma (RCC). In a recent 3 years, 63 patients (mean age, 60 years; range 26-81 years) with 64 RCCs were treated by RFA. The lesions had a diameter between 1.8 and 9.8 cm (average diameter, 3.1 cm). The indications for RFA treatment included chronic renal insufficiency (n = 10), presence of solitary kidney (n =3), bilateral renal carcinoma (BRCC) (n =2), advanced age (n =12), significant medical comorbidity (n =29) or refusal of conventional therapy (n =7). Tumors were treated by laparoscopy-assisted (n =41), open surgical (n =18) or percutaneous US guidance (n =4). Follow-up CEUS and contrast-enhanced CT were performed 1 month after treatment to assess the necrotic area. Technical success was defined as elimination of areas that enhanced at imaging within the entire tumor. On the 1-month CEUS and CT imaging after RFA, 62 of 64 tumors (96.9%) were successfully ablated with one session, and residual tumors were found in two RCCs. One of the two tumors was subjected to additional RFA treatment. We could not obtain a complete ablation in the other tumor of a patient with solitary kidney. The diagnostic concordance between the CEUS and 1-month follow-up CT was 100%. Sixty-one patients survived in the follow-up phase which ranged from 2 to 34 months. One patient with solitary kidney died of systemic disease progression and one patient was lost to follow-up. Of the 61 tumors without residual on both CT and CEUS after RFA, four had suspicious findings of recurrence on follow-up CEUS, and two of them were confirmed by subsequent CT examination. With CT as the reference imaging procedure in the assessment of renal tumor ablation, the sensitivity, specificity, positive predictive value, and negative predictive value of CEUS for detecting recurrence during follow-up were 100%, 96.6%, 50%, and 100%. Despite its limitation of false-positive value, CEUS is potentially effective in assessing the therapeutic response to RFA of RCC.

Clinical application of prospective electrocardiogram-gated 320-detector computed tomography coronary angiography

to compare the success rate, radiation dose, image quality and diagnosis of prospective electrocardiogram(ECG)-gated 320-detector computed tomography coronary angiography (CTCA) versus retrospective ECG-gated CTCA. patients suspected coronary artery disease were divided into two groups which underwent 320-detector CTCA with prospective ECG-gated and retrospective ECG-gated scanning (n = 240 each, HR < 65 bpm). Curved-planar reconstruction (CPR), maximum intensity projection (MIP) and volume rendering (VR) were performed to demonstrate the coronary arteries. The image quality was defined as excellent, good and poor by motion and stair-step artifacts. Effective radiation exposure dose was estimated from the dose-length product. Effective radiation dose, image quality and diagnosis were evaluated. the success rate of examination was 100% in prospective ECG-gated group and retrospective ECG-gated group. The mean effective radiation dose of prospective ECG-gated CTCA [(3.3 ± 1.3) mSv] was significantly lower than that of retrospective ECG-gated CTCA [(13.0 ± 1.6) mSv, P < 0.01]. Segments of diagnostic image quality (95.42%, 3435/3600) and non-diagnostic coronary segments (4.58%, 165/3600) in prospective ECG-gated group were similar as those of retrospective ECG-gated group (95.81%, 3449/3600 and 4.19%, 151/3600, all P > 0.05). Compared with CAG, the sensitivity, specificity, false positive and false negative value in prospective ECG-gated group (93.22%, 99.21%, 91.64%, 99.05%) and retrospective ECG-gated group (94.55%, 98.80%, 95.86%, 98.54%) were not significantly different. though the effective radiation dose is significantly lower, the success rate, image quality and diagnosis of prospective ECG-gated 320-detector CTCA is comparable with that of retrospective ECG-gated 320-detector CTCA on patients with stable heart rates less than 65 bpm.

Phase-Contrast Diffuse Optical Tomography: Pilot Results in the Breast

We sought to investigate the utility of phase-contrast diffuse optical tomography (PCDOT) for differentiation of malignant and benign breast masses in humans and to compare PCDOT with conventional diffuse optical tomography (DOT) for analysis of breast masses in humans. Thirty-five breast masses were imaged in 33 patients (mean age, 51 years; range, 22-80) using PCDOT. Images characterizing the tissue refractive index, and absorption and scattering coefficients of breast masses were obtained with a finite element-based reconstruction algorithm. Theses images were then analyzed and compared with the biopsy/pathology results for all the cases examined. Malignant lesions tended to have a decreased refractive index, allowing them to be discriminated from benign lesions in most cases, whereas absorption and scattering images were unable to accurately discriminate benign from malignant lesions. The sensitivity, specificity, false-positive value, and overall accuracy for refractive index imaging were 81.8%, 70.8%, 29.2%, and 74.3%, respectively. The accuracy of refractive index imaging increases with increasing patient age. Refractive index is a new parameter for optical imaging that may be helpful in differentiating between malignant and benign masses in the breast.

M1702 A Macroscopically Normal Appendix Should Be Removed At Laparoscopy for Abdominal Pain in the Absence of An Identifiable Cause

Introduction: Some authors recommend leaving a ‘normal' appendix in situ during laparoscopy for abdominal pain (1,2). We question the safety of this rational following a case where we adopted such practice. Three days later an inflamed appendix was removed at open appendicectomy in the same patient.We therefore sought to correlatemacroscopic assessment at appendicectomy with that of reported histological findings. Method: All appendix samples over a three year period (1/1/2003-1/1/2006) were identified. Patient notes were then reviewed with patient age, sex, surgical approach, grade of surgeon(s), operative and histological findings recorded. For comparison with surgical findings the histological diagnosis was taken as being most accurate. Results: 972 appendicectomies were performed. We obtained 876 case notes (90.1%). There was 100% congruity between surgeons and pathologists when perforation, abscess or gangrene of the appendix noted (n=235). When inflammation was the sole recorded finding 8.3% of cases (37/445) were reported as histologically normal. This false positive value rose to 46.6% (26/57) when surgeons used vague terms to describe inflammation such as catarrhal inflammation or congestion. 33.1% (47/139) of appendixes perceived to be normal at appendicectomy demonstrated histological signs of inflammation. For both inflamed and normal appearing appendixes the choice of operative approach (laparoscopic vs. open) or seniority of operating surgeon had no effect on the correlation between surgical and pathological findings. Of 16 neoplastic lesions (12 carcinoid, 3 adenoma, 1 adenocarcinoma) only 3 were identified at the time of surgery. 2 were incidental findings at elective surgery the remainder presented as acute appendicitis. A mass was palpable in the caecum of the third case. Conclusions: The ability of surgeons to correctly diagnose a normal or mildly inflamed appendix is poor. At laparoscopy to investigate acute abdominal pain, in the absence of other identifiable pathology, a macroscopically normal appendix should be removed. The ability to detect features of neoplastic lesions of the appendix is also poor. Consequently it is essential that histological assessment is performed on all appendicectomy specimens. As follow up is not routine for the majority of patients who undergo appendicectomy must be vigilant when reviewing histology reports. 1. Teh SH, O'Ceallaigh S, Mckeon JG,O'DonohoeMK, TannerWA, Keane FB. Eur.J.Surg. 2000;166:3889. 2. van Dalen R, Bagshaw PF, Dobbs BR, RobertsonGM, Lynch AC, Frizelle FA. Surg.Endosc. 2003;17:1311-3.

Screening of Subtelomeric Rearrangements in 100 Korean Pediatric Patients with Unexplained Mental Retardation and Anomalies Using Subtelomeric FISH (Fluorescence In Situ Hybridization)

Rearrangements of the subtelomeric regions of chromosomes account for a significant proportion of the underlying genetic defects in both idiopathic mental retardation (MR) and multiple congenital anomalies. To detect the rearrangements, a set of subtelomeric fluorescence in situ hybridization (FISH) probes has been developed. The aim of this study was to reveal the frequency of subtelomeric rearrangements in Korean patients with MR or multiple anomalies. We performed a FISH study using a commercially available subtelomeric FISH probes on a series of unrelated Korean pediatric patients with MR or multiple anomalies without identifiable causes. We used a checklist to evaluate the developmental delay and/or MR. Patients who were shown to have chromosome abnormalities, metabolic disorders, or recognizable dysmorphic syndromes by clinical and laboratory findings were excluded. As a result, 100 patients were eligible for the Subtelomeric FISH study, and a total of 29 patients (29%) were suspected to have subtelomeric rearrangements on initial screening by the multiprobe FISH kit. Among theses, confirmatory FISH studies by using single locus-specific FISH probes were performed in 24 patients. One patient (a 10-yr-old girl) was confirmed to have rearrangement, deletion of the telomeric portion of the short arm of chromosome 4 (4p). Her clinical manifestation was compatible with Wolf-Hirschhorn syndrome, which is known to be caused by 4p deletion. The frequency of subtelomeric rearrangements in this study was 1.1% (1/95), lower than those previously reported (0.5-16.3%). We suggest that subtelomeric FISH test is a useful screening tool for patients with idiopathic MR and/or dysmorphism regardless of its false positive value.