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PubMed1999

Testicular sperm extraction: comprehensive analysis with simultaneously performed histology in 1418 biopsies from 766 subfertile men.

The introduction of intracytoplasmic sperm injection (ICSI) has revolutionized treatment of male-factor infertility. Even with a single spermatozoon a pregnancy can be achieved. In cases of azoospermia due to obstruction or highly impaired spermatogenesis, spermatozoa can be retrieved directly from testicular tissue recovered by testicular biopsy followed by sperm extraction. The predictive value of histology from semi-thin sections of testicular biopsies was assessed in relation to testicular sperm extraction (TESE) results, using 1418 biopsy samples from 766 subfertile men which were evaluated simultaneously using a modified Johnsen score and an ordinal classification system for spermatozoa in TESE samples. In 655 men bilateral samples were available. Based on histological findings and TESE results, the quality of spermatogenesis in the right testes was significantly better than that in the left testes. There was a difference between the two sides in 35.7% of all patients for histology and 32.7% for TESE results. When best results from either testis were used for analysis, 76.9% of all men revealed spermatozoa in TESE preparations, although during histological evaluation of semi-thin sections only 64% of all men had shown mature spermatids. In a core group of 250 azoospermic men without anamnestic hints to obstruction and most likely to benefit from ICSI, TESE was successful in 62.8% men. Subdivision of this group dependent on follicle stimulating hormone (FSH) serum concentrations revealed that even in cases of increased FSH concentration, between 39.1 and 64.7% of men showed mature spermatids in their TESE samples. A subset of 70 azoospermic men from the main sample with symptoms and history suggestive of an obstruction and considered as positive controls showed a positive TESE result in all patients. The histology had failed to predict this in 2.9% of all cases. Nevertheless, in five men an early stage of testicular tumour (carcinoma in situ = CIS) was detected. Two of these males suffered from bilateral CIS. This reflects a prevalence of 0.7% testicular malignancy in the group of patients without a history of excurrent duct obstruction. The data demonstrate that a trial TESE with histology based on the semi-thin sectioning technique is a powerful diagnostic and therapeutic procedure, which justifies the invasive nature of sperm retrieval for ICSI. In addition, the results stress the importance of bilateral biopsies to gain optimal diagnostic and therapeutic results.

Adult↗
PubMed1995

Sample adequacy in detecting Chlamydia trachomatis.

OBJECTIVE: Chlamydia trachomatis is an important etiological agent in female genital infection and may result in infertility. In recent years rapid diagnostic methods have become widely used as alternatives to cell culture. Our objective was to evaluate the technique of direct fluorescence assay (DFA) in estimating the presence of C. trachomatis. METHODS: Specimens taken from 40 infertile and 20 fertile women were examined by DFA for the presence of C. trachomatis. RESULTS: Six of forty (15%) infertile women were found to be positive whereas no positive specimens were detected in the control group. When the specimens were grouped into those which were adequate or inadequate, 19 and five specimens, respectively, were adequate in the infertile and healthy groups. If only adequate specimens are included in estimating the presence of Chlamydia, the percentage is 31.6%. CONCLUSIONS: In order to use DFA as a more reliable and rapid diagnostic test of C. trachomatis in female genital infection, false-negativity must be eliminated. Specimens must be collected adequately and concentrated in order to achieve optimal diagnostic success.

Cervix Uteri↗
PubMed2001

[Usefulness of thoracic imaging and computed tomography in evaluation of neoplastic changes of lungs and mediastinum in children].

Radiological methods of imaging diagnostics allow to evaluate exactly and to monitor the treatment course of pathological lesions in chest. Basic examinations are: plain chest X-ray and computer tomography. Optimal diagnostic algorithm of neoplastic changes in chest is not always univocally defined. The aim of the study is to compare the results of estimation of the presence and type of neoplastic changes in mediastinum and lungs based on X-ray and computer tomography. The results indicate that initial and control X-ray examination allows to diagnose mediastinal lymphadenopathy coexisting with pulmonary hilus extension. CT is used to diagnose and monitor lung tissue and mediastinal changes.

Adolescent↗
PubMed1989

[General problems of selection and interpretation of diagnostic methods].

The author draws attention to general principles which must be respected in the selection and interpretation of diagnostic methods. He discusses the importance of basic characteristics of the diagnostic test (reliability, accuracy, sensitivity, specificity, predictive value) and their application in the examination process. He explains the importance of ROC analysis in the selection of the optimal diagnostic method. He refers to the criteria which must be taken into account when introducing and evaluating a new examination method.

Diagnosis↗
PubMed2000

Venous thromboembolic disease: an observational study in medical-surgical intensive care unit patients.

PURPOSE: Acute and chronic illness, immobility, and procedural and pharmacologic interventions may predispose patients in the intensive care unit (ICU) to venous thromboembolic (VTE) disease. The purpose of this study was to observe potential risk factors and diagnostic tests for VTE, and prophylaxis against VTE in medical-surgical ICU patients. MATERIALS AND METHODS: In a prospective observational study, 93 consecutive patients admitted to a mixed medical-surgical ICU were followed. We recorded demographics, admitting diagnoses, APACHE II score, VTE risk factors, antithrombotic, anticoagulant and thrombolytic agents, diagnostic tests for deep venous thrombosis (DVT) and pulmonary embolus (PE), and clinical outcomes. RESULTS: Patients were 65.5 (15.5) years old with an APACHE II score of 21.1 (9.0); 44 (47.3%) were female. Admission diagnoses were medical (58, 67.4%) and surgical (35, 37.6%). The duration of ICU stay was 3 days (interquartile range: 1, 8.5 days) and the ICU mortality rate was 20.4% (19 of 93). We observed 8 VTE events among 5 of 93 patients (incidence 5.4% [0.8 to 10.0]); 2 patients had DVT and PE before admission, 1 had DVT as an admitting diagnosis, 1 had DVT on day 2 and PE on day 3, and 1 had PE on day 2. Over 804 ICU patient-days, 2 of 5 ultrasound examinations diagnosed DVT and 2 of 3 ventilation-perfusion lung scans diagnosed PE. Of 64 patients in whom heparin was not contraindicated and who were not anticoagulated, subcutaneous heparin prophylaxis was prescribed for 40 (62.5%) patients. ICU-acquired VTE risk factors were mechanical ventilation (odds ratio [OR] 1.56), immobility (OR 2.14), femoral venous catheter (OR 2.24), sedatives (OR 1.52), and paralytic drugs (OR 4.81), whereas VTE heparin prophylaxis (OR 0.08), aspirin (OR 0.42), and thromboembolic disease stockings (OR 0.63) were associated with a lower risk. Only warfarin (OR 0.07, P =.01) and intravenous heparin (OR 0.04, P<.01) were associated with a significantly decreased risk of VTE. CONCLUSIONS: Several ICU-acquired risk factors for VTE were documented in this medical-surgical ICU. VTE prophylaxis was underprescribed, and VTE diagnostic tests were infrequent. Further research is required to determine the incidence, predisposing factors, attributable morbidity, mortality, and costs of VTE in medical-surgical ICU patients, the optimal diagnostic test strategies, and the most cost-effective approaches of prophylaxis.

APACHE↗
PubMed1994

Generating explanations and tutorial problems from Bayesian networks.

We present a system that generates explanations and tutorial problems from the probabilistic information contained in Bayesian belief networks. BANTER is a tool for high-level interaction with any Bayesian network whose nodes can be classified as hypotheses, observations, and diagnostic procedures. Users need no knowledge of Bayesian networks, only familiarity with the particular domain and an elementary understanding of probability. Users can query the knowledge base, identify optimal diagnostic procedures, and request explanations. We describe BANTER's algorithms and illustrate its application to an existing medical model.

Algorithms↗
PubMed2000

Combining diagnostic test results to increase accuracy.

When multiple diagnostic tests are performed on an individual or multiple disease markers are available it may be possible to combine the information to diagnose disease. We consider how to choose linear combinations of markers in order to optimize diagnostic accuracy. The accuracy index to be maximized is the area or partial area under the receiver operating characteristic (ROC) curve. We propose a distribution-free rank-based approach for optimizing the area under the ROC curve and compare it with logistic regression and with classic linear discriminant analysis (LDA). It has been shown that the latter method optimizes the area under the ROC curve when test results have a multivariate normal distribution for diseased and non-diseased populations. Simulation studies suggest that the proposed non-parametric method is efficient when data are multivariate normal.The distribution-free method is generalized to a smooth distribution-free approach to: (i) accommodate some reasonable smoothness assumptions; (ii) incorporate covariate effects; and (iii) yield optimized partial areas under the ROC curve. This latter feature is particularly important since it allows one to focus on a region of the ROC curve which is of most relevance to clinical practice. Neither logistic regression nor LDA necessarily maximize partial areas. The approaches are illustrated on two cancer datasets, one involving serum antigen markers for pancreatic cancer and the other involving longitudinal prostate specific antigen data.

Journal Article↗
PubMed1997

Magnetic resonance angiography in the resectability assessment of suspected pancreatic tumours.

The aim of this prospective study was to evaluate MRI, including MR angiography (MRA), in the preoperative assessment of the resectability of suspected malignancy of the pancreas. A total of 17 patients with suspected pancreatic carcinoma and planned surgery were investigated with conventional angiography, ultrasonography with Doppler technique, MRI and MRA. The MRA protocol included both 2D inflow angiography and 3D phase-contrast angiography. Surgery was carried out in 13 patients. The image quality of MRA was judged satisfactory in all cases. The findings with respect to vascular involvement agreed between the radiological methods in all but 3 cases. When the findings were correlated with the final diagnosis, one false-negative case was found for each of the three methods. The results suggest that MRI with MRA, including both the phase-contrast and inflow techniques, has a similar diagnostic value to that of conventional angiography and ultrasonography in the preoperative assessment of the portal venous system in patients with pancreatic carcinoma. Further studies are needed to establish the optimal diagnostic procedure.

Biopsy↗
PubMed2001

Dipyridamole-atropine-induced myocardial infarction in a patient with patent epicardial coronary arteries.

BACKGROUND: The diagnostic accuracy of the physical and pharmacological stress echocardiography tests is higher than routine exercise electrocardiography. They have an acceptable safety profile and have been rarely associated with severe adverse effects. CASE REPORT: We present a case of acute anterior myocardial reinfarction immediately after exercise and pharmacological (dipyridamole-atropine) stress echocardiography testing 1 month after successful stent implantation in LAD. Our patient was a 43-year-old man with a history of heavy smoking and hypertension. Remarkably, the stress echocardiogram was non-diagnostic few hours before the infarction occurred. Angiography performed 4 months after the reinfarction revealed neither a culprit lesion nor stent thrombosis. CONCLUSION: Aggressive "last generation" pharmacological stress testing may provide optimal diagnostic accuracy, but as in our case, complications may occur, even after negative stress testing. To our knowledge, this is the first reported case of an acute myocardial infarction as a severe complication of stress testing, which developed in a patient after stent implantation.

Adult↗
PubMedDate not supplied

Role of ultrasonography in the diagnosis and management of thyroid cancer.

OBJECTIVE: To review the role of ultrasonography in the detection and management of thyroid cancer. METHODS: Viewpoints are presented on the appropriate applications and the advantages of ultrasonography, based on an extensive personal experience with more than 1,500 ultrasound examinations for assessment of thyroid nodules and for follow-up surveillance of patients with thyroid cancer. RESULTS: Ultrasonography is ideal for thyroid imaging because of the high echogenicity of thyroid tissue, the superficial site of the thyroid that allows the use of high-frequency transducers yielding high resolution, and the low expense compared with other techniques. In patients with a thyroid nodule, ultrasonography can assist in distinguishing benign from malignant disease. Ultrasound studies will characterize the presence of cystic versus solid elements, the degree of echogenicity of solid elements, the existence of calcifications, and the regularity and definition of the nodule borders. Although individual sonographic features of thyroid nodules are not specific for benign or malignant lesions, a constellation of typical features has more diagnostic value. Hypoechogenicity, poorly defined irregular margins, and microcalcifications are characteristics that should increase the index of suspicion for a malignant nodule. Cytologic examination of fine-needle aspirates is the optimal diagnostic test, and ultrasonographic guidance for performance of the aspiration biopsy is often helpful and sometimes critical. Ultrasonography is also useful for detection of cervical lymph node metastatic lesions. Lymph nodes involved with metastatic thyroid cancer tend to become rounded and bulging, and they lose their hilar echoes as their structure becomes disrupted. CONCLUSION: Because of its high resolution and relatively reasonable cost, ultrasonography is valuable in the diagnosis and management of thyroid cancer.

Humans↗
PubMed2004

The appropriate diagnostic threshold for ventilator-associated pneumonia using quantitative cultures.

BACKGROUND: The use of quantitative cultures of the bronchoalveolar lavage (BAL) effluent to distinguish between posttraumatic inflammatory response and ventilator-associated pneumonia (VAP) is becoming more common. However, the diagnostic threshold of either 10 or 10 colonies/mL remains debatable. Because mortality from VAP is related to treatment delay, some have chosen a lower diagnostic threshold (>10 colonies/mL). This may result in unnecessary antibiotic use with its sequelae: increased resistant organisms, antibiotic-related complications, and increased costs. The purpose of this study is to determine the optimal diagnostic threshold for VAP diagnosis using quantitative cultures of the BAL effluent. METHODS: Data on patients with fiberoptic bronchoscopy with BAL are maintained in a prospectively collected database at our Level I trauma center. This database was reviewed for timing and frequency of BAL and the colony counts of each organism identified. Indication for bronchoscopy was clinical evidence of VAP. VAP was defined as >10 colonies/mL in the BAL effluent. A false-negative BAL was defined as any patient who had <10 colonies/mL and developed VAP with the same organism up to 7 days after the previous culture. RESULTS: Over a 46-month period, 526 patients underwent 1,372 fiberoptic bronchoscopy procedures with BAL. Of these, 72% were male patients, 91% followed blunt injury, and mean age and Injury Severity Score were 43 years and 30, respectively. Overall mortality was 14%. There were 1,898 organisms identified (42% were gram-positive and 58% were gram-negative). VAP was diagnosed in 38% of BAL. Overall, there were 43 episodes in 38 patients defined as false-negative (3%). The false-negative rate was 9% in patients with 10 organisms. The most common false-negative organisms were Pseudomonas and Acinetobacter species. CONCLUSION: The VAP diagnostic threshold for quantitative BAL in trauma patients should be >10 colonies/mL. One may consider a threshold of >10 colonies/mL in severely injured patients with Pseudomonas or Acinetobacter species.

Adult↗
PubMed1990

Mammography-guided stereotactic fine-needle aspiration cytology of nonpalpable breast lesions: prospective comparison with surgical biopsy results.

We assessed the usefulness of fine-needle aspiration cytology (FNAC) in evaluating nonpalpable breast abnormalities by prospectively performing stereotactic mammography-guided FNAC on 100 women undergoing surgical excisional biopsy. Mammographic and cytologic diagnoses, on a scale of 1 (benign) to 4 (malignant), were assigned for each case and compared with the surgical pathologic diagnosis. Sensitivity and specificity were examined at different diagnostic cutoff points for regarding a mammographic or cytologic diagnosis as positive or negative. Of the 100 breast biopsy specimens, 70 were benign and 30 were malignant. For both mammography and FNAC, the optimal diagnostic cutoff point was between diagnosis 2 (mammography, probably benign; cytology, atypical) and 3 (mammography and cytology both suspicious for malignancy). At this cutoff point, FNAC had a sensitivity of 0.77 and specificity of 1.00, vs 0.73 sensitivity and 0.79 specificity for mammography. Pearson coefficient analysis revealed significant correlations between both mammographic and FNAC diagnoses and surgical pathology (p less than .001 for both). Our results suggest that use of mammography-guided FNAC may reduce the number of breast biopsies performed for benign lesions.

Adult↗
PubMed1994

[Adding atropine improves the diagnostic accuracy of dipyridamole-echo test].

BACKGROUND: The clinical experience with dipyridamole stress echocardiography for the diagnosis of coronary artery disease (CAD) revealed that patients with less severe extent of CAD and limited impairment of coronary reserve are frequently not recognized by the test. Increasing myocardial oxygen consumption adding atropine to dipyridamole may improve the diagnostic accuracy of dipyridamole for the detection of CAD. METHODS: Fifty-two patients (48 men, aged 53 +/- 7 years) underwent a high-dose dipyridamole-echo stress test (0.84 mg/kg over 10 minutes) and coronary arteriography within 15 days from the test. Eighteen out of 52 patients were referred for chest pain; 11 suffered from a previous myocardial infarction (MI) and 23 were studied in the early phase after a first acute MI. Starting after 4 minutes from the end of dipyridamole infusion, atropine was added, in 2 doses of 0.5 mg each, at 1-minute interval in those patients with no echocardiographic evidence of myocardial ischemia after dipyridamole alone. Left ventricular wall motion was analyzed on a 11-segment left ventricular model in a qualitative manner. RESULTS: Dipyridamole-echo stress test was positive in 23/52 (44%) and negative in 29/52 (56%) patients. In these patients atropine was added resulting in an additional echo positivity in 14/29 patients. Coronary arteriography was normal in 6 patients (12%); 1-vessel CAD was diagnosed in 23 (44%), 2-vessel CAD in 13 (25%) and 3-vessel CAD in 10 (19%) cases. The sensitivity for CAD diagnosis was 48% (22/46) for dipyridamole alone and 76% (35/46) for dipyridamole-atropine echo (p < .005), while the specificity was 83% (5/6) and 80% (4/5) respectively. Diagnostic accuracy increased from 52% (27/52) to 75% (39/52) (p < .001). The better diagnostic accuracy of dipyridamole-atropine echo stress test was mainly related to the increased sensitivity of the combined test in patients with 1-vessel CAD (from 39% to 70%) (p < .005). Peak heart rate was significantly higher after the addition of atropine (100 +/- 17 beats/min) compared to basal (64 +/- 10) and dipyridamole (85 +/- 12) in those patients with a positive dipyridamole-atropine echo stress test. No limiting side effects were elicited with the addition of atropine to dipyridamole. CONCLUSIONS: The combination of atropine and dipyridamole induces a chronotropic stress adjunctive to flow maldistribution phenomena that permits to increase diagnostic accuracy of dipyridamole-echo stress test particularly in patients with less severe extent of CAD; it is usually well tolerated and safe and may be considered as a useful procedure for optimizing diagnostic value of dipyridamole-echo stress test.

Aged↗
PubMed1976

[The development of colposcopy (author's transl)].

In 1925, in this Journal, Hans Hinselmannn gave the reslults of his experience with the method of colposcopy he devised for the early recognition of cancer of the uterine cervix. In 50 years it has proved to be an indispensable procedure in experienced hands, by which the prestages and early stages of the most frequent genital cancer in women, carcinoma of the cervix, can be detected while still of microscopic dimensions (microcarcinoma). Papanicolaou's vaginal cytology used in combination with colposcopy increases diagnostic accuracy to more than 95%. Cytology, as a preliminary orienting laboratory procedure, and colposcopy as a clinical investigation method togethe - if the two individual methods are used in their proper places - offer optimal diagnostic prospects. The opportunities of mastering colposcopy and its use in the cancer prophylaxis program are pointed out.

Adult↗
PubMed1996

Image processing and computer-aided diagnosis.

The future of image processing and CAD in diagnostic radiology is more promising now than ever, with increasingly impressive results being reported from various observer performance studies in both mammography and chest radiography. Clinical trials in years to come will help optimize the accuracy of the programs and determine the actual contribution of CAD to the interpretation process. Radiologists using output from computer analyses of images, however, will still make the final decision regarding diagnosis and patient management. Nonetheless, studies have indicated that the computer output need not have greater overall accuracy than a given radiologist in order to improve his or her performance. A systematic and gradual introduction of CAD into radiology departments will be necessary so that radiologists can become familiar with the strengths and weaknesses of each CAD program, thereby avoiding either excessive reliance or a dismissive attitude toward the computer output. This should ensure the acceptance of CAD and optimal diagnostic performance by the radiologist. Thus, an appropriate role for each CAD program will be determined for each radiologist, according to his or her individual training and observational skills, reducing intraobserver variations and improving diagnostic performance.

Diagnosis, Computer-Assisted↗
PubMed1991

Oncologic imaging. Staging and follow-up of renal and adrenal carcinoma.

Computed tomography (CT) has emerged from the 1980s to play a dominant role in the pretreatment staging of renal and adrenal carcinomas. For detection, definition (staging), and determination of resectability or recurrence, CT with intravenous contrast enhancement, and more recently, magnetic resonance imaging (MRI) with gadolinium-DTPA, may be the only cross-sectional imaging studies required before institution of appropriate therapy. Carcinoma of the kidney is frequently diagnosed by serendipity or detected on incidental ultrasound or CT examinations. Real-time ultrasound and color flow Doppler offer unique information on tumor vascularity and major venous vascular involvement. Positive predictive values of 96% can be achieved for the diagnosis of renal cell carcinoma using contrast-enhanced CT scanning. For follow-up CT and MRI are the best imaging techniques for evaluation of the retroperitoneum. MRI may distinguish tumor recurrence from fibrosis in selected cases. Because primary neoplasms of the adrenal gland are rare and often exceed 10 cm at the time of initial diagnosis, the functional nature (endocrine) of adrenal carcinoma may be part of the clinical presentation. Because initial stage is critical to survival and extent of surgical therapy, a knowledge of tumor classification is essential to the optimal diagnostic evaluation. Newer imaging tests, CT and MRI, have superseded conventional urography, ultrasound, and radionuclide studies for the diagnosis and staging of adrenal cancer. Early diagnosis and low stage at presentation are critical to survival in patients with adrenal carcinoma. The current concepts for pretreatment imaging evaluation and the role of CT, MRI, and ultrasound are outlined. An oncologic imaging approach based on tumor staging and classification for patients with real or suspected renal cell carcinoma and adrenal carcinoma is essential to optimal patient care.

Adrenal Gland Neoplasms↗
PubMed1991

Diagnosis of popliteal artery entrapment syndrome: the role of duplex scanning.

The authors present a new diagnostic procedure to quickly and noninvasively diagnose the popliteal artery entrapment syndrome. A large personal experience on the surgical treatment of such a disease (29 cases in 22 patients) allowed us to focus on the optimal diagnostic procedure useful to detect this problem at an early stage. The technique is based on continuous-wave Doppler and duplex scanning studies done both in the resting state and during active contraction of the calf muscles. If compression of the popliteal artery occurs with contraction of the calf muscles, it will be detected by a decrease in flow. This finding will also direct the radiologist to obtain films when the maneuver is repeated. This makes it unlikely that the diagnosis will be missed. Since July 1988 a total of 1212 patients were evaluated with continuous-wave Doppler for suspected chronic ischemia. From this group 41 patients were selected to be studied again with the combined continuous-wave Doppler and duplex scanning method for possible popliteal artery entrapment syndrome. Two cases were discovered and verified by dynamic angiography guided by continuous-wave Doppler and treated surgically.

Adult↗
PubMed1986

An algorithm for differential diagnosis in jaundice and its applications.

During the recent years a broad spectrum of diagnostic methods have appeared for the differentiation of obstructive and nonobstructive jaundice: ultrasound examination, CT-scan, direct cholangiography, etc. These investigations are costly and not without risks. It is therefore essential to devise an optimal diagnostic strategy for each patient. Extensive clinical and clinical chemical information was collected from 1,002 jaundiced patients. By application of Bayes' theorem and logistic discriminant analysis a diagnostic algorithm was developed based upon 21 variables of the 107 variables collected. This algorithm permitted a probabilistic classification of jaundiced patients into four diagnostic categories: acute non-obstructive, chronic non-obstructive, benign obstructive and malignant obstructive jaundice. Adopting a probability limit of 0.80, 683 patients (69 p. 100) were correctly classified, 34 patients (3.5 p. 100) were wrongly so, and 268 patients (27 p. 100) could not be classified with a probability above 0.80 (doubtful cases). The algorithm was also tested in a further series of 110 jaundiced patients and found to perform equally well: 88 patients classified, 22 patients remaining doubtful. Patients with doubtful diagnoses should be referred to a non-invasive test such as ultrasound examination, whereas patients with definite diagnoses can be referred to invasive tests (liver biopsy, direct cholangiography) as appropriate. The diagnostic algorithm seems to be a reliable tool for the primary differential diagnosis of the jaundiced patient and can be used in the planning of further diagnostic tests for the individual patient.

Algorithms↗