Genetic analysis of protein C deficiency in nineteen Japanese families: five recurrent defects can explain half of the deficiencies

OBJECTIVE: The lack of sensitivity and specificity of conventional imaging techniques based on morphological critera is responsible for considerable limitations in the staging and surveillance of oral cancer. Therefore, this study investigates the contribution of [F18]-2-fluordesoxyglucose (FDG) positron emission tomography (PET) to tumor management with special regard to lymphnode involvement and therapeutic monitoring after radiotherapy. DESIGN: Prospective observational study. PATIENTS: Twenty-one patients with advanced oral cancer, predominantly T3/T4. INTERVENTION: FDG-PET scans before and after preoperative radio(chemo)therapy. Standardized uptake values (SUV) were determined for the tumor site and lymphnode areas. PET scans were correlated to histological findings after ablative tumor surgery. RESULTS: FDG-PET yielded superior sensitivity and specificity for tumor and lymphnode assessment. The effect of radiotherapy was reflected by the metabolic activity of the tumor, which shows a close correlation between the decrease of FDG uptake and histologic tumor regression. PET detected distant metastases and simultaneous tumors. CONCLUSION: FDG-PET is a challenging imaging technique with the potential to improve staging procedures for oral cancer. In the monitoring of metabolic activity of the tumor in the course of radio(chemo)therapy, FDG-PET allows objective measurement of the treatment response.     

Whole-body 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) for accurate staging of Hodgkin's disease

BACKGROUND: Staging of Hodgkin's disease (HD) is accomplished by a variety of invasive and non-invasive modalities. This prospective study was undertaken to investigate the value of whole-body positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) in defining regions involved by lymphoma compared with conventional staging methods in patients with HD. PATIENTS AND METHODS: Fourty-four newly diagnosed patients with HD underwent FDG-PET as part of their initial staging work-up. PET findings were correlated with findings of conventional staging including computed tomography, ultrasound, bone scanning, bone marrow biopsy, liver biopsy and laparotomy. When results of FDG-PET differed to those obtained by conventional methods reevaluation was performed by biopsy, if possible, or magnetic resonance imaging. RESULTS: The results of FDG-PET were compared with three hundred twenty-one conventional staging procedures performed in 44 patients. FDG-PET was positive in 38 of 44 (86%) patients at sites of documented disease. PET detected additional lesions in five cases previously not identified by conventional staging methods. In another case a nodal lesion suspect on CT was negative at FDG-PET and was settled as true negative by biopsy. As a consequence of PET findings five patients had to be upstaged and one patient had to be downstaged, resulting in changes in treatment strategy in all six cases (14%). FDG-PET failed to visualize sites of HD in four patients. In two of our patients a false positive PET result was obtained. CONCLUSIONS: Our data indicate that FDG-PET provides an imaging technique that appears to visualize involved lesions in most patients with HD and is useful in the management of these patients.     

Applications of PET in lung cancer

An estimated 180,000 new cases of lung cancer will be diagnosed in the United States this year, and lung cancer accounts for approximately 25% of all cancer deaths. The overall 5-year survival rate is 14%, and this has not changed over the past several decades. Lung cancer diagnosis and treatment is a major health problem globally. Most lung cancers are detected initially on chest radiographs, but many benign lesions have radiologic characteristics similar to malignant lesions. Thus, additional studies are required for further evaluation. Computed tomography (CT) is most frequently used to provide additional anatomic and morphologic information about the lesion, but it is limited in distinguishing benign from malignant abnormalities in the lung, pleura, and mediastinum. Because of the indeterminate results from anatomic imaging, biopsy procedures including thoracoscopy and thoracotomy may be used even through one-half of the lesions removed are benign and do not need to be removed. FDG-PET imaging provides physiologic and metabolic information that characterizes lesions that are indeterminate by CT and that accurately stages the distribution of lung cancer. Exploiting the fundamental biochemical differences between cancer and normal tissues, FDG imaging takes advantage of the increased accumulation of FDG in transformed cells. FDG-PET is very sensitive (approximately 95%) for the detection of cancer in patients who have indeterminate lesions on CT. The specificity (approximately 85%) of PET imaging is slightly less than the sensitivity because some inflammatory processes such as active granulomatous infections accumulate FDG avidly. The high-negative predictive value of PET suggests that lesions considered negative on the study are benign, biopsy is not needed, and radiographic follow-up is recommended. Several studies have documented the increased accuracy of PET compared with CT in the evaluation of the hilar and mediastinal lymph node status in patients with lung cancer. If the mediastinum is normal on PET imaging and there is no other evidence of metastatic disease, the patient has a thoracotomy. If the mediastinum is abnormal on PET imaging, mediastinoscopy is performed with the PET images providing the lymph node stations to target. Whole-body PET studies detect metastatic disease that is unsuspected by conventional imaging and demonstrate some of the anatomic abnormalities detected by CT to be benign lesions. Management changes have been reported to occur in up to 41% of patients based on the results of the whole-body studies.     

Role of superoxide dismutase in ischemic brain injury: a study using SOD-1 transgenic mice

In 1991, this prospectively designed study was started to assess the potentials of positron emission tomography with 18FDG in the diagnostic workup for the detection of lymph node metastases in testicular cancer, since there were no data available concerning this subject at this time. In 54 patients (27 patients with pure seminoma, 27 patients with non-seminomatous tumors) 18FDG-PET results were compared with the findings obtained with abdominal computed tomography, serum level of tumor markers (AFP, beta-HCG), and the histopathological findings after primary or post-chemotherapy retroperitoneal lymph node dissection. In 21 patients with pure seminoma (clinical stage I according to the Lugano classification) 18FDG-PET results were identical with those of the abdominal computed tomography, so PET does not add relevant informations in this group of patients. In 7 patients presenting with non-seminomatous testicular cancer (stage I), PET was not able to detect the existing micrometastases in 4 patients. In 1/7 case PET examination showed a suspicious focal lesion, this lymph node had 2 micrometastases within inflammatory changes. In 1/7 patient 18FDG-PET definitely revealed metastatic lesions, while the CT scans where judged to be unobtrusive and tumor marker levels were within the normal range. In the 4 patients with pure seminomas stage II B and II C (N = 6), that have undergone retroperitoneal lymph node dissection following chemotherapy, 18FDG-PET correctly predicted absence of tumor in 3 out of these 4, and in 1/4 patient the benign nature of a persistent large tumor after two cycles of polychemotherapy was correctly identified which eventually turned out to be a ganglioneuroma. This lesion falsely was classified as malignant tumor with abdominal computed tomography, and in 2/4 patients post-chemotherapy residual retroperitoneal lesions in the CT scans could not be assessed exactly whether or not malignant tumor was present. In 20 patients presenting with non-seminomatous testicular cancer (stage II and III) 18FDG-PET was able to demonstrate therapeutic effects of chemotherapy by showing decreasing tracer activity in those regions, that had hypermetabolic foci prior to chemotherapy. It became evident in testicular cancer that there is a single entity which is not characterized by increased glucose metabolism, the mature teratoma. In lesions detected by abdominal computed tomography which do not present increased 18FDG uptake, mature teratoma as well as scar/necrosis or rare other tumors with normal glucose metabolism can be supposed, but additional characteristics based on different 18FDG uptake were not observed. In 1/20 case post-chemotherapy PET scan detected a hypermetabolic lesion, which was suspicious for metastatic spread, but in the histopathological examination this lesion was identified as inflammatory tissue reaction. Based on the data reported here in 18FDG-PET cannot be considered a standard diagnostic tool in the staging examinations in testicular cancer. It is of clinical relevance in patients who present residual tumor after chemotherapy. In this situation 18FDG-PET is helpful in deciding whether or not a residual mass post-chemotherapy contains active tumor. 18FDG-PET can not replace retroperitoneal lymph node dissection for staging purposes.     

Metabolic imaging of malignant pleural mesothelioma with fluorodeoxyglucose positron emission tomography

BACKGROUND: The diagnosis of malignant mesothelioma is a challenging medical problem. CT often cannot differentiate between benign diffuse pleural thickening and malignant mesothelioma, while thoracentesis and CT-guided biopsies are insensitive. We have assessed the value of positron emission tomography (PET) with 2-fluoro-2-deoxy-D-glucose (FDG) in the evaluation of malignant mesothelioma. METHODS: Twenty-eight consecutive patients referred for the evaluation of suspected malignant mesothelioma were evaluated by FDG-PET imaging. Measured attenuation correction was performed in 26 of 28 cases for quantitation with the standardized uptake value (SUV) method. The results of PET imaging were compared with those of video-assisted thoracoscopy or surgical biopsies. RESULTS: Surgical biopsy specimens confirmed the presence of malignant disease in 24 patients and demonstrated benign processes in the remaining four. The uptake of FDG was significantly higher in malignant than in benign lesions (SUV=4.9+/-2.9 and SUV=1.4+/-0.6, respectively; p<0.0001). With a SUV cutoff of 2.0 to differentiate between malignant and benign disease, a sensitivity of 91% and a specificity of 100% could be achieved, although the activity in some epithelial mesotheliomas tended to be close to this threshold. FDG-PET images provided excellent delineation of the active tumor sites. Hypermetabolic lymph node involvement was noted on FDG-PET images in 12 patients, 9 of which appeared normal on CT scans. Histologic examination in six patients confirmed malignant nodal disease in five cases and indicated granulomatous lymphadenitis in one. CONCLUSION: In this highly selected population, FDG-PET imaging was a sensitive method to identify malignant mesothelioma and determine the extent of the disease process.     

Metabolism of L-phenylalanine and L-tyrosine by the phototrophic bacterium Rhodobacter capsulatus

We have investigated whether increased tumor uptake of fluorine-18 fluorodeoxyglucose (FDG) detected with positron emission tomography (PET) early after initiating tamoxifen therapy ("metabolic flare") predicts a hormonally responsive breast cancer. Eleven postmenopausal women with biopsy-proved estrogen receptor-positive (ER+) metastatic breast cancer were studied by PET with FDG and 16alpha[18F]fluoro-17beta-estradiol (FES) before and 7-10 days after initiation of tamoxifen therapy. FDG and FES uptake was evaluated semiquantitatively in 21 lesions. The PET results were correlated with follow-up evaluation, continued until the patient became unresponsive to hormone therapy (3-24 months). There were seven responders and four nonresponders based on clinical follow-up. None of the responders had a clinical flare reaction, but all demonstrated metabolic flare, with a mean +/- standard deviation increase in tumor standardized uptake value (SUV) for FDG of 1.4+/-0. 7. No evidence for flare was noted in the nonresponders (change in SUV for FDG -0.1+/-0.4; P = 0.008 vs. responders). The degree of ER blockade by tamoxifen was greater in responders (mean decrease in SUV 2.7+/-1.7) than in nonresponders (mean decrease 0.8+/-0.5) (P = 0.04). The lesions of responders had higher baseline SUVs for FES than did those of three of four nonresponders (>/=2.2 vs 相似文献   

Mechanism and clinical usefulness of S4-S1 interval in heart failure associated with left ventricular inflow pattern]

Technetium-99m-tetrofosmin, a myocardial perfusion imaging agent was used for estimation of cardiac output by means of first-pass radionuclide angiography performed in the anterior projection. Region of interests (ROIs) were assigned over right ventricle, left ventricle and whole chest, and time activity curves (TACs) were obtained. Cardiac output indices (COIs) were calculated by the following equation; COI = p3/2. Qc/[symbol: see text] A(s)ds, where p = number of pixels of the ventricular ROI, Qc = the peak count rate of the TAC obtained from the whole chest's ROI and [symbol: see text] A(s)ds = the area under ventricular TAC. The COI (y) determined by ROI over the left ventricle yield the best correlation with the cardiac output by conventional radionuclide method (x) (y = 0.0381x + 6.22, r = 0.828, n = 48, p < 0.001). In conclusion, cardiac output can be easily measured with first pass data using myocardial perfusion imaging agent.     

Kinetic analysis of glucose metabolism by FDG-PET versus proliferation index of Ki-67 in meningiomas--comparison with gliomas

I compared glucose metabolism by 18F-fluorodeoxy-glucose (FDG)-PET with proliferative potentials determined by using Ki-67 in meningiomas and gliomas. Ki-67 labeling index (LI) as proliferation index was used to assess tumor aggressiveness. In FDG-PET, I measured tumor versus contralateral gray matter ratio (T/N), standardized uptake value (SUV), kinetic rate constants (k1, k2, k3) which were analyzed according to the three compartment FDG model, and kinetic cerebral metabolic rate of glucose (kCMRGl). Significantly elevated FDG uptake in T/N, kCMRGl was found in a high Ki-67 LI (above 2%) group compared to a low Ki-67 LI group in gliomas, but there was not found significant difference between these two groups in meningiomas. Tumor k3 value, an indicator of hexokinase activity, of a high Ki-67 LI group was significantly higher than that of a low Ki-67 LI group. It was found that k3 correlated with Ki-67 LI. The k3 value is useful for estimating the biological aggressiveness of meningiomas.     

Comparative signal intensity measurements in dynamic gadolinium-enhanced MR mammography

Increases in signal intensity enhancement were measured in defined regions of interest (ROIs) to allow distinction between malignant and benign tumors with dynamic gadolinium-enhanced magnetic resonance (MR) mammography. Twenty patients with palpable breast lesions (15 malignant, five benign) underwent MR mammography. The dynamic gradient-echo sequence was performed with intravenous bolus injection of gadopentetate dimeglumine and consisted of 25 images with a time resolution of 30 seconds. Contrast enhancement was calculated by comparing user-defined ROIs on pre- and postcontrast images. An increase in signal intensity of 70% or more on the 1-minute postcontrast image was used as the criterion of malignancy. MR mammographic results correlated with histopathologic findings in all patients when the defined ROI was in the most enhancing part of the tumor. For the ROI in areas of submaximal enhancement or when the ROI surrounded the whole lesion, only five and nine tumors, respectively, fulfilled the malignancy criterion. All malignant tumors showed large variations in signal intensity enhancement that depended on the position of the ROI in the tumor. Dynamic, gadolinium-enhanced MR mammography allows distinction of benign from malignant breast tumors when the selected ROI is in the most enhancing part of the lesion.     

Alterations in adhesion molecule (CD11b/CD18 and CD62L) expression on granulocytes after chemotherapy

The evaluation of brain tumor recurrence and therapy-induced benign changes following surgery and/or irradiation is a diagnostic challenge for imaging methods based on either morphology (cCT/MRI) or function (SPECT/PET). Current literature and the present data of our own patients demonstrate the diagnostic efficiency of IMT-SPECT and FDG-PET in the detection of recurrence and in-vivo grading. Thirty-nine patients suspected of brain tumor recurrence at follow-up were studied by FDG-PET and IMT-SPECT. Thirty-four of 39 patients showed recurrences; in 12 cases even a change in the grade of malignancy was observed. All high-grade recurrences could be confirmed by either methods. IMT-SPECT showed a higher sensitivity in detecting low-grade tumors at recurrence. In contrast to IMT-SPECT, FDG-PET supports sufficient in-vivo grading. Both methods can be used to differentiate between tumor recurrence and radionecrosis. In conclusion the results of our study demonstrate the efficiency of IMT-SPECT and FDG-PET in confirming recurrences and determining the actual tumor grade.     

Pretargeted immunoscintigraphy: effect of hapten valency on murine tumor uptake

A method of radioimmunoscintigraphy using bivalent "Janus" haptens with an apparent enhanced affinity ("avidity") for the antibody is described. Janus with 50 micrograms pretargeted Mab WC3A11 resulted in significantly higher murine tumor concentrations (approximately 7%/g) compared to monovalent haptens (approximately 1.4%/g, p < 0.001), and the same high tumor-to-background ratios (approximately 3/1). Janus was synthesized by coupling two molecules of BABE together with a 1,4 butanedithiol linker. Janus itself was rapidly excreted (T1/2b = 42 min) by the kidneys and did not concentrate in any other organs or tissues. Three-step pretargeted immunoscintigraphy (binder, chaser, tracer) with 111In- or 67Ga-Co(III) Janus produced excellent mouse tumor images in 3 hr with high tumor-to-background ratios. The use of short-lived tracers, such as 99mTc and 68Ga, with a T1/2p of hours to image antibodies that localize slowly over several days in vivo is accessible with this new technology.     

Detection of paraneoplastic anti-neuronal autoantibodies on paraffin-embedded tissues

Although the detection of pancreatic carcinoma has been considerably improved by recently developed imaging procedures, differential diagnosis between cancer and benign tumor masses, as well as lymph node staging, is still difficult. In vivo evaluation of regional glucose metabolism by means of positron emission tomography (PET) and fluorine-18-labelled fluorode-oxyglucose (FDG) is a new approach utilizing metabolic instead of morphological tumor properties for diagnosis. PATIENTS AND METHODS. A total of 85 patients with suspected pancreatic carcinoma were investigated by FDG-PET prior to surgery. Static PET scans were evaluated visually as well as quantitatively, taking increased FDG uptake as a sign of malignancy. PET results were correlated with intraoperative findings and histopathology of surgical specimens. RESULTS. Forty-seven out of 55 (85%) malignant tumors and 23 out of 30 (77%) benign lesions were correctly classified by PET. Lymph node metastases were present in 31 patients, 19 of them (61%) positive in PET. In 7 our of 13 (54%) patients with liver metastases, PET detected hypermetabolic lesions. False-negative findings were mainly due to disturbance of glucose metabolism in diabetic patients, while most false-positive results could be attributed to acute inflammatory lesions in chronic pancreatitis. CONCLUSIONS. Our results indicate that classification of pancreatic masses can be improved by use of FDG-PET, which might lead to a reduction of unnecessary laparotomies in patients with benign or incurable disease.     

Feasibility for evaluation of the efficacy of conventional ventilatory support in very low birth weight infants

Morbidity and mortality analysis in prematurely born low birth weight (LBW) neonates, very low birth weight (VLBW) neonates and extremely low birth weight (ELBW) neonates forms the cornerstone in current pediatric decision-making from both medical and socioeconomic point of view. The successful introduction of artificial ventilation for neonatal respiratory failure treatment has changed tremendously the prognosis of many diseases with a fatal outcome. This retrospective observational longitudinal study was designed to evaluate the changes in the following main indices: mean airway pressure (MAP), oxygenation index (OI), arterial-to-alveolar oxygen tension ratio (a/A PO2), alveolar-arterial oxygen gradient (A-a)DO2, ventilation index and VEI in VLBW infants treated with conventional ventilatory support (CV), assess the information yield of these indices as indicators of gas exchange at each and every one moment of CV, and to analyze their feasibility, accuracy and real-time convenience as indicators of the adequacy of inhalation therapy and their role as an indispensable tool in constructing the optimal treatment regimen in VLBW infants. Forty-seven VLBW infants requiring ventilatory support within 24 hours of birth were enrolled in the study. Four of the infants survived and the remaining 43 died. The data collected were entered into a high-yield Neonatal Intensive Computer File and the indices were followed up sequentially and thoroughly analyzed as the primary outcome measures of the study. Our results show that: 1. The combination of indices we propose is a useful high-yield discriminating method for evaluating the efficacy of neonatal ventilatory support, arterial blood gas exchange and clinical status. 2. These indices allow early diagnosis of the changes in pulmonary mechanics, hemodynamics and blood saturation. 3. Using the combination of indices improves the diagnostic reliability and information yield of each one of them. 4. The twofold pattern of change of the indices in VLBW infants is well-recognized:--whereas a/A and OI change rapidly in the group of non-survivors reflecting the delicate balance in optimal gas-exchange using conventional methods in the survivors group there is a sustained tendency towards an increase in a/A values with a concomitant decrease in OI values. The airway pressure is constant in the presence of great fluctuations in OI values reflecting the breakdown in oxygenation at the high price paid for its sustenance in the nonsurvivors group whereas the mean airway pressure showed a gradual decrease in the survivors group and allowed early weaning from mechanical ventilation. (A-a)DO2 remained high in the non-survivors group thus reflecting a high-degree, practically constant shunting whereas the same index showed a tendency towards decrease in the survivors group. 5. These indices allow optimal management of neonatal ventilation and oxygenation and timely correction or a change of the ventilatory or/and oxygenation strategy. 6. This information forms the basis for prognostic conclusions regarding the current status or the survival of the neonates.     

Age and experimental obstructive emphysema. A morphometrical study on the rat

Age, as a risk factor in the development of experimental obstructive emphysema, is proposed as the hypothesis of this study. Ninety-two Wistar rats were organized into two age groups: adult (16 weeks) and middle-aged (56 weeks). Each age group was subdivided into three groups: a control group, consisting of unmanipulated animals; a "cannula" group consisting of animals into whose trachea a cannula was implanted; and a "valve" group, consisting of animals into whose trachea a valve had been implanted. The survival was one month. A histomorphometric study was performed on the lungs and the results were compared statistically. Throughout the experiment the amount of food consumed by each animal and the variations in weight were monitored. After sacrifice, the lungs were processed for light microscopy. Thirteen histomorphometric variables were quantified and subsequently systematized into three groups: those which quantified the size of the distal airspace ("area of the alveolar section", "alveolar chord" and "mean linear intercept"): those which quantified the tissue ("wall thickness", "tissue density", "internal perimeter of each alveolar section", "internal alveolar perimeter per field" and "alveolar section/section perimeter"); and those which quantified the elastic fibre ("elastic fibre area", "elastic fibre perimeter", "elastic fibre area/elastic fibre perimeter", "elastic fibre density" and "elastic fibre density per tissue density"). The results were compared statistically and the sensitivity, specificity and misclassification indices were calculated, as well as the attributable and relative risk. From the results, it was observed that, in general, the animals of the valve and cannula groups in both age groups displayed a decrease in food intake and a body weight loss. The middle-aged animals were the only group which displayed significant differences in all the morphometric variables except wall thickness, when the cannula and valve groups were compared with the control group. In both the cannula and valve groups, the values of the variables which quantified the distal airspace increased, while the values of the variables which quantified the lung tissue and the elastic fibre decreased. In the manipulated middle-aged group, the attributable risk of developing emphysema was 56.66% and the relative risk 5.55; in the group of manipulated adult animals, the attributable risk was 23.55% and the relative risk 1.66. The results of this study lead us to propose that the middle-aged rats with experimental airflow obstruction displayed a greater risk of developing emphysema than the adult rats which were subjected to the same procedure.     

Likelihood of malignancy in a solitary pulmonary nodule: comparison of Bayesian analysis and results of FDG-PET scan

OBJECTIVE: To compare the probability of cancer in a solitary pulmonary nodule using standard criteria with Bayesian analysis and result of 2-[F-18] fluoro-2-deoxy-D-glucose-positron emission tomographic (FDG-PET) scan. SETTING: A university hospital and a teaching Veteran Affairs Medical Center. METHODS: Retrospective analysis of 52 patients who had undergone both CT scan of the chest and a FDG-PET scan for evaluation of a solitary pulmonary nodule. FDG-PET scan was classified as abnormal or normal. Utilizing Bayesian analysis, the probability of cancer using "standard criteria" available in the literature, based on patient's age, history of previous malignancy, smoking history, size and edge of nodule, and presence or absence of calcification were calculated and compared to the probability of cancer based on an abnormal or normal FDG-PET scan. Histologic study of the nodules was the gold standard. RESULTS: The likelihood ratios for malignancy in a solitary pulmonary nodule with an abnormal FDG-PET scan was 7.11 (95% confidence interval [CI], 6.36 to 7.96), suggesting a high probability for malignancy, and 0.06 (95% CI, 0.05 to 0.07) when the PET scan was normal, suggesting a high probability for benign nodule. FDG-PET scan as a single test alone was more accurate than the standard criteria and standard criteria plus PET scan in correctly classifying nodules as malignant or benign. CONCLUSION: FDG-PET scan as a single test was a better predictor of malignancy in solitary pulmonary nodules than the standard criteria using Bayesian analysis. FDG-PET scan can be a useful adjunct test in the evaluation of solitary pulmonary nodules.     

Serendipity in diagnostic imaging: magnetic resonance imaging of the breast

BACKGROUND: Magnetic resonance imaging (MRI) of the breast has been proposed as a noninvasive diagnostic test for evaluation of suspicious ("index") lesions noted on mammography and/or clinical breast examination (CBE). However, women may have incidental ("serendipitous") lesions detected by MRI that are not found on mammography or CBE. To understand better whether or not biopsy procedures should be performed to evaluate serendipitous lesions, we estimated the breast cancer risk for women with this type of lesion. METHODS: A decision analysis model was used to estimate the positive predictive value (i.e., the chance that a woman with a serendipitous lesion has cancer) of MRI for serendipitous lesions in women who had an abnormal mammogram and/or CBE suspicious for cancer (where a biopsy procedure is recommended). We restricted the analysis to data from women whose index lesions were noncancerous and used meta-analysis of published medical literature to determine the likelihood ratios (measures of how test results change the probability of having cancer) for MRI and the combination of CBE and mammography. The positive predictive value of MRI was calculated using the U.S. population prevalence of cancer (derived from registry data) and the likelihood ratios of the diagnostic tests. RESULTS: Under a wide variety of assumptions, the positive predictive value of MRI was extremely low for serendipitous lesions. For instance, assuming sensitivity and specificity values for MRI of 95.6% and 68.6%, respectively, approximately four of 1000 55- to 59-year-old women with serendipitous lesions would be expected to have cancer (positive predictive value = 0.44%, 95% confidence interval = 0.24%-0.67%). CONCLUSION: In women with a suspicious lesion discovered by mammography and/or CBE that is found to be benign, serendipitous breast lesions detected by MRI are extremely unlikely to represent invasive breast cancer. Immediate biopsy of such serendipitous lesions may, therefore, not be required.     

Effects of a high NaCl diet on eating and drinking patterns in pygmy goats

PURPOSE: Our goal was to determine the spectrum of 2-[18F]fluoro-2-deoxy-D-glucose (FDG) PET findings in patients with round atelectasis (RA). METHOD: All patients from 1992 to 1997 with radiologic features of RA and FDG-PET scans were evaluated. There were nine men ranging in age from 52 to 75 years (mean 65 years). All had chest radiographs and CT scans that were correlated with FDG-PET. FDG-PET was considered positive if lesion activity was greater than mediastinal activity and negative if lesion activity was the same as or less than mediastinal activity. RESULTS: Nine patients had 10 lesions, ranging in size from 1.2 to 5.0 cm (mean 3.1 cm). Lesion locations were right lower lobe (n = 5), left lower lobe (n = 4), and lingula (n = 1). All lesions were homogeneous and of soft tissue attenuation on CT. None contained air bronchograms or calcification. All had in-curving vessels and bronchi (comet tail sign), adjacent pleural thickening, and volume loss on CT. All lesions were negative on FDG-PET. Four lesions were percutaneously biopsied and showed chronic inflammation consistent with RA. Two lesions were unchanged on 2 and 3 year follow-up CT and were presumed to be RA as were four other lesions with characteristic CT features and negative FDG-PET. CONCLUSION: Our experience suggest that RA in not metabolically active on FDG-PET imaging. Thus, FDG-PET scans can play a role in differentiating RA from malignancy when there are few or atypical features of RA on chest radiographs and CT.     

Detection of recurrent and metastatic colorectal cancer: comparison of positron emission tomography and computed tomography

BACKGROUND: This study evaluates the clinical value of positron emission tomography (PET) with 2-[F-18] fluoro-2-deoxy-D-glucose (FDG) as compared to computed tomography (CT) in patients with suspected recurrent or metastatic colorectal cancer (CRC). METHODS: A retrospective review of the records of 58 patients who had FDG-PET for evaluation of recurrent or advanced primary CRC was performed. FDG-PET results were compared with those of CT and correlated with operative and histopathologic findings, or with clinical course and autopsy reports. RESULTS: Recurrent or advanced primary CRC was diagnosed in 40 and 11 patients, respectively. The sensitivity and specificity of FDG-PET were 91% and 100% for detecting local pelvic recurrence, and 95% and 100% for hepatic metastases. These values were superior to CT, which had sensitivity and specificity of 52% and 80% for detecting pelvic recurrence, and 74% and 85% for hepatic metastases. FDG-PET correctly identified pelvic recurrence in 19 of 21 patients; CT was negative in 6 of these patients and equivocal in 4. FDG-PET was superior to CT in detecting multiple hepatic lesions and influenced clinical management in 10 of 23 (43%) patients. CONCLUSION: FDG-PET is more sensitive than CT in the clinical assessment of patients with recurrent or metastatic CRC, and provides an accurate means of selecting appropriate treatment for these patients.     

Analysis of abnormal intra-QRS potentials. Improved predictive value for arrhythmic events with the signal-averaged electrocardiogram

BACKGROUND: Using the signal-averaged ECG (SAECG), this study developed a new electrical index for predicting arrhythmic events: abnormal intra-QRS potentials (AIQP). METHODS AND RESULTS: We studied 173 patients followed after myocardial infarction for a mean duration of 14 +/- 7 months. Sixteen arrhythmic events occurred, defined as sudden cardiac death, documented sustained ventricular tachycardia, or non-fatal cardiac arrest. Noninvasive indices of arrhythmia risk were measured, including AIQP, conventional SAECG, Holter, and left ventricular ejection fraction (LVEF). Abnormal intra-QRS potentials were defined as abnormal signals occurring anywhere within the QRS period. They were estimated with a lead-specific, parametric modeling method that removed the smooth, predictable part of the QRS. AIQPs are characterized by the remaining transient, unpredictable component of the QRS and manifest as low-amplitude notches and slurs. A combined XYZ-lead AIQP index exhibited higher specificity (95%) and predictive value (PV) (+PV, 47%; -PV, 94%) than the conventional SAECG in combination with Holter and LVEF (specificity, 89%; +PV, 25%; -PV, 93%). CONCLUSIONS: AIQP improved specificity and predictive value, compared with conventional tests, for prediction of arrhythmic events. AIQP emerged as the best noninvasive univariate predictor of arrhythmic events after myocardial infarction in this study. A review of several other reports shows that AIQP in the present study outperformed the conventional predictive indices reported in those other data sets.