Significant Diagnostic Information Research Articles

Comparison of Different Methods of Assessing Alveolar Ridge Dimensions Prior to Dental Implant Placement

The aim of this study was to compare ridge-mapping measurement before surgical flap reflection and measurement using images from cone beam computerized tomography (CBCT) to direct caliper measurement following surgical exposure of the bone. Sixteen subjects with 25 sites for planned implant placement or ridge augmentation were recruited. An acrylic stent was fabricated for each subject. The stent provided three buccal/lingual pairs of consistent measurement points for each implant site located 4, 7, and 10 mm from the summit of the alveolar soft tissue. Two independent examiners participated. Comparisons of bucco-lingual ridge width using ridge-mapping versus direct caliper measurements showed that 94% and 89% of the pairs of measurement deviations were within +/- 1 mm for examiners 1 and 2, respectively. The corresponding comparison of CBCT images versus direct caliper measurements showed 70% and 55% agreement for examiners 1 and 2, respectively. CBCT image measurements provided lower levels of agreement than ridge-mapping measurements because of the more frequent and larger magnitudes of deviations compared to direct caliper measurements. Most often, ridge mapping provides measurements of the bucco-lingual ridge width consistent with those obtained by direct caliper measurement following surgical exposure of the bone. As applied in this study, CBCT was less consistent compared to direct caliper measurements and did not provide any additional, significant diagnostic information.

Intrinsic fluorescence spectroscopy for endoscopic detection and localization of the endobronchial cancerous lesions

Fluorescence spectroscopy contains diagnostic information about the lung biochemistry and morphology, including tissue optical properties and fluorophores. However, the fluorophore information is generally masked by the optical properties of the tissue, which complicates the evaluation of their role in lung-cancer detection. In this work, we have developed a method for extracting the intrinsic fluorescence spectra from the endoscopic measurements of the combined fluorescence and reflectance spectra. Principle components and classification analysis was performed to evaluate the diagnostic potential of the extracted intrinsic fluorescence spectra from in vivo combined fluorescence and reflectance spectral measurements. We evaluated the diagnostic sensitivity and specificity of both the intrinsic fluorescence and the fluorescence spectra. The results showed that the intrinsic fluorescence spectra contain significant diagnostic information that had been masked by the lung optical properties. We have also found that the intrinsic fluorescence has improved the specificity for endobronchial-cancer detection, although with a slight decrease in the detection sensitivity, when compared to the fluorescence spectra. This may indicate that intrinsic fluorescence analysis could be used to improve the diagnostic specificity of fluorescence spectroscopy and imaging.

On the initial perturbation of mesospheric dust associated irregularities by high powered radio waves

Important observational manifestations of subvisible mesospheric dust are Polar Mesospheric Summer Echoes (PMSEs) which are produced by scattering from electron irregularities produced by dust charging. It has been observed that the PMSE strength can be artificially modified by using a ground-based ionospheric heating facility to perturb the electron irregularity source region that is believed to produce PMSE. Recently it has become evident that significant diagnostic information may be available about the dust layer from the temporal behavior of the electron irregularities during the heating process which modifies the background electron temperature. Particularly interesting and important periods of the temporal behavior are during the turn-on and turn-off of the radio wave heating. Most past theoretical models and experimental investigations have concentrated primarily on the later period. The objective here is to consider the temporal behavior and possibilities for diagnostic information available during the turn-on period of the radio wave. First, approximate analytical models are developed and compared to a more accurate full computational model as a reference. Then from the temporal behavior of the electron irregularities during the turn-on of the radio wave, the analytical models are used to obtain possible diagnostic information for various charged dust and background plasma quantities.

Radiation Exposure and Pregnancy: When Should We Be Concerned?

The potential biological effects of in utero radiation exposure of a developing fetus include prenatal death, intrauterine growth restriction, small head size, mental retardation, organ malformation, and childhood cancer. The risk of each effect depends on the gestational age at the time of exposure, fetal cellular repair mechanisms, and the absorbed radiation dose level. A comparison between the dose levels associated with each of these risks and the estimated fetal doses from typical radiologic examinations lends support to the conclusion that fetal risks are minimal and, therefore, that radiologic and nuclear medicine examinations that may provide significant diagnostic information should not be withheld from pregnant women. The latter position is advocated by the International Commission on Radiological Protection, National Council on Radiation Protection, American College of Radiology, and American College of Obstetrics and Gynecology. However, although the risks are small, it is important to ensure that radiation doses are kept as low as reasonably achievable.

Quantitative Measures of Right Ventricular Dysfunction by Echocardiography in the Diagnosis of Acute Nonmassive Pulmonary Embolism

Transthoracic echocardiography (TTE) is used in the risk assessment of patients with pulmonary embolism (PE), but the incremental diagnostic information from quantitative measures of right ventricular (RV) size, pressure, and function by TTE has yet to be fully evaluated. In 300 consecutive patients with suspected first nonmassive PE, TTE and ventilation/perfusion scintigraphy were performed. Among measures of RV anatomy, RV pressure estimates, and estimates of global and regional RV function with significant diagnostic information in a logistic regression analysis, the acceleration time of RV outflow less than 89 milliseconds, the ratio of RV to left ventricular diameter greater than 0.78, RV outflow tract fractional shortening less than 35%, and signs of RV strain on electrocardiogram had independent, incremental diagnostic information (area under the receiver operating characteristics curve = 0.81). If D-dimer greater than 4.1 mmol/L was included, the area under the curve increased to 0.88. The negative and positive predictive values if any 2 of 3 factors in the final model were present were 88% and 70%, respectively. TTE is able to identify differential diagnoses and enhance pretest probability of PE significantly. TTE could therefore be considered as an integral part of the initial diagnostic workup of patients suspected of PE, especially if definitive diagnostic imaging has limited availability.

Integrated multislice CT and Tc–99m Sestamibi SPECT–CT evaluation of solitary pulmonary nodules

The purpose of this study was to evaluate efficacy of multislice computed tomography (MSCT) and single photon emission computed tomography (SPECT)-CT with Tc-99m Sestamibi in the assessment of solitary pulmonary nodules of uncertain significance. Scintigraphy was performed using a 'hybrid' g-camera that allows simultaneous acquisition of SPECT and CT images, with interesting results in diagnostic oncology. Between September 2003 and August 2004, 23 patients with a solitary pulmonary nodule detected on CT underwent SPECT-CT using Tc-99m Sestamibi as a radiotracer. Nodules with positive scintigraphy were immediately subjected to biopsy or surgical resection. Nodules with negative scintigraphy were followed up after 3-4 months by MSCT with automatic segmentation software (Advanced Lung Analysis, ALA) and histological characterisation. Of the 23 nodules (size range 0.8-2 cm) discovered with MSCT, 11 showed intense uptake of Tc-99m Sestamibi. Ten lesions were true positive: seven adenocarcinomas, one squamous cell carcinoma, one large cell carcinoma and one metastasis. The only false positive was histologically classified as a large cell granuloma. Twelve lesions had negative scintigraphy: five fibrous lesions, three hamartomas, three granulomas and one adenocarcinoma (false negative). Benign nodules without tracer uptake underwent another CT scan 3-4 months later, which confirmed stability of the nodule size. Correlation of Sestamibi SPECT with histology showed sensitivity (Se) of 90.9 %, specificity (Sp) of 91.6 %, diagnostic accuracy of 91.3 %, positive predictive value (PPV) of 90.9% and negative predictive value (NPV) of 91.6 %. The integrated use of MSCT and Tc-99m Sestamibi SPECT-CT could be very useful in the management of solitary pulmonary nodules (SPNs). In particular, in our preliminary study, scintigraphy provided significant diagnostic information to differentiate benign from suspicious pulmonary nodules. The use of scintigraphy could be helpful to anticipate histological assessment and surgical treatment of SPNs identified at CT.

Towards an automated virtual slide screening: theoretical considerations and practical experiences of automated tissue-based virtual diagnosis to be implemented in the Internet

AimsTo develop and implement an automated virtual slide screening system that distinguishes normal histological findings and several tissue – based crude (texture – based) diagnoses.Theoretical considerationsVirtual slide technology has to handle and transfer images of GB Bytes in size. The performance of tissue based diagnosis can be separated into a) a sampling procedure to allocate the slide area containing the most significant diagnostic information, and b) the evaluation of the diagnosis obtained from the information present in the selected area. Nyquist's theorem that is broadly applied in acoustics, can also serve for quality assurance in image information analysis, especially to preset the accuracy of sampling. Texture – based diagnosis can be performed with recursive formulas that do not require a detailed segmentation procedure. The obtained results will then be transferred into a "self-learning" discrimination system that adjusts itself to changes of image parameters such as brightness, shading, or contrast.MethodsNon-overlapping compartments of the original virtual slide (image) will be chosen at random and according to Nyquist's theorem (predefined error-rate). The compartments will be standardized by local filter operations, and are subject for texture analysis. The texture analysis is performed on the basis of a recursive formula that computes the median gray value and the local noise distribution. The computations will be performed at different magnifications that are adjusted to the most frequently used objectives (*2, *4.5, *10, *20, *40). The obtained data are statistically analyzed in a hierarchical sequence, and in relation to the clinical significance of the diagnosis.ResultsThe system has been tested with a total of 896 lung cancer cases that include the diagnoses groups: cohort (1) normal lung – cancer; cancer subdivided: cohort (2) small cell lung cancer – non small cell lung cancer; non small cell lung cancer subdivided: cohort (3) squamous cell carcinoma – adenocarcinoma – large cell carcinoma. The system can classify all diagnoses of the cohorts (1) and (2) correctly in 100%, those of cohort (3) in more than 95%. The percentage of the selected area can be limited to only 10% of the original image without any increased error rate.ConclusionThe developed system is a fast and reliable procedure to fulfill all requirements for an automated "pre-screening" of virtual slides in lung pathology.

Efficient RT-Level Fault Diagnosis

Increasing IC densities necessitate diagnosis methodologies with enhanced defect locating capabilities. Yet the computational effort expended in extracting diagnostic information and the stringent storage requirements constitute major concerns due to the tremendous number of faults in typical ICs. In this paper, we propose an RT-level diagnosis methodology capable of responding to these challenges. In the proposed scheme, diagnostic information is computed on a grouped fault effect basis, enhancing both the storage and the computational aspects. The fault effect grouping criteria are identified based on a module structure analysis, improving the propagation ability of the diagnostic information through RT modules. Experimental results show that the proposed methodology provides superior speed-ups and significant diagnostic information compression at no sacrifice in diagnostic resolution, compared to the existing gate-level diagnosis approaches.

Combined reflectance and fluorescence spectroscopy for in vivo detection of cervical pre-cancer

Optical technologies, such as reflectance and fluorescence spectroscopy, have shown the potential to provide improved point-of-care detection methods for cervical neoplasia that are sensitive, specific, and cost-effective. Our specific goals are to analyze the diagnostic potential of reflectance and fluorescence spectra, alone and in combination, to discriminate normal and precancerous cervical tissue in vivo and to identify which classification features contain significant diagnostic information. Reflectance spectra are measured at four source-detector separations and fluorescence emission spectra are measured at 16 excitation wavelengths, from 324 sites in 161 patients. These 20 spectral features are permuted in all possible combinations of one, two, and three; and classification algorithms are developed to evaluate the diagnostic performance of each combination. Algorithms based on fluorescence spectra alone yield better diagnostic performance than those based on reflectance spectra alone. The combination of fluorescence and reflectance do not significantly improve diagnostic performance compared to fluorescence alone, except in the case of discriminating high-grade precancers from columnar normal tissue. In general, fluorescence emission spectra at 330- to 360-nm and 460- to 470-nm excitation provide the best diagnostic performance for separating all pairs of tissue categories.

CEA, CA 242, CA 19-9, CA 72-4 and hCGβ in the Diagnosis of Recurrent Colorectal Cancer

Objective: The purpose of this study was to compare the utility of serum CEA, CA 19-9, CA 242, CA 72-4 and human chorionic gonadotropin (hCG)β in the follow-up of 102 surgically treated colorectal cancer patients, out of which 40 patients developed clinical recurrence. Methods: In patients with recurrent disease, serum samples were obtained at the time of clinical recurrence, and in the disease-free group, they were obtained postoperatively. The combined use of the markers was evaluated with logistic regression analysis. The sensitivities of the different tumour markers at various specificity levels were compared by receiver operating characteristic (ROC) curve analysis. Results: When the five tumour markers, Dukes stage and location of the primary tumour were evaluated together in the same model, only CEA provided significant diagnostic information (p < 0.0005) in addition to the location of the primary tumour (p = 0.003). The diagnostic information provided by the other serum tumour markers was insignificant, although CA 72-4 approached borderline significance (p = 0.053). ROC curves were constructed and the difference in the values of the area under the curve (AUC) between the different serum tumour markers was determined at the time of clinical recurrence. Of the individual markers, the highest AUC was observed for CEA (AUC = 0.931). The difference in AUC values between CEA and the other tumour markers was highly significant (p ≤ 0.001). Conclusions: CEA had the highest diagnostic accuracy in detecting recurrent colorectal cancer. Inclusion of CA 19-9, CA 242, CA 72-4 or hCGβ in the model did not improve the accuracy, although CA 72-4 approached borderline significance (p = 0.053). Thus, CEA seems to retain its position as the surveillance marker of choice for patients surgically treated for colorectal cancer.

Positron emission tomography in gastric and esophageal cancer.

Positron emission tomography using the positron emitting glucose analogue 18F-fluorodeoxyglucose has recently emerged as a promising metabolism-based whole-body imaging tool for cancer diagnosis and follow-up. Several reports have recently appeared indicating the potential and limitations of this technique. The review limits its scope to the recent advances of 18F-fluorodeoxyglucose positron emission tomography in the clinical management of gastric and esophageal cancer. New studies have been reported on the use of 18F-fluorodeoxyglucose positron emission tomography to assess the early and late metabolic response of a gastroesophageal tumor to chemo(radiation) therapy. The metabolic response as measured by serial 18F-fluorodeoxyglucose positron emission tomography, performed before and during treatment or some weeks thereafter, can be used to predict the clinical and histopathologic response. Moreover, the metabolic positron emission tomography response seems to be related to overall and disease-free survival. Gastroesophageal 18F-fluorodeoxyglucose positron emission tomography could add significant diagnostic information to the different phases of patient management. At initial diagnosis of esophageal cancer, positron emission tomography detects more distant lymph node and organ metastases compared with conventional diagnostics, allowing a more accurate selection of the most appropriate treatment. Serial 18F-fluorodeoxyglucose positron emission tomography performed before and during chemotherapy allows early identification of nonresponding tumors. 18F-fluorodeoxyglucose positron emission tomography performed after a treatment allows accurate assessment of the residual tumor load. 18F-fluorodeoxyglucose positron emission tomography allows accurate detection and restaging of recurrent disease.

Estimating the Probability of Cancer with Several Tumor Markers in Patients with Colorectal Disease

Objective: The purpose of this study was to evaluate and compare serum tumor markers, carcinoembryonic antigen (CEA), CA 19-9, CA 242, CA 72-4 and hCGβ, and their value in the diagnosis of malignant colorectal disease. Methods: The serum concentrations of the markers were measured in 204 patients with colorectal cancer and in 104 inpatients with benign colorectal disease. The combined use of the markers was evaluated with a logistic regression analysis. Results: When all five markers were evaluated in the same model, only CEA and CA 72-4 provided significant diagnostic information (p < 0.001), indicating that their combination improves the accuracy. The probability of cancer for each patient was calculated entering CEA and CA 72-4 in the logistic regression model. Receiver-operating characteristic curves were constructed, and the difference in the area under the curve (AUC) values was determined between the markers and the calculated probability of cancer. Of the individual markers, the highest AUC was observed for CEA (AUC = 0.746). The difference in the AUC between CEA and CA 72-4 (AUC = 0.716) was insignificant (p = 0.492), but between CEA and the other three markers it was significant (p < 0.015). The calculated probability of cancer index, based on a combination of CEA and CA 72-4, had a significantly higher AUC (AUC = 0.804) than CEA alone (AUC = 0.746; p = 0.046). Conclusions: The diagnostic value of CA 72-4 was additive to that of CEA in colorectal cancer, and both markers contributed with significant diagnostic information. As a diagnostic test, the probability of cancer calculated with logistic regression provided higher accuracy than any of the markers alone, implying that it might be a useful diagnostic tool.

Multilevel Wavelet Feature Statistics for Efficient Retrieval, Transmission, and Display of Medical Images by Hybrid Encoding

Many common modalities of medical images acquire high-resolution and multispectral images, which are subsequently processed, visualized, and transmitted by subsampling. These subsampled images compromise resolution for processing ability, thus risking loss of significant diagnostic information. A hybrid multiresolution vector quantizer (HMVQ) has been developed exploiting the statistical characteristics of the features in a multiresolution wavelet-transformed domain. The global codebook generated by HMVQ, using a combination of multiresolution vector quantization and residual scalar encoding, retains edge information better and avoids significant blurring observed in reconstructed medical images by other well-known encoding schemes at low bit rates. Two specific image modalities, namely, X-ray radiographic and magnetic resonance imaging (MRI), have been considered as examples. The ability of HMVQ in reconstructing high-fidelity images at low bit rates makes it particularly desirable for medical image encoding and fast transmission of 3D medical images generated from multiview stereo pairs for visual communications.

Role of 99mTc-Hexakis-2-Methoxy-Isobutylisonitrile in the Diagnosis and Staging of Lung Cancer

Preliminary studies have shown that (99m)Tc-hexakis-2-methoxyisobutylisonitrile (MIBI) is an interesting tracer for various tumors. The aim of this study was to determine the feasibility of using (99m)Tc-MIBI as a diagnostic and staging procedure for lung cancer. We prospectively compared the results of biopsy with (99m)Tc-MIBI imaging in patients with potentially resectable lung lesions (stages IIIA or lower). In the patients with radiopharmaceutical uptake, the staging provided by CT was compared with that obtained with (99m)Tc-MIBI. Ninety-nine of the 116 patients examined had lung cancer. For the diagnosis of malignancy, the specificity of (99m)Tc-MIBI was 100%, sensitivity was 89.8%, positive predictive value was 100%, negative predictive value was 62.9%, and accuracy was 91.4%. In the 87 patients with radiopharmaceutical uptake in their lung cancer, the values for the specificity and sensitivity of (99m)Tc-MIBI in the detection of mediastinal lymph node metastases were 100% and 54.5%, respectively. The corresponding values for CT in the same patients were 87.6% and 63.3%, respectively. The difference in specificity is statistically significant (p = 0.011). This study demonstrates that (99m)Tc-MIBI provides significant diagnostic and staging information in patients with lung lesions. The high specificity and positive predictive value of (99m)Tc-MIBI suggest that this radiopharmaceutical could be a very useful tool for the diagnosis of lung cancer, especially in consideration of its low costs and wide availability.

Continuous 12-lead ST-segment monitoring improves identification of low-risk patients with chest pain and a worse in-hospital outcome.

Various strategies have been proposed to improve diagnosis and triage of patients with chest pain at low risk, but uncertainty still exists on the optimal combination of diagnostic tools that should be used in this subset of patients. The aim of this study was to evaluate the incremental benefit of continuous 12-lead ST-segment monitoring over that provided by conventional diagnostic tools in patients with chest pain. Of 232 consecutive patients referred because of chest pain, 52 were classified as low-risk according to the Agency for Health Care Policy and Research unstable angina guidelines and observed for 12 h with serial cardiac enzymes and electrocardiograms (ECG) (every 3 h). All patients also underwent both echocardiography at entry and continuous 12-lead ST-segment monitoring during the observation period. During a mean hospital stay of 3.7 days (range 1-14 days), a benign outcome was observed in 37 patients (71%), whereas 15 patients (29%) had major cardiac events or recurrence of chest pain of ischemic origin. Addition of ST-segment monitoring findings to baseline clinical data as well as to serial enzymes and ECG features added significant incremental prognostic value (p < 0.001). Multivariate analysis showed reproduction of pain by chest pressure (p < 0.05) and presence of ST-segment changes (> or = 0.1 mV) during 12-lead ST-segment monitoring (p < 0.001) as independent predictors of a benign or unfavorable outcome. In low-risk patients with chest pain, continuous 12-lead ST-segment monitoring provides significant incremental diagnostic and prognostic information to currently used clinical, enzymatic, and ECG data, and is helpful in identifying the subset of patients with a worse in-hospital outcome.

MRI staging using gadodiamide for soft-tissue tumors of the head and neck region. Results from a phase II trial and a 5-year clinical follow-up

In order to document the safety, tolerability and efficacy of gadodiamide outside CNS, an open, non-drug comparative study was performed in patients with tumors of the head and neck region. Fifty adult patients were included and 48 patients received the contrast medium. The examinations were performed on a 1.5 T imager using transverse, non-enhanced T1- and PD-/T2-weighted conventional spin-echo sequences, followed by a contrast-enhanced transverse T1-weighted sequence. Post-contrast images provided more diagnostic information compared to unenhanced images in 33 of 48 patients (69%). This information was of significant help in four and of moderate help in 14 cases. Post-contrast images compared to non-enhanced T1-weighted showed improvement in lesion delineation for 29 of the 43 patients where a lesion was observed. Only in two patients was the diagnostic information lower post-contrast. A comparison between all pre-contrast images versus contrast medium enhanced showed post-contrast images to give more diagnostic information in 14 and less in nine patients. No patient experienced discomfort in relation to gadodiamide injection. Only one adverse event occurred which was described as thirst, being of moderate intensity. The 5-year clinical outcome was analyzed and compared with the pre-operative staging. The case-books of all patients were reviewed and in 44 patients all information could be found. Of those, 18 were still alive, one with active disease (AAD) and 17 with no evidence of disease (NED). Two of those four patients, where information was incomplete, showed NED and two had died. This trial showed that contrast-enhancement using gadodiamide for evaluation of soft tissue tumors in the head and neck region was safe and provided statistically significant more diagnostic information compared with unenhanced images. MRI, when compared with palpation/inspection, changed tumor staging in ≈30% of all cases.

New electrocardiographic criteria for posterior wall acute myocardial ischemia validated by a percutaneous transluminal coronary angioplasty model of acute myocardial infarction

The standard 12-lead electrocardiogram (ECG) fails to detect ST-segment elevation in patients with posterior wall acute myocardial ischemia. However, additional posterior leads V 7-9 provide limited additional diagnostic information to the standard 12-lead ECG when an ischemic criterion of 1-mm ST elevation is used. No study is available to delineate the ischemic criteria in the posterior electrocardiographic leads. Continuous 15-lead ECGs (standard 12 lead + V 7-9) were recorded in 53 subjects undergoing elective left circumflex coronary angioplasty (posterior ischemia model). ST amplitudes (J + 60 ms) at preangioplasty baseline were subtracted from maximal ST amplitudes during balloon occlusion to create a positive or negative change score (ΔST) for each of the 15 leads. During 53 left circumflex occlusions, 26 subjects (49%) had ΔST elevation of ≥1 mm and 24 subjects (45%) had ΔST elevation ranging from 0.5 to 0.95 mm in ≥1 posterior leads. Five subjects (9%) had ΔST elevation of ≥1 mm in the posterior leads without ΔST elevation anywhere in any of the 12 leads. The sensitivity in detecting myocardial ischemia using 15-lead ECGs (58%) was not statistically different from the standard 12-lead ECG (49%) (p = 0.06). Adjusting the ischemic criterion from 1 to 0.5 mm in V 7-9 significantly improved the sensitivity from 49% in the 12-lead ECG to 94% in the 15-lead ECG (p = 0.000). In addition, 12 subjects (23%) had posterior ST-segment elevation without anterior ST-segment depression. Thus, posterior leads V 7-9 contribute significant additional diagnostic information above and beyond the standard 12-lead ECG only when a new ischemic criterion of 0.5 mm instead of 1 mm ST elevation is applied to the posterior leads.

The clinical use of imaging techniques with exercise testing

The addition of nuclear imaging techniques to basic exercise electrocardiography (ECG) has provided significant diagnostic and prognostic information in the evaluation of patients with suspected coronary artery disease. During the last decade, new classes of isotopes (technetium-and rubidium-based perfusion agents) and refinements in single-photon emission computed tomography (SPECT) and positron emission tomography (PET) have become better accepted. These new studies have added to the diagnostic armamentarium available to physicians, but at considerable costs with an estimated 4.8 million procedures performed this year. Nuclear imaging techniques can assess myocardial blood flow (perfusion imaging) or function (ventriculography). Another imaging modality, stress echocardiography, has also achieved widespread acceptance with clinical guidelines for its use published in 1997. This review addresses these imaging techniques in diagnostic evaluation of the patient with suspected coronary artery disease.

Combined thallium-201 and dynamic iodine-123 iodophenylpentadecanoic acid single-photon emission computed tomography in patients after acute myocardial infarction with effective reperfusion.

Considerable derangements of energy metabolism are to be expected during ischemia and reperfusion. In ischemic myocardium, the oxidative degradation of carbohydrates is shifted toward the anaerobic production of lactate and the oxidation of fatty acids is suppressed. The aim of this study was to examine the uptake and metabolism of iodine-123 (123I) iodophenylpentadecanoic acid (IPPA) in stunned myocardium. In 15 patients, SPECT with 201Tl and 123I IPPA as well as echocardiography with low-dose dobutamine stimulation were performed 12 +/- 5 days after myocardial infarction with reperfusion. Follow-up echocardiography was carried out 24 +/- 8 days later for documentation of functional improvement. Uptake of 201Tl and 123I IPPA were obtained in five left ventricular segments, and dynamic SPECT imaging was used for calculation of the fast and the slow components of the biexponential myocardial 123I IPPA clearance. Wall motion improved in 14 of 26 dysfunctional segments (54%). Stunned segments were characterized by a reduced 123I IPPA extraction, a shorter half-life of the fast, and a longer half-life of the slow clearance component. All parameters of the combined 201Tl/123I IPPA study predicted functional recovery with similar accuracies (area under the receiver operator characteristic curves between 0.68 and 0.76; p = NS). Analysis of 201Tl uptake alone could not predict functional recovery in this study. Stunned myocardium is characterized by a disturbance of fatty acid metabolism. For prediction of functional improvement, 123I IPPA imaging added significant diagnostic information.

Diagnostic Value of Calretinin in Mast Cell Lesions of the Skin.

The diagnosis of mast cell lesions of the skin can occasionally be challenging. Calretinin, a 29 kD neuron-specific calcium-binding protein found mostly in the CNS and retina, has been shown to be a positive marker for mesotheliomas, and is also expressed in mast cells. We studied the diagnostic value of calretinin and compared our results to other established ancillary studies used to identify mast cells, such as Toluidine blue and the Leder stain. Sixty-three cases were studied, including 45 mast cell lesions (22 urticaria pigmentosum, 17 mastocytomas, and six telangiectasia macularis eruptiva perstans [TMEP]), seven nevi, three melanomas, four granular cell minors of the skin, three cutaneous lymphomas, and one granulocytic sarcoma. Patients ranged in age from less than 1 to 85 years with a median age of 29 years. The group consisted of 36 females and 27 males. Calretinin was expressed in all 45 mast cell lesions. Negative staining for calretinin was seen in all skin lesions that potentially could be considered in the differential diagnosis of mast cell lesions such as nevi, melanomas, lymphomas, and the granulocytic sarcoma. However, calretinin expression was noted in four/four granular cell tumors. Leder and Toluidine blue stains were positive in all 45 mast cell lesions, and all nonmast cell lesions were negative with these stains. In conclusion, our study demonstrated that calretinin is a sensitive and specific marker of mast cells and can be an aid in distinguishing mast cell lesions from other skin lesions considered in the differential diagnosis. Calretinin may be more sensitive than the currently used special stains utilized to diagnose mast cell lesions having few diagnostic mast cells such as TMEP. However, this immunoperoxidase stain does not add significant diagnostic information in most cases, when compared with the currently used less expensive special stains and, therefore, is not cost-effective. Int J Surg Pathol 8(2):119-122, 2000