Genotoxic evaluation of norfloxacin and pipemidic acid with the Escherichia coli Pol A-/Pol A+ and the ames test

OBJECTIVE: Aim of the study was to compare image quality of spiral (helical) versus conventional (sequential) routine brain scans obtained on a spiral CT scanner of the latest generation. MATERIALS AND METHODS: In a prospective study 60 patients scheduled for cranial CT were examined in spiral (27 cases) or conventional technique (33 cases) after randomization. Two blinded observers rated artifacts, gray--white-matter contrast and overall image quality. RESULTS: No significant differences in artifacts were detected. Concerning gray--white-matter contrast and overall image quality, none or small differences in favour of conventional scans were found depending on the observer. CONCLUSION: On a modern scanner image quality of spiral brain scans in adults is nowadays comparable to or only slightly less than that of conventional scans. On such a machine, spiral mode can be recommended if, for example, rapid scanning or high-quality secondary reconstructions are needed.     

Acute right ventricular dilatation: a new helical CT sign of massive pulmonary embolism

Acute right heart failure is a principal cause of circulatory collapse and death in patients with massive pulmonary embolism (PE). The purpose of this study was to investigate if helical computed tomography (CT) could contribute to the assessment of the right ventricle (RV) in those with massive PE. Over an 8-month period 79 helical CT pulmonary angiograms were performed to investigate suspected PE. Emboli were demonstrated in 28 (35%) patients and seven (9%) were considered to have had a major thromboembolic event. The CT scans of all patients were evaluated using parameters derived in the axial plane (maximum minor axis RV and LV dimensions, RV:LV minor axis ratio and RV wall thickness). Acute right ventricular dilatation with an RV:LV ratio> 1.5:1 (range 1.6:1-2.3:1, mean 2:1) was found in all seven patients who had sustained major PE. In the remaining group of 21 with lesser degrees of embolism no patient had an RV:LV ratio > 1.1:1 (range 0.8-1.1, mean 1.0). To our knowledge, this CT sign has not been described before. CONCLUSION: Helical CT can identify acute RV dilatation in addition to making the primary diagnosis in patients with massive PE. This observation may help identify those at greatest risk of a second fatal event and facilitate therapeutic strategy.     

Prevalence of acute pulmonary embolism in central and subsegmental pulmonary arteries and relation to probability interpretation of ventilation/perfusion lung scans

PURPOSE: The purpose of this investigation is to determine the prevalence of acute pulmonary embolism (PE) limited to subsegmental pulmonary arteries. BACKGROUND: Contrast-enhanced helical (spiral) and electron-beam CT, in the hands of experienced radiologists who are skillful with this modality, are sensitive for the detection of acute PE in central pulmonary arteries, but have a low sensitivity for the detection of PE limited to subsegmental pulmonary arteries. The potential for CT to diagnose PE, therefore, is partially dependent on the prevalence of PE limited to subsegmental pulmonary arteries. METHODS: Data are from the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED). The largest pulmonary arteries that showed PE, as interpreted by the PIOPED angiographic readers, were identified in 375 patients in PIOPED with angiographically diagnosed PE. RESULTS: Among all patients with PE, 6% (95% confidence interval [CI], 4 to 9%) had PE limited to subsegmental branches of the pulmonary artery. Patients with high-probability ventilation/ perfusion (V/Q) scans had PE limited to subsegmental branches in only 1% (95% CI, 0 to 4%). Among patients with low-probability V/Q lung scans, 17% (95% CI, 8 to 29%) had PE limited to the subsegmental branches. Patients with low-probability V/Q scans and no prior cardiopulmonary disease had PE limited to the subsegmental pulmonary arteries in 30% (95% CI, 13 to 53%), whereas patients with low-probability V/Q scans who had prior cardiopulmonary disease had PE limited to subsegmental pulmonary arteries in 8% (95% CI, 2 to 22%) (p < 0.05). CONCLUSION: Based on data from all patients with PE in PIOPED, the prevalence of PE limited to subsegmental pulmonary arteries is low, 6%. PE limited to subsegmental pulmonary arteries was most prevalent among patients with low-probability V/Q scans, particularly if they had no prior cardiopulmonary disease.     

Visual assessment of the accuracy of retrospective registration of MR and CT images of the brain

In a previous study we demonstrated that automatic retrospective registration algorithms can frequently register magnetic resonance (MR) and computed tomography (CT) images of the brain with an accuracy of better than 2 mm, but in that same study we found that such algorithms sometimes fail, leading to errors of 6 mm or more. Before these algorithms can be used routinely in the clinic, methods must be provided for distinguishing between registration solutions that are clinically satisfactory and those that are not. One approach is to rely on a human observer to inspect the registration results and reject images that have been registered with insufficient accuracy. In this paper, we present a methodology for evaluating the efficacy of the visual assessment of registration accuracy. Since the clinical requirements for level of registration accuracy are likely to be application dependent, we have evaluated the accuracy of the observer's estimate relative to six thresholds: 1-6 mm. The performance of the observers was evaluated relative to the registration solution obtained using external fiducial markers that are screwed into the patient's skull and that are visible in both MR and CT images. This fiducial marker system provides the gold standard for our study. Its accuracy is shown to be approximately 0.5 mm. Two experienced, blinded observers viewed five pairs of clinical MR and CT brain images, each of which had each been misregistered with respect to the gold standard solution. Fourteen misregistrations were assessed for each image pair with misregistration errors distributed between 0 and 10 mm with approximate uniformity. For each misregistered image pair each observer estimated the registration error (in millimeters) at each of five locations distributed around the head using each of three assessment methods. These estimated errors were compared with the errors as measured by the gold standard to determine agreement relative to each of the six thresholds, where agreement means that the two errors lie on the same side of the threshold. The effect of error in the gold standard itself is taken into account in the analysis of the assessment methods. The results were analyzed by means of the Kappa statistic, the agreement rate, and the area of receiver-operating-characteristic (ROC) curves. No assessment performed well at 1 mm, but all methods performed well at 2 mm and higher. For these five thresholds, two methods agreed with the standard at least 80% of the time and exhibited mean ROC areas greater than 0.84. One of these same methods exhibited Kappa statistics that indicated good agreement relative to chance (Kappa > 0.6) between the pooled observers and the standard for these same five thresholds. Further analysis demonstrates that the results depend strongly on the choice of the distribution of misregistration errors presented to the observers.     

Molecular analysis of the malR gene of Clostridium butyricum NCIMB 7423, a member of the LacI-GalR family of repressor proteins

OBJECTIVE: The purpose of our study was to evaluate helical CT using axial, coronal, and three-dimensional (3D) reconstruction in the examination of potential kidney donors and to compare the results with angiography and surgery when possible. We also reviewed previously published reports. SUBJECTS AND METHODS: Thirty-six patients underwent unenhanced and enhanced helical CT (3-mm collimation, 150-170 ml of i.v. contrast material injected at 4 ml/sec; pitch 1.5; 17-sec scan delay) with coronal and 3D shaded-surface-display reconstructions made from 1.5-mm overlapping reconstructions. All CT scans were interpreted independently of each other by two observers unaware of other findings. A third observer, who was aware of other findings, also interpreted the images. Results were compared with angiography (24 cases) and surgery (24 cases). Our results are compared with those of other investigators. RESULTS: Axial CT was the best method for detecting accessory arteries (24%) and early branching (10%); it also detected relevant venous and ureteral anatomy and incidental findings. The coronal and 3D images rarely added information that resulted in changed patient treatment. CT findings were concordant with those of digital angiography in 89% of kidneys and were 98% concordant with surgery. CONCLUSION: Helical CT can show arterial, venous, and ureteral anatomy and can also show important incidental findings. If only helical CT is used, a few small accessory vessels and an occasional renal artery stenosis may be missed. Axial images are generally diagnostic and may be supplemented by multiplanar and 3D images read concurrently.     

Roles of a neuronal cell-surface molecule, neuropilin, in nerve fiber fasciculation and guidance

PURPOSE: To determine whether infiltrative lung, airway, or vascular disease can be differentiated as the cause of mosaic attenuation on thin-section computed tomographic (CT) scans of the lung. MATERIALS AND METHODS: Thin-section CT scans were reviewed in 70 patients examined at three institutions. A mosaic attenuation pattern and pathologic or clinical proof of a specific type of disease were demonstrated. Causes of the mosaic pattern included infiltrative lung disease (n = 37), airway disease (n = 22), and vascular disease (n = 11). Thin-section CT findings were assessed independently by two observers blinded to clinical findings. RESULTS: The type of disease was identified correctly at CT in 58 (83%) of 70 patients by observer 1 and 57 (81%) of 70 patients by observer 2. Infiltrative lung disease was diagnosed correctly by both observers in 34 (92%) of 37 cases. Observer 1 identified 21 (95%) of 22 cases of airway disease and three (27%) of 11 cases of vascular disease. Observer 2 identified 19 (86%) of 22 cases of airway disease and four (36%) of 11 cases of vascular disease. CONCLUSION: Infiltrative lung disease and airway disease may be differentiated reliably as the cause of mosaic attenuation on lung CT scans, whereas vascular disease is often misinterpreted as infiltrative lung disease or airway disease.     

Using unenhanced helical CT with enteric contrast material for suspected appendicitis in patients treated at a community hospital

OBJECTIVE: We evaluated the accuracy of unenhanced helical CT with enteric contrast material in the diagnosis of appendicitis in children and adults treated at a community hospital. SUBJECTS AND METHODS: Over an 8-month period, 100 consecutive patients with right lower quadrant pain and suspected appendicitis were prospectively evaluated. Thin-collimation helical CT scanning was performed after administration of enteric contrast material. CT interpretations were correlated with surgical pathology (45 patients) and clinical follow-up (55 patients). RESULTS: The findings of 33 CT scans were interpreted as positive for appendicitis (29 true-positives and four false-positives), and the findings of 67 were interpreted as negative for appendicitis (66 true-negatives and one false-negative). Sensitivity was 97%, specificity was 94%, accuracy was 95%, positive predictive value was 88%, and negative predictive value was 99%. In the 67 CT scans with negative findings for appendicitis, an alternative diagnosis was made for 36 patients (54%). CONCLUSION: Unenhanced helical CT with enteric contrast material for the evaluation of appendicitis can be implemented in a community hospital. In our study, such imaging achieved excellent accuracy.     

Ghosting of pulmonary nodules with respiratory motion: comparison of helical and conventional CT using an in vitro pediatric model

OBJECTIVE: The study was designed to compare helical CT with varying pitch and reconstruction intervals and conventional CT for revealing pulmonary nodules in a model that simulates respiratory motion in children. MATERIALS AND METHODS: CT scans were obtained in an experimental model with one nodule (3 or 10 mm) in each scan. One-second scans were obtained at rates of 10, 20, and 30 respirations per minute using conventional CT with 4-mm collimation and table incrementation and helical CT with 4-mm collimation and either 4-mm/sec (pitch, 1:1) or 8-mm/sec (pitch, 2:1) table speed. Reconstructions were at 1-, 2-, and 4-mm intervals for scans obtained using 4-mm/sec table speed and at 1- and 4-mm intervals for scans obtained using 8-mm/sec table speed. Images were independently reviewed by three radiologists who estimated the number of nodules on each image. RESULTS: Ghosting (depiction of more than one nodule in a study) was seen in 79%, 80%, and 75% of helical CT scans obtained with a 1:1 pitch using 1-, 2-, and 4-mm reconstruction intervals, respectively. By comparison, ghosting was seen in only 54% and 58% of helical CT scans with a 2:1 pitch using 1-mm reconstruction intervals and 4-mm reconstruction intervals, respectively, and in 56% of conventional CT scans (p < .0001). A single nodule was detected on all other scans, and at least one nodule was seen on all scans. CONCLUSION: Ghosting of nodules is common in this model. Ghosting was seen less often on conventional scans and helical scans with 2:1 pitch than it was on helical scans with 1:1 pitch. Nonetheless, ghosting was seen on more than 50% of all scans with each technique.     

Observers and participants in an intergroup setting.

High- and low-self-esteem participant and observer (control) Ss received feedback about the performance of in-groups and out-groups. Self-evaluations and evaluations of the groups were assessed. Results suggest that participant group members (vs observers) enhance evaluations of both groups under conditions of failure feedback. Intergroup bias was obtained over and above these effects for participant high-self-esteem Ss. However, participant low-self-esteem Ss favored failing out-groups. Results suggest that individuals with different levels of self-esteem may differ in terms of their inferred status within groups. Intragroup comparisons may then influence one's choice of group for social identification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Unsuspected pulmonary embolism: prospective detection on routine helical CT scans

PURPOSE: To determine the prevalence of unsuspected pulmonary embolism (PE) on routine thoracic helical computed tomographic (CT) scans and to quantify the improvement in PE detection by using a cine-paging mode on a workstation instead of hard-copy review. MATERIALS AND METHODS: Seven hundred eighty-five patients referred for routine contrast medium-enhanced thoracic CT within 9 months were prospectively recruited. Helical CT was performed. Studies were prospectively interpreted by four radiologists. Two radiologists performed routine, undirected, hard-copy consensus review for official interpretation; two of three thoracic radiologists independently performed a dedicated workstation-based search for PE. The presence of PE involving the main, lobar, or segmental pulmonary arteries was assigned a score of 1-5 (1 = definitely negative, 5 = definitely positive) by each independent reviewer. Patients with a score of 4 or 5 underwent lower-extremity ultrasound, ventilation-perfusion scintigraphy, or both, followed by pulmonary CT angiography if the findings were still equivocal. RESULTS: Twelve (1.5%) of the 785 patients had unsuspected PE, with an inpatient prevalence of 5% (eight of 160) and an outpatient prevalence of 0.6% (four of 625). Of the 12 patients with unsuspected PE, 10 (83%) had cancer. Of the 81 inpatients with cancer, seven (9%) had unsuspected PE. A dedicated workstation-based search resulted in detection of PE in three more patients (25%) than did hard-copy interpretation. CONCLUSION: The prevalence of unsuspected PE was highest among inpatients with cancer. A directed, workstation-based search can improve the PE detection rate over that with hard-copy review.     

Helical CT of pulmonary nodules in patients with extrathoracic malignancy: CT-surgical correlation

OBJECTIVE: Our aim was to assess the sensitivity of helical CT for revealing pulmonary nodules. Thoracotomy with palpation of the deflated lung, resection, and histologic examination of palpable nodules was used as the gold standard. SUBJECTS AND METHODS: Thirteen patients underwent helical CT (slice thickness, 5 mm; reconstruction intervals, 3 mm and 5 mm; interpreted by two independent observers). Subsequently, patients underwent unilateral (n = 6) or bilateral (n = 7) surgical exploration, and CT-surgical correlation of 20 lungs was performed. RESULTS: Ninety nodules were resected (61 were smaller than 6 mm; 13 were 6-10 mm; 11 were larger than 10 mm; in five nodules, the size was not recorded at surgery). Sixty-nine nodules were located in the pulmonary parenchyma and 21 in the visceral pleura. Of the 90 lesions, 43 (48%) were found on histology to represent metastases. For lesions detected by at least one observer, the sensitivity of helical CT was 69% for intrapulmonary nodules smaller than 6 mm, 95% for intrapulmonary nodules larger than or equal to 6 mm, and 100% for histologically proven intrapulmonary metastases larger than or equal to 6 mm. For lesions smaller than or equal to 10 mm, sensitivity was better using a reconstruction interval of 3 mm rather than of 5 mm. CONCLUSION: In this study, the sensitivity of helical CT exceeded the sensitivity of conventional CT in previous reports. However, because of limitations in the detection of intrapulmonary nodules smaller than 6 mm and of pleural lesions, complete surgical exploration should remain the procedure of choice in patients undergoing pulmonary metastasectomy. Preoperative helical CT should be used to guide the surgeon to lesions that are difficult to palpate.     

Detection of choledocholithiasis: comparison of unenhanced helical CT and endoscopic retrograde cholangiopancreatography

PURPOSE: To compare unenhanced helical computed tomography (CT) and endoscopic retrograde cholangiopancreatography (ERCP) in the detection of common bile duct calculi. MATERIALS AND METHODS: Within 13 months, 51 patients (aged 18-94 years) with clinically suspected choledocholithiasis underwent unenhanced helical CT immediately before undergoing ERCP. CT scans were evaluated for the presence of bile duct stones, ampullary stones, the gallbladder and gallbladder stones, intrahepatic biliary dilatation, and the size of the bile duct at the porta hepatis and in the pancreatic head. ERCP images were evaluated for the presence of bile duct or ampullary stones, as well as for biliary dilatation. RESULTS: Unenhanced helical CT depicted common bile duct stones in 15 of 17 patients found to have stones at ERCP. Three patients had stones impacted at the ampulla, all of which were detected with CT. In addition, there was one false-positive finding at CT. CT had a sensitivity of 88%, a specificity of 97%, and an accuracy of 94% in the diagnosis of common bile duct stones. CONCLUSION: Unenhanced helical CT is useful for evaluating suspected choledocholithiasis.     

Metastatic pheochromocytoma in a parakeet

OBJECTIVE: The aim of this study was to determine the frequency of diagnostic findings of bronchiectasis on thin-section CT and the usefulness of those findings in distinguishing patients with cylindrical bronchiectasis from healthy subjects. MATERIALS AND METHODS: The study was retrospective and included 26 healthy adults, 10 consecutive patients with surgically proven cylindrical bronchiectasis, and 49 patients who had been prospectively diagnosed at three institutions as having cylindrical bronchiectasis. All patients had 1.0- to 1.5-mm-collimation CT scans obtained at 10-mm intervals through the chest. The CT scans were independently reviewed in random order by two chest radiologists. RESULTS: Findings in patients with bronchiectasis that were not seen by either observer in any of the healthy subjects included visualization of a bronchus within 1 cm of the costal pleura and visualization of a bronchus abutting the mediastinal pleura. The two observers saw these findings on 96 (81%) and 63 (53%) of 118 CT scans in the 59 patients with bronchiectasis, respectively. Lack of tapering of bronchi was seen in five (10%) of 52 reviews in healthy subjects compared with 95% of reviews in patients with bronchiectasis. Bronchoarterial ratios greater than 1 were identified in 11 (21%) of 52 reviews in healthy subjects compared with 95% of reviews in patients with bronchiectasis. We calculated good agreement between the two observers (kappa values equal to or greater than .63). CONCLUSION: In most cases, thin-section CT allows reliable distinction of patients with cylindrical bronchiectasis from healthy subjects.     

Dual-phase helical CT of the liver: value of an early-phase acquisition in the differential diagnosis of noncystic focal lesions

OBJECTIVE: Contrast-enhanced helical CT images of the liver are usually obtained during the portal vein phase (PVP), during which the parenchyma achieves peak enhancement. The purpose of this study was to determine whether the addition of arterial-phase (AP) scans would lead to improved characterization of focal lesions. MATERIALS AND METHODS: We reviewed the CT appearance of 102 focal lesions with a proven diagnosis. In the first part of the study, we assessed whether the addition of AP scans influenced the diagnostic performance of the three observers. In the second part of the study, we analyzed the morphologic appearance revealed on CT scans of the different types of lesions in the AP and PVP. RESULTS: The addition of AP scans led to a significant increase in the number of correct diagnoses: 71 lesions (70%) were correctly diagnosed with CT scans in both the AP and the PVP, compared with 54 lesions (53%) correctly diagnosed with CT scans in the PVP alone (p < .01). The largest difference was observed in the diagnosis of focal nodular hyperplasia (FNH) and adenoma (16/24 correct diagnoses instead of 6/24) (p < .005). Conversely, AP images did not significantly contribute to the diagnosis of hemangiomas and metastases. The following morphologic features were seen much more often on AP scans than on PVP scans and had a high positive predictive value (PPV): spoke-wheel pattern (FNH; PPV, 100%), central feeding vessel (FNH; PPV, 100%), and heterogeneous appearance with hyperdense components (hepatocellular carcinoma; PPV, 75%). CONCLUSION: Our data show that the radiologists' evaluation of CT scans in both the AP and the PVP improves the differentiation of hepatocellular carcinoma and FNH from other types of hepatic neoplasms.     

"Stand down for the homeless". Podiatric screening of a homeless population in Cleveland

The reliability of helical CT as sole preoperative diagnostic technique for abdominal aortic aneurysms (AAA) and its accuracy in detecting vascular anomalies in the abdominal region was evaluated retrospectively in 42 patients with asymptomatic AAA > 40 mm. A single breath-holding helical scan was performed with 5 mm slice thickness, during a single injection of contrast medium, resulting in a 20 cm z-axis coverage. Axial images were reconstructed and used to generate high quality multiplanar reformatted images. Digital subtraction angiography (DSA) was performed in the first 18 patients and then in case of associated peripheral vascular disease (6 patients). Helical CT exactly showed, in all cases, the proximal and distal extent of the AAA. The visceral vessels as well as the inferior vena cava and renal veins were always clearly depicted, showing anatomical variants or pathological involvement in 19 patients. DSA gave sufficient details on the distal run-off but did not allow a reliable visualization of the visceral branches, venous anomalies and true extent of AAA. In our experience helical CT should be considered as the sole method for preoperative imaging of AAA. It allows a complete and precise evaluation; it is fast, with low doses of radiations and does not require hospitalization.     

A source of data is not a measuring instrument.

Discusses a study by J. I. Berzins et al (see PA, Vol 53:Issue 5) which used a national sample and made multiple analyses of data on the outcome of psychotherapy. While they appropriately stress the disagreements among sources of data, their hope for a remedy is futile. A source of data yields observations from a distinctive role providing distinctive experience. When an observer representing a source makes judgments about the complex variables of interest to current psychotherapeutic theory, he is actively processing his own experience. His observations may agree fairly well with parallel observers representing that source, but will not agree as well with observers from other sources. Nearly exact agreement can be obtained only from inanimate measuring instruments or from observers functioning like instruments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automatic registration of pelvic computed tomography data and magnetic resonance scans including a full circle method for quantitative accuracy evaluation

The purpose of this study is to develop a method for registration of CT and MR scans of the pelvis with minimal user interaction and to obtain a means for objective quantification of the registration accuracy of clinical data without markers. CT scans were registered with proton density MR scans using chamfer matching on automatically segmented bone. A fixed threshold was used to segment CT, while morphological filters were used to segment MR. The method was tested with transverse and coronal MR scans of 18 patients and sagittal MR scans of 8 patients. The registration accuracy was estimated by comparing (triangulating) registrations of a single CT scan with MR in different orientations in a "full circle." For example, CT is first matched on transverse MR, next transverse MR is matched independently on coronal MR, and finally coronal MR is matched independently on CT. The product of the three transformations is the identity if all matching steps are perfect. Deviations from identity occur both due to random errors and due to some types of systematic errors. MR was registered on MR (to close the "circle") by minimization of rms voxel value differences. CT-MR registration takes about 1 min, including user interaction. The random error for CT-MR registration with transverse or coronal MR was 0.5 mm in translation and 0.4 degree in rotation (standard deviation) for each axis. A systematic registration error of about 1 mm was demonstrated along the MR frequency encoding direction, which is attributed to the chemical shift. In conclusion, the presented algorithm efficiently and accurately registers pelvic CT and MR scans on bone. The "full circle" method provides an estimate of the registration accuracy on clinical data.     

Evaluation of complications of kidney transplantation using artificial neural networks

The aim of this study was to develop an artificial neural network (ANN) to differentiate between rejection, acute tubular necrosis (ATN) and normally functioning kidneys in a group of patients with renal transplants. The performance of ANN was compared with that of an experienced observer using a database of 35 patients' records, each of which included 12 quantitative parameters derived from renograms and clinical data as well as a clinical evaluation. These findings were encoded as features for a three-layered neural network to predict the outcome of biopsy or clinical diagnosis. The network was trained and tested using the jackknife method and its performance was then compared to that of a radiologist. The network was able to correctly classify 31 of the 35 original cases and gave a better diagnostic accuracy (88%) than the radiologist (83%), by showing an association between the quantitative data and the corresponding pathological results (r = 0.78, P < 0.001). We conclude that an ANN can be trained to differentiate rejection from acute tubular necrosis, as well as normally functioning transplants, with a reasonable degree of accuracy.     

Rat bone marrow-derived mast cells co-cultured with 3T3 fibroblasts in the absence of T-cell derived cytokines require stem cell factor for their survival and maintain their mucosal mast cell-like phenotype

The aim of this study was to compare the accuracy of computed tomography (CT) and single photon emission computerized tomography (SPECT) in the diagnosis of dementia. Fifty-two patients with clinical diagnosis of dementia and 11 controls were studied. The scans were interpreted by one experienced neuroradiologist and one nuclear radiologist, both blinded to the clinical data. In the diagnosis of dementia, CT and SPECT showed equal sensitivity (82.7%) and statistically similar specificity (63.8 and 81.8%, respectively). The specificity of SPECT in diagnosing Alzheimer's disease (100%) was statistically superior to CT (69%). However, both methods showed similar sensitivity in detecting Alzheimer's disease. In conclusion, SPECT and CT showed similar accuracy in the diagnosis of dementia. The quite high specificity of SPECT in Alzheimer's disease may be useful for confirming that diagnosis, particularly for patients with presenile onset of the disease.