Gene rearrangement and truncated mRNA in cell lines with 11q23 translocation

This study was done to evaluate the diagnostic accuracy of bedside chest radiography for pneumonia, adult respiratory distress syndrome (ARDS), or both in patients receiving mechanical ventilation. The series consisted of 40 patients; diagnostic accuracy was defined as the area under the receiver operating characteristic curve. Overall diagnostic accuracy for ARDS was 0.84. Overall diagnostic accuracy for pneumonia was 0.52. Review of previous radiographs and knowledge of clinical data did not enhance diagnostic accuracy for ARDS or pneumonia. Diagnostic accuracy for pneumonia was minimally reduced when ARDS was present. There was an increase in false-negative results because the diffuse areas of increased opacity in ARDS obscured the radiographic features of pneumonia. The authors conclude that chest radiography is of limited value for the diagnosis of pneumonia in patients receiving mechanical ventilation. The high false-negative and false-positive ratings for pneumonia resulted in a low diagnostic accuracy. The high diagnostic accuracy for ARDS was primarily due to the well-defined radiographic appearance of ARDS and few false-positive ratings.     

Early detection of pneumonia in febrile neutropenic patients: use of thin-section CT

OBJECTIVE: The purpose of this study was to evaluate the usefulness of thin-section CT for early detection of pneumonia in neutropenic patients with an unknown site of infection and normal or nonspecific findings on chest radiographs. SUBJECTS AND METHODS: Eighty-seven patients with febrile neutropenia that persisted for more than 2 days despite empiric antibiotic treatment underwent 146 prospective examinations. If findings on chest radiographs were normal (n = 126) or nonspecific (n = 20), thin-section CT (1-mm collimation, 10-mm increment) was done. If thin-section CT scans showed opacities, bronchoalveolar lavage was recommended. RESULTS: Findings on chest radiographs were nonspecific for pneumonia in 20 (14%) of 146 cases, and CT findings in those cases were suggestive of pneumonia. Microorganisms were detected in 11 of those 20 cases. Seven of the 11 cases were not optimally treated before CT diagnosis, the other four were sufficiently treated. Findings on chest radiographs and thin-section CT scans were normal in 56 (38%) of 146 cases. In 70 (48%) of 146 cases, findings on chest radiographs were normal, whereas findings on thin-section CT scans were suggestive of pneumonia. Microorganisms were detected in 30 of the 70 cases. Nineteen of 30 cases were not optimally treated before CT, whereas the other 11 cases were sufficiently treated before CT. In 22 (31%) of these 70 cases, an opacity was observed on the chest radiograph during the 7 days after the CT study. Only three (5%) of 56 pneumonias occurred during the first 7 days after thin-section CT studies with normal findings (p < .005). Additional risk factors for pneumonia occurring later that were detectable on chest radiographs were poorly defined nodules (p < .05), consolidation (p < .05), and younger age (p < .05). CONCLUSION: Thin-section CT scans show findings suggestive of pneumonia about 5 days earlier than chest radiographs show suggestive findings. When thin-section CT scans show findings suggestive of pneumonia, the probability of pneumonia being detected on chest radiographs during the 7-day follow-up is 31%, whereas the probability is only 5% when the findings on the prior thin-section CT scan were normal (p < .005). All neutropenic patients with fever of unknown origin and normal findings on chest radiographs should be examined with thin-section CT.     

The hepatopulmonary syndrome: radiologic findings in 10 patients

OBJECTIVE: The purpose of this study was to review the radiologic manifestations of the hepatopulmonary syndrome. MATERIALS AND METHODS: We retrospectively reviewed clinical records, chest radiographs, 99m Tc-macroaggregated albumin (MAA) perfusion lung scans, chest CT scans, and pulmonary angiograms of 10 patients with proven hepatopulmonary syndrome. RESULTS: Chest radiographs showed basilar, medium-sized (1.5-3.0 mm) nodular or reticulonodular opacities in all cases. CT was done in eight cases and showed basilar dilatation of lung vessels with a larger than normal number of visible branches. The vascular basis for these opacities was best appreciated on conventional CT scans of 10-mm sections. No individual arteriovenous malformations were seen on CT scans. High-resolution CT scans showed no evidence of interstitial fibrosis. 99mTc-MAA perfusion lung imaging, done in seven patients, showed pulmonary arteriovenous shunting in five. Contrast echocardiography confirmed intrapulmonary shunting in these five patients. Pulmonary angiography, done in four cases, showed subtle distal vascular dilatation in two and moderate dilatation with early venous filling in two but did not reveal any individual arteriovenous malformations. CONCLUSION: Chest radiographs in hepatopulmonary syndrome usually show bibasilar nodular or reticulonodular opacities. Conventional CT shows that these opacities represent dilated lung vessels. High-resolution CT is useful in excluding pulmonary fibrosis or emphysema as the cause of these opacities. 99mTc-MMA perfusion imaging or contrast echocardiography can be used to confirm intrapulmonary arteriovenous shunting.     

Aspiration after administration of oral contrast material in children undergoing abdominal CT for trauma

OBJECTIVE: The practice of routinely administering oral contrast material to children undergoing abdominal CT for blunt trauma is controversial, primarily because of the increased risk of aspiration. The purpose of this study was to determine how often aspiration occurs in this population of children. MATERIALS AND METHODS: We retrospectively studied 50 children who underwent abdominal CT scans after blunt trauma. All children received diluted 3% water-soluble oral contrast material. The medical record of each child was reviewed for evidence of aspiration pneumonia as many as 48 hr after the CT. In each patient, sections of the CT scan through the lung bases were examined for opacities. When lung opacities were identified, they were classified as atelectasis, confusion, laceration, or nonspecific. We made attenuation measurements of lung opacities larger than 1 cm, and each measurement was compared with the attenuation measurement of contrast material in that patient's stomach. Student's two-tailed t test was used to compare the two measurements. RESULTS: Four patients were febrile after the CT scan, but in none was aspiration pneumonia suspected to be the cause. The remaining 46 patients did not have any clinical evidence of aspiration. Twelve of the 50 patients had pulmonary opacities revealed by CT that were sufficiently large that attenuation measurements could be obtained. The opacity in one of these patients was classified as nonspecific, and the attenuation was as high as that of contrast material in the stomach. CONCLUSION: No clinically symptomatic episodes of aspiration pneumonia were found in 50 pediatric patients with blunt trauma who were given oral contrast material for abdominal CT. Although one of the children had CT findings that suggested clinically silent aspiration of oral contrast material, no evidence was found that administration of oral contrast material was harmful.     

Pulmonary embolism: prospective comparison of spiral CT with ventilation-perfusion scintigraphy

PURPOSE: To compare prospectively the accuracy of spiral computed tomography (CT) with that of ventilation-perfusion scintigraphy for diagnosing pulmonary embolism. MATERIALS AND METHODS: Within 48 hours of presentation, 142 patients suspected of having pulmonary embolism underwent spiral CT, scintigraphy, and (when indicated) pulmonary angiography. Pulmonary angiography was attempted if interpretations of spiral CT scans and of scintigrams were discordant or indeterminate and intermediate-probability, respectively. RESULTS: In the 139 patients who completed the study, interpretations of spiral CT scans and of scintigrams were concordant in 103 patients (29 with embolism, 74 without). In 20 patients, intermediate-probability scintigrams were interpreted (six with embolism at angiography, 14 without); diagnosis with spiral CT was correct in 16. Interpretations of spiral CT scans and those of scintigrams were discordant in 12 cases; diagnosis with spiral CT was correct in 11 cases and that with scintigraphy was correct in one. Spiral CT and scintigraphic scans of four patients with embolism did not show embolism. Sensitivities, specificities, and kappa values with spiral CT and scintigraphy were 87%, 95%, and 0.85 and 65%, 94%, and 0.61, respectively. CONCLUSION: In cases of pulmonary embolism, sensitivity of spiral CT is greater than that of scintigraphy. Interobserver agreement is better with spiral CT.     

Role of interleukin 8 in the genesis of acute respiratory distress syndrome through an effect on neutrophil apoptosis

OBJECTIVE: To evaluate the role of interleukin 8 (IL-8) in the regulation of neutrophil (PMN) apoptosis in normal plasma and plasma from patients with early, fulminant acute respiratory distress syndrome (ARDS). DESIGN: Experimental study using cultured human PMNs. SETTING: University hospital, level I trauma center. PARTICIPANTS: Plasma was obtained from 6 patients with early, fulminant posttraumatic ARDS (mean Injury Severity Score, 26). All samples were drawn within 24 hours after injury. Plasma was also taken from 13 healthy control subjects. These controls were also used as sources of PMNs. MAIN OUTCOME MEASURES: Effect of early, fulminant ARDS and normal plasma on spontaneous apoptosis, CD16, and CD11-b expression in PMNs in vitro; levels of IL-8 in plasma; correlation of extracellular IL-8 concentration with rate of PMN apoptosis; and effect of IL-8 blockade on PMN apoptosis, CD16, and CD11-b expression in ARDS and normal plasma. RESULTS: Plasma from patients with early, fulminant ARDS inhibited spontaneous PMN apoptosis at 24 hours (35%+/-5% vs 54%+/-5%; P=.01). Neither CD16 nor CD1l-b differed significantly between the 2 groups. The mean plasma level of IL-8 in patients with early, fulminant ARDS was 359+/-161 pg/mL vs 3.0+/-0.4 pg/mL in healthy controls (P<.05). Interleukin 8 inhibited apoptosis in plasma-free medium at low doses (1-50 pg/mL) but had no significant effect at higher doses (100-5000 pg/mL) (P<.05). Interleukin 8 blockade with monoclonal antibody suppressed apoptosis in normal plasma (28%+/-5% with monoclonal antibody vs 51%+/-5% without monoclonal antibody; P=.008) but not in plasma from patients with early, fulminant ARDS (29%+/-5% with monoclonal antibody vs 34%+/-6% without monoclonal antibody; P=.67). It had no effect on CD16 or CD11-b expression in either plasma. CONCLUSIONS: Plasma from patients with early, fulminant ARDS contains soluble factors that inhibit PMN apoptosis in vitro. Low levels of IL-8 inhibit PMN apoptosis in normal plasma. Although plasma levels of IL-8 are markedly elevated in early, fulminant ARDS, IL-8 is not directly responsible for the antiapoptotic effect of plasma from patients with early, fulminant ARDS.     

Use of chest computed tomography in the staging of pediatric Wilms' tumor: interobserver variability and prognostic significance

PURPOSE: To determine the specificity and prognostic significance of computed tomography (CT) of the chest in pediatric Wilms' tumor. PATIENTS AND METHODS: Patients treated for newly diagnosed Wilms' tumor at St Jude Children's Research Hospital between December 1978 and July 1995 were included in the study if an initial chest radiograph and CT were available and if pulmonary involvement (determined by chest radiographs) was absent. For the 202 patients studied, radiographs and CT scans were reviewed blindly and independently by three experienced radiologists for the presence of pulmonary nodules. Outcome variables consisted of intraobserver variability (in a subsample of 40 cases) and concordance between ratings on radiographs and CT scans (both by McNemar's test), interrater variability (by logistic regression), and the cumulative incidence of pulmonary relapse for patients with and without positive CT scans, by reviewer. RESULTS: As expected, ratings of pulmonary involvement on radiographs were discordant with CT ratings. There was marked variability among reviewers in CT ratings (P = .0001). Of 202 CT scans, 78 were read as positive by at least one reviewer, 41 were rated positive by only one reviewer, 18 by two reviewers, and 19 by all three. Intrarater variability on repeat reviews was not significant. Patients with nodules identified on CT had a significantly higher pulmonary relapse rate when analyzed separately by reviewer. However, for the 14 patients who had pulmonary relapse, CT scans were rated positive by all three reviewers in only five cases and as negative by all three in another five cases. CONCLUSION: The variability in interpretation of chest CT scans in patients with Wilms' tumor limits the predictive utility of these studies. Optimal, standardized techniques and central review are essential if chest CT is to be used for staging in cooperative studies.     

Acute eosinophilic pneumonia: radiographic and CT findings in six patients

OBJECTIVE: Our objective was to assess the radiographic and CT findings of acute eosinophilic pneumonia. CONCLUSION: Initial and follow-up chest radiographs, chest CT scans (n = 5) and clinical data in six patients with acute eosinophilic pneumonia were reviewed by two chest radiologists. The predominant initial radiographic finding was diffuse bilateral reticular densities (four [67%] of six patients). Areas of ground-glass opacity were observed on CT scans in all patients (5 of 5) and were bilateral, random, and patchy in distribution in four (80%) of five patients. Smooth septal thickening and pleural effusions were observed in four patients. The disease manifested as rapid onset of severe dyspnea and fever and rapid resolution with (n = 3) or without (n = 3) steroid therapy. Bilateral reticular densities on chest radiographs and, on CT scans, ground-glass opacity with smooth septal thickening and pleural effusion associated with acute fever and dyspnea may suggest the diagnosis of acute eosinophilic pneumonia.     

Automatic patient-instruction devices in thin-section CT of the thorax: impact on image quality

PURPOSE: To determine what influence automatic patient-instruction (API) devices have on image quality of chest computed tomographic (CT) scans and whether the qualitative outcome justifies their routine use. MATERIALS AND METHODS: Thin-collimation CT scans of two age- and sex-matched groups of 64 patients each were evaluated prospectively for the presence of breathing artifacts and for concomitant deterioration of image quality. Breathing commands in group 1 were given with the API device and in group 2 with technologist-performed patient instruction. Cardiac motion artifacts were not evaluated. The frequency of scans repeated owing to breathing artifact was determined. RESULTS: Image quality was worse in group 1 compared with that of group 2. The percentage of scans repeated was higher with API (38%) than without API (16%). CONCLUSION: API devices cannot be recommended for thin-section CT of the thorax. The large number of scans that must be repeated leads to a considerable increase in patient irradiation, scanning time, and cost.     

Effect of cigarette smoke on CYP1A1, CYP1A2 and CYP2B1/2 of nasal mucosae in F344 rats

BACKGROUND: Dobutamine stress echocardiography (DSE) is sensitive and specific in detecting myocardial ischemia of male patients. However, there have been few reports about the use of DSE for the detection of coronary artery disease (CAD) in women. METHODS: DSE was evaluated in 51 consecutive women who underwent concomitant quantitative coronary angiography. Forty-four of the 51 patients received stress thallium-201 single-photon emission computed tomography (SPECT), and 30 of the 51 patients had interpretable results (exercise level > or = 85% of age-predicted maximal heart rate) of treadmill exercise. Twenty-nine patients had angiographically documented CAD defined as > or = 50% diameter stenosis. RESULTS: The overall sensitivity of DSE and stress 201Tl SPECT in detecting CAD was 93% and 79% (p = nonsignificant), and the specificity was 82% and 75% (p = nonsignificant), respectively. A combination of both tests increased the sensitivity (96%) at the expense of some decrease in specificity (60%). The agreement of DSE and 201Tl SPECT was 68% (30 of 44; kappa statistic = 0.35; p < 0.0001). The overall sensitivity, specificity, and accuracy in detecting CAD by treadmill exercise test and DSE were 71% vs 93% (p = nonsignificant), 44% vs 82% (p = 0.036), and 57% vs 88% (p = 0.003). In patients with abnormal results of treadmill exercise testing, the false-positive rate in detecting CAD was 2 (18%) of 11 in patients with abnormal results of DSE and 7 (88%) of 8 in those with normal results of DSE (p = 0.005). In patients with normal results of treadmill exercise testing, the false-negative rate in detecting CAD was 4 (100%) of 4 in patients with abnormal results of DSE and 0 (0%) of 7 in those with normal results of DSE (p = 0.003). CONCLUSION: The diagnostic accuracy of DSE was similar to that of stress 201Tl SPECT in women. DSE was able to stratify female patients with either abnormal or normal results of treadmill exercise testing and to avoid unnecessary cardiac catheterization.     

Usefulness of CT in patients with intestinal obstruction who have undergone abdominal surgery for malignancy

OBJECTIVE: The purpose of this study was to evaluate the usefulness of CT in determining the causes of intestinal obstruction in patients who have undergone abdominal surgery for malignancy. MATERIALS AND METHODS: We analyzed the CT scans of 55 patients with benign (n = 26) or malignant (n = 29) intestinal obstruction that developed after abdominal surgery for malignancy. After calculating the diagnostic accuracy of interpretations by three radiologists, we compared CT findings for benign and malignant intestinal obstructions with respect to peritoneal involvement patterns and other ancillary findings. Multivariate logistic regression analysis was used to determine the diagnostic performance of CT in revealing causes of obstruction. RESULTS: Diagnostic accuracies of the three radiologists were 67%, 75%, and 78%. CT findings indicating malignant obstruction were a mass at the site of obstruction or prior surgery, lymphadenopathy, or an abrupt transition zone and irregular bowel wall thickening at obstructed sites (p < .05). Conversely, the chance for benign obstruction increased when CT revealed mesenteric vascular changes, a large amount of ascites, or a smooth transition zone and smooth bowel wall thickening at the obstructed site (p < .05). With multivariate logistic regression analysis using two variables (a mass at the site of obstruction or prior surgery and lymphadenopathy), we calculated the overall accuracy of CT as 84% (46/55 patients). CONCLUSION: CT is useful in differentiating benign from malignant intestinal obstructions in patients who have undergone abdominal surgery for malignancy. However, CT has limitations in patients not having a demonstrable peritoneal mass.     

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.     

Detection of emboli after surgery for intracerebral aneurysms

BACKGROUND: Neurological change after surgery for cerebral aneurysm caused by embolic events is commonly suspected, but direct detection of emboli has not been possible in the past. Transcranial Doppler ultrasound (TCD) is able to detect emboli, and large numbers of emboli detected in TCD studies have been associated with radiological changes and clinical deterioration. METHODS: During a 2-year period, 11 patients were observed to have emboli during routine TCD studies after aneurysm surgery. The computed tomographic (CT) scans of these patients were reviewed for low-density areas, suggesting ischemia. All patients studied during a 1-year interval (July 1995-July 1996) served as a control group and were reviewed for similar CT findings, and the two groups were compared using Fisher's exact test. RESULTS: Nine of the 11 patients (82%) observed to have emboli developed low-density areas on their CT scans, whereas 30 of the 123 (24%) patients without emboli developed low-density areas on their CT scans. The difference was significant (P < 0.001, Fisher's exact test). Credible sources for emboli were readily identified in each of the 11 patients. CONCLUSION: TCD allows detection of emboli after aneurysm surgery, and this detection is strongly associated with CT evidence of ischemia. Although detection of emboli was relatively rare in this study, rates of emboli occurrence may increase if systematic monitoring is used.     

Pathological and High Resolution CT Findings in Churg-Strauss Syndrome

Objective To investigate the Churg-Strauss syndrome (CSS) associated lung involvement,concentrating on clinical characteristics,pathological findings of lung involvements,response to treatment,and prognosis.Methods We retrospectively analyzed the characters of the clinical manifestations,thin-section CT and pathological findings of CSS.The study involved 16 patients.Clinical data were obtained by chart review.All patients underwent transbronchial lung biopsy (TBLB).Six of them underwent surgical lung biopsy as well.Results The patients included 7 men and 9 women,aged from 14 to 61 years (median,47.5 years).Extrathoracic organs involved included nervous system (7/16) and skin (5/16).Respiratory symptoms included cough (12/16),exertional dyspnea (11/16),hemoptysis (4/16),and chest pain (3/16).CT findings included bilateral ground-glass opacities (12/16),bilateral patchy opacities (12/16),and centrilobular nodules (6/16).The pathological findings of TBLB demonstrated increased eosinophils (3/16),vasculitis (3/16),and interstitial pneumonia (16/16).The pathological findings of surgical lung biopsy of 6 cases showed ne-crotizing vasculitis in 4 cases,capillaries in S,eosinophilic pneumonia in 3,granulomas in 2,and airway abnormalities in 3.All patients improved in symptoms after therapy during the study period (range,3 to 51 months; median,15 months).Conclusions Asthma may be present in CSS patient when there is bronchial involvement.Ground-glass opacities and consolidation seen on high-resolution CT reflect the presence of eosinophilic pneumonia,vasculitis,and pulmonary alveolar hemorrhage.TBLB has significant limitations for the diagnosis of CSS.Early diagnosis and therapy can result in satisfactory prognosis.     

The accuracy of CT and MR evaluation of the sella turcica for detection of adrenocorticotropic hormone-secreting adenomas in Cushing disease

PURPOSE: To document the accuracy of CT and MR of the sella turcica for detecting adrenocorticotropic hormone-secreting adenomas in Cushing disease. METHODS: The radiologic findings of the sella turcica prior to transsphenoidal surgery are reviewed in 141 patients who had biochemical evidence of pituitary-dependent Cushing disease. Axial thin-collimation CT scans with sagittal and coronal reformations before and after contrast enhancement were obtained in 125 patients. Seventy-eight patients had MR examinations with a 1.5-T superconducting magnet. In 11 of the patients gadolinium-enhanced MR scans were also obtained. The preoperative interpretation of the imaging studies was correlated with the surgical findings and patients follow-up. RESULTS: The sella turcica was enlarged in 43 cases (30%). In 125 patients reformatted or direct coronal thin-collimation CT scans were available. Seventy-eight of the patients had MR. In the 12 patients with pituitary macroadenomas, the accuracy of CT (n = 10) and MR (n = 10) in respect to detection of the lesion was 100%. Of the 98 microadenomas assessed by CT, 47 (48%) were directly depicted as distinct hypodense lesions. In only 31 of 73 cases (42%), however, could CT predict the precise anatomic location and extent of the lesions. Only patients in whom the hypercortisolism was corrected by later surgery were considered for the correlation analysis. Of the 52 microadenomas assessed by MR, 28 (53%) were directly depicted as distinct lesions of reduced signal intensity on T1-weighted images, and in only 21 of 41 cases (52%) did MR show good correlation to the surgical findings. Some degree of partially empty sella was found in 22% of the patients. CONCLUSIONS: Although both the sensitivity and the diagnostic accuracy of imaging methods of the sella turcica have been considerably improved in comparison with previous reports, they still provide only a minor contribution to the diagnosis and differential diagnosis of Cushing syndrome.     

Cerebral paragonimiasis in early active stage: CT and MR features

OBJECTIVE: Diagnosis of cerebral paragonimiasis in its early active stage is important because curative chemotherapy is possible. Accordingly, this study was undertaken to evaluate the CT and MR features of early active cerebral paragonimiasis. MATERIALS AND METHODS: We retrospectively reviewed the CT scans (n = 29) and MR images (n = 7) of the brain in 20 patients between 7 and 59 years old who had cerebral paragonimiasis in the early active stage. The diagnosis was based on a positive antibody test by enzyme-linked immunosorbent assay (ELISA) for paragonimiasis in serum and CSF. The diagnosis was confirmed surgically in seven patients. RESULTS: The most common and characteristic imaging finding was a conglomerate of ringlike enhancing lesions (grape-cluster appearance) with surrounding edema in one cerebral hemisphere in 11 patients (55%). Other nonspecific findings included a solitary ringlike lesion (n = 4) or irregular enhancing lesions (n = 2), localized hemorrhage with (n = 3) or without (n = 2) enhancing lesions, and a poorly defined non-hemorrhagic, nonenhancing lesion (n = 1). CONCLUSION: CT and MR findings of clustered ring-enhancing lesions, seen in approximately half of the cases of early cerebral paragonimiasis, are suggestive of cerebral paragonimiasis.     

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.     

Thermoregulatory responses of mesic and xeric rodent species to photoperiod manipulations

PURPOSE: To evaluate hypertrophied bronchial arteries on thin-section computed tomographic (CT) scans in patients with bronchiectasis by using CT angiographic correlation. MATERIALS AND METHODS: Spiral CT angiography was performed prospectively in 14 patients (eight men, six women; age range, 34-71 years) with bronchiectasis who were suspected of having bronchial arterial hypertrophy at thin-section CT (performed without contrast medium). The inclusion criteria were tubular (in six patients) or nodular (in 14 patients) areas of soft-tissue attenuation that had an appearance unlike that of lymph nodes at thin-section CT and that were within the mediastinum and around the central airway. These findings were subsequently correlated with the spiral CT angiographic findings. RESULTS: At comparative analysis of thin-section CT scans and CT angiograms, seven of the eight (88%) tubular lesions and 19 of the 36 (53%) nodular lesions in the mediastinal soft tissue were proved to be hypertrophied bronchial arteries. All of the six (100%) tubular and 19 of the 21 (90%) nodular lesions around the walls of the main (primary) and lobar bronchi were hypertrophied bronchial arteries. In eight (57%) patients, CT angiograms showed 11 intraluminal protrusions caused by hypertrophied bronchial arteries in the main bronchi, lobar bronchi, or both. CONCLUSION: Nodular and tubular structures in the mediastinum and around the central airway on thin-section CT scans in the patients with bronchiectasis are suggestive of hypertrophied bronchial arteries. Recognition of the hypertrophied bronchial artery can be critical for the bronchoscopist.     

Computed tomography in evaluation of patients with stage III melanoma

BACKGROUND: Metastatic disease is detected infrequently by computed tomography (CT) in early stage melanoma. The diagnostic yield of routine CT for stage III melanoma is less established, despite extensive use in clinical practice. METHODS: Charts from 347 asymptomatic patients with stage III melanoma were reviewed. Findings suggestive of metastatic melanoma identified by head or body CT, chest radiography, bone scan, or liver function studies were confirmed histologically or by progression of disease. RESULTS: Individual CT scans identified 33/788 (4.2%) instances of metastatic melanoma, with 66/788 (8.4%) false positive studies. No metastases were identified among 104 head CT scans. Chest CT had the highest yield in patients with cervical adenopathy (7/35, 20%), and the lowest yield with groin adenopathy (1/50, 2%). Pelvic CT diagnosed metastases in 7/94 (7.4%) patients with groin adenopathy, but no patients with palpable axillary (n = 76) or cervical (n = 21) nodes. Metastatic melanoma was diagnosed in 11/136 (8.1%) patients having complete body CT imaging (chest, abdomen, and pelvis), including six patients (4.4%) identified by CT alone. CONCLUSIONS: Routine CT in patients with clinical stage III melanoma infrequently identifies metastatic disease. Head CT in the asymptomatic patient, chest CT in patients with groin adenopathy, and pelvic CT in the presence of axillary or cervical adenopathy are not indicated. Selective use of chest CT in patients with cervical adenopathy or pelvic CT in the presence of groin disease may be useful.