[Ultrasound follow-up of palpable solid, probably benign breast lesions (BI-RADS category III)]. / Sonographische Verlaufskontrollen bei palpablen soliden, wahrscheinlich gutartigen Brustläsionen (BI-RADS Kategorie III).

PURPOSE: To determine whether palpable non-calcified solid breast masses with benign morphology on ultrasound can be classified as probably benign and whether these lesions fulfill the criteria required for BI-RADS (TM) category III. MATERIALS AND METHODS: This analysis includes 78 patients with 80 palpable non-calcified solid masses that were classified as probably benign at initial sonography. Of 78 patients, 66 had periodic imaging surveillance (2 - 8 years, mean 4.6 years). The remaining 12 patients had a biopsy after initial imaging. RESULTS: In the 64 patients under surveillance, palpable lesions remained stable at follow-up. In 2 patients lesions increased in size during follow-up and no malignancy was diagnosed at subsequent open biopsy. In 19 of the 66 patients, 29 additional nonpalpable lesions of similar morphology were detected on ultrasound. No malignancy was diagnosed in the 12 patients, who had a biopsy after initial imaging. CONCLUSION: Our data suggest that palpable non-calcified solid breast masses with benign morphology on ultrasound can be classified as probably benign (BI-RADS (TM) category III). Biopsy can be averted when lesions remain stable at follow-up.

[Malignant and benign diseases of the breast in 41 male patients: mammography, sonography and pathohistological correlations]. / Maligne und benigne Erkrankungen der Brust bei 41 männlichen Patienten: Mammographie und Sonographie mit histopathologischer Korrelation.

AIM: The goal of our study was to evaluate findings in mammography and sonography in male patients with pathohistologically proven diseases of the breast. MATERIAL AND METHODS: Mammographies and sonographies, which were obtained in 41 male patients in a 6-year period, were retrospectively evaluated in accordance with the BI-RADS(R) classification. RESULTS: Histologically 13 carcinomas, 21 gynecomastias, 3 pseudogynecomastias, 2 epithelial inclusion cysts and 2 other benign lesions were diagnosed. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of mammography in differentiation of benign versus malignant disease were 92 %, 89 %, 80 %, 96 % and 90 %, respectively. Additional sonography did not change these results. However, sonography increased diagnostic confidence in 18.2 % (2/11) of suspicious lesions. CONCLUSION: In our study the invasive ductal carcinoma of male patients was a predominantly lobulated, ill-defined lesion in mammography and sonography. The differentiation of carcinoma to pseudogynecomastia and diffuse or dendritic gynecomastia was securely feasible. However, we could not reliably distinguish between carcinoma and some benign mass lesions. In cases of mammographically diagnosed masses or unclear mammography, additional sonography should be performed to increase the diagnostic confidence.

Measurement of time-to-peak parameter by use of a new standardization method in patients with stenotic or occlusive disease of the carotid artery.

BACKGROUND AND PURPOSE: A quantitative, easily obtained measure of cerebral hemodynamics would be valuable in planning surgical or interventional therapy for patients with stenotic or occlusive disease of the carotid artery. We evaluated the recently introduced standardized time-to-peak variable (stdTTP), obtained with dynamic susceptibility contrast-enhanced MR (DSC-MR) imaging, in different states of stenotic/occlusive carotid artery disease. METHODS: We examined 24 patients with unilateral, high-grade stenosis (85%-95%) of one internal carotid artery (ICA) and 10 patients with stenosis (85%-95%) of one ICA and occlusion of the contralateral ICA. Mean stdTTP was evaluated in the central vascular territories of the anterior, middle, and posterior cerebral arteries and the anterior and posterior border zones and compared with the mean stdTTP values from 36 cerebral hemispheres without hemodynamic impairment. RESULTS: Patients showed no significant prolongation of stdTTP in the central vascular territories compared with the reference group, whereas significant prolongations of stdTTP were measured in the anterior and posterior border zones in patients with ICA disease (ANOVA, P <.05) and were most prominent in higher grades of carotid disease. Hemispheres with hemodynamic impairment always showed a stdTTP > 3.5 s in the border zones. CONCLUSION: The StdTTP quantitatively describes the hemodynamic impairment in cerebral hemispheres supplied by a stenosed or occluded ICA. An stdTTP value of > 3.5 s, as has been postulated, seems to point out hemodynamic impairment.

Role of Doppler sonography in the evaluation of accessory spleens after splenectomy.

OBJECTIVE: Splenectomy influences the Doppler blood flow pattern in the splenic artery. Blood flow in this vessel might return to normal if an accessory spleen increases in size after splenectomy. Our objective was to evaluate the resistive index of the splenic artery depending on the presence or absence of a hypertrophic accessory spleen in splenectomized patients. METHODS: The resistive index of the splenic artery was evaluated by duplex Doppler sonography in 19 splenectomized patients (8 with a hypertrophic accessory spleen) and in 8 healthy volunteers. The resistive index was measured within 3 cm of the origin of the splenic artery, and 3 different measurements were averaged. The presence or absence of a hypertrophic accessory spleen was diagnosed on the basis of sonography, computed tomography, magnetic resonance imaging, or scintigraphy, as well as by the presence or absence of Howell-Jolly bodies on a peripheral blood smear. RESULTS: The resistive index of the splenic artery in the splenectomized patients without a hypertrophic accessory spleen (mean +/- SD, 0.82 +/- 0.06; n = 11) was significantly (P < or = .0001) higher than in splenectomized patients with a hypertrophic accessory spleen (0.63 +/- 0.06; n = 8) and in control subjects (0.63 +/- 0.05; n = 8). CONCLUSIONS: In the splenectomized patient, a hypertrophic accessory spleen is associated with a normal resistive index in the splenic artery.

A standardized method of generating time-to-peak perfusion maps in dynamic-susceptibility contrast-enhanced MR imaging.

BACKGROUND AND PURPOSE: Perfusion MR imaging, performed as dynamic-susceptibility contrast-enhanced MR imaging, is sensitive to hemodynamic risks for patients with cerebrovascular disease. We sought to define a quantitative parameter for perfusion MR imaging, which shows brain areas at hemodynamic risk and enables direct comparison of different perfusion MR imaging examinations. METHODS: A new standardization procedure for the time-to-peak (TTP) parameter, standardized time to peak (stdTTP), was introduced. The stdTTP automatically calculates a time offset correlated to the earliest enhancing voxels in a section and rescales all TTP values accordingly. Because of a close relation between this offset and stdTTP of early enhancing voxels in central vascular territories (CVTs), stdTTP provides an estimate of the bolus run time between CVTs and related border zones (BZs). The stdTTP in CVTs and BZs was measured in 11 patients without hemodynamic impairment by using high temporal resolution dynamic-susceptibility contrast-enhanced perfusion MR imaging. RESULTS: An excellent comparability of different dynamic susceptibility contrast-enhanced MR imaging studies was found. The stdTTP in CVTs was 0.4 +/- 0.5 s (minimum, 0 s; maximum, 1.3 s) for the anterior, 0.5 +/- 0.3 s (minimum, 0 s; maximum, 1.0 s) for the middle, and 1.4 +/- 0.5 s (minimum, 0.4 s; maximum, 2.4 s) for the posterior cerebral artery. In the anterior BZ, stdTTP was 2.3 +/- 0.4 s (minimum, 1.6 s; maximum, 3.2 s), and in the posterior BZ, stdTTP was 2.8 +/- 0.4 s (minimum, 2.0 s; maximum, 3.4 s). CONCLUSION: The results suggest a limit for stdTTP of approximately 3.5 s in the anterior and posterior BZs. The stdTTP could serve as a quantitative measure for the hemodynamic risk assessment of patients with cerebrovascular disease. Because stdTTP can be directly derived from the measured curves, the hemodynamic situation of a patient can be judged with a minimum of computational effort.

Selective loss of vergence control secondary to bilateral paramedian thalamic infarction.

The supranuclear pathways for vergence eye movements are poorly understood. The authors report a 57-year-old patient who presented with selective loss of vergence control and dissociation of light and near reaction. MRI showed a symmetric paramedian thalamic infarction without midbrain lesion. The findings suggest that this syndrome is due to an interruption of supranuclear fibers to midbrain vergence neurons.

Pyrofluid inhalation in "fire-eaters": sequential findings on CT.

We report the sequential computed tomography (CT) findings in two fire-eaters after accidental inhalation of pyrofluid. The initial chest radiographic findings were ambiguous and the interpretation of the radiographs was biased by clinical history unrelated to fire eating. On CT, pneumatoceles were the major findings in both patients. The pneumatoceles resolved rapidly, leaving only minimal scarring. Our cases illustrate the sequential evolution of pneumatoceles in fire-eaters after the inhalation of pyrofluid and documents the rapidity with which the lesions regress. The rare accidental inhalation of pyrofluid in fire-eaters may produce a puzzling clinical and radiographic picture and can be confused with other lung disorders.

Vaccinations and steroids in MS: effects on disease progression and mood.

OBJECTIVE: To investigate the effects of vaccinations and steroids on disease progression and mood in patients with multiple sclerosis (MS). MATERIAL AND METHODS: Twenty-three patients with clinically definite MS were questioned with respect to vaccination history and the cumulative dose of steroids given during their life-time. EDSS scores and MRI scans of the brain were obtained and used to quantify clinical and MRI disease progression. Mood was assessed by using a self-estimated adjective mood scale. RESULTS: The number of vaccinations showed no effect on disease progression or mood. High cumulative steroid doses were associated with rapid MRI disease progression and the number of supratentorial MRI lesions. The absence of band-like MRI lesions was correlated with rapid clinical and MRI disease progression. Self-estimated mood tended to be worse in patients with chronic-progressive MS compared to those with relapsing-remitting MS. CONCLUSION: Neither clinical nor MRI-documented disease progression nor mood are influenced by the total number of vaccinations whereas high cumulative steroid doses and the absence of band-like MRI lesions indicate rapidly progressive MS. Self-estimated mood tends to be worse in patients with chronic-progressive MS compared to patients with relapsing-remitting MS.

Subjective differentiation of normal and pathological bronchi on thin-section CT: impact of observer training.

The effect of observer training on sensitivity, specificity and interobserver agreement in the differentiation between normal and pathological bronchi on computed tomography (CT) was studied. The wall thickness of bronchi with normal walls and with pathologically thickened walls were subjectively scored by three independent observers before and after a training period of 2 weeks. Sensitivity, specificity and interobserver agreement were calculated for reading sessions before and after training. Increase and decrease in agreement after training were determined. There was a statistically significant difference (p=0.001) between objectively measured wall thickness of normal and pathological bronchi, both for reference bronchi and for bronchi used for reading sessions. While training increased interobserver agreement, it had no effect on sensitivity (0.46 versus 0.44 after training) and specificity (0.71 versus 0.72 after training) in detecting pathological bronchi. Increased agreement after training was significantly (p=0.001) more frequent than decreased agreement. There is a discrepancy between the effect of training on interobserver agreement and on sensitivity and specificity in the subjective differentiation between normal and pathological bronchi. Interobserver agreement alone is not a reliable indicator of a beneficial effect of training in the evaluation of this parameter.

Radiographic findings in patients with acquired immunodeficiency syndrome, pulmonary infection, and microbiologic evidence of Mycobacterium xenopi.

The authors studied radiographs and clinical histories of 29 patients with acquired immunodeficiency syndrome, symptoms of pulmonary infection, and simultaneous microbiologic evidence of Mycobacterium xenopi in the respiratory tract. The presence, nature, and distribution of radiographic abnormalities were determined and analyzed in accord with clinical information. In 26 (90%) patients, M. xenopi was the only microorganism that could be isolated. Chest radiographs were normal in 13 patients (45%) and abnormal in 16 patients (55%). Radiographic abnormalities were bilateral in 94% of cases and predominantly involved the lower lobes. Patchy peribronchial opacities (44%) and miliary nodules (24%) were the most common abnormalities. Reticular opacities and parenchymal consolidation were seen in 12% of patients. Pleural effusion was seen in 18% of patients. No patients had cavitations or adenopathy. There was no statistically significant difference regarding the mean age (38.7+/-7.3 years vs. 40.2+/-11.0 years), the duration of clinically evident human immunodeficiency virus infection (2.7+/-1.2 years vs. 2.8+/-1.4 years), and the mean of CD4 cell counts (50.6+/-15.3 cells/ml vs. 47.4+/-15.9 cells/ml) between the patients with and without abnormalities on chest radiographs. In patients with acquired immunodeficiency syndrome, pulmonary infection, and simultaneous microbiologic evidence of M. xenopi, chest radiographs can be normal in a substantial number of cases. When radiographic abnormalities are present, they differ from those seen in patient not infected with the human immunodeficiency virus who had pulmonary infection caused by M. xenopi and from patients with acquired immunodeficiency syndrome and pulmonary infection with nontuberculous mycobacteria other than M. xenopi. Although these findings are not specific, they may be of importance in the imaging of patients with acquired immunodeficiency syndrome, notably in areas where M. xenopi is endemic.

Imaging of the brain using the fast-spin-echo and gradient-spin-echo techniques.

The aim of our study was to compare gradient-spin-echo (GRASE) to fast-spin-echo (FSE) sequences for fast T2-weighted MR imaging of the brain. Thirty-one patients with high-signal-intensity lesions on T2-weighted images were examined on a 1.5-T MR system. The FSE and GRASE sequences with identical sequence parameters were obtained and compared side by side. Image assessment criteria included lesion conspicuity, contrast between different types of normal tissue, and image artifacts. In addition, signal-to-noise, contrast-to-noise, and contrast ratios and were determined. The FSE technique demonstrated more lesions than GRASE and with generally better conspicuity. Smaller lesions in particular were better demonstrated on FSE because of lower image noise and slightly weaker image artifacts. Gray-white differentiation was better on FSE. Ferritin and hemosiderin depositions appeared darker on GRASE, which resulted in better contrast. Fatty tissue was less bright on GRASE. With current standard hardware equipment, the FSE technique seems preferable to GRASE for fast T2-weighted routine MR imaging of the brain. For the assessment of hemosiderin or ferritin depositions, GRASE might be considered.

Double inversion recovery imaging of the brain: initial experience and comparison with fluid attenuated inversion recovery imaging.

The purpose of this study was to evaluate the diagnostic efficacy of the double inversion recovery fast spin echo (DIR-FSE) sequence for brain imaging compared to the fluid-attenuated inversion recovery (FLAIR) sequence. DIR-FSE and FLAIR-FSE sequences were obtained and compared side by side. Image assessment criteria included lesion conspicuity, contrast between different types of normal tissue, image quality, and artifacts. In addition, contrast ratios and contrast-to-noise ratios were determined. Scan time of DIR-FSE was 33% longer than scan time of FLAIR-FSE. Overall lesion conspicuity was equal on DIR-FSE and FLAIR-FSE; however, DIR-FSE showed particular advantages for infratentorial lesions and lesions with only poor contrast on T2-weighted images, whereas FLAIR was slightly superior for small superficial cerebral abnormalities. Gray-white differentiation was better with DIR-FSE. Cerebrospinal fluid suppression was equal on both sequences; cerebrospinal fluid pulsation artifacts were more pronounced on DIR-FSE but did not cause diagnostic difficulties on these images. We conclude that DIR-FSE might be obtained if infratentorial lesions and abnormalities with only slightly prolonged T2 relaxation times are suspected. Otherwise, FLAIR-FSE seems preferable.

[Urgent diagnostic steps in acute manifestation of intraspinal processes]. / Dringliche diagnostische Schritte bei akuter Manifestation von intraspinalen Prozessen.

Immediate diagnostic clarification is required in patients who develop acute or subacute symptoms suggestive of an intraspinal lesion. In case of symptoms indicating a monoradicular lesion a spinal CT investigation is mostly sufficient. Since polyradicular syndromes are often due to inflammation, examination of the cerebrospinal fluid is the most important diagnostic measure. However, in case of symptoms suggestive of intramedullary lesions, spinal MRT is by far the most effective diagnostic procedure. In patients with symptoms suggestive of a lesion of the cauda equina spinal CT is sufficient in most cases as a first measure, particularly if the lesion can be precisely localized by clinical examination. The decision as to which diagnostic method should be performed first is relevant mainly because of the limited availability of MRT examinations within the daily clinical routine. MRT should thus be used selectively in patients with lesions that cannot be identified by alternative diagnostic methods.

Severity assessment of acute pulmonary embolism with spiral CT: evaluation of two modified angiographic scores and comparison with clinical data.

Spiral computed tomography (CT) has shown promising results in the detection of acute pulmonary embolism. The aim of this study was to investigate whether the severity of acute pulmonary embolism could be quantitatively assessed with spiral CT examinations and to test the potential clinical impact of this information. In a consecutive series of 123 patients screened with spiral CT for suspected acute pulmonary embolism, 31 patients (25%) had evidence of emboli. The severity of pulmonary arterial obstruction in those 31 spiral CT examinations was evaluated by two independent observers using angiographic scores previously described by Walsh (29) and Miller (30), adapted to the needs of spiral CT. Clinical patient subgroups were defined according to oxygen saturation, heart rate, and echocardiographic signs of right ventricular strain. CT severity scores were then correlated to each other and to clinical parameters using the Spearman rank test. Interobserver agreement was calculated using the analysis of variance. Both modified Walsh and Miller scores were readily reproducible and showed interobserver agreements of 0.85 and 0.96, respectively (p = 0.001). Patients with mild and marked clinical abnormalities showed statistically significant differences between CT severity scores. Differences between severity scores of patients with moderate and marked clinical abnormalities were somewhat significant. No significant mean severity score differences were seen between patients with mild and moderate clinical abnormalities. Although correlations of severity scores and detailed clinical parameters within the defined subgroups were moderate to poor, threshold scores greater than 10 (Miller) and greater than 11 (Walsh) always indicated marked clinical abnormalities. The modified scores presented in this study constitute a readily reproducible method for the quantitative assessment of acute pulmonary embolism severity on spiral CT examinations.

Radiographic detection of intrabronchial malpositions of nasogastric tubes and subsequent complications in intensive care unit patients.

OBJECTIVE: The aim of our study was to illustrate the radiographic spectrum of the intrabronchial malposition of nasogastric tubes and subsequent complications, and to discuss the role of radiography in the detection of such malpositions. DESIGN: Retrospective clinical investigation. SETTING: Tertiary care university teaching hospital. PATIENTS AND METHODS: We reviewed chest radiographs of 14 intensive care patients with nasogastric tubes malpositioned in the tracheobronchial tree. The site and anatomic location of the malposition were recorded. Complications due to tube malpositioning were monitored on follow-up radiographs and on computed tomographic examinations, which were available in 4 patients. RESULTS: Nine of 14 nasogastric tubes were inserted in the right and 5 in the left tracheobronchial tree. Tube tips were malpositioned in the lower lobe bronchi (50%), the intermediate bronchus (36%), and the main bronchi (14%). There was perforation of the bronchial system with subsequent pneumothorax in 4 patients. In 4 other patients, pneumonia developed at the former site of the malpositioned tube tip. Radiographic detection of nasogastric tube malpositioning was prompt in 9 patients and delayed in 5 patients. CONCLUSIONS: Whereas clinical signs of nasogastric tube malpositioning in intensive care patients may be absent or misleading, chest radiography can accurately detect nasogastric tube malpositions in the tracheobronchial tree, may prevent complications, and avoid the use of further costly or invasive diagnostic techniques.

Azygos arch cannulation by central venous catheters: radiographic detection of malposition and subsequent complications.

The aim of this study was to determine the frequency of radiographically evident central venous catheter misplacement in the azygos arch and to analyze whether the frequency of azygos arch cannulation is dependent on the anatomical site of catheter insertion. We reviewed 1,287 postprocedural examinations and 3,441 follow-up examinations. Catheters had been inserted through the left (6%) or right (15%) internal jugular veins and through the left (32%) or right (46%) subclavin veins. Radiographs were analyzed for possible catheter malposition in the azygos arch and for complications related to this malposition. Catheter malposition in the azygos arch was seen on 16/1,287 (1.2%) postprocedural radiographic examinations. Of the 16 malpositioned catheters, 11 (69%) had been inserted in the left subclavian vein, three (19%) in the left jugular vein, two (12%) in the right subclavian vein, and none (0%) in the right jugular vein. There was a statistically significant difference in the frequency of azygos arch cannulation between left- and right-sided catheters (p = 0.001). All complications consisted of venous perforations and were seen in three of 16 cases (19%). Azygos arch cannulation is a rare but hazardous central venous catheter malposition that occurs early after catheter insertion and carries a substantial risk for complication. The risk for azygos arch cannulation is substantially increased if catheters are inserted in left-sided veins. Because of the severity of subsequent complications, radiologists should be vigilant in the detection of this rare malposition.

Sonomorphology of the gallbladder in critically ill patients. Value of a scoring system and follow-up examinations.

PURPOSE: The aim of the study was to assess the value of a scoring system for the diagnosis of acalculous cholecystitis (AC) on ultrasound (US) follow-up examinations and to discuss the merits of scoring system compared to clinical outcome and pathohistologic findings. MATERIAL AND METHODS: In this prospective study, 21 patients at the intensive care unit (ICU) of a medical department were examined by follow-up US. Sonographic parameters of the gallbladder (GB) were obtained (longitudinal and transversal diameter, wall thickening, contents, and pericholecystic fluid) and scored (2 points: distension of GB, thickening of GB wall; 1 point: striated thickening of GB wall, sludge, and pericholecystic fluid; range (0-8). The US findings were correlated with clinical findings and histology at cholecystectomy or autopsy. RESULTS: Of a total of 77 follow-up examinations in these 21 patients, US demonstrated GB distension in 19 patients, wall thickening in 18, sludge in 15, striated thickening of the GB wall in 13, and pericholecystic fluid in 12 patients. Of these, 41 (53%) examinations were scored > or = 6, and 36 (47%) examinations < or = 5. None of the patients with a maximum score during follow-up of < or = 5 (n = 8) had pathohistologic proof of AC or died due to GB complications. Patients with maximum scores of > or = 6: had pathohistologic proof of AC (n = 4); survived with normalization of GB morphology (n = 4); had a normal GB at autopsy (n = 1); or were lost for pathohistologic proof at autopsy (n = 2). CONCLUSION: Our results indicate that regular, short-term follow-up allows early diagnosis and immediate therapy for AC. The scoring system could be helpful in differentiating between patients with an abnormal GB without AC (score < or = 5) and those with an abnormal GB (score > or = 6) with a suspicion of AC. In the latter group, more aggressive diagnostic and therapeutic procedures may be indicated.

Spinal cord lesions in patients with multiple sclerosis: comparison of MR pulse sequences.

PURPOSE: To compare T2-weighted conventional spin-echo (CSE), fast spin-echo (FSE), shorttau inversion recovery (STIR) FSE, and fluid-attenuated inversion recovery (FLAIR) FSE sequences in the assessment of cervical multiple sclerosis plaques. METHODS: Twenty patients with clinically confirmed multiple sclerosis and signs of cervical cord involvement were examined on a 1.5-T MR system. Sagittal images of T2-weighted and proton density-weighted CSE sequences, T2-weighted FSE sequences with two different sets of sequence parameters, STIR-FSE sequences, and FLAIR-FSE sequences were compared by two independent observers. In addition, contrast-to-noise measurements were obtained. RESULTS: Spinal multiple sclerosis plaques were seen best on STIR-FSE images, which yielded the highest lesion contrast. Among the T2-weighted sequences, the FSE technique provided better image quality than did the CSE technique, but lesion visibility was improved only with a repetition time/echo time of 2500/90; parameters of 3000/150 provided poor lesion contrast but the best myelographic effect and overall image quality. CSE images were degraded by prominent image noise; FLAIR-FSE images showed poor lesion contrast and strong cerebrospinal fluid pulsation artifacts. CONCLUSIONS: The STIR-FSE sequence is the best choice for assessment of spinal multiple sclerosis plaques. For T2-weighted FSE sequences, shorter echo times are advantageous for spinal cord imaging, long echo times are superior for extramedullary and extradural disease. FLAIR-FSE sequences do not contribute much to spinal imaging for multiple sclerosis detection.

Bronchial wall thickness: appropriate window settings for thin-section CT and radiologic-anatomic correlation.

PURPOSE: To analyze the influence of computed tomographic (CT) window settings on bronchial wall thickness and to define appropriate window settings for its evaluation. MATERIALS AND METHODS: Three inflation-fixed lungs were scanned with a section thickness of 1.5 mm by using a high-spatial-frequency algorithm. Wall thickness in 10 bronchial specimens was measured with planimetry. Window centers were altered in a range of -200 to -900 HU and window widths in a range of 400-1,500 HU. Relative and absolute differences between CT and planimetric values were calculated. CT and planimetric measures were correlated. Inter- and intraobserver variabilities were determined. RESULTS: Window widths less than 1,000 HU resulted in a substantial overestimation of bronchial wall thickness, whereas widths greater than 1,400 HU resulted in an underestimation of bronchial wall thickness. There was no interaction between "width" and "center" regarding their influence on bronchial walls (F = 0.23; P = .99). Correlation between CT and planimetry was statistically significant (r = .85; P = .0001). Differences between the two observers were not statistically significant; results of the measurements of the two observers correlated well (r = .97; P = .001). CONCLUSION: Bronchial wall thickness on thin-section CT scans should be evaluated with window centers between -250 and -700 HU and with window widths greater than 1,000 HU. Other than window settings, notably window widths less than 1,000 HU, can lead to substantial artificial thickening of bronchial walls.