Tracheobronchomalacia: dynamic airway evaluation with multidetector CT

OBJECTIVE. The objective of our study was to evaluate the role of dynamic inspiratory-expiratory imaging with multidetector CT in patients with suspected tracheobronchomalacia. CONCLUSION. Multidetector CT with inspiratory-expiratory imaging is a promising method in the evaluation of patients with dynamic airway collapse. In our study, the degree of dynamic collapse correlated well with bronchoscopic results. Dynamic expiratory multidetector CT may offer a feasible alternative to bronchoscopy in patients with suspected tracheobronchomalacia.     

Frequency and severity of air trapping at dynamic expiratory CT in patients with tracheobronchomalacia

OBJECTIVE: The purpose of this study was to compare the frequency and severity of air trapping in patients with and without tracheobronchomalacia using dynamic expiratory volumetric CT. MATERIALS AND METHODS: The study group consisted of 20 subjects, including 10 patients with bronchoscopically proven tracheobronchomalacia and 10 control subjects of similar ages without tracheobronchomalacia. All 20 subjects underwent MDCT performed at the end of deep inspiration and during dynamic expiration. The images were analyzed at three lung levels, and the extent of air trapping was assessed visually using a 5-point scale. For each subject, a total air-trapping score was derived by summing the values for the three lung levels (possible range, 0-12). Statistical analysis was performed using the Mann-Whitney U test. RESULTS: In the tracheobronchomalacia group, 10 (100%) of 10 patients showed air trapping, with a median score of 5 (range, 2-12). In the control group, six (60%) of 10 subjects showed air trapping, with a median score of 2 (range, 0-3). The median total air-trapping score was significantly higher (p < 0.001) for the tracheobronchomalacia group compared with the control group. Excessive central airway collapse (expiratory reduction in cross-sectional area of > 50%) was seen on CT scans in all tracheobronchomalacia patients but in none of the control subjects. CONCLUSION: Air trapping was observed with a higher frequency and greater severity in patients with tracheobronchomalacia than in a control group of patients of similar ages without tracheobronchomalacia.     

Tracheobronchomalacia: comparison between end-expiratory and dynamic expiratory CT for evaluation of central airway collapse

PURPOSE: To compare dynamic expiratory and end-expiratory computed tomography (CT) for depicting central airway collapse in patients with acquired tracheobronchomalacia (TBM). MATERIALS AND METHODS: Institutional review board approval was obtained, and informed consent was not needed. Retrospective review was performed of all patients with a CT diagnosis of TBM in a 10-month period (n = 34) who underwent evaluation of airway disease by means of three different sequences at multi-detector row CT: end inspiration, dynamic expiration, and end expiration (the latter was performed only at the levels of the aortic arch, carina, and bronchus intermedius). Fourteen patients (11 men, three women; age range, 19-79 years) who had comparable images obtained with all three sequences at any of these three levels were included in the study. The degree of airway collapse was measured by two thoracic radiologists in consensus by calculating the percentage change in the area of the airway between inspiratory and expiratory scanning. Statistical analysis was performed by using the paired t test. RESULTS: Dynamic expiratory CT elicited a significantly greater degree of airway collapse than end-expiratory CT at all three levels (P < .005). The mean percentages of airway collapse at each of the three levels were as follows: aortic arch, 53.9% with dynamic expiration versus 35.7% with end expiration (P = .0046); carina, 53.6% with dynamic expiration versus 30.9% with end expiration (P < .0001); and bronchus intermedius, 57.5% with dynamic expiration versus 28.6% with end expiration (P = .0022). CONCLUSION: Dynamic expiratory CT elicits a significantly greater degree of airway collapse than standard end-expiratory CT in patients with TBM.     

Multislice helical CT of the central airways

Multislice helical CT has revolutionized the non-invasive evaluation of the central airways with CT. The quick speed of image acquisition afforded by MSCT improves the quality of end-inspiration images and has expanded the ability to assess the airway during dynamic exhalation. Furthermore, the improved quality of multiplanar and three-dimensional images provided by MSCT has ushered in an exciting era of alternative methods of viewing CT data that are more visually accessible and often more anatomically meaningful. At present, the author routinely obtains multiplanar reformation and three-dimensional images for assessment of a variety of central airway abnormalities, including airway stenoses and webs, complex airway diseases, extrinsic airway compression, tracheobronchomalacia, and poststent placement. Further advances in CT technology, data processing, and image display, and increased clinical experience with advanced imaging reconstruction methods, will likely further expand the role of multiplanar and three-dimensional reconstruction images in the assessment of a wide variety of central airways disorders in the near future.     

Multi-detector CT evaluation in patients suspected of tracheobronchomalacia: comparison of end-expiratory with dynamic expiratory volumetric acquisitions

Purpose

The aim of this study was to compare dynamic expiratory imaging and end-expiratory imaging using multi-detector CT (MDCT) of the central airways in patients suspected of tracheobronchomalacia (TBM).

Methods

This study had local ethical committee approval. Seventy patients suspected of TBM were prospectively included. All patients underwent evaluation of central airways by three different low-dose MDCT acquisitions: end inspiration, end expiration, and dynamic expiration. Degree of airway collapse was measured by calculating the percentage change in the area and diameter of the airways between inspiratory and the two expiratory techniques at three levels of the trachea and in the sagittal diameter of the right and left main bronchi. Three threshold levels of percentage reduction in diameter or area (30%, 50%, and 70%) for defining TBM were evaluated.

Results

In the entire population, the mean percentage of airway collapse was significantly greater with dynamic expiratory imaging than with the end-expiratory imaging at three different levels: lower thoracic trachea (26% vs. 16.6%, p < 0.009), right (25.2% vs. 14%, p < 0.01) and left main (24.7% vs. 13.3%, p < 0.01) bronchus. Whatever the threshold value for defining TBM, dynamic expiratory imaging always resulted in diagnosing TBM in more patients than end-expiratory imaging.

Conclusions

Dynamic expiratory imaging shows a significantly greater degree and a significantly greater extent of airway collapse than standard end-expiratory imaging in patients suspected of TBM. Further evaluation of the clinical relevance of such findings is warranted.     

Relapsing polychondritis: prevalence of expiratory CT airway abnormalities

PURPOSE: To retrospectively determine the prevalence of expiratory computed tomographic (CT) abnormalities, including malacia and air trapping, in patients with relapsing polychondritis and to retrospectively determine the frequency with which expiratory abnormalities are accompanied by inspiratory abnormalities on CT scans. MATERIALS AND METHODS: Institutional review board approval was obtained, and informed consent was not required for this retrospective HIPAA-compliant study. A computerized hospital information system was used to identify all patients with clinically diagnosed or biopsy-proved relapsing polychondritis who were referred for CT airway imaging during a 17-month period. The study cohort comprised 18 patients (15 women, three men; mean age, 47 years; age range, 20-71 years). Multidetector helical CT was performed in all patients by using a standard protocol, which included end-inspiratory and dynamic expiratory volumetric imaging. Two observers who were blinded to the original scan interpretations simultaneously reviewed CT scans. Findings were recorded in consensus. Dynamic expiratory CT scans were assessed for malacia that involved the trachea and main bronchi (reduction in cross-sectional area of more than 50%) and for air trapping (failure of lung parenchyma to increase in attenuation during expiration). Air trapping was visually classified according to pattern and extent (lobular, segmental, lobar, or whole lung). Inspiratory CT scans were evaluated for tracheal and bronchial stenosis (>25% luminal diameter narrowing compared with a corresponding uninvolved segment), wall thickening (>2 mm), and calcification. RESULTS: Expiratory CT abnormalities were present in 17 (94%) of 18 patients and included malacia in 13 patients (72%) and air trapping in 17 patients (94%). Inspiratory CT abnormalities were found in eight (47%) of 17 patients who had expiratory CT abnormalities. Calcification of the airway walls was present in seven (39%) of 18 patients. All patients who had inspiratory CT abnormalities demonstrated expiratory CT abnormalities. CONCLUSION: Expiratory CT abnormalities were present in the majority of patients with relapsing polychondritis who were referred for airway imaging, yet only half of these patients demonstrated abnormalities on routine inspiratory CT scans. Thus, dynamic expiratory CT should be a standard component of imaging assessment in patients with relapsing polychondritis.     

2003 AUR Memorial Award. Dynamic expiratory volumetric CT imaging of the central airways: comparison of standard-dose and low-dose techniques

RATIONALE AND OBJECTIVES: Investigators in this study compared standard-dose and low-dose inspiratory and expiratory computed tomographic (CT) images with regard to their usefulness for measuring the tracheal lumen in patients with or without tracheobronchomalacia (TBM). MATERIALS AND METHODS; Hospital records were reviewed to identify 10 consecutive patients with bronchoscopically proved TBM and 10 control subjects without TBM who underwent paired volumetric inspiratory and dynamic expiratory examinations with multisection CT. A low-dose (40-80 mA) technique was used for dynamic expiratory CT in 14 (70%) of the 20 subjects, and a standard dose (240-280 mA) was used in the remaining six (30%). All images were reviewed in a randomized, blinded fashion by two observers, who measured the tracheal lumen to determine the presence of TBM by consensus. The degree of confidence in measuring the tracheal lumen was graded on a four-point scale from 0(no confidence) to 3 (highest level of confidence), also by consensus of the two observers. Statistical analysis for differences in confidence level was performed with the Mann-Whitney U test. The image noise level was assessed by measuring the standard deviation of the presternal soft tissue, and statistical analysis for differences in noise level was performed with the t test. RESULTS: The level of confidence in tracheal lumen measurement was high, regardless of respiratory phase and dose (inspiratory mean, 2.9; median, 3; range, 2-3; expiratory low-dose mean, 2.6; median, 3; range, 2-3; expiratory standard-dose mean, 2.8; median, 3; range, 2-3). There was no significant difference in confidence level between standard- and low-dose techniques (P = .53). Excessive central airway collapse (expiratory reduction in cross-sectional diameter, > 50%) was seen in all 10 patients with TBM and in none of the control subjects. CONCLUSION: The acquisition of paired inspiratory and dynamic expiratory images with multisection helical CT is a promising method for diagnosing TBM. The low-dose technique performs as well as the standard-dose technique for the dynamic expiratory phase, with a similar degree of confidence for measuring the tracheal lumen.     

Tracheomalacia incidentally detected on CT pulmonary angiography of patients with suspected pulmonary embolism

OBJECTIVE: The aim of this study was to determine the frequency of tracheomalacia incidentally detected on CT pulmonary angiography in patients with suspected pulmonary embolism. MATERIALS AND METHODS: CT records of 163 consecutive patients imaged with CT pulmonary angiography for suspected pulmonary embolism were retrospectively reviewed at our institution. The patients underwent CT pulmonary angiography with three different types of CT scanners. All images were visually assessed by two thoracic radiologists for excessive collapse of the trachea and the main bronchi. The cross-sectional area of the lumen at the site of maximal collapse of the airway was measured, and the percentage of luminal narrowing was calculated by comparing it with the cross-sectional area of the airway lumen at an adjacent area without collapse. We defined tracheomalacia as a 50% or greater decrease in tracheal lumen. RESULTS: Sixteen (10%) of 163 patients showed evidence of tracheomalacia (seven men, nine women; age range, 41-95 years; mean age, 72 years). The most common presenting symptom was shortness of breath, which was observed in 13 (81%) of 16 patients. Known causes of tracheomalacia were found in 15 (94%) of 16 patients, prior intubation was confirmed in 12 patients, and history of asthma or chronic obstructive pulmonary disease was observed in five patients. CONCLUSION: Tracheomalacia is a relatively common incidental finding on CT pulmonary angiography studies. The central airways, as well as pulmonary vasculature, should be reviewed carefully for clinical interpretation in patients with suspected pulmonary embolism. Paired expiratory-inspiratory CT is recommended if patients present with known causes of tracheomalacia such as prior intubation, chronic obstructive pulmonary disease, or asthma.     

Ultrafast CT of laryngeal and tracheobronchial obstruction in symptomatic postoperative infants with esophageal atresia and tracheoesophageal fistula

We evaluated the role of ultrafast CT in the diagnosis and follow-up of nine consecutive, symptomatic infants with suspected laryngeal and tracheobronchial obstruction after surgery for esophageal atresia. With 80% or more area collapse as a criterion for the diagnosis of laryngomalacia and 50% or more for tracheomalacia, six patients had tracheomalacia, one had laryngomalacia, and two had both. Tracheomalacia was focal in four patients and diffuse, involving the thoracic trachea, in the other four. Associated bronchomalacia was present in two patients. The site and degree of abnormality were verified by endoscopy in five of nine patients. The degree of tracheal collapse did not always correlate with the size of the esophageal pouch or with the site of the tracheo-esophageal fistula. These findings support the concept that the larynx and/or tracheal walls are often abnormal in symptomatic infants with esophageal atresia, tracheoesophageal fistula, and airway obstruction. Ultrafast CT was a reliable technique for detecting and assessing the site, extent, severity, and dynamics of airway collapse in five of seven symptomatic infants with congenital tracheoesophageal anomalies when the imaging findings were compared with endoscopic findings and previously published normal standards.     

Tracheobronchomalacia: evolving role of dynamic multislice helical CT

Paired inspiratory and dynamic expiratory multislice CT imaging is a promising method for diagnosing TBM. A low-dose technique should be considered for the dynamic portion to reduce radiation exposure. Visual and quantitative analysis of the central airways provide a comprehensive assessment by allowing for the accurate diagnosis of TBM, determining its extent, assessing for predisposing conditions, and aiding selection of candidates for stent placement or tracheoplasty procedures. This technique can also be helpful for assessing response of airway dynamics following therapeutic intervention.     

Tracheobronchial anomalies and stenoses: detection with low-dose multidetector CT with virtual tracheobronchoscopy--comparison with flexible tracheobronchoscopy

PURPOSE: To prospectively assess the sensitivity and specificity of low-dose multidetector computed tomography (CT) with virtual tracheobronchoscopy (VT) for evaluation of suspected airway stenoses and/or abnormalities by using flexible tracheobronchoscopy (FT) as the reference standard. MATERIALS AND METHODS: The study was approved by the local ethics committee; parental consent was obtained. Forty-five patients with clinically and/or radiographically suspected tracheobronchial stenosis and/or anomaly underwent FT and contrast material-enhanced single-phase multidetector CT with VT. CT was performed with an age- and weight-adjusted low-dose protocol: 120 or 80 kV; 120 or 60 mA; collimation, 1.5 or 0.75 mm; gantry rotation, 0.5 second. Mean effective dose was calculated for all examinations. Postprocessing was performed with surface rendering of VT images and multiplanar reformations. CT images were analyzed in consensus by two radiologists who were blinded to FT results. Statistical analysis was performed with 2 x 2 contingency tables; 95% confidence intervals (CIs) were calculated with the Blyth-Still-Casella procedure. RESULTS: Mean patient age was 4.4 years (range, 2 months to 16 years; 53% male patients). Tracheobronchial narrowing and/or abnormality were depicted at FT in 38 of 45 patients. In 33 of 38 patients, multidetector CT with VT depicted a tracheobronchial narrowing and/or anomaly. In 10 of 38 patients, tracheobronchial stenosis was induced by vascular anomalies. Five patients with normal findings at multidetector CT with VT had tracheobronchomalacia with inspiratory airway stenosis at FT. Sensitivity and specificity of CT with VT were 86.8% (95% CI: 73.3%, 94.7%) and 85.7% (95% CI: 44.6%, 99.3%), respectively. Positive and negative predictive values were 97.1% (95% CI: 84.9%, 99.9%) and 54.5% (95% CI: 25.0%, 80.0%), respectively. Overall accuracy was 86.7% (95% CI: 74.3%, 94.0%). Mean effective dose was 1.1 mSv (range, 0.5-1.8 mSv). CONCLUSION: Multidetector CT with VT with a low-dose protocol had high sensitivity and specificity for depiction of tracheobronchial narrowings and/or anomalies. However, tracheal narrowing due to tracheobronchomalacia was difficult to diagnose at single-phase multidetector CT with VT.     

Defining normal upper airway motion in asymptomatic children during sleep by means of cine MR techniques

PURPOSE: To define normal upper airway motion in asymptomatic children during sleep by means of dynamic cine magnetic resonance (MR) techniques. MATERIALS AND METHODS: In children referred for MR of the brain who required sedation, a sagittal midline cine MR sequence was performed. Motion of the nasopharynx, oropharynx, and hypopharynx was characterized as static patent, dynamic patent, intermittent collapse, or static collapsed; maximal diameter and greatest change in size were calculated in millimeters. Mouth position (open or closed) was determined. Parameters were compared with age (t test) and mouth position (Fisher exact test). RESULTS: In the 148 subjects (mean age, 3.4 years), the nasopharynx showed dynamic motion in 53 (36%). The oropharynx was most commonly collapsed in 98 (66%) of the patients. The hypopharynx showed dynamic motion in 72 (49%) of the patients and was never collapsed. Vertical motion was present in 77 (52%) of the patients. The mouth was open in 96 (65%) of the patients. There was a statistically significant correlation between mouth position and dynamic motion in the oropharynx (P =.006) and in the nasopharynx (P <.006) but not in the hypopharynx (P =.655). CONCLUSION: Dynamic changes in diameter were often seen in the nasopharynx and in the hypopharynx of asymptomatic sleeping children. However, collapse of the hypopharynx was not normally encountered.     

Multidetector computed tomography of pediatric large airway diseases: state-of-the-art

Advances in multidetector computed tomography (MDCT) technology have given rise to improvements in the noninvasive and comprehensive assessment of the large airways in pediatric patients. Superb two-dimensional and three-dimensional reconstruction MDCT images have revolutionized the display of large airways and enhanced the ability to diagnose large airway diseases in children. The 320-MDCT scanner, which provides combined detailed anatomic and dynamic functional information assessment of the large airways, is promising for the assessment of dynamic large airway disease such as tracheobronchomalacia. This article discusses imaging techniques and clinical applications of MDCT for assessing large airway diseases in pediatric patients.     

Cholesterol granuloma of the petrous apex: MR and CT evaluation

We reviewed the clinical, CT, and MR findings in seven consecutive patients who had a total of nine cholesterol granulomas. Preoperative MR scans were available for five of the seven patients; two patients were studied with MR after treatment only (one had a recurrent lesion and the other was asymptomatic at the time of study). Preoperative CT scans were available for all patients, except one patient who was examined after developing a symptomatic recurrence. All lesions were detected by both imaging methods. Seven preoperative lesions (five patients) and one symptomatic recurrence (one patient) demonstrated increased signal intensity of both T1- and T2-weighted MR images. Three surgically drained lesions (three patients) showed a marked reduction in signal intensity on T1-weighted images. Pre- and postoperative lesions had different patterns of signal intensity on the chemical-shift images, which were obtained in two instances. The MR appearance of cholesterol granuloma differs from that of most other lesions that occur in the petrous apex. CT did not differentiate between pre- and postoperative lesions in all cases, while MR demonstrated a dramatic change on T1-weighted images and chemical-shift studies. Our findings indicate that MR is more specific than CT in suggesting the correct diagnosis of cholesterol granuloma and that MR appears to be the technique of choice in the follow-up of previously treated patients.     

Noninvasive evaluation of extra-/intracranial anastomoses by dynamic CT and Doppler sonography

In order to find a reliable noninvasive method of evaluating patency and function of extra-/intracranial arterial bypass, pre- and postoperative angiograms were compared with the results of pre- and postoperative dynamic computed tomographic (CT) scans and Doppler sonographic findings. Doppler sonography alone is a reliable method for determining patency and relative function of the anastomosis. Dynamic CT permits qualitative evaluation of cerebral perfusion and, by comparison of pre- and postoperative scans, assessment of the contribution of the extra-/intracranial bypass to the circulation of the affected hemisphere. Combined use of Doppler sonography and dynamic CT provides sufficient information about the postoperative status of cerebral perfusion to obviate the use of conventional angiography in routine cases.     

Cine CT demonstration of nonfixed upper airway obstruction

Cine CT, with its very rapid imaging capabilities, was used to evaluate eight adult patients suspected of nonfixed upper airway obstruction. A method was developed for such imaging, which provides 10 images at each of 12 contiguous levels, extending from the soft palate through the extrathoracic trachea. These give a dynamic view of the airway during at least one full respiratory cycle and take about 6 sec to obtain. Results were compared with similar studies in 10 normal volunteers. Seven of the patients showed intermittent obstruction on cine CT, while the eighth was judged normal. All results agreed with subsequent further investigations or confirmed clinical diagnoses. The pathology demonstrated included chondromalacia, laryngeal spasm, and polychondritis. Four patients were evaluated for sleep apnea. All showed dynamic abnormalities of the airway, although they were studied awake and asymptomatic, during normal quiet respiration. All were subsequently shown to have severe sleep apnea. We conclude that cine CT has the potential to provide information quickly and noninvasively on upper airway dynamics and has certain definite advantages over conventional studies.     

CT prognostic criteria of survival after malignant glioma surgery

The serial pre- and postoperative computed tomographic (CT) scans of 115 patients entered in the Cooperative Brain Tumor Study between 1975 and 1982 were analyzed in order to define CT prognostic criteria and to test the hypothesis that radical glioma surgery prolongs patient survival. The CT parameters of mass size, associated edema, and intensity of enhancement were quantitated on all scans. Clinical parameters evaluated included gender, age, length of survival, and useful (Karnofsky greater than 30) survival. Data analyses indicated postoperative residual tumor burden was inversely related to length of survival (p less than 0.01). Postoperative associated edema and intensity of image enhancement were also of prognostic value and showed an inverse relation to survival. Younger patients proved more likely than older patients to attain long-term survival. Residual tumor burden of less than 45 mm diameter on postoperative CT scans was associated with 70% chance of long-term survival. These findings support the radical surgical management of glioma.     

The role of computed tomography in the preoperative assessment and follow-up of oromandibular reconstruction with microvascular osteomyocutaneous free flaps

OBJECTIVE: To investigate the capacity of helical CT in the pre- and post-operative management of oromandibular reconstruction of patients with oropharyngeal carcinoma using microvascular composite free flaps. MATERIALS/METHODS: Thirty-four patients with oropharyngeal cancer were examined by helical CT and nine (six men and three women) submitted to oromandibular reconstruction. The osteomyocutaneous flaps used for reconstruction were taken from the iliac crest in six cases and from the fibula in three cases. All patients were examined by CT 1 - 4 days postoperatively and then at 6 monthly intervals. Double helical scans were performed in all cases, with slices of 2 - 3 mm for primary lesion studies and 5 mm for lymph node staging, pitch >/=1 and RI=1. Multiplanar (MPR) and 3D reconstructions were obtained from pre- and postoperative CT examinations. RESULTS: Preoperative CT showed massive bone infiltration in six of the nine surgical patients and marginal infiltration in three. These findings were confirmed histologically. There were no false negatives. The immediate postoperative examination showed correct flap positioning in eight of nine cases. The flap underwent ischemic necrosis in two cases; CT showed very early signs of bone ischemia in both. CT detected two cases of recurrence after about 1 year. CONCLUSIONS: Axial CT permitted adequate assessment of the extent of mandibular infiltration and detected early ischemic complications and distant recurrences. Integration with MPR and 3D reconstructions simplified the choice of flap type and size and enabled the postoperative assessment of correct flap positioning. This helped the surgeon plan subsequent rehabilitation with osseo-integrated implants.     

Renal imaging in long-term dialysis patients: a comparison of CT and sonography

Patients undergoing long-term dialysis are subject to cyst formation, hemorrhage, and neoplasia in their native kidneys. Detection of these complications with incremental dynamic CT and detection with sonography were compared prospectively in 41 patients (79 kidneys) who had been undergoing dialysis intermittently for 3 or more years. Acquired cystic kidney disease (five or more cysts per kidney) was identified in 59% of kidneys by use of CT and in 18% by use of sonography. CT showed a complete renal contour definition in all cases, sonography did so in only 57%. Three solid renal tumors (2- to 4-cm diameter) were identified with both techniques with no false-negative evaluations. Four benign hemorrhagic cysts were identified with combined CT (hyperdense mass) and sonography (benign cysts). CT provided the best anatomic image quality and was more accurate for detection of acquired cystic kidney disease. CT and sonography were equivalent for detection of solid tumors. Our results suggest that dynamic contrast-enhanced CT scanning with the supplemental use of sonography is the best imaging regimen for the evaluation of suspected acquired cystic kidney disease and its potential complications.     

Resective surgery for intractable epilepsy in children: radiologic evaluation.

Epilepsy surgery is gaining popularity for the treatment of children with intractable seizures in whom either a focal or extensive unilateral structural brain lesion is demonstrated. We evaluated the pre- and postoperative imaging findings in 29 patients (aged 22 days to 19 years) who underwent hemispherectomies, 12 total and 17 subtotal. Pathologic correlation was obtained in all cases. Preoperatively, positron emission tomography and electroencephalography demonstrated abnormalities in all of the 28 children studied, but frequently could not characterize the lesion. CT or MR or both demonstrated focal or unilateral lesions in only 19 of these but gave additional information regarding the nature of the lesion. Preoperative angiographic findings were abnormal in five of 17 patients studied and were particularly useful in the evaluation of the extent of abnormality in patients with Sturge-Weber syndrome. Postoperatively, CT and MR demonstrated early complications such as the development of epidural blood and fluid collections, parenchymal hemorrhage, infection, and early hydrocephalus. Postoperatively, MR demonstrated the early development of septations, the presence of subarachnoid hemorrhage, and/or the deposition of hemosiderin in four patients, findings that historically have been associated with the development of devastating clinical complications. From these data, a recommended protocol of radiologic evaluation for patients undergoing hemispherectomy has been established.