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(Chest. 2000;117:1697-1705.)
© 2000 American College of Chest Physicians

Efficacy of Chest CT in a Pediatric ICU*

A Prospective Study

Karen E. Thomas, FRCR; Catherine M. Owens, FRCR; Joseph Britto, MD; Simon Nadel, MRCP; Parviz Habibi, FRCP and Rosemary Nicholson, MSc

* From the Departments of Diagnostic Radiology (Drs. Thomas and Owens and Ms. Nicholson) and Pediatrics (Drs. Britto, Nadel, and Habibi), Imperial College School of Medicine at St. Mary’s Hospital, London, United Kingdom.

Correspondence to: Karen E. Thomas, FRCR, Department of Diagnostic Radiology, St. Mary’s Hospital, Paddington, London, England W2 1NY; e-mail: karenthomas5{at}yahoo.com


   Abstract
TOP
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 Conclusion
 References
 
Study objectives: (1) To determine whether chest CT provides additional information compared with chest radiography regarding the nature of intrathoracic disease in critically ill children, (2) to determine whether such information alters clinical management, (3) to assess the role of a low-dose high-resolution CT (HRCT) protocol in pediatric ICU (PICU) patients.

Design: Prospective study.

Setting: Specialized PICU in a teaching hospital serving London and the south of England.

Patients: Twenty children (age range, 3 weeks to 12 years; median, 11 months) underwent chest CT during a 33-month period. Inclusion criteria were (1) inconclusive diagnosis from chest radiograph (CXR) or (2) CXR appearances inconsistent with high oxygenation or ventilatory requirements (PaO2 to fraction of inspired oxygen ratio < 30 or mean airway pressure > 15 cm H2O).

Interventions: Low-dose HRCT scans (50 mA, 2-mm slice thickness at intervals of 10 or 15 mm) were performed on 12 patients, and helical CT (50 to 250 mA; pitch, 1 to 1.5) performed on 8 patients.

Measurements and results: CT provided additional information regarding the nature of intrathoracic disease in 17 of 20 patients (85%) and resulted in changes to subsequent clinical management in 12 of 20 patients (60%).

Conclusions: Chest CT can add to the accuracy of intrathoracic diagnosis provided by the CXR and may directly influence the acute management of critically ill children. The CT protocol should be tailored to the clinical and radiologic question posed for each individual patient. Noncontiguous HRCT can often provide accurate assessment of pulmonary parenchymal and pleural disease at a reduced radiation dose compared with helical CT.

Key Words: critical care • mechanical ventilation • pediatric ICU • radiation dosage • radiography • tomography, computed


   Introduction
TOP
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 Conclusion
 References
 
The chest radiograph (CXR) is the most frequent radiologic investigation performed on patients in an ICU.1 It is used to assess the position of support equipment, evaluate parenchymal infiltrates, atelectasis, effusions, and pneumothoraces, and to exclude iatrogenic complications after interventional procedures.2 The utility and efficacy of the portable CXR on the ICU have been extensively studied. It has a high diagnostic yield in both adult3 4 5 6 and pediatric7 8 patients, it is easily and rapidly available, and inexpensive, and the radiation dose is small. However, it also has well-recognized limitations. Between 6% and 37% of portable CXRs obtained on critically ill patients may be technically suboptimal9 owing to both patient and equipment factors. Recent advances such as digitization and phosphor plate technology10 11 have led to significant technical improvements, but interpretation can remain difficult and diagnosis equivocal or inconclusive.12 Particular problems occur in the detection of anteromedial or subpulmonic pneumothoraces, pleural effusions or empyemas (especially if loculated or subpulmonic), pulmonary cavitation, and abscess formation, and in the assessment of mediastinal disease.

Several studies have examined the role of chest CT in adult ICU patients13 14 15 16 17 18 and suggest that, in selected patients, contiguous slice chest CT can provide additional diagnostic information not available from CXR and may directly influence patient management. To our knowledge, there are no published data on the indications for and efficacy of chest CT in the pediatric ICU (PICU) population.

The potential advantages of chest CT must be balanced against the potential risks of transporting a critically ill patient to the CT scanner, the radiation dose, and the cost. There is concern regarding the radiation dose involved in chest CT,19 20 21 and this is especially pertinent in children. Dose reduction in contiguous or helical CT scanning may be achieved by reducing the tube current (milliamperes)22 23 or by increasing the pitch in helical scanning.24 High-resolution CT (HRCT) scanning provides an alternative method for dose reduction because of its noncontiguous nature and lower radiation dose to radiosensitive organs such as the breast. Lowering the tube current can provide further dose savings without significantly impairing diagnostic accuracy in adult25 26 27 and pediatric28 HRCT. The applications of HRCT in the investigation of diffuse lung disease and airways pathologies in adults are well established,29 and its use in pediatric practice is expanding.30 31 32 However, the role of HRCT in the ICU patient is largely unexplored.

The aims of our study were to assess whether CT can provide additional information compared with CXR regarding the nature of intrathoracic disease in critically ill children, to determine whether gaining such new information significantly alters subsequent clinical management, and, finally, to assess the role of a low-dose HRCT protocol in PICU patients.


   Materials and Methods
TOP
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 Conclusion
 References
 
Twenty children (13 boys, 7 girls; age range, 3 weeks to 12 years; median, 11 months) receiving intensive care were entered into the study prospectively during a period of 33 months. All children had suspected lung (parenchymal, airway, or pleural) or mediastinal disease with (1) inconclusive diagnosis from CXR or (2) CXR appearances inconsistent with high ventilatory requirements (PaO2 to fraction of inspired oxygen ratio < 30 and/or mean airway pressure > 15 cm H2O). Admission diagnoses are shown in Table 1 . Severity of illness was assessed by the pediatric risk of mortality score33 on the day of CT scanning (range, 1 to 18; median, 12). All patients were transferred to the CT scanner by a specialized mobile PICU team. Eighteen of 20 children were endotracheally intubated and received mechanical ventilation at the time of the CT scan, and were transferred to the CT scanner using a modified Drager Oxylog 2000 (Drager; Lubeck, Germany) or babyPAC (Pneumopac Ltd; Luton, England) transport ventilator. All were intubated for clinical reasons; in no case was intubation performed to facilitate scanning or improve image quality. Arterial blood gas measurements were recorded before and after transfer. A level of monitoring identical to that available in the PICU was maintained during transport and involved the continual monitoring of ECG, noninvasive BP, invasive BP, central venous pressure, core to peripheral temperature gap, oxygen saturation, respiratory rate, and end-tidal carbon dioxide. Three children met the study criteria but were receiving high-frequency oscillatory ventilation with respiratory status too unstable to justify transferring to conventional ventilation for transport to the CT scanner and were omitted from the study.


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  		Table 1.. Admission Diagnosis, CT Indication, CT Findings, and Management Outcome in 20 Patients*

 
All CT scans were performed on a Toshiba Xpress HS1 (Toshiba; Tokyo, Japan) CT scanner. The CT protocol was tailored to the clinical and radiologic question posed. When contiguous data were required, patients underwent helical scanning (50 to 250 mA; 120 kilovolts [peak]; slice thickness, 5 to 10 mm; pitch, 1 or 1.5; reconstructed on a soft tissue algorithm). In cases of suspected diffuse lung disease and for the investigation of potential pleural pathology, in which contiguous data are not essential for diagnosis, a low-dose HRCT protocol was performed (2 mm/10 or 15 mm, 50 mA, 130 kilovolts [peak], reconstructed on a bone algorithm). A field of view was used appropriate to the size of each child. Eight helical scans and 12 HRCT scans were performed. In one patient, a limited helical examination was undertaken after HRCT, and in another child, additional 2-mm slices were obtained through an area of interest after the routine HRCT protocol. Scans were obtained without the need to suspend mechanical ventilation. HRCT sections were timed to coincide with peak inspiration when possible. In one child with suspected bronchiolitis obliterans, HRCT sections were performed at end-expiration by means of coordination with manual-assisted ventilation.

CXR findings and diagnoses were documented before CT scanning. CT scans were reviewed by a specialized pediatric radiologist with a subspeciality interest in chest radiology and a pediatric radiologist-in-training. A consensus opinion was reached. Both CXR and CT were assessed for the presence and distribution of airspace shadowing, interstitial shadowing, lobar/segmental collapse, pneumothorax/pneumomediastinum, cystic airspace disease, pleural fluid, and any abnormality in cardiothymic contour. The positions of endotracheal tubes, central venous lines, and intercostal (IC) drains were recorded.

The CT scan was considered to have provided significant additional information not available from CXR alone if a new diagnosis was made or if a diagnosis suspected but not conclusive radiographically or clinically was confirmed or excluded. When CT provided superior anatomic information regarding the distribution of disease but no new diagnostic information, this was considered a negative result. Any changes in clinical management resulting directly from information derived from CT were assessed by the clinical team.

The study was approved by the St. Mary’s Local Research Ethics Committee, and informed consent obtained from parents or guardians of children undergoing CT scanning.


   Results
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 Conclusion
 References
 
In 17 of 20 children (85%), CT provided additional information regarding the nature of intrathoracic disease. In 10 of 17 children, this involved a further diagnosis, and in 7 of 17 children, the exclusion of a disease process suspected either radiographically or clinically.

In 9 of 20 children (45%), new information led to positive therapeutic interventions (n = 7) or longer term management decisions (n = 2). In 3 of 20 children (15%), inappropriate therapeutic maneuvers were avoided. Clinical management was unaltered by CT scanning in eight children (40%).

Transport of critically ill children to the CT scanner was achieved safely. Using the criteria of Kanter and Tompkins,34 transport was not associated with any morbidity in terms of physiologic deterioration or equipment-related adverse events. Indications for CT scanning, CT protocol, and results and interventions in individual patients are summarized in Table 1 . Two brief case histories are given below, followed by further examples to illustrate the impact of chest CT on clinical management.

Case 1
A 2-month-old girl presented with suspected viral bronchiolitis. She experienced a severe air leak after intubation and ventilation, resulting in several sequential pneumothoraces affecting both lungs. Despite the insertion of multiple IC chest drains, she remained unstable with persistently high ventilatory and oxygenation requirements. CXR (Fig 1 , top) demonstrated a septated cystic lesion at the right base, in addition to a residual right pneumothorax. HRCT (Fig 1 , bottom) was performed to differentiate between pleural and parenchymal location of the cystic lesion and to guide any further drainage attempts. A right lower lobe pulmonary parenchymal cyst, anterior right pneumothorax, and bilateral basal consolidation were demonstrated. Under CT guidance, both the cyst and pneumothorax were drained, resulting in a significant reduction in ventilatory requirements. The patient made a good recovery, and chest CT 6 months later showed no abnormality at the right base. The cause of the parenchymal cyst is presumed to be related to barotrauma.



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  		Figure 1.. Top: CXR in a 2-month-old girl with bronchiolitis and air leak demonstrating a persistent air collection at the right base despite the insertion of IC drains for recurrent pneumothoraces. Bottom: HRCT revealed a pulmonary parenchymal cyst in the right lower lobe, an anterior right pneumothorax, and bilateral basal consolidation. Cutaneous markers for CT-guided drainage are present. A significant reduction in ventilatory requirements occurred after drainage of the cyst and pneumothorax.

 
Case 4
A previously healthy 8-month-old boy initially presented with adenovirus bronchiolitis but developed chronic lung disease with repeated PICU admissions involving increasing ventilatory support and difficulties in extubation. At 13 months of age, CXR (Fig 2 , top) demonstrated overinflated lungs, collapse and consolidation of the right upper lobe with volume loss and dilated air-filled bronchi, bilateral lower lobe peribronchial thickening, and some linear shadows in the left lower zone. These findings, in association with the clinical features, were compatible with but not diagnostic of bronchiolitis obliterans. Expiratory HRCT (Fig 2 , middle and bottom) demonstrated mosaic attenuation caused by extensive air-trapping in association with bronchial wall thickening and dilatation, diagnostic of bronchiolitis obliterans. In both this patient and an additional child (patient 12), the provision of this definitive diagnosis contributed significantly to management and prognostic planning.



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  		Figure 2.. An 8-month-old boy presented with adenovirus bronchiolitis but progressed to chronic lung disease with repeated admissions to the PICU. CXR at 13 months of age (top) showed overinflation of the lungs, collapse and consolidation of the right upper lobe with volume loss and dilated air-filled bronchi, bilateral lower lobe peribronchial thickening, and some linear shadows in the left lower zone. Expiratory HRCT, shown at two levels (middle, bottom), demonstrated mosaic attenuation caused by extensive air-trapping in association with bronchial wall thickening and dilatation, diagnostic of bronchiolitis obliterans. Collapse of the right upper lobe around dilated bronchi was also confirmed.

 
Additional cases included two children with severe respiratory distress in whom both CXR and clinical setting were not typical of ARDS. HRCT showed classic dependent infiltrates (Fig 3 ) and resulted in the institution of prone positioning,35 with significant improvement in clinical status owing to alveolar recruitment. The percutaneous drainage of a tension pneumatocele in a 6-week-old girl with Staphylococcus aureus pneumonia was planned after CT. However, spontaneous decompression occurred, and after drainage of the resulting pneumothorax, the adjacent lung reinflated. In several cases, CT was useful in confirming or excluding the presence of pneumothoraces when confident diagnosis was difficult on plain radiograph alone (Fig 4 ).



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  		Figure 3.. Top: CXR on a 3-year-old boy with "nonaccidental trauma" and a possible history of aspiration during resuscitation showed bilateral airspace shadowing, which appeared to affect the upper zones predominantly. However, HRCT (bottom) demonstrated classic gravity-dependent bilateral consolidation with air bronchograms affecting all zones, consistent with ARDS. Prone positioning was instituted.

 


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  		Figure 4.. Top: A 5-year-old child sustained hepatic and splenic injuries after a fall from a five-story building. No definite abnormality was identified on supine CXR. Bottom: Helical CT demonstrated a right anterior pneumothorax. A small left pneumothorax was also present on more caudal slices. Drainage was performed before laparotomy.

 
In three patients, CXR suggested possible mediastinal masses or lymphadenopathy; contrast-enhanced helical scanning was undertaken, and in all three cases, mediastinal disease was excluded. In a 12-month-old child admitted with bacterial tracheitis and pneumonia, CXR showed extensive airspace shadowing and segmental collapse in the right middle and lower lobes with appearances suggestive of cavitation and a possible effusion or empyema. CT excluded pulmonary abscess formation, airway compression, and a significant pleural effusion. In an 8-month-old boy, CT documented the extent of a parapneumonic loculated empyema (diagnosed on CXR and ultrasound examination) and excluded an underlying lung abscess before surgical decortication.


   Discussion
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
Conclusion
 References
 
Critically ill patients on the ICU require rapid diagnostic procedures that are both sensitive and specific so that appropriate management decisions can be made promptly.17 In the majority of patients, sufficient information is provided by the CXR. However, portable supine radiographs may be technically inadequate because of patient factors such as poor inspiratory effort, motion artifact, variation in positioning, inability to sit erect to demonstrate air fluid levels, or limitations of portable radiographic equipment including variations in radiographic technique, shorter focus film distance, low-power equipment, and the production of a false silhouette sign mimicking lower lobe disease if the x-ray beam is not directly tangential to the diaphragm.36 Even with experience, the interpretation of portable CXRs for pneumothoraces, pleural collections, abscess formation, and mediastinal disease can be difficult.

The incidence of pneumothorax as a result of barotrauma patients receiving mechanical ventilation is 4 to 15%, and can be as high as 60% if underlying pneumonia or ARDS is present.37 The size of a pneumothorax occurring in a critically ill patient correlates poorly with its clinical significance,12 and all must be evaluated clinically for the need for treatment. Mechanical ventilation perpetuates an air leak, and many pneumothoraces will progress to tension pneumothoraces.37 Artifacts such as dressings, tubing, bags, and tracks of previous chest drains may both mimic and obscure genuine pneumothoraces. In the supine patient, the majority of pneumothoraces are anteromedial or subpulmonic in location,38 and a smaller number are posteromedial. Apicolateral air collections are relatively uncommon. In a study by Tocino et al,38 despite an awareness of this difference in distribution from the erect patient, 30% of pneumothoraces in supine critically ill patients were not detected initially by a clinician or radiologist, and half of these progressed to tension pneumothoraces. The transverse plane of CT is ideal for the demonstration of the air–lung interface of an anterior pneumothorax in a supine patient, and CT has proven invaluable in the detection of occult pneumothoraces in patients with head injury39 and abdominal trauma.40 Other manifestations of barotrauma, such as pneumomediastinum and pneumopericardium, are usually distinguishable from pneumothoraces on CXR, although confusion may occasionally arise. Central pneumatoceles (Fig 1) are a rare manifestation of air leak41 and should be considered in the differential diagnosis of a hyperlucency not typical of a pneumothorax. CT has an important role in detecting the presence of severe subcutaneous emphysema, which can both mimic and obscure parenchymal disease, pulmonary cavitation, and pneumothoraces on CXR.41

The radiographic signs of supine pleural effusions are well-described,42 yet Ruskin et al43 have demonstrated that the supine CXR is only moderately sensitive and specific for the detection of pleural fluid. It can be difficult to distinguish between an effusion and posterior basal atelectasis.15 Loculated and subpulmonic collections can cause difficulties, as can moderately large but symmetric effusions. A decubitus CXR can aid diagnosis, but a technically good film is often difficult to obtain in patients with unstable conditions. Ultrasound remains the first line for further investigation of pleural fluid collections, has the advantage of being rapidly available at the bedside,2 and provides information on internal septations. However, CT provides a superior modality in circumstances where ultrasound is not easily performed (for example, trauma patients with multiple dressings or open wounds) or when the presence of effusions is one of several diagnostic questions, in the presence of complex pleuroparenchymal disease, or to define the location and extent of loculated pleural collections.

Chest CT has proved particularly effective in documenting the nature of suppurative lung disease.14 44 45 The differentiation of empyema and pulmonary abscess is often problematic on CXR because of difficulty defining the pleuroparenchymal interfaces, especially if more than one pathologic process is present. CT can clearly differentiate between these disorders, often with important therapeutic implications.

The investigation of mediastinal disease is not commonly required in the ICU. However, the cross-sectional plane of CT provides excellent definition of mediastinal masses, abscesses, or hematoma. Contrast-enhanced helical CT plays a rapidly increasing role in the diagnosis of cardiovascular abnormalities such as pulmonary emboli46 and traumatic aortic injury.47

Several studies have examined the efficacy of chest CT in adult ICU patients,13 14 15 16 17 18 some of which have attempted to quantify the impact of CT on clinical management.13 16 18 In the largest studies, Mirvis et al14 found that chest CT provided significantly more diagnostic information than was available from CXR in 61 of 87 cases (70%), and Miller et al18 demonstrated new findings on CT in 84% of examinations, of which 32 of 108 CT scans (30%) were considered clinically important. Chest CT was judged to have significantly influenced subsequent management in 24 of 108 cases (22%),18 5 of 19 cases (26%),13 and 15 of 20 cases (75%),16 either by altering management strategy or indicating the need for maintenance of existing therapeutic maneuvers. These studies were all retrospective and involved adult patients scanned with conventional contiguous slice CT13 14 15 16 17 or helical CT.18 To our knowledge, ours is the first study to examine the efficacy of chest CT in PICU patients and the first to be performed prospectively. In addition, in view of the advances in the use of HRCT and the requirement to keep radiation dose as low as possible in children, we have tailored the CT protocol to the individual clinical and radiologic question and have introduced a low-dose HRCT protocol as part of our ICU chest CT scanning options.

Although our study size was relatively small and the age range diverse, our initial results demonstrated that chest CT has a high diagnostic yield in selected critically ill children, providing significant additional information in 17 of 20 patients (85%) and resulting in changes to subsequent clinical management in 12 of 20 children (60%). We believe that our high yield results from careful case selection and collaborative discussions between clinical and radiologic teams before making the decision for CT scanning. The numbers of children requiring chest CT are small (20 patients represents 2.5% of admissions to our specialist PICU during 33 months), and the indications for scanning in each individual should be carefully judged. In the majority of patients, CXR provides sufficient diagnostic information to guide clinical management, and although chest CT may provide superior anatomic definition of disease, it will not significantly effect management.

We have introduced the use of a low-dose HRCT protocol in PICU patients. In addition to providing information on pleural and parenchymal disease, its use in demonstrating bronchiolitis obliterans was an application not anticipated at the onset of the study. The radiation dose reduction of low-dose HRCT compared with helical CT is considerable. On our Toshiba Xpress scanner, the effective dose to a 1-year-old child undergoing helical CT at 150 mA is approximately 7.25 millisieverts (approximately equivalent to 145 CXRs) compared with 0.35 millisieverts (equivalent to seven CXRs) if an HRCT protocol (2 mm/15 mm) is performed at 50 mA. Further dose savings may be possible by limiting the number of high-resolution slices, as suggested by Lee et al.27 For example, the use of only five slices, spaced at intervals throughout the thorax, would not have significantly altered the interpretation of any of our HRCT scans. Helical CT scanning remains necessary in cases requiring continuous volume data, such as mediastinal disease, parenchymal abscess formation, airway compression, or pulmonary thromboembolic disease. The dose for helical CT can also be reduced by lowering the tube current 22 23 or increasing the pitch, with little or no significant loss in image quality, strategies well-described but, unfortunately, not yet in widespread use. During the period of our study, our policy has developed, and we now routinely perform pediatric helical CT with a tube current of 50 to 100 mA and, in many cases, an extended pitch of 1.5 or 2. Halving the current or increasing the pitch to 2 will each reduce the radiation dose by 50%.

In addition to providing diagnostic information, CT can aid therapeutic interventions. Image-guided insertion of IC drains for the treatment of pneumothoraces or pleural effusions, especially if loculated, is associated with a higher success rate and fewer complications than conventional tube placement. The work by Zuhdi et al48 also confirms that CT-guided percutaneous drainage of tension pneumatoceles, secondarily infected pneumatoceles, and lung abscesses can be safely and effectively performed in children, resulting in significant improvements in ventilatory status.

The intrahospital transfer of critically ill children to a diagnostic facility may be associated with transport-related morbidity, and these risks must be balanced against the potential benefits of CT scanning. However, the risks associated with both intra- and interhospital transfer can be minimized by the use of specialized mobile intensive care teams.49 50 51

The impact of chest CT on final clinical outcome is difficult to assess in the ICU population and remains unproved both in adult16 18 and pediatric patients. A randomized disease-, age-, and severity-controlled study will be necessary to investigate this further in the context of the multifactorial causes of morbidity and mortality in this patient group.


   Conclusion
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 Conclusion
References
 
This preliminary study suggests that chest CT can improve the accuracy of intrathoracic diagnosis provided by the CXR and directly influence the management of critically ill children. The appropriate selection of patients in whom chest CT will be beneficial is essential: in the majority of children, CXR provides adequate information, and chest CT is not required. Children most likely to benefit from chest CT include those in whom the radiographic findings fail to adequately explain the clinical course and oxygenation or ventilatory requirements, those in whom a specific diagnostic question is raised on CXR, and those in whom there is an unexplained failure of intrathoracic disease to respond to appropriate therapy. Further work with larger patient numbers will be required to refine the patient selection criteria used in this initial study. The decision to undertake CT scanning should be made after joint consultation among ICU physicians, radiologists, and the specialized transport team; the potential benefits of chest CT must outweigh the potential risks of transport and radiation dose. The CT protocol, helical or HRCT, should be tailored to the individual clinical and radiologic question. Noncontiguous low-dose HRCT can often provide accurate assessment of parenchymal and pleural disease at a significantly reduced radiation dose compared with helical CT.


   Footnotes
 
Abbreviations: CXR = chest radiograph; HRCT = high-resolution CT; IC = intercostal; PICU = pediatric ICU

Received for publication July 1, 1998. Accepted for publication December 28, 1999.


   References
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 Conclusion
 References
 

  1. Ofenfors, C (1978) Intensive care radiology: problems of interpretation. Radiol Clin North Am 16,407-439[ISI][Medline]
  2. Yu, C-J, Yang, P-C, Chang, D-B, et al (1992) Diagnostic and therapeutic use of chest sonography: value in critically ill patients. AJR Am J Roentgenol 159,695-701[Abstract/Free Full Text]
  3. Greenbaum, DM, Marschall, KE (1982) The value of routine daily chest x-rays in intubated patients in the medical intensive care unit. Crit Care Med 10,29-30[ISI][Medline]
  4. Bekemeyer, WB, Crapo, RO, Calhoon, S, et al (1985) Efficacy of chest radiography in a respiratory intensive care unit: a prospective study. Chest 88,691-696[Abstract/Free Full Text]
  5. Janower, ML, Jennas-Nocera, Z, Mukai, J (1984) Utility and efficacy of portable chest radiography. AJR Am J Roentgenol 142,265-267[Abstract/Free Full Text]
  6. Henschke, CI, Pasternak, GS, Schroeder, S, et al (1983) Bedside chest radiography: diagnostic efficacy. Radiology 149,23-26[Abstract/Free Full Text]
  7. Sivit, CJ, Taylor, GA, Hauser, GJ, et al (1989) Efficacy of chest radiography in pediatric intensive care. AJR Am J Roentgenol 152,575-577[Abstract/Free Full Text]
  8. Hauser, GJ, Pollack, MM, Sivit, CJ, et al (1989) Routine chest radiographs in pediatric intensive care: a prospective study. Pediatrics 83,465-470[Abstract/Free Full Text]
  9. Sherrier, RH, McAdams, HP (1986) Digital processing of portable films can reduce need for repeat studies. Diagn Imaging Clin Med 8,117-118
  10. MacMahon, H, Vyborny, C (1994) Technical advances in chest radiography. AJR Am J Roentgenol 163,1049-1059[Abstract/Free Full Text]
  11. Sagel, SS, Jost, RG, Glazer, HS, et al (1990) Digital mobile radiography. J Thorac Imaging 5,36-48[ISI][Medline]
  12. Henschke, CI, Yankelevitz, DF, Wand, A, et al (1996) Accuracy and efficacy of chest radiography in the intensive care unit. Radiol Clin North Am 34,21-31[ISI][Medline]
  13. Roddy, LH (1981) Thoracic computed tomography in the critically ill patient. Crit Care Med 9,515-518[ISI][Medline]
  14. Mirvis, SE, Tobin, KD, Kostrubiak, I, et al (1987) Thoracic CT in detecting occult disease in critically ill patients. AJR Am J Roentgenol 148,685-689[Abstract/Free Full Text]
  15. Peruzzi, W, Garner, W, Bools, J, et al (1988) Portable chest roentgenography and computed tomography in critically ill patients. Chest 93,722-726[Abstract]
  16. Golding, RP, Knape, P, Strack van Schijndel, RJM, et al (1988) Computed tomography as an adjunct to chest x-rays of intensive care patients. Crit Care Med 16,211-216[ISI][Medline]
  17. Snow, N, Bergin, KT, Horrigan, TP (1990) Thoracic CT scanning in critically ill patients. Chest 97,1467-1470[Abstract/Free Full Text]
  18. Miller, WT, Tino, G, Friendberg, JS (1998) Thoracic CT in the intensive care unit: assessment of clinical usefulness. Radiology 209,491-498[Abstract/Free Full Text]
  19. DiMarco, AF, Briones, B (1993) Is chest CT performed too often? [editorial]. Chest 103,985-986
  20. DiMarco, AF, Renston, JP (1994) In search of the appropriate use of chest computed tomography. Chest 106,332-333[Free Full Text]
  21. Nishizawa, K, Marajuma, T, Takayama, M, et al (1991) Determination of organ doses and effective dose equivalents from computed tomographic examinations. Br J Radiol 64,20-28[Abstract]
  22. Naidich, DP, Marshall, CH, Gribbin, C, et al (1990) Low dose CT of the lungs: preliminary observations. Radiology 175,729-731[Abstract/Free Full Text]
  23. Mayo, JR, Hartman, TE, Lee, KS, et al (1995) CT of the chest: minimal tube current required for good image quality with the least radiation dose. AJR Am J Roentgenol 164,603-607[Abstract/Free Full Text]
  24. White, KS (1996) Helical/spiral CT scanning: a pediatric radiology perspective. Pediatr Radiol 26,5-14[CrossRef][ISI][Medline]
  25. Zwirewich, CV, Mayo, JR, Muller, NL (1991) Low dose high resolution CT of lung parenchyma. Radiology 180,413-417[Abstract/Free Full Text]
  26. Mayo, JR, Jackson, SA, Muller, NL (1993) High resolution CT of the chest: radiation dose. AJR Am J Roentgenol 160,479-481[Abstract/Free Full Text]
  27. Lee, KS, Primack, SL, Staples, CA, et al (1994) Chronic infiltrative lung disease: comparison of diagnostic accuracies of radiography and low conventional dose thin-section CT. Radiology 191,669-673[Abstract/Free Full Text]
  28. Ambrosino, MM, Genieser, NB, Roche, KJ, et al (1994) Feasibility of high-resolution, low-dose CT in evaluating the pediatric chest. Pediatr Radiol 24,6-10[CrossRef][ISI][Medline]
  29. Webb, WR, Muller, NL, Naidich, DP (1996) High resolution CT of the lung 2nd ed. Lippincott-Raven Philadelphia, PA.
  30. Lynch, DA, Brasch, RC, Hardy, KA, et al (1990) Pediatric pulmonary disease: assessment with high resolution ultrafast CT. Radiology 176,243-248[Abstract/Free Full Text]
  31. Kuhn, JP (1993) High resolution computed tomography of pediatric pulmonary parenchymal disorders. Radiol Clin North Am 31,533-551[ISI][Medline]
  32. Seely, JM, Effman, E, Muller, N (1997) High resolution CT of pediatric lung disease: imaging findings. AJR Am J Roentgenol 168,1269-1275[Abstract/Free Full Text]
  33. Pollack, MM, Ruttiman, UE, Getson, R (1988) Pediatric risk of mortality (PRISM) score. Crit Care Med 16,1110-1116[ISI][Medline]
  34. Kanter, RK, Tompkins, JM (1989) Adverse events during interhospital transport: physiological deterioration associated with pretransport severity of illness. Pediatrics 84,43-48[Abstract/Free Full Text]
  35. Pelosi, P, Crotti, S, Brazzi, L, et al (1996) Computed tomography in adult respiratory distress syndrome: what has it taught us? Eur Respir J 9,1055-1062[Abstract]
  36. Zylak, CJ, Littleton, JT, Durizch, ML (1988) Illusory consolidation of the left lower lobe: a pitfall of portable radiography. Radiology 167,653-655[Abstract/Free Full Text]
  37. Tocino, I, Westcott, JL (1996) Barotrauma. Radiol Clin North Am 34,59-81[ISI][Medline]
  38. Tocino, I, Miller, MH, Fairfax, WR (1985) Distribution of pneumothorax in the supine and semirecumbent critically ill adult. AJR Am J Roentgenol 144,901-905[Abstract/Free Full Text]
  39. Tocino, I, Miller, MH, Frederick, PR, et al (1984) CT detection of occult pneumothorax in head trauma. AJR Am J Roentgenol 143,987-990[Abstract/Free Full Text]
  40. Wall, S, Federle, M, Jeffrey, R, et al (1983) CT diagnosis of unsuspected pneumothorax after blunt abdominal trauma. AJR Am J Roentgenol 141,919-921[Abstract/Free Full Text]
  41. Tocino, I (1992) Abnormal air and pleural fluid collections. Goodman, LR Putman, CE eds. Critical care radiology ,137-160 WB Saunders Philadelphia, PA.
  42. Weiner, MD, Garay, SM, Leitman, BS, et al (1991) Imaging of the intensive care patient. Clin Chest Med 12,169-198[ISI][Medline]
  43. Ruskin, JA, Gurney, JW, Thorson, MK, et al (1987) Detection of pleural effusions on supine chest radiographs. AJR Am J Roentgenol 148,681-683[Abstract/Free Full Text]
  44. Pugatch, RD, Faling, LJ, Robbins, AH, et al (1978) Differentiation of pleural and pulmonary lesions using computed tomography. J Comput Assist Tomogr 2,601-606[ISI][Medline]
  45. Stark, DD, Federle, MP, Goodman, PC, et al (1983) Differentiating lung abscess and empyema; radiography and computed tomography. AJR Am J Roentgenol 141,163-167[Abstract/Free Full Text]
  46. Remy-Jardin, M, Remy, J, Deschildre, F, et al (1996) Diagnosis of pulmonary embolism with spiral CT: comparison with pulmonary angiography and scintigraphy. Radiology 200,699-706[Abstract/Free Full Text]
  47. Gavant, ML, Menke, PG, Fabian, T, et al (1995) Blunt traumatic aortic injury: detection with helical CT of the chest. Radiology 197,125-133[Abstract/Free Full Text]
  48. Zuhdi, MK, Spear, RM, Worthen, M, et al (1996) Percutaneous catheter drainage of tension pneumatocele, secondarily infected pneumatocele and lung abscess in children. Crit Care Med 24,330-333[CrossRef][ISI][Medline]
  49. Insel, J, Weissman, C, Kemper, M, et al (1986) Cardiovascular changes during transport of critically ill and post-operative patients. Crit Care Med 14,539-542[ISI][Medline]
  50. Ehrenwerth, J, Sorbo, S, Hackel, A (1986) Transport of critically ill adults. Crit Care Med 14,543-547[ISI][Medline]
  51. Britto, J, Nadel, S, Maconochie, I, et al (1995) Morbidity and severity of illness during interhospital transfer: impact of a specialised paediatric retrieval team. BMJ 311,836-839[Abstract/Free Full Text]



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J. M. Boone, E. M. Geraghty, J. A. Seibert, and S. L. Wootton-Gorges
Dose Reduction in Pediatric CT: A Rational Approach
Radiology, August 1, 2003; 228(2): 352 - 360.
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