Multidetector Computed Tomography In Evaluation Research Articles

Steal from Skeletonized Internal Thoracic Artery Graft during Hemodialysis after Coronary Artery Bypass Grafting

We used transthoracic Doppler echocardiography to evaluate the potential for flow variation in a skeletonized internal thoracic artery (ITA) graftc ipsilateral to an upper-extremity arteriovenous fistula during postoperative hemodialysis. Between October 2008 and May 2009, 7 patients in chronic hemodialysis underwent coronary artery bypass grafting. We selected 5 of these patients according to the following inclusion criteria: patients who were undergoing chronic hemodialysis via a left upper-extremity arteriovenous fistula and in whom the skeletonized left ITA was anastomosed to the left anterior descending artery as an in situ graft; the right ITA was not used as a graft; postoperative multidetector computed tomography evaluation of the coronary artery demonstrated patency of the left ITA. The following parameters were calculated at baseline, after the dialysis pump was on, before the pump was turned off, and after the pump was off: peak systolic velocity, end-diastolic velocity, time-averaged mean velocity, pulsatility index, and ITA diameter. Flow was calculated with the following formula: Flow = Time-Averaged Mean Velocity x (Half the Diameter of the ITA)2 x 60 x pi. When the hemodialysis pump was started, there was a significant reduction in the flow of the left ITA (P = .01), whereas there was no variation in the flow of the right ITA (P = .54). During dialysis, no patients experienced hypotension, arrhythmia, or angina. Just after the end of dialysis, the left ITA flow significantly increased (P = .01). Flow reduction of the ITA graft ipsilateral to an upper-extremity arteriovenous fistula develops during postoperative hemodialysis, even when the skeletonization technique is used.

Imaging of early pancreatic cancer on multidetector row helical computed tomography

Early pancreatic cancer is small and limited to the pancreas. In contrast, small pancreatic cancer may include peripancreatic vasculature or metastasis involvement. This study evaluates images of early pancreatic cancer on multidetector CT (MDCT) using contrast-enhanced multiphasic imaging, and post-processed pancreatic duct images. CT findings and pathological features were analysed in eight patients with early pancreatic cancer. Pathological evaluation included location, size and histological grading of the tumour. MDCT evaluation covered the maximum diameter of the main pancreatic duct (MPD), stenosis or obstruction of the MPD, loss of normal lobar texture and associated pancreatitis. Attenuation differences between normal pancreatic parenchyma and the tumour (AD-PT) were also measured. Focal stenosis or obstruction of the MPD with dilatation of the distal MPD was demonstrated in all patients. Associated pancreatitis occurred in six patients with tumours measuring 12 mm or greater. Loss of normal lobar texture was recognised in four cases with the tumour measuring 14 mm or greater. Statistically, low-attenuated lesions and high-attenuated lesions differed with respect to the tumour size (p<0.01), and a positive relationship was demonstrated between the tumour size and AD-PT (r = 0.84). In seven cases, AD-PT is higher during the arterial phase than the pancreatic phase. Early pancreatic cancer appears as low attenuation on early phase, and as high- to iso-attenuation during the pancreatic and delayed phases in respect to the tumour size. Focal stenosis or obstruction of the MPD with dilatation of the distal MPD observed on curved reformation imaging seems important in the diagnosis of early pancreatic cancer.

Multidetector computed tomography evaluation of secondary hepatopulmonary fusion in a neonate

Hepatopulmonary fusion is a rare condition in which a dense adhesion occurs between the right lung and herniated hepatic parenchyma in patients with right-sided congenital diaphragmatic hernia. Plain radiographic and magnetic resonance imaging (MRI) findings of hepatopulmonary fusion in a neonate have been reported in a retrospective study with a small patient population and a case report. However, to our knowledge, there is no report regarding the secondary hepatopulmonary fusion (after right-sided congenital diaphragmatic hernia repair) evaluated with multidetector computed tomography (MDCT) in a neonate. We report a case of secondary hepatopulmonary fusion in a neonate, in which multiplanar and three-dimensional (3D) images were helpful in delineating the precise anatomy for preoperative evaluation. Understanding the diagnostic limitations of plain radiographs and MRI, the use of MDCT with its multiplanar and 3D imaging may emerge as a useful noninvasive imaging modality in the evaluation of possible hepatopulmonary fusion in pediatric patients with right-sided congenital diaphragmatic hernia.

64-slice multidetector computed tomography evaluation of gastrointestinal tract perforation site: detectability of direct findings in upper and lower GI tract

To evaluate wall discontinuity, as observed using 64-slice multidetector-row computed tomography (64-MDCT), as a direct finding (DF) indicating the perforation site in patients with gastrointestinal (GI) tract perforations. We retrospectively studied 41 consecutive patients presenting with acute abdomen and exhibiting extraluminal air (EA) on 64-MDCT. Three readers evaluated the distribution of EA, extraluminal faeces, dirty mass, dirty fat sign, extraluminal fluid collection and bowel wall thickening (i.e. conventional findings, CFs) as well as DFs. Twenty-two cases were surgically or endoscopically confirmed to have upper GI tract perforations, and 19 had lower GI tract perforations. The DFs correctly identified the sites of perforation in 80.5% of patients when 2-mm-thick imaging slices were used. For the detection of upper GI tract perforations, the sensitivity, specificity and accuracy were 95.5%, 94.7% and 95.1% for the DFs and 50.0%, 100% and 73.2% for the CFs, respectively. Significant differences in sensitivity (p < 0.001) and diagnostic accuracy (p < 0.05) were observed between the DFs and CFs for upper GI perforations but not for lower GI tract perforations. DFs of the perforation site by using 64-MDCT were more sensitive and accurate than CFs for the detection of upper GI tract perforations.

Interobserver agreement in the interpretation of computed tomography in acute pulmonary embolism

Multidetector computed tomography (MDCT) is one of the best diagnostic tools for the diagnosis of pulmonary embolism (PE). However, differences in MDCT interpretation, depending on the operator personal expertise, is an important factor that could interfere with the right diagnosis and, consequently, with the more adequate and well-timed therapy. The aim of the present study was to evaluate the interobserver agreement in the interpretation of MDCT for the diagnosis of acute PE. On a blind basis, 4 radiologists with different expertise in CT interpretation evaluated 46 different MDCT executed for acute PE. They had to verify the presence or absence of PE and, in the positive case, localize (right-left) and quantify (massive, segmentarian or subsegmentarian) it. The interobserver concordance was expressed using the Cohen K statistic. The mean concordance between the 4 operators was high (0.82; range, 0.68-0.95). Ruling out the massive PE cases, the mean concordance over the other cases was only moderate (0.47; range, 0.16-0.84). We found a very good interobserver agreement in MDCT evaluation for the diagnosis of massive PE, whereas we observed a lower concordance in regard to segmentarian and subsegmentarian PE. In the case of negative or nonmassive PE diagnosis, a second evaluation of the CT performed by an expert CT radiologist would probably be effective to decrease the CT evaluation error.

Added Value of Multiplanar Reformation in the Multidetector CT Evaluation of the Female Pelvis: A Pictorial Review

Although computed tomography (CT) is generally not the first-line imaging test of choice for the evaluation of female pelvic disorders, it is often the initial diagnostic examination performed in the emergency setting in patients who present with abdominal pain and nonspecific clinical symptoms. Multidetector CT coupled with reconstruction software permits isotropic voxel acquisition that can be used to generate two-dimensional multiplanar reformatted (MPR) images for evaluation of the female pelvis with no additional radiation exposure. Multidetector CT with MPR allows improved visualization of the normal anatomy and anatomic variants as well as greater diagnostic accuracy in the evaluation of the female pelvis. Although ultrasonography and magnetic resonance imaging remain the primary imaging modalities for the assessment of most female pelvic disorders, more accurate diagnosis of these disorders at multidetector CT may obviate additional imaging tests and allow more appropriate management.

MDCT evaluation of injuries after tram accidents in pedestrians

Multidetector computed tomography (MDCT) is especially suited for emergency diagnostics in multiple trauma patients. The objectives of this study were to investigate the types and frequencies of injuries associated with tram accidents in pedestrians. Eighteen consecutive pedestrian patients with multiple traumas after tram accidents were evaluated with MDCT in our Level I Trauma Center. The mean age in our patient cohort was 36.9 years with a range from 14-92 years. There was a trend for accident events occurring more commonly during the winter months in middle-aged men, often under the influence of alcohol. Patients were divided into two groups with unilateral or complex injury patterns. In both groups, leading diagnoses were head (83.3%) and thorax injuries (66.6%). Abdominal injuries (44.4%) were less common and mainly found in the complex injuries group. The most serious injuries occurred in the complex injuries group when the victim was caught under or between tramcars. A wide range of injuries is associated with tram accidents in pedestrians, which can be classified into two main injury patterns, unilateral and complex. The life-limiting injuries in this setting involved the head with a mortality rate of 22.2% (four patients) in our cohort.

Multidetector CT evaluation of total anomalous pulmonary venous connections: comparison with echocardiography

Although echocardiography is the first-line imaging modality in the diagnosis of total anomalous pulmonary venous connection (TAPVC), multidetector CT (MDCT) could have advantages in the diagnosis of TAPVC in certain cases. To compare MDCT with echocardiography in the evaluation of TAPVC. Enrolled in the study were 23 patients with surgically proven TAPVC. The echocardiography and MDCT findings were independently interpreted by a paediatric cardiologist and cardiac radiologist in terms of: (1) the drainage site of the common pulmonary vein, (2) stenosis of the vertical vein, and (3) the course of the atypical vessel into the systemic vein in the case of vertical vein stenosis. The findings from both modalities were correlated with the results obtained at surgery (n=22) or autopsy (n=1). In all patients, MDCT correctly depicted the drainage site of the common pulmonary vein, stenosis of the vertical vein and the course of the atypical vessel into the systemic vein (sensitivity 100%, specificity 100%). The specificity of echocardiography was 100% for the three defined findings. The sensitivity of echocardiography, however, was 87%, 71% and 0%, respectively. MDCT can facilitate the diagnosis of TAPVC in certain cases.

Multidetector CT Evaluation of Abdominal Wall for Breast Reconstruction: Take a Look at the Veins

HomeRadiologyVol. 251, No. 3 PreviousNext CommunicationsLetters to the EditorMultidetector CT Evaluation of Abdominal Wall for Breast Reconstruction: Take a Look at the VeinsAlessandro Cina, Liliana Barone-Adesi, Marzia Salgarello, Lorenzo BonomoAlessandro Cina, Liliana Barone-Adesi, Marzia Salgarello, Lorenzo BonomoAuthor AffiliationsDepartment of Bioimaging and Radiological Sciences, Catholic University of the Sacred Heart, Agostino Gemelli Hospital, 1 A. Gemelli, 00168, Rome, Italy e-mail: [email protected]Alessandro CinaLiliana Barone-AdesiMarzia SalgarelloLorenzo BonomoPublished Online:Jun 1 2009https://doi.org/10.1148/radiol.2513090009MoreSectionsFull textPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In References1 Phillips TJ, Stella DL, Rozen WM, Ashton M, Taylor GI. Abdominal wall CT angiography: a detailed account of a newly established preoperative imaging technique. Radiology 2008; 249(1): 32–44. Link, Google Scholar2 Blondeel PN, Arnstein M, Verstraete K, et al. Venous congestion and blood flow in free transverse rectus abdominus myocutaneous and deep inferior epigastric perforator flap. Plast Reconstr Surg 2000; 106(6): 1295–1299. Crossref, Medline, Google Scholar3 Schaverien M, Saint-Cyr M, Arbique G, Brown SA. Arterial and venous anatomies of the deep inferior epigastric perforator and superficial inferior epigastric artery flaps. Plast Reconstr Surg 2008; 121(6): 1909–1919. Crossref, Medline, Google Scholar4 Cina A, Barone-Adesi L, Salgarello M, Bonomo L. Perspective evaluation of multidetector CT vs color Doppler US for planning breast reconstructive surgery with deep inferior epigastric artery perforators [abstr]. In: Radiological Society of North America scientific assembly and annual meeting program. Oak Brook, Ill: Radiological Society of North America, 2008; 321. Google ScholarArticle HistoryPublished in print: 2009 FiguresReferencesRelatedDetailsCited ByJournal of Oral and Maxillofacial Surgery, Vol. 72, No. 1Recommended Articles Venous Anatomy and Collateral Pathways of the Pelvis: An Angiographic ReviewRadioGraphics2022Volume: 42Issue: 5pp. 1532-1545Imaging Findings in Transgender Patients after Gender-affirming SurgeryRadioGraphics2019Volume: 39Issue: 5pp. 1368-1392Vascularized Lymph Node Transfer: A Primer for the RadiologistRadioGraphics2020Volume: 40Issue: 4pp. 1073-1089Imaging of Abdominal Wall Masses, Masslike Lesions, and Diffuse ProcessesRadioGraphics2020Volume: 40Issue: 3pp. 684-706Varicose Veins of the Lower Extremity: Doppler US Evaluation Protocols, Patterns, and PitfallsRadioGraphics2022Volume: 42Issue: 7pp. 2184-2200See More RSNA Education Exhibits Preoperative Perforator Flap Mapping for Autologous Breast ReconstructionDigital Posters2018Ultra-High Frequency Ultrasound Doppler as a Roadmap for Preoperative Evaluation of Perforator FlapsDigital Posters2020Surgical Reconstruction in Head and Neck: A Pictorial ReviewDigital Posters2019 RSNA Case Collection Scar endometriosisRSNA Case Collection2020Inferior epigastric artery pseudoaneurysmRSNA Case Collection2021Arterioportal fistulaRSNA Case Collection2021 Vol. 251, No. 3 Metrics Altmetric Score PDF download

ECG-gated multidetector computed tomography for the assessment of the postoperative ascending aorta

This study was undertaken to define the role of electrocardiographically (ECG)-gated multidetector computed tomography (MDCT) in the assessment of the postoperative ascending aorta. From November 2006 to June 2007, 21 patients, [11 men, ten women; age +/- standard deviation (SD): 62.7+/-10.8 years] with a history of ascending aorta replacement underwent ECG-gated MDCT and were prospectively included in our study. Ascending aorta replacement had been performed with different surgical techniques: Bentall-De Bono (four patients, 19%), Tirone-David (five patients, 23%), and modified Tirone-David with creation of aortic neosinuses (12 patients, 57%). Two patients were excluded from MDCT evaluation because they failed to fulfil the inclusion criteria. Transthoracic echocardiography was used as the reference standard. All patients provided informed consent. In all patients, ECG-gated MDCT provided a clear depiction of the aortic annulus, aortic root and ascending aorta, enabling accurate measurements in all cases. The aortic valve area (3.4+/-0.2 cm(2)), the diameter of the sinotubular junction (31.6+/-1.8 mm), the diameter of the neosinuses in the case of modified Tirone-David procedures (37.3+/-2.1 mm) and the distance between the cusps and the graft wall during systole (3.1+/-0.7 mm) fell within standard ranges and showed a good correlation (r=0.89) with the values obtained with transthoracic echocardiography. MDCT is currently considered a compulsory diagnostic step in patients with suspected or known aortic pathology. MDCT is a reliable technique for anatomical and functional assessment of the postoperative aortic root and provides cardiac surgeons with new and detailed information, enabling them to formulate a prognostic opinion regarding the outcome of the surgical procedure.

MDCT evaluation of pulmonary embolism in children and young adults following a lateral tunnel Fontan procedure: optimizing contrast-enhancement techniques

Pulmonary embolism (PE) is a life-threatening thromboembolic complication in patients who have undergone a Fontan procedure for augmenting pulmonary blood flow in the setting of single-ventricle physiology. In patients following a Fontan procedure, lack of proper contrast agent mixing in the right atrium and sluggish, low-velocity blood flow within the Fontan circulation often results in suboptimal contrast enhancement within the pulmonary artery for evaluating PE. Unfortunately, there is a paucity of information describing the optimal contrast-enhancement technique with multidetector CT (MDCT) for evaluating PE in children and young adults following a Fontan procedure. We illustrate the MDCT imaging findings of suboptimal contrast enhancement within the pulmonary artery, which can be mistaken for PE, in patients following a lateral Fontan procedure, and we discuss MDCT techniques to optimize contrast enhancement within the pulmonary artery in these patients for evaluating PE. The MDCT imaging findings in pediatric and young adult patients following a lateral Fontan procedure and with clinically suspected PE are illustrated. We describe intravenous contrast agent injection techniques that can be used to optimize the contrast enhancement in the pulmonary artery in patients following a lateral Fontan procedure. The use of a suboptimal contrast-enhancement technique led to initial misdiagnosis and incomplete evaluation of PE in the three patients following a lateral Fontan procedure. Imaging in two patients showed that optimal evaluation of thrombosis in the Fontan pathway and PE in the pulmonary arteries can be successfully achieved with simultaneous upper- and lower-limb injections of contrast agent. This series demonstrates that suboptimal contrast enhancement can result in misdiagnosis or incomplete evaluation of PE in children and young adults following a lateral Fontan procedure. Careful attention to optimizing contrast enhancement during MDCT examination for evaluation of PE in these patients is essential to prevent misdiagnosis and incomplete evaluation.

Combined Assessment of Coronary Anatomy and Myocardial Perfusion Using Multidetector Computed Tomography for the Evaluation of Coronary Artery Disease

Multidetector computed tomography (MDCT) is increasingly used as an alternative to invasive coronary angiography. Although computed tomographic coronary angiography (CTCA) has been validated against invasive coronary angiography and nuclear myocardial perfusion imaging, the potential of MDCT to evaluate perfusion has not been fully explored. We sought to (1) develop a new technique for quantitative assessment of myocardial enhancement based on analysis of MDCT images acquired for CTCA, (2) identify the underlying causes of myocardial hypoenhancement detected by MDCT, and (3) determine the added diagnostic value of the MDCT perfusion index when combined with CTCA. We studied 84 patients undergoing clinical CTCA (64 patients with invasive coronary angiogram and a control group of 20 patients). MDCT perfusion index was calculated from x-ray attenuation measured in 16 myocardial segments. Hypoenhancement was automatically detected using comparisons with the normal range obtained in the control group, and its added value was determined against invasive coronary angiographic findings combined with known previous myocardial infarction. Myocardial hypoenhancement was detected in 29 of 64 patients in 47 vascular territories, of which 36 (77%) were abnormal by the reference technique. Of these 36 abnormalities, 10 (28%) were associated with previous myocardial infarction, whereas 26 (72%) corresponded to significant coronary stenosis. The addition of MDCT perfusion index to CTCA improved its diagnostic accuracy (sensitivity 0.87 to 0.96, accuracy 0.84 to 0.88, despite a decrease in specificity 0.79 to 0.68). In conclusion, myocardial hypoenhancement is a potentially valuable addition to MDCT evaluation of coronary artery disease without additional cost in radiation dose or contrast load.

Value of multidetector computed tomography evaluation of myocardial perfusion in the assessment of ischemic heart disease: comparison with nuclear perfusion imaging

MDCT-derived myocardial perfusion has not yet been validated against accepted standards. We developed a technique for quantification of myocardial perfusion from MDCT images and studied its diagnostic value against SPECT myocardial perfusion imaging (MPI). Ninety-eight patients were studied. Abnormal perfusion was detected by comparing normalized segmental x-ray attenuation against values obtained in 20 control subjects. Disagreement with resting MPI was investigated in relationship to MDCT image quality, severity of MPI abnormalities, and stress MPI findings. Resting MPI detected mild or worse abnormalities in 20/78 patients. MDCT detected abnormalities in 15/20 patients (sensitivity of 0.75). Most abnormalities missed by MDCT analysis were graded as mild on MPI. Additional abnormalities found in 16/78 patients were not confirmed on resting MPI (specificity of 0.72). However, 8 of these 16 apparently false positive MDCT perfusion tests had abnormal stress MPI; of these 8 patients, 7 had optimal MDCT image quality, while in 6/8 remaining patients, image quality was suboptimal. When compared with resting MPI, MDCT detected perfusion abnormalities with high accuracy. Moreover, half of MDCT perfusion abnormalities not confirmed by resting MPI were associated with abnormal stress MPI. Importantly, this information can be obtained without additional radiation dose or contrast agent.

An Evaluation of Multidetector Computed Tomography in Detecting Pancreatic Injury: Results of a Multicenter AAST Study

Efforts to determine the suitability of low-grade pancreatic injuries for nonoperative management have been hindered by the inaccuracy of older computed tomography (CT) technology for detecting pancreatic injury (PI). This retrospective, multicenter American Association for the Surgery of Trauma-sponsored trial examined the sensitivity of newer 16- and 64-multidetector CT (MDCT) for detecting PI, and sensitivity/specificity for the identification of pancreatic ductal injury (PDI). Patients who received a preoperative 16- or 64-MDCT followed by laparotomy with a documented PI were enrolled. Preoperative MDCT scans were classified as indicating the presence (+) or absence (-) of PI and PDI. Operative notes were reviewed and all patients were confirmed as PI (+), and then classified as PDI (+) or (-). As all patients had PI, an analysis of PI specificity was not possible. PI patients formed the pool for further PDI analysis. As sensitivity and specificity data were available for PDI, multivariate logistic regression was performed for PDI patients using the presence or absence of agreement between CT and operative note findings as an independent variable. Covariates were age, gender, Injury Severity Score, mechanism of injury, presence of oral contrast, presence of other abdominal injuries, performance of the scan as part of a dedicated pancreas protocol, and image thickness < or =3 mm or > or =5 mm. Twenty centers enrolled 206 PI patients, including 71 PDI (+) patients. Intravenous contrast was used in 203 studies; 69 studies used presence of oral contrast. Eight-nine percent were blunt mechanisms, and 96% were able to have their duct status operatively classified as PDI (+) or (-). The sensitivity of 16-MDCT for all PI was 60.1%, whereas 64-MDCT was 47.2%. For PDI, the sensitivities of 16- and 64-MDCT were 54.0% and 52.4%, respectively, with specificities of 94.8% for 16-MDCT scanners and 90.3% for 64-MDCT scanners. Logistic regression showed that no covariates were associated with an increased likelihood of detecting PDI for either 16- or 64-MDCT scanners. The area under the curve was 0.66 for the 16-MDCT PDI analysis and 0.77 for the 64-MDCT PDI analysis. Sixteen and 64-MDCT have low sensitivity for detecting PI and PDI, while exhibiting a high specificity for PDI. Their use as decision-making tools for the nonoperative management of PI are, therefore, limited.

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

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

Abstract 2234: Value of Multi-Detector Computed Tomography Evaluation of Myocardial Perfusion in the Assessment of Ischemic Heart Disease: Comparison with Nuclear Perfusion Imaging

While CT coronary angiography (CTCA) is gaining acceptance as a diagnostic technique, MDCT derived myocardial perfusion has not been validated against an accepted reference standard. We sought to develop a technique for quantitative assessment of myocardial perfusion from MDCT images, and investigate the diagnostic value of resting MDCT perfusion in comparison with SPECT myocardial perfusion imaging (MPI). We studied 98 consecutive patients undergoing CTCA who also had MPI. 20 patients with normal MPI were used as controls. MDCT perfusion was measured in 16 segments in terms of x-ray attenuation. Abnormal resting perfusion was detected by comparison against normal values obtained in the control group. Accuracy of detection was determined against resting MPI on a segment, vascular territory and patient basis. To determine the causes of resting perfusion defects detected by MDCT but not confirmed by resting MPI, stress MPI data were used. Perfusion abnormalities were detected by resting MPI in 36/78 patients in 58 vascular territories. MDCT detected these abnormalities in 31/36 patients (sensitivity 0.86). Abnormalities found in additional 28/78 patients were not confirmed by resting MPI (specificity 0.33). However, 23 of these 28 apparently false positive resting MDCT perfusion tests (82%) were associated with abnormal stress MPI. In the majority of these 23 patients (16 or 70%), the quality of MDCT images was optimal, while in the remaining 5/28 patients with resting MDCT perfusion abnormalities that were not confirmed by stress MPI, 4 (80%) had suboptimal images. Resting MDCT can accurately detect perfusion abnormalities in agreement with resting MPI. Moreover, the majority of abnormalities not confirmed by resting MPI were associated with stress-induced ischemia. Therefore, myocardial perfusion assessment, even at rest, is a potentially valuable addition to MDCT tools for noninvasive evaluation of coronary artery disease without additional radiation or contrast load, which promises not only to improve the diagnostic accuracy of cardiac CT, but is also likely to prove as a cost-effective, single-stop alternative to costly serial testing.

Multidetector CT Evaluation of Active Extravasation in Blunt Abdominal and Pelvic Trauma Patients

Timely localization of a bleeding source can improve the efficacy of trauma management, and improvements in the technology of computed tomography (CT) have expedited the work-up of the traumatized patient. The classic pattern of active extravasation (ie, administered contrast agent that has escaped from injured arteries, veins, or urinary tract) at dual phase CT is a jet or focal area of hyperattenuation within a hematoma that fades into an enlarged, enhanced hematoma on delayed images. This finding indicates significant bleeding and must be quickly communicated to the clinician, since potentially lifesaving surgical or endovascular repair may be necessary. Active extravasation can be associated with other injuries to arteries, such as a hematoma or a pseudoaneurysm. Both active extravasation and pseudoaneurysm (unlike bone fragments and dense foreign bodies) change in appearance on delayed images, compared with their characteristics on arterial images. Other clues to the location of vessel injury include lack of vascular enhancement (caused by occlusion or spasm), vessel irregularity, size change (such as occurs with pseudoaneurysm), and an intimal flap (which signifies dissection). The sentinel clot sign is an important clue for locating the bleeding source when other more localizing findings of vessel injury are not present. Timely diagnosis, differentiation of vascular injuries from other findings of trauma, signs of depleted intravascular volume, and localization of vascular injury are important to convey to interventional radiologists or surgeons to improve trauma management.

07: Value of Multi-Detector Computed Tomography Evaluation of Myocardial Perfusion in the Assessment of Ischemic Heart Disease: Comparison With Nuclear Perfusion Imaging

07: Value of Multi-Detector Computed Tomography Evaluation of Myocardial Perfusion in the Assessment of Ischemic Heart Disease: Comparison With Nuclear Perfusion Imaging

Usefulness of MDCT evaluation of the intraluminal surface of esophageal masses using only effervescent powder without injection of hypotonic agent

This study evaluated the inner surface of esophageal masses using multidetector computed tomography (MDCT) after esophageal distention with an ingested effervescent powder without inducing pharmacological esophageal hypotonia. From September 2004 to December 2005, 38 patients underwent MDCT after esophageal distention using only an effervescent powder that was ingested only 35 s after injecting the contrast agent and twice 50 s after the injection. Ten patients had a normal esophagus and twenty-eight patients had an esophageal mass detected by endoscopy. The degree of distention at three levels (upper, middle, and lower) and the intraluminal surface of the esophageal mass were evaluated. The surface between the normal and esophageal mass were analyzed using an ANOVA test. Esophageal distention in the upper and middle thirds was classified as either "good" or "fair" in 90.8% of cases. In the lower third, 81.6% of cases were either "good" or "fair". All esophageal cancers had an irregular surface but all normal lining and benign esophageal masses had a smooth surface. MDCT after esophageal distention using the effervescent powder ingested twice achieved good-to-fair distention in the esophagus, and is a useful diagnostic modality for identifying the intraluminal surface of esophageal masses.

Multidetector computed tomography evaluation of left ventricular volumes: Sources of error and guidelines for their minimization

Although multidetector computed tomography (MDCT) is known to overestimate left ventricular (LV) end-systolic and end-diastolic volumes (ESV, EDV) compared to magnetic resonance imaging reference, the potential sources of error have not been thoroughly investigated. We sought to quantitatively assess the effects of the number of reconstructed phases and number of slices used for volume calculation on the accuracy of LV volume measurements. MDCT images obtained in 28 patients (Philips Brilliance 64) were reconstructed at 10, 20, 33, and 100 phases per cardiac cycle. For each number of phases, ESV was measured between aortic valve closure and mitral valve opening and normalized by reference ESV measured at 100 phases/R-R. Both reference ESV and EDV were measured using 20 and separately 10 fixed-thickness slices. Reproducibility was assessed using repeated measurements. In 16 of 28 patients, the timing of end-systole varied with increasing number of reconstructed phases, resulting in a gradual decrease in ESV from 118 +/- 20% of reference ESV to 100 +/- 0%. Reduction in number of slices caused a significant increase in EDV and ESV (4.2 +/- 3.2% and 6.4 +/- 5.5%, respectively), roughly twice the corresponding intraobserver variability (2.5 +/- 1.5% and 3.8 +/- 2.4%). Misidentification of end-systole due to insufficient number of reconstructed phases significantly affects ESV measurements. Also, the number of slices used for volume calculation affects both ESV and EDV beyond intermeasurement variability. To ensure accurate quantification of LV volumes, reconstruction at time intervals smaller than 5% of the RR-interval (>20 phases/cardiac cycles) and tracing endocardial borders in >10 slices are recommended.