Computed Tomography Imaging In Evaluation Research Articles

Improved differentiation of cavernous malformation and acute intraparenchymal hemorrhage on CT using an AI algorithm

This study aimed to evaluate the utility of an artificial intelligence (AI) algorithm in differentiating between cerebral cavernous malformation (CCM) and acute intraparenchymal hemorrhage (AIH) on brain computed tomography (CT). A retrospective, multireader, randomized study was conducted to validate the performance of an AI algorithm in differentiating AIH from CCM on brain CT. CT images of CM and AIH (< 3 cm) were identified from the database. Six blinded reviewers, including two neuroradiologists, two radiology residents, and two emergency department physicians, evaluated CT images from 288 patients (CCM, n = 173; AIH, n = 115) with and without AI assistance, comparing diagnostic performance. Brain CT interpretation with AI assistance resulted in significantly higher diagnostic accuracy than without (86.92% vs. 79.86%, p < 0.001). Radiology residents and emergency department physicians showed significantly improved accuracy of CT interpretation with AI assistance than without (84.21% vs. 75.35%, 80.73% vs. 72.57%; respectively, p < 0.05). Neuroradiologists showed a trend of higher accuracy with AI assistance in the interpretation but lacked statistical significance (95.83% vs. 91.67%, p = 0.56). The use of an AI algorithm can enhance the differentiation of AIH from CCM in brain CT interpretation, particularly for nonexperts in neuroradiology.

The clinical value of CT spectral imaging in preoperative evaluation of pathological types of gastric cancer.

Gastric cancer (GC) is the fifth most common cancer worldwide and the third leading cause of cancer death. Due to the low rate of early diagnosis, most patients are already in the advanced stage and lose the chance of radical surgery. To investigate the clinical value of computed tomography (CT) spectral imaging in preoperative evaluation of pathological types of gastric cancer patients. 121 patients with gastric cancer were selected. CT energy spectrum imaging was performed on the patients. The water and iodine concentration of the lesion were measured, and the standardized iodine concentration ratio was calculated. The iodine concentration, iodine concentration ratio and water concentration level of different pathological types were analyzed and compared. The iodine concentration and iodine concentration ratio of gastric mucinous carcinoma patients in venous phase and parenchymal phase were lower than those of gastric non-mucinous carcinoma patients, and the differences were statistically significant (P< 0.05). The iodine concentration and iodine concentration ratio of patients with mucinous adenocarcinoma in venous phase and parenchymal phase were lower than those of patients with choriocarcinoma, and the differences were statistically significant (P< 0.05). The iodine concentration and iodine concentration ratio of middle and high differentiated adenocarcinoma patients in venous phase and parenchymal phase were lower than those of low differentiated adenocarcinoma patients, and the differences were statistically significant (P< 0.05). However, there was no significant difference in water concentration levels among venous, arterial, and parenchymal phases in all pathological types of gastric cancer patients (P> 0.05). CT spectral imaging plays an important role in the preoperative evaluation of patients with gastric cancer. The pathological types of gastric cancer are different, and the iodine concentration will change accordingly. CT spectral imaging can effectively evaluate the pathological types of gastric cancer and has high clinical application value.

Role of Computed Tomography Imaging in Pediatric Abdominal Masses

Introduction: Abdominal masses are commonly encountered in the pediatric population, with a broad differential diagnosis that encompasses benign and malignant entities. The main goal of abdominal imaging in the context of a suspected pediatric abdominal mass is to confirm its presence, as nonneoplastic entities can mimic an abdominal mass, and to detect specific imaging findings that narrow the differential diagnosis. Computed Tomography (CT) is currently the most powerful and versatile imaging procedure for the evaluation of abdominal masses It plays an important role in characterizing the mass and extent of disease and assisting in presurgical planning [1].&#x0D; Aim: The purpose of this article is to describe the role of CT imaging in evaluation of pediatric abdominal masses.&#x0D; Materials and Methods: Five case reports of abdominal masses in pediatric age group have been discussed.&#x0D; All the five patients underwent CT scan on Philips brilliance 256 slice machine.&#x0D; CT imaging findings with their histopathological diagnosis have been described.&#x0D; Case Summary:&#x0D; Case 1 :Wilm’s tumor&#x0D; Case 2 : Rhabdomyosarcoma&#x0D; Case 3 : Ewing’s sarcoma of sacrum&#x0D; Case 4 : Germ cell tumor of ovary&#x0D; Case 5 : Pelvic myxoid chondrosarcoma&#x0D; Conclusion: Abdominal masses in the pediatric age group include a spectrum of lesions of diverse origin and significance. CT imaging plays a key role in defining the characteristics and extent of mass lesions found in infants and children. Imaging with histopathological correlation can be very helpful in the management of the patient.

Right Ventricular and Pulmonary Computed Tomography Assessments in Paradoxical Low-Flow Low-Gradient Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement

BackgroundPatients with paradoxical low-flow low-gradient aortic stenosis (pLFLG AS) have high mortality and a high degree of transcatheter aortic valve replacement (TAVR) futility. Computed tomography (CT) enables accurate simultaneous right ventricular (RV) and parenchymal lung disease evaluation, which may provide useful objective markers of AS severity, concomitant pulmonary comorbidities, and TAVR improvement. However, the prevalence of RV dysfunction and its association with pulmonary disease in pLFLG AS are unknown. The study objective was to test the hypothesis that pLFLG AS patients undergoing TAVR have decreased RV function without a significant parenchymal lung disease. MethodsBetween August 2016 and March 2020, 194 consecutive AS patients completed high-resolution CT imaging for TAVR evaluation. Subjects were stratified based on echocardiographic criteria as the study group, pLFLG (n = 27), and 2 consecutive control groups: classic severe, normal-flow, high-gradient (n = 27) and normal-flow, low-gradient (NFLG) (n = 27) AS. Blinded biventricular function and lung parenchymal disease assessments were obtained by high-resolution CT imaging. ResultsPatient demographics were similar between groups. pLFLG AS had a lower RV ejection fraction (49 ± 10%) than both classic severe (58 ± 7%, p < 0.001) and NFLG AS (55 ± 65%, p = 0.02). There were no significant differences on lung emphysema (p = 0.19), air fraction (p = 0.58), or pulmonary disease presence (p = 0.94) and severity (p = 0.67) between groups. ConclusionspLFLG AS patients have lower RV ejection fraction than classic severe and NFLG AS patients in the absence of significant parenchymal lung disease on CT imaging. These findings support the direct importance of RV function in the pathophysiology of aortic valve disease.

Estimating subjective evaluation of low-contrast resolution using convolutional neural networks.

To develop a convolutional neural network-based method for the subjective evaluation of computed tomography (CT) images having low-contrast resolution due to imaging conditions and nonlinear image processing. Fourradiological technologists visually evaluated CT images that were reconstructed using three nonlinear noise reduction processes (AIDR 3D, AIDR 3D Enhanced, AiCE) on a CT system manufactured by CANON. The visual evaluation consisted of two items: low contrast detectability (score: 0-9) and texture pattern (score: 1-5). Four AI models with different convolutional and max pooling layers were constructed and trained on pairs of CANON CT images and average visual assessment scores of four radiological technologists. CANON CT images not used for training were used to evaluate prediction performance. In addition, CT images scanned with a SIEMENS CT system were input to each AI model for external validation. The mean absolute error and correlation coefficients were used as evaluation metrics. Our proposed AI model can evaluate low-contrast detectability and texture patterns with high accuracy, which varies with the dose administered and the nonlinear noise reduction process. The proposed AI model is also expected to be suitable for upcoming reconstruction algorithms that will be released in the future.

Intelligent Algorithm-Based CT Imaging for Evaluation of Efficacy of Docetaxel Combined with Fluorouracil on Patients with Gastric Cancer.

The study focused on the dual-source computed tomography (CT) images segmented by the decision tree algorithm, to explore the efficacy of docetaxel combined with fluorouracil therapy on gastric patients undergoing chemotherapy. In this study, 98 patients with gastric cancer who were treated in the hospital were selected as the research subjects. The decision tree algorithm was applied to segment dual-source CT images of gastric cancer patients. The decision tree is established according to the feature ring and the segmentation position. The machine inductively learns from the decision tree to extract the features of the CT image to obtain the optimal segmentation boundary. The observation group was treated with docetaxel combined with fluorouracil, and the control group was treated with docetaxel combined with tegafur gimeracil oteracil potassium capsules. The general data of the two groups of patients were comparable and not statistically significant (P > 0.05). The two groups were compared for clinical efficacy, physical status, KPS score, improvement rate, and adverse drug reactions after treatment. The results showed that the improvement rate of physical fitness in the observation group was 38.78%, and the improvement rate in the control group was 18.37%. The total effective rate in the observation group was 42.85%, and the total effective rate in the control group was 36.73%. Obviously, the curative effect and improvement rate of physical fitness in the observation group were significantly better than those in the control group (P < 0.05). In conclusion, the decision tree algorithm proposed in this study demonstrates superb capabilities in feature extraction of CT images. The machine inductively learns from the decision tree to extract the features of the CT image to obtain the optimal segmentation boundary. The effect of docetaxel combined with fluorouracil is better than that of docetaxel combined with tegafur gimeracil oteracil potassium capsules.

Use of computed tomography for distinguishing heterotopic pancreas from gastrointestinal stromal tumor and leiomyoma.

To determine whether morphologic features and semiquantitative parameters of computed tomography (CT) could be used to distinguish heterotopic pancreas from gastrointestinal stromal tumor(GIST) and leiomyoma. This retrospective study evaluated CT images of heterotopic pancreases (n = 28), GISTs (n = 57), and leiomyomas (n = 26) located in the upper gastrointestinal tract. Morphologic imaging features of lesions were analyzed, including location, contour, margin, attenuation, growth pattern, enhancement type, enhancement degree, enlarged vessels feeding or draining the mass, hyperenhancement of the overlying mucosa, low intralesional attenuation, calcification, and a duct-like structure. Semiquantitative parameters included long diameter (LD), short diameter (SD), LD/SD ratio, and lesion and aorta CT values during plain CT (Lp and Ap), arterial phase (La and Aa), and venous phase (Lv and Av). Diagnostic performance of these findings and parameters were evaluated by receiver operating characteristic (ROC) analysis. Morphologic CT findings (including lesion contour, margin, attenuation, growth pattern, enhancement type, and enhancement degree) and semiquantitative parameters except for LD/SD were demonstrated to be significant for differentiating heterotopic pancreas from GIST and leiomyoma (all P < 0.01). Of these, location, low intralesional attenuation, duct-like structure and LD, SD, Lv, and Sv values showed good diagnostic performance with the areas under curve (AUC) higher than 0.70. The presence of a duct-like structure demonstrated the best diagnostic ability with AUC of 0.929 [95% confidence interval (CI) 0.864-0.969], sensitivity of 5.7% (95% CI 67.3-96.0), and specificity of 100% (95% CI 95.7-100), respectively. When the three morphologic features (location, low intralesional attenuation, duct-like structure) were used in combination, the AUC was improved to 0.980 (95% CI 0.952-1). CT features, especially the morphologic features, could be used to differentiate heterotopic pancreas from GIST and leiomyoma in the upper gastrointestinal tract and, thus, provide a more accurate method for non-invasive preoperative diagnosis. Additionally, the presence of a duct-like structure demonstrated to be a reliable indicator for heterotopic pancreas among the morphologic and semiquantitative CT features.

Acetabular Ossicles: Epidemiology and Correlation With Femoroacetabular Impingement

To investigate (1) the prevalence, size, and location of acetabular ossicles in general population; (2) differentiation between the characteristic types of acetabular ossicles: unfused ossification centers (true os acetabuli), rim fractures, labral calcifications and loose bodies; and (3) correlation between acetabular ossicles, and femoroacetabular impingement (FAI) with symptoms. Patients aged 16 to 60 years who underwent abdominal and pelvic computed tomography (CT) with non-orthopaedic indications in 2016 and patients who underwent hip arthroscopy surgery from 2010 to 2016 in our institution were included for asymptomatic and symptomatic groups, respectively. Two investigators evaluated CT images to find the prevalence, size, location of acetabular ossicles, and relationship with symptoms and FAI. We correlated them with types of ossicles. This study included 5684 patients with 11368 hips (2790 male and 2894 female; mean age, 44.3 years) for asymptomatic group, and 264 patients with 289 hips (171 male and 93 female; mean age, 34.4 years) for symptomatic group. The prevalence of ossicles in symptomatic and asymptomatic groups was 8.65% (25/289) and 3.33% (378/11,368), respectively. The distribution of ossicles types in general population were labral calcifications (55.09%), rim fractures (35.73%), unfused ossification center (1.24%), and loose bodies (7.94%). Labral calcification had the smallest size and mostly was asymptomatic. Rim fracture was correlated with FAI in general (83.33%; P < .001) but not with any types of FAI. Size of ossicles was related with symptom (895.28 vs 103.64 mm3; P < .001). The prevalence of acetabular ossicles in general population are 3.46%, with significantly higher prevalence of acetabular ossicles were found in symptomatic group (8.65% vs 3.33%). Size of acetabular ossicles was significantly associated with hip pain. Labral calcification was the most common type of acetabular ossicles. Significant relationship was found between rim fracture and FAI but not with any specific types of FAI. Level III, Retrospective comparative study.

Diagnostic Accuracy of Zero-Echo Time MRI for the Evaluation of Cervical Neural Foraminal Stenosis.

A cohort study. The aim of this study was to evaluate the clinical utility of Zero-Echo-Time (ZTE) magnetic resonance imaging (MRI) for the assessment of cervical neural foraminal stenosis (CNFS) through the comparison of inter-modality [computed tomography (CT) and ZTE-MRI] CNFS grade severity agreements. Conventional MRI limited in its ability to provide direct visualization of cortical bone. The highly organized tissue structure of cortical bone results in very short T2 values that preclude acquisition of sufficient signal intensity and positive image contrast. ZTE imaging permits visualization of tissues with very short transverse relaxation times, and is capable of displaying images with CT-like contrast. Thirty-four subjects were recruited from a clinical cohort of patients undergoing standard of care MRI and CT imaging for evaluation of CNFS. Standard of care CT imaging studies were obtained on all subjects within 6 months of their ZTE-MRI acquisition (mean time interval: 25.3 ± 54.1 days; median: 0 days). ZTE-MRI and CT imaging studies were evaluated and severity of CNFS was graded on a scale from 0 to 5 (0 = none; 5 = severe). Weighted-kappa statistics were used to assess agreement between ZTE and CT grades of CNFS on both sides (right and left) of each motion segment. Ordinal logistic mixed-effects regression analyses evaluated the effects of inter-modality position differences (flexion-extension curvature) on inter-modality differences in CNFS grade. Substantial agreement (κ = 0.72) was found between ZTE- and CT-based grades of CNFS. Significant inter-modality differences in cervical spine curvature were found for all motion segments, except C2-3 and C3-4 (P < 0.05). However, no significant relationship was found between inter-modality differences in curvature, and inter-modality differences in CNFS grade for any motion segment (P = 0.28). Results of the current study suggest that ZTE-MRI is well-suited for the evaluation of CNFS and may have the potential to obviate the need for concurrent CT scans in some cases. 2.

Performance of Magnetic Resonance Susceptibility-Weighted Imaging for Detection of Calcifications in Patients With Hepatic Echinococcosis.

We evaluated the performance of susceptibility-weighted imaging (SWI) for identification of hepatic calcifications in alveolar echinococcosis and cystic echinococcosis. The SWI images of 58 lesions in 40 patients (age, 49 ± 14 y) with alveolar echinococcosis (n = 22) or cystic echinococcosis (n = 18) were reviewed for calcifications. First, calcifications were suggested by visual assessment. Second, ratios of minimum intralesional intensity and mean lumbar muscle intensity were recorded. Computed tomography (CT) served as the criterion standard. Thirty-seven lesions showed calcifications on CT. Susceptibility-weighted imaging provided a sensitivity of 89.2% (95% confidence interval [CI], 50.1-75.7) and a specificity of 57.1% (95% CI, 34.4-77.4) for calcifications detected by visual assessment. Receiver operating characteristic curves demonstrated a sensitivity of 67.6% and a specificity of 85.0% for an intensity ratio of 0.61. A specificity of 100% (95% CI, 80.8-100) and a sensitivity of 84.5% (95% CI, 67.3-93.2) were achieved by SWI for calcifications with a density greater than 184 HU in CT. Identification of hepatic calcifications is possible with SWI. Susceptibility-weighted imaging offers the potential to reduce the need for of CT imaging for evaluation of echinococcosis.

Clinical and radiological features of advanced RET-rearranged lung cancer.

e23104 Background: RET fusion gene was found in 1–2% of non-small cell lung cancer (NSCLC). Most of the reports published so far investigated only surgical specimens, and details of advanced tumors were unknown. This study explored the clinical and radiological characteristics of RET-rearranged lung cancers in advanced stages. Methods: Among 1,074 advanced NSCLC patients who were treated at The Cancer Institute Hospital, Tokyo, from 2012 to 2016, 14 cases (14/1,074 = 1.3%) were treated as RET- rearranged lung cancer. The cases were identified by FISH and / or by RT-PCR (FISH 3, RT-PCR 2, FISH and RT-PCR 8, unknown 1). The fusion partner genes included KIF5B (n = 10), CCDC6 (n = 1). Three were unknown. The tumor size, location, and shape/margins of the primary tumor as well as lymphadenopathy and site of metastasis were recorded based on computed tomography (CT) images taken right before the initial chemotherapy. Results: The median age of the 14 patients was 64 years (range, 34–79), with 10 patients (71%) over 60 years old. Nine patients (64%) were women, whereas 10 patients (71%) were never smokers. Eight patients were classified as stage IV and 6 underwent recurrence after surgery. We successfully evaluated CT images at the initial chemotherapy of 12 patients. Of the 7 patients whose primary lesions were detectable, all were located peripherally and were of a solid tumor type without ground-glass, air bronchograms, or cavitation. The median size of the primary lesion was 3.0 cm (range, 1.2–6.8), and 3 lesions were less than 3.0 cm. Only 5 patients had lymphadenopathy (4 were of Stage IV, 1 was a recurrence), most of which were isolated with a median size of 1.5 cm (range, 1.2–3.5). The sites of distant metastases included 8 pleural disseminations, 5 lungs, 5 bones, 3 livers, 2 brains, and 0 adrenals. Conclusions: Advanced RET-rearranged lung cancer manifested as a relatively small and peripherally located solid primary lesion with isolated lymphadenopathy. Pleural dissemination was frequently observed, whereas brain metastasis was less frequent. These features differ from EGFR-mutated or ALK-fused lung cancers.

Clinical analysis of contributors to the delayed gallbladder opacification following the use of water-soluble contrast medium.

ObjectivesGallbladder opacification (GBO) on computed tomography (CT) imaging may obscure certain pathological or emergent conditions in the gallbladder, such as neoplasms, stones, and hemorrhagic cholecystitis. This study aimed to investigate the clinical contributing factors that could predict the presence of delayed GBO determined by CT.MethodsThis study retrospectively evaluated 243 consecutive patients who received enhanced CT or intravenous pyelography imaging and then underwent abdominal CT imaging within 5 days. According to the interval between imaging, the patients were divided into group A (1 day), group B (2 or 3 days), and group C (4 or 5 days). Three radiologists evaluated CT images to determine GBO. Fisher’s exact test and multivariate backward stepwise elimination logistic regression were performed.ResultsPositive GBO was significantly associated with the interval between imaging studies, contrast type, contrast volume, renal function, and hypertransaminasemia (P<0.05). Multivariate backward stepwise elimination logistic regression analysis of the three groups identified contrast type and hypertransaminasemia as independent predictors of GBO in group B patients (odds ratio [OR], 13.52, 95% confidence interval [CI], 1.72–106.38 and OR, 3.43, 95% CI, 1.31–8.98, respectively; P<0.05). Hypertransaminasemia was the only independent predictor of GBO in group C patients with an OR of 7.2 (95% CI, 1.62–31.73). Hypertransaminasemia was noted in three patients (100%) who initially underwent imaging 5 days prior to GBO.ConclusionDelayed GBO on CT imaging may be associated with laboratory hypertransaminasemia, particularly in patients receiving contrast medium over a period of ≥4 days. A detailed clinical history, physical examination, and further workup are of paramount importance for investigating the underlying cause behind the hypertransaminasemia.

CT imaging for evaluation of calcium crystal deposition in the knee: initial experience from the Multicenter Osteoarthritis (MOST) study

Role of intra-articular calcium crystals in osteoarthritis (OA) is unclear. Imaging modalities used to date for its evaluation have limitations in their ability to fully characterize intra-articular crystal deposition. Since Computed Tomography (CT) imaging provides excellent visualization of bones and calcified tissue, in this pilot project we evaluated the utility of CT scan in describing intra-articular calcium crystal deposition in the knees. We included 12 subjects with and four subjects without radiographic chondrocalcinosis in the most recent visit from the Multicenter Osteoarthritis (MOST) study, which is a longitudinal cohort of community-dwelling older adults with or at risk for knee OA. All subjects underwent CT scans of bilateral knees. Each knee was divided into 25 subregions and each subregion was read for presence of calcium crystals by a musculoskeletal radiologist. To assess reliability, readings were repeated 4 weeks later. CT images permitted visualization of 25 subregions with calcification within and around the tibio-femoral and patello-femoral joints in all 24 knees with radiographic chondrocalcinosis. Intra-articular calcification was seen universally including meniscal cartilage (most common site involved in 21/24 knees), hyaline cartilage, cruciate ligaments, medial collateral ligament and joint capsule. Readings showed good agreement for specific tissues involved with calcium deposition (kappa: 0.70, 95% CI 0.62-0.80). We found CT scan to be a useful and reliable tool for describing calcium crystal deposition in the knee and therefore potentially for studying role of calcium crystals in OA. We also confirmed that "chondrocalcinosis" is a misnomer because calcification is present ubiquitously.

New classification system for ossification of the posterior longitudinal ligament using CT images

BackgroundOssification of the posterior longitudinal ligament (OPLL) is most frequently seen in the cervical spine. The types of cervical OPLL are classified into continuous, mixed, segmental, and other based on plain lateral X-ray. Computed tomography (CT) imaging is often used in clinical practice for evaluating ossified lesions as it can detect their precise location, size, and shape. However, to date, no CT classification of OPLL lesions has been proposed. MethodsOne hundred and forty-four patients diagnosed with cervical OPLL by plain radiograph were included in this study. Sagittal and axial CT images of the cervical spine were obtained. We propose three classification systems: A, B, and axial. Classification A comprises two lesion types: bridge and nonbridge. Classification B requires examiners to describe all vertebral and intervertebral levels where OPLL exits in the cervical spine. Axial classification comprises central and lateral lesions identified on axial CT images. Seven observers evaluated CT images using this classification system, and intra- and interrater reliability were examined. ResultsAveraged Fleiss’ kappa coefficient of interrater agreement was 0.43 ± 0.26 among the seven observers, averaged intrarater reliability for the existence of OPLL was 72.4 ± 8.8 % [95 % confidence interval (CI) 67.5–76.8]. Fifty-four patients (37.5 %) had the bridge type and 90 the nonbridge type according to Classification A; 102 (70.8 %) had central and 42 (29.2 %) lateral OPLL in the axial classification. Four representative cases defined according to the three classification types are reported here. ConclusionSubcommittee members of the Investigation Committee on the Ossification of the Spinal Ligaments of the Japanese Ministry of Public Health and Welfare propose three new classification systems of cervical OPLL based on CT imaging: A, B, and axial.

Role of FAST or Abdominal Ultrasound to Limit CT Imaging in Evaluation of the Pediatric Abdominal Trauma Patient

Blunt abdominal trauma (BAT) can produce serious intra-abdominal injuries (IAI) in children. An early diagnosis is important to reduce morbidity and mortality, but pediatric patients sustaining BAT rarely require an operative intervention. Although the computed tomography (CT) scan is currently the best diagnostic tool to detect IAI, increased awareness of the risks of radiation exposure, high costs, and low utility has led to efforts to reduce the use of CT in the workup of pediatric trauma patients. Focused assessment with sonography for trauma (FAST) is an accurate, noninvasive, and rapid method of evaluating patients with BAT. Many institutions have developed criteria using physical signs and common biochemical markers of abdominal injury in combination with FAST as a screening tool to prevent the overuse of CT in children. We review the use of FAST and scoring systems as tools to limit CT imaging in the evaluation of the pediatric abdominal trauma patient.

Computed Tomography Use Among Children Presenting to Emergency Departments With Abdominal Pain

To evaluate trends in and factors associated with computed tomography (CT) use among children presenting to the emergency department (ED) with abdominal pain. This study was a cross-sectional, secondary analysis of the National Hospital Ambulatory Medical Care Survey data from 1998 to 2008. We identified ED patients aged <19 years with abdominal pain and collected patient demographic and hospital characteristics, and outcomes related to imaging, hospital admission, and diagnosis of appendicitis. Trend analysis was performed over the study period for the outcomes of interest, and a multivariate regression model was used to identify factors associated with CT use. Of all pediatric ED visits, 6.0% were for abdominal pain. We noted a rise in the proportion of these patients with CT use, from 0.9% in 1998 to 15.4% in 2008 (P < .001), with no change in ultrasound/radiograph use, diagnosis of appendicitis, or hospital admission. Older and male patients were more likely to have a CT scan, whereas black children were one-half as likely to undergo a CT scan compared with white children (odds ratio: 0.50 [95% confidence interval: 0.31-0.81]). Admitted children had much higher odds of undergoing a CT scan (odds ratio: 4.11 [95% confidence interval: 2.66-6.35]). There was a plateau in CT use in 2006 to 2008. There was a dramatic increase in the utilization of CT imaging in the ED evaluation of pediatric patients with abdominal pain. Some groups of children may have a differential likelihood of receiving CT scans.

Feasibility of Diastolic Function Assessment With Cardiac CT: Feasibility Study in Comparison With Tissue Doppler Imaging

This study aimed to demonstrate the feasibility of multidetector row computed tomography (CT) for assessment of diastolic function in comparison with 2-dimensional (2D) echocardiography using tissue Doppler imaging (TDI). Diastolic left ventricular (LV) function plays an important role in patients with cardiovascular disease. 2D echocardiography using TDI has been used most commonly to evaluate diastolic LV function. Although the role of cardiac CT imaging for evaluation of coronary atherosclerosis has been explored extensively, its feasibility to evaluate diastolic function has not been studied. Patients who had undergone 64-multidetector row CT and 2D echocardiography with TDI were enrolled. Diastolic function was evaluated using early (E) and late (A) transmitral peak velocity (cm/s) and peak mitral septal tissue velocity (Ea; cm/s). Peak transmitral velocity (cm/s) was calculated by dividing peak diastolic transmitral flow (ml/s) by the corresponding mitral valve area (cm(2)). Mitral septal tissue velocity was calculated from changes in LV length per cardiac phase. Subsequently, the estimation of LV filling pressures (E/Ea) was determined. Seventy patients (46 men; mean age 55 ± 11 years) who had undergone cardiac CT and 2D echocardiography with TDI were included. Good correlations were observed between cardiac CT and 2D echocardiography for assessment of E (r = 0.73; p < 0.01), E/A (r = 0.87; p < 0.01), Ea (r = 0.82; p < 0.01), and E/Ea (r = 0.81; p < 0.01). Moreover, a good diagnostic accuracy (79%) was found for detection of diastolic dysfunction using cardiac CT. Finally, the study showed a low intraobserver and interobserver variability for assessment of diastolic function on cardiac CT. Cardiac CT imaging showed good correlations for transmitral velocity, mitral septal tissue velocity, and estimation of LV filling pressures when compared with 2D echocardiography. Additionally, cardiac CT and 2D echocardiography were comparable for assessment of diastolic dysfunction. Accordingly, cardiac CT may provide information on diastolic dysfunction.

Acute Stroke Triage to Intravenous Thrombolysis and Other Therapies with Advanced CT or MR Imaging: Pro MR Imaging

In this article and the companion piece, two sets of experts present their views on the use of computed tomography (CT) or magnetic resonance (MR) imaging to select patients with acute stroke to undergo available reperfusion therapies. Specifically, in this article, two neurologists provide the clinical background and motivation behind the use of advanced imaging in stroke triage—most notably with regard to major clinical trials—to extend the time window for intravenous thrombolysis beyond the currently recommended 3-hour window after stroke. To date, these trials have focused almost exclusively on the use of MR imaging and MR angiography to determine patient eligibility. In this article, the authors compare the MR and CT methods of triage. In the companion article, three neuroradiologists expand on the benefits and limitations of advanced CT imaging in stroke evaluation and offer their perspective on which modality to choose and why.

Intraductal Papillary Mucinous Neoplasm of the Pancreas: Assessment of the Likelihood of Invasiveness with Multisection CT

To evaluate the capabilities of multisection computed tomography (CT) in determining the likelihood of invasiveness of intraductal papillary mucinous neoplasm (IPMN). The institutional review board approved this research and waived informed consent from the patients. Two radiologists blinded to the pathologic assessment of malignancy or parenchymal invasion of IPMN retrospectively evaluated CT images of 61 consecutive surgically resected tumors (26 adenomas, 15 noninvasive carcinomas, and 20 invasive carcinomas) in patients who underwent multiphase contrast material-enhanced CT with 0.5- or 1-mm collimation. The findings were statistically analyzed by using univariate and multivariate analyses, with the optimal cutoff levels of each continuous parameter determined by generating receiver operating characteristic curves. The following findings showed significant differences among the three groups: maximum diameter of the main pancreatic duct (MPD), size (length of major axis) of the largest mural nodule in the MPD or in any associated cystic lesion, abnormal attenuating area in the surrounding parenchyma, calcification in the lesion, protrusion of the MPD into the ampulla of Vater, and bile duct dilatation. An MPD diameter of 6 mm or larger, a mural nodule of 3 mm or larger, and an abnormal attenuating area were independently predictive of malignancy. A mural nodule of 6.3 mm or larger in the MPD and an abnormal attenuating area were independently predictive of parenchymal invasion. According to these criteria, the sensitivity, specificity, and accuracy for identifying malignancy were 83%, 81%, and 82% and for identifying parenchymal invasion were 90%, 88%, and 89%, respectively. Multisection CT is useful for distinguishing among adenoma, noninvasive carcinoma, and invasive carcinoma in patients with IPMN.

Early Invasive Cervical Cancer: CT and MR Imaging in Preoperative Evaluation—ACRIN/GOG Comparative Study of Diagnostic Performance and Interobserver Variability

To retrospectively compare diagnostic performance and interobserver variability for computed tomography (CT) and magnetic resonance (MR) imaging in the pretreatment evaluation of early invasive cervical cancer, with surgical pathologic findings as the reference standard. This HIPAA-compliant study had institutional review board approval and informed consent for evaluation of preoperative CT (n = 146) and/or MR imaging (n = 152) studies in 156 women (median age, 43 years; range, 22-81 years) from a previous prospective multicenter American College of Radiology Imaging Network and Gynecologic Oncology Group study of 172 women with biopsy-proved cervical cancer (clinical stage > or = IB). Four radiologists (experience, 7-15 years) interpreted the CT scans, and four radiologists (experience, 12-20 years) interpreted the MR studies retrospectively. Tumor visualization and detection of parametrial invasion were assessed with receiver operating characteristic curves (with P < or = .05 considered to indicate a significant difference). Descriptive statistics for staging and kappa statistics for reader agreement were calculated. Surgical pathologic findings were the reference standard. For CT and MR imaging, respectively, multirater kappa values were 0.26 and 0.44 for staging, 0.16 and 0.32 for tumor visualization, and -0.04 and 0.11 for detection of parametrial invasion; for advanced stage cancer (> or =IIB), sensitivities were 0.14-0.38 and 0.40-0.57, positive predictive values (PPVs) were 0.38-1.00 and 0.32-0.39, specificities were 0.84-1.00 and 0.77-0.80, and negative predictive values (NPVs) were 0.81-0.84 and 0.83-0.87. MR imaging was significantly better than CT for tumor visualization (P < .001) and detection of parametrial invasion (P = .047). Reader agreement was higher for MR imaging than for CT but was low for both. MR imaging was significantly better than CT for tumor visualization and detection of parametrial invasion. The modalities were similar for staging, sharing low sensitivity and PPV but relatively high NPV and specificity.