Multidetector Row Research Articles

Preoperative imaging evaluation of pancreatic pathologies for the objective prediction of pancreatic fistula after pancreaticoduodenectomy.

In performing pancreaticoduodenectomy (PD) or when conducting clinical trials involving PD procedure, a universal platform for predicting the risk of postoperative pancreatic fistula (POPF) is indispensable. In this article, the most significant imaging studies that focused on the objective preoperative assessment of pancreatic pathologies in association with the occurrence of POPF after PD were reviewed. Several recently developed imaging modalities can objectively predict the occurrence of POPF after PD by assessing the elasticity, fibrosis, and fatty infiltration of the pancreas. These valuable imaging modalities include: (1) acoustic radiation force impulse ultrasound (US) electrography which provides information about the elastic properties of the pancreas; (2) contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) with/without contrast-enhancement which reflect the histological degree of pancreatic fibrosis; and (3) multi-detector row CT and/or MRI which reflects the microscopic fatty infiltration of the pancreas. The precise and objective preoperative risk assessment of POPF enables surgeons to customize appropriate management strategies for individual patients undergoing PD. This would be also beneficial for stratifying patients for enrolment in relevant studies that involve pancreatic head resection, as objective criteria could be set for the definitive evaluation of collected data related to surgical outcomes across different institutions and surgeons.

Volume and dimensions of angiographically normal coronary arteries assessed by multidetector computed tomography

BackgroundThe objective of this study was to determine normal values for coronary artery volume (CAV) and individual vasculature and segment dimensions. MethodsWe examined 200 healthy volunteers with an Agatston score of 0 and a normal, high quality coronary CTA. Using 320 slice multidetector row CT and designated vessel tracing software with border detection algorithm, the main coronary arteries and branches were delineated and total and segmental dimensions calculated. Results2931 segments (98.9%) could be adequately delineated. Of the 173 subjects with adequate coronary delineations, 140 subjects (81%) received nitroglycerin (NTG) prior to the scan. CAV was 4.33 ml (95% CI: 2.27–6.39) in subjects with NTG and 2.55 ml (95% CI: 0.34–4.76) in subjects without NTG (p < 0.0001). Left ventricular mass (LVM) was strongly correlated with CAV (p < 0.0001) independently of body surface area and gender, whereas gender was not independently correlated with CAV. From right, balanced to left coronary dominance, the left anterior descending artery vasculature mean contribution to CAV increased slightly (37%, 40% and 43%, p = 0.002), and the mean contributions of right coronary artery (RCA) and left circumflex artery (LCX) vasculature was inversely related - from right, balanced to left 46%, 32% and 16% for RCA (p < 0.0001); and 16%, 27% and 38% for LCX (p < 0.0001). ConclusionNormal values for coronary artery volume as assessed by coronary CTA are reported. They strongly correlate with NTG administration and left ventricular mass. The respective contribution of the left and right coronary vascularture is influenced by coronary dominance.

Contour variations of the body and tail of the pancreas: evaluation with MDCT

To analyze morphology/contour variations of the pancreatic body and tail in subjects free of pancreatic disease. We retrospectively reviewed triple-phase, contrast-enhanced multi-detector row computed tomography (3P-CE-MDCT) examinations of 449 patients who had no clinical or CT evidence of pancreatic diseases. These patients were evaluated for morphologic/contour variations of the pancreatic body and tail, which were classified into two types. In Type I, a portion of normal pancreatic parenchyma protrudes >1cm in maximum diameter from the body or tail (Ia-anteriorly; Ib-posteriorly). Type II was defined as a morphologic anomaly of the pancreatic tail (IIa-globular; IIb-lobulated; IIc-tapered; IId-bifid). Thirty-eight (8.5%) out of 449 patients had body or tail variations. Of those, 23 patients showed Type I variant: Ia in 21 and Ib in two. Type II variant was identified in 15 patients: IIa in eight, IIb in two, IIc in two and IId in three. Protrusion of the anterior surface of the normal pancreas, especially in the tail, was the most frequently occurring variant. Recognizing the types and subtypes of morphology/contour variations of the pancreatic body and tail could help prevent misinterpretation of normal variants as pancreatic tumors on unenhanced MDCT.

Diagnostic accuracy of indocyanine green fluorescence imaging and multidetector row computed tomography for identifying hepatocellular carcinoma with liver explant correlation.

Indocyanine green (ICG)-fluorescence imaging is useful for detecting hepatocellular carcinoma (HCC) during surgery, but its accuracy has not been compared to that of multidetector row computed tomography (MDCT) with liver explant correlation. The aim of the present study was to clarify the precise diagnostic accuracy of ICG-fluorescence imaging for detecting HCC in a whole explant liver survey. Thirty-three patients with end-stage liver disease (mean age, 53years) were prospectively enrolled in the present study. The mean Model for End-stage Liver Disease score was 14.6. One month before and 1week prior to living donor liver transplantation, all patients underwent MDCT and administration of ICG. Following whole liver resection, the explanted liver was sliced. Gross examination and ICG-fluorescence imaging of both sides of the cut specimen was carried out and all focal liver lesions were recorded. Pathologic examination diagnosed 18 of 84 focal liver lesions as HCC. Of those, MDCT and ICG-fluorescence imaging diagnosed 12 and 13 HCCs, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MDCT were 66.7%, 92.4%, 70.6%, 91.0%, and 86.9%, respectively, compared with those of ICG-fluorescence imaging at 72.2%, 31.8%, 22.4%, 80.8%, and 40.5%, respectively. The sensitivity of ICG-fluorescence imaging for detecting HCC with liver explant correlation was similar to that of MDCT. However, ICG-fluorescence imaging had low specificity in the setting of decompensated cirrhotic explant liver correlation.

Transcatheter aortic valve thrombosis: the relation between hypo-attenuated leaflet thickening, abnormal valve haemodynamics, and stroke.

The presence of hypo-attenuated leaflet thickening (HALT) and/or reduced leaflet motion on multi-detector row computed tomography (MDCT) has been proposed as a possible marker for early transcatheter aortic valve thrombosis. However, its association with abnormal valve haemodynamics on echocardiography (another potential marker of thrombosis) and clinical outcomes (stroke) remains unclear. The present study evaluated the prevalence of HALT on MDCT and abnormal valve haemodynamics on echocardiography. In addition, the occurrence of ischemic stroke and/or transient ischemic attack (TIA) was assessed. A total of 434 patients (mean age 80 ± 7 years, 51% male) who underwent transcatheter aortic valve replacement (TAVR) were evaluated. Transcatheter valve haemodynamics were assessed on echocardiography at discharge, 6 months, and thereafter yearly (up to 3 years post-TAVR). The presence of HALT and/or reduced leaflet motion was assessed on MDCT performed 35 days [interquartile range 19-210] after TAVR in 128 of these 434 patients. Possible TAVR valve thrombosis was defined by mean transvalvular gradient ≥20 mmHg and aortic valve area (AVA) ≤1.1cm2 on echocardiography or by the presence of HALT or reduced leaflet motion on MDCT. The occurrence of ischemic stroke/TIA at follow-up was recorded. HALT and/or reduced leaflet motion was present in 12.5% of 128 patients undergoing MDCT, and was associated with a slightly higher mean transvalvular gradient (12.4 ± 8.0 mmHg vs. 9.4 ± 4.3 mmHg; P = 0.026) and smaller AVA (1.49 ± 0.39 cm2 vs. 1.78 ± 0.45 cm2, P = 0.017). Only one patient with HALT on MDCT revealed abnormal valve haemodynamics on echocardiography. At 3-year follow-up, abnormal valve haemodynamics on echocardiography were observed in 3% of patients. HALT on MDCT and abnormal valve haemodynamics on echocardiography were not associated with increased risk of ischemic stroke/TIA. On MDCT, 12.5% of patients showed HALT or reduced leaflet motion, whereas only one of these patients had abnormal valve haemodynamics on echocardiography. Neither HALT nor increased transvalvular gradient were associated with stroke/TIA.

Distinct MDCT imaging features to differential diagnosis of hepatic paragonimiasis and small hepatocellular carcinoma.

We used multi-row detector computed tomography (MDCT) to identify the distinguishing characteristics of hepatic paragonimiasis and small hepatocellular carcinoma lesions. We analyzed a cohort of 60 patients, of which 26 had hepatic paragonimiasis and 34 with a small (≤ 3cm) hepatocellular carcinoma. MDCT detected 65 lesions that were retrospectively reviewed and analyzed based on their imaging features. Both groups showed distinct MDCT imaging features that could contribute to an accurate diagnosis. In the paragonimiasis group, 75% (21/28) lesions were located in the hepatic subcapsular region, whereas only 10.8% (4/37) of lesions in the hepatocellular carcinoma group were subcapsular. Most hepatic paragonimiasis lesions (57.1%; 16/28) also showed characteristic tubular or tunnel features that were not present in hepatocellular carcinomas. Further, 71.4% (20/28) paragonimiasis lesions were rim enhanced with irregular tract-like non-enhanced internal areas with a characteristic target loop, while 94.6% (35/37) of small hepatocellular carcinoma lesions showed homogenous enhancement in the arterial and venous phase. In addition, the period CT values for hepatic paragonimiasis were less than those of hepatic carcinomas (P<0.001). These clinically significant findings illustrate the diagnostic features that enable one to distinguish hepatic paragonimiasis from small hepatocellular carcinomas.

The Value of 320-Row Multidetector CT Bronchial Arteriography in Recurrent Hemoptysis after Failed Transcatheter Arterial Embolization

PurposeTo retrospectively assess the value of computed tomographic (CT) bronchial arteriography (BA) with 320-row multidetector CT in the management of patients with recurrent hemoptysis immediately after bronchial artery embolization (BAE). Materials and MethodsAmong 135 consecutive patients treated with BAE between April 2014 and March 2016, recurrent hemoptysis developed in 15, and 10 subsequently underwent multidetector CT. Vascular abnormalities and associated anatomy were evaluated to determine the potential cause of BAE failure, and the clinical impacts of CT BA were analyzed. ResultsCT BA revealed an additional 22 abnormal vessels in the qualified 10 patients, and 8 patients were treated again within 24 hours after the first BAE based on multidetector CT findings. Of the 22 abnormal vessels, 16 were embolized, including 4 orthotopic arteries, 8 ectopic arteries, and 4 nonbronchial systemic arteries (NBSAs); the remaining 6 abnormal arteries were not embolized because of normal BA (n = 1), anatomic inaccessibility (n = 2), or cessation of hemoptysis with conservative therapy (n = 3). There were no further cases of recurrent hemoptysis after the second intervention, with a mean follow-up of 7.7 months ± 6.7. Overall, initial conventional BA missed 65% of potential bleeding arteries (22 of 34). After CT BA, 73% of the newly identified vessels (16 of 22) were embolized. ConclusionsMultiple unrecognized abnormal ectopic bronchial arteries and NBSAs are the major causes of failure of initial BAE. Multidetector CT BA can precisely identify a large number of feeding vessels that are missed on conventional BA, allowing for repeat embolization with a high success rate.

SIZING AORTIC VALVE ANNULUS FOR TRANSCATHETER AORTIC VALVE PROSTHESIS SELECTION: IMPACT OF AORTIC VALVE CALCIFICATION BURDEN ON THE AGREEMENT BETWEEN AUTOMATED 3-DIMENSIONAL TRANSESOPHAGEAL ECHOCARDIOGRAPHY AND MULTIDETECTOR ROW COMPUTED TOMOGRAPHY

Background: Accurate aortic annulus (AA) sizing is key for selection of appropriate transcatheter aortic valve replacement (TAVR) prosthesis size. Head-to-head comparison of novel automated 3-dimensional transesophageal echocardiography (3DTEE) algorithm and multidetector row computed tomography (

Abstract P2-01-17: The combination of preoperative computed tomography lymphography and intraoperative fluorescence imaging navigation for sentinel lymph node biopsy of early breast cancer patients

Abstract Background: Sentinel lymph nodes (SLN) biopsy has been established as a standard of care in the treatment of early breast cancer. This technique represents a minimally invasive, highly accurate method of axillary staging and is an alternative to conventional axillary lymph node dissection. The combination of the radioisotope and dye-staining methods is the most accurate way to identify SLN. We had reported feasibility and safety of a new technique of SLN identification using fluorescence imaging of indocyanine green (ICG) injection without any need for training. Recently, SLN identification using computed tomography lymphography (CTLG) has been reported in Japan. This study investigated a usefulness of the combination of CTLG and fluorescence imaging for SLN biopsy of early breast cancer patients. Patients and method: Between January 2013 and March 2016, 296 breast cancer patients without clinical evidence of lymph node metastasis were treated. On the day before the operation, CTLG was performed using 64-row multidetector CT. We performed an intradermal injection in the periareolar area, using 4 ml of contrast agent with 1 ml of local anesthetic. The contrasted lymph route and SLN were identified in reconstructed three-dimensional imaging. The SLN spot was indicated by CT laser light navigator system. We established typical pattern of the lymphography: stain defect of SLN, stagnation of lymphatic route for preoperative diagnosis of metastatic SLN. During the operation, fluorescence images were obtained using the fluorescence imaging system, Photpdynamic Eye (pde-neo, Hamamatsu Photonics Co., Japan). After 0.5 ml dye mixed indigocarmin and ICG was injected intradermally into the periareolar skin, lymphatic route was observed with fluorescence images. SLN biopsy was performed referring to the point by axillary compression technique by plastic device. Intraoperative pathological analysis of SLN was examined. Results: The median age of the 296 patients was 59 (range 28 – 90) years old. One patient was male and others were female. CTLG and fluorescence imaging were safely performed in all patients. CTLG could visualize lymphatic route and accurately identify SLN in 284 (95.9 %) and 290 (98.0 %) cases, respectively, whereas fluorescence imaging identified successfully lymphatic route and SLN in all patients. Lymphatic routes of CTLG were completely consistent with those of fluorescence imaging. The number of SLN identified by CTLG was significantly lower than that by fluorescence imaging (1.1 vs. 1.6, p&amp;lt;0.01). Thirty-nine of 296 patients had metastatic SLN pathologically, and 10 of them had micrometastases of SLNs. The accuracy for metastatic diagnosis of SLN using CTLG without micrometastasis was 83.9 %, sensitivity was 82.1 % and specificity was 84.1 %. The positive predictive value was 35.9 % and negative predictive value was 97.7 %. Conclusion: The combination of CTLG and fluorescence imaging revealed easy and effective to detect SLN. The fluorescence imaging was more high detection rate and number of SLN than CTLG. Otherwise, preoperative diagnosis of SLN metastasis using CTLG would be useful to detect negative SLNs. Citation Format: Abe H, Teramoto A, Yamasaki K, Yoneda K, Ogawa M, Kawasaki M, Kameyama M. The combination of preoperative computed tomography lymphography and intraoperative fluorescence imaging navigation for sentinel lymph node biopsy of early breast cancer patients [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-01-17.

Optimal scan timing for artery-vein separation at whole-brain CT angiography using a 320-row MDCT volume scanner.

A 320-row multidetector CT (MDCT) is expected for a good artery-vein separation in terms of temporal resolution. However, a shortened scan duration may lead to insufficient vascular enhancement. We assessed the optimal scan timing for the artery-vein separation at whole-brain CT angiography (CTA) when bolus tracking was used at 320-row MDCT. We analyzed 60 patients, who underwent whole-brain four-dimensional CTA. Difference in CT attenuation between the internal carotid artery (ICA) and the superior sagittal sinus (Datt) was calculated in each phase. Using a visual evaluation score for the depiction of arteries and veins, we calculated the difference between the mean score for the intracranial arteries and the mean score for the veins (Dscore). We assessed the time at which the maximum Datt and Dscore were simultaneously observed. The maximum Datt was observed at 6.0 s and 8.0 s in the arterial-dominant phase and at 16.0 s and 18.0 s in the venous-dominant phase after the contrast media arrival time at the ICA (Taa). The maximum Dscore was observed at 6.0 s and 8.0 s in the arterial-dominant phase and at 16.0 s in the venous-dominant phase after the Taa. There were no statistically significant differences in Datt (p = 0.375) or Dscore (p = 0.139) between these scan timings. The optimal scan timing for artery-vein separation at whole-brain CTA was 6.0 s or 8.0 s for the arteries and 16.0 s for the veins after the Taa. Advances in knowledge: Optimal scan timing allowed us to visualize intracranial arteries or veins with minimal superimposition.

Stability of pixel density in cone-beam computed tomographic images

The use of cone-beam computed tomography (CBCT) is well accepted for dental diagnosis. However, there has not been adequate evaluation of the image quality that takes into consideration pixel density and dimensional integrity. As a result, some manufacturers claim without substantiation that their CBCT adequately displays CT numbers (CTN). Several authors have claimed that the same volume data can be obtained with CBCT as with multi-detector row computed tomography (MDCT). The density of CBCT images are not displayed as actual CTN because of structural limitations that include radiating condition, scatter radiation, dynamic range limitation of the detector, beam hardening, imaging parameters and object positioning. Another author has reported that the pixel density of CBCT can be used like CTN because there is linearity between pixel density in CBCT and the concentration of the materials. We also found a correlation between pixel density of CBCT and MDCT images. We took into consideration differences in the exposure condition and position of the object in the exposure field for the two image types. Our first goal was to check the stability of the density for the two image types. Then we clarified the correlation of the pixel density between the CBCT and MDCT images by exposing various materials and analyzing the results.

Occult mucin-producing cholangiocarcinoma in situ: a rare clinical case with difficult tumour staging

BackgroundMucin-producing cholangiocarcinoma (MPCC) is an uncommon tumour that is clinically characterized by mucin-hypersecretion. Because the initial symptoms of MPCC may be attributed to the viscus mucobilia, the primary tumour mass may potentially be unrecognizable. We report an interesting case of curatively resected occult MPCC in situ.Case presentationA 70-year-old man was referred to our hospital with increased levels of biliary enzymes. Multidetector row computed tomography (MDCT) demonstrated a diffuse dilatation of the entire biliary system without evidence of tumour mass. Additionally, there were numerous variably sized cysts throughout the liver. The cyst of S4 was the largest, followed by that of S1, which connected with the right hepatic duct. Endoscopic retrograde cholangiography showed intrabiliary mucus, predominantly in the left hepatic duct, but failed to show a communication of both cysts with the bile duct. We clinically suspected that minute MPCC was present within the S1 cyst and performed left hepatectomy, caudate lobectomy, and resection of the extrahepatic bile duct. Macroscopically, papillary adenocarcinoma in situ was present in the S1 cyst, and a final diagnosis of MPCC originating from the bile duct of the caudate lobe was made.ConclusionsFor MPCC, in practice, we should consider the possibility that this tumour can be occult. In this complicated setting, demonstrating the communication to the responsible dilated duct is a clue to the diagnosis. Multidirectional MDCT images succeeded in specifically demonstrating this communication, which is insensitive to the presence of excessive mucobilia.

Detectiono of Pancreatic Carcinoma and Liver Metastases with Contrast-Enhanced Ultrasonography: Comparison with Contrast-Enhanced Multi-Detector Row CT

To compare Contrast-enhanced ultrasonography with contrast material-enhanced multi-detector row computed tomography (CT) in detection of pancreatic carcinoma and liver metastases. This study included 60 patients (48 men, 12 women; mean age, 63.2 years) consisting of 40 patients with pathologically confirmed pancreatic carcinoma (mean size, 3.6 cm) and 20 without a pancreatic lesion. seventy-six liver metastases (mean size, 1.5 cm) in 20 patients with pancreatic carcinoma were diagnosed at pathologic examination or multimodality assessment. Three readers blinded to the final diagnosis interpreted all contrast-enhanced ultrasonography and contrast-enhanced CT images and graded the presence (or absence) of pancreatic carcinoma and liver metastasis on patient-by-patient and lesion-by-lesion bases. Receiver operating characteristic analysis, to compare the diagnostic performance of contrast-enhanced ultrasonography and CT imaging. No significant differences were observed between CT and contrast-enhanced ultrasonography in depiction of pancreatic carcinoma. However, contrast-enhanced ultrasonography had greater sensitivity in depicting liver metastasis than did CT (P<0.05) and in the lesion-by-lesion analysis (P<0.05). Contrast-enhanced ultrasonography was equivalent to dynamic contrast-enhanced CT in depicting pancreatic carcinoma and had better sensitivity for depicting liver metastases, suggesting the usefulness of Contrast-enhanced ultrasonography for evaluation of patients with pancreatic carcinoma.

Optic Nerve Canal Relation to Posterior Paranasal Sinuses in Indian Ethnics: Review and Objective Classification.

Posterior paranasal sinuses consisting of posterior ethmoid and sphenoid sinuses show varying pneumatization and relationship to Optic Nerve Canal (ONC). Most commonly ONC is superolateral to sphenoid sinus, however varied protrusion of ONC into the sinuses may occur. Rarely it may pass completely through the sinus. Optic Nerve (ON) is covered by a thin bony layer or by periosteum and sinus mucosa without bone. Extensive pneumatization of sphenoid sinus and bony dehiscence predisposes to ON injury. The posterior ethmoid cell namely the Onodi cell is of great surgical importance when the ON is along its lateral wall and surrounds the nerve. These varied relations imply that a detailed knowledge of the intimate relationship of ONC with the posterior paranasal sinuses is necessary to avoid unintentional complications during the surgeries involving the ONC region. To assess relationship of ONC to the posterior paranasal sinuses in Indian Ethnic study group. Retrospective review of 100 paranasal sinus Computed Tomography (CT) scans were done using 64 row Multi Detector Computed Tomography (MDCT). Multiplanar reformation images were assessed for ONC relation to posterior ethmoid and sphenoid sinuses, wall dehiscence, and Pneumatization of Anterior Clinoid Process (PACP). 200 optic nerve canals were assessed and grouped into four types based on the modification of Delano et al., classification. The most common OCN was Type-1 (60%), followed by Type-2 (15%), Type-3 (14%) and Type-4 (11%). Dehiscence was seen in 35(17.5%) mostly in Type-3 canals. PACP was seen in 30 (15%). Knowledge of ON relationship to posterior paranasal sinuses will reduce the devastating complications during sinus surgeries. Our modified ONC classification is based on the bony canal morphology and the degree of protrusion into sinuses. As with other reported studies worldwide, Type-1 ONC is the commonest among the Indians also. Type-2 and 3 ONC with sinus wall dehiscence and PACP are the most important anatomical variations which may potentially predispose to risk of surgical injury to the optic nerves.

Role of dual source multidetector row cardiac computed tomography angiography in diagnosis and management of congenital heart disease patients.

IntroductionPrimary evaluation of patients with congenital heart disease (CHD) traditionally relies on echocardiography and conventional cardiac angiography (CCA), both of which have potential limitations.AimTo test the hypothesis that cardiac computed tomography angiography (CCTA) is useful in the diagnosis and management of these patients.Material and methodsThe 3-year observational, analytical, retrospective, cohort study included a total of 111 tomographic studies of patients with congenital heart disease. Computed tomography scans were read twice and medical records were reviewed. The Aristotle complexity was assessed as well as and the contribution of new data in relation to clinical suspicion and diagnostic change was evaluated by two expert readers who were blinded for clinical outcome in consensus reading. The confidence interval was set at 95% and a p-value of < 0.05 was used as the cutoff for statistical significance.ResultsIn total, 111 patients were included (56 men and 55 women) with a mean age of 7.2 years (1 day–71 years). The therapeutic procedure was performed without additional tests in 85.8% of patients. New findings were observed in 60.4% of patients and a subsequent change in management in 46.9%. New unexpected findings in CCTA prompted changes in management in 86.8% of patients. There were no significant differences in age between patients with new findings vs. patients without such findings in CCTA suggesting that CCTA-supported diagnosis of CHD is independent of age.ConclusionsUse of dual-source cardiac computed tomography yields good diagnostic performance in congenital heart disease, prompts changes in management in more than one-third of patients, and reveals new findings in relation to the presumed diagnosis in most patients.

Usefulness of Computed Tomography Image Processing by OsiriX Software in Detecting Wooden and Bamboo Foreign Bodies.

Objective The aim of this study was to evaluate the usefulness of reconstructed computed tomography (CT) images using OsiriX software in detecting wooden and bamboo foreign bodies. Methods Four sizes of wet and dry wooden and bamboo foreign bodies were selected to be analyzed. Those in the air and in the head of edible swine were scanned with a multidetector row CT scanner. The images were evaluated with OsiriX software in the bone and the abdomen window setting as unprocessed images. Three-dimensional rendered images assigned colors and opacity by a 16-bit color look-up table (CLUT) editor in OsiriX software were evaluated as processed images. Results In the unprocessed images, dry and wet foreign bodies in the air were not detected except a part of wet wooden foreign bodies, and all the dry and wet foreign bodies in the swine's head mimicked air with linear shapes. In the processed images, all the dry and wet foreign bodies in the air were detected clearly, and all the wooden and some of the bamboo foreign bodies in the swine's head were detected clearly. Conclusions CT images processed using OsiriX software, especially with a CLUT editor, were useful in detecting wooden and bamboo foreign bodies.

Pacemaker-induced Metallic Artifacts in Coronary Computed Tomography Angiography: Clinical Feasibility of Single Energy Metal Artifact Reduction Technique.

Coronary computed tomography angiography (CCTA) in patients with pacemaker suffers from metallic lead-induced artifacts, which often interfere with accurate assessment of coronary luminal stenosis. The purpose of this study was to assess a frequency of the lead-induced artifacts and artifact-suppression effect by the single energy metal artifact reduction (SEMAR) technique. Forty-one patients with a dual-chamber pacemaker were evaluated using a 320 multi-detector row CT (MDCT). Among them, 22 patients with motion-free full data reconstruction images were the final candidates. Images with and without the SMEAR technique were subjectively compared, and the degree of metallic artifacts was compared. On images without SEMAR, severe metallic artifacts were often observed in the right coronary artery (#1, #2, #3) and distal anterior descending branch (#8). These artifacts were effectively suppressed by SEMAR, and the luminal accessibility was significantly improved in #3 and #8. While pacemaker leads often cause metallic-induced artifacts, SEMAR technique reduced the artifacts and significantly improved the accessibility of coronary lumen in #3 and #8.

Relationship Between Mandibular Ramus Height and Masticatory Muscle Function in Patients With Unilateral Hemifacial Microsomia.

To clarify the relationship between mandibular ramus height and function of masticatory muscles in patients with hemifacial microsomia. Retrospective study of imaging and physiological data. Images and physiological data were obtained from the records of Sapporo Medical University Hospital. A total of 29 patients with hemifacial microsomia who showed Pruzansky grades I, II deformity. Mandibular ramus height and masticatory muscle volume were evaluated with multi-detector row computed tomography. The electromyographic value was measured by the K7 Evaluation System. The hemifacial microsomia patients were classified into three groups based on the mandibular ramus height ratio of the affected and unaffected sides: group 0, >1.00; group 1, 1.00 to 0.85; group 2, <0.85. The Tukey-Kramer method and Games-Howell method were used to determine correlations between parameters. Decreased mandibular ramus height was significantly correlated with both reduced electromyographic values of the masseter muscle (P < .05) and the amount of mandibular lateral deviation at the time of maximum opening (P < .05) on the affected side. These differences were prominent in unilateral hemifacial microsomia patients classified as group 2. Decreased mandibular ramus height may cause dysfunction of the masseter muscles but not the temporal muscle on the affected side in patients with hemifacial microsomia.

Extra radiation dose of lungs in male examinees during cardiac computed tomography

The use of multi-detector row computed tomography in cardiac examinations is increasing globally. Several hospitals are yet to establish a practical method for evaluating the extra scattering dose in the lungs (Dlung) of male examinees with different body-weights undergoing cardiac computed tomography. To measure the dose in each slice of a lung (Dlung,i), thermoluminescent dosimeters are inserted into Rando and tissue-equivalent phantoms made of polymethylmethacrylate and derived from ICRU 48 with masses from 10 to 90 kg. Dlung was evaluated by weighing the scanned volume of each slice. A practical method for determining Dlung involves 64-slice computed tomography scans using a Philips Brilliance computed tomography at 120 kV and 200 mAs, with a thickness of 1.0 mm. Dlung,i increased with distance from the scanning region. This experiment yielded Dlung values from 12.1 ? 2.1 mSv (90 kg) to 23.0 ? 3.8 mSv (10 kg). Finally, a simple equation can be used to derive the relationship between Dlung and the body-weights of a male examinee. Experimental results are compared with others in the literature.

Automatic 3D aortic annulus sizing by computed tomography in the planning of transcatheter aortic valve implantation

BackgroundAccurate imaging assessment of aortic annulus (AoA) dimension is paramount to decide on the correct transcatheter heart valve (THV) size for patients undergoing transcatheter aortic valve implantation (TAVI). We evaluated the feasibility and accuracy of a novel automatic framework for multidetector row computed tomography (MDCT)-based TAVI planning. MethodsAmong 122 consecutive patients undergoing TAVI and retrospectively reviewed for this study, 104 patients with preoperative MDCT of sufficient quality were enrolled and analyzed with the proposed software. Fully automatic (FA) and semi-automatic (SA) AoA measurements were compared to manual measurements, with both automated and manual-based interobserver variability (IOV) being assessed. Finally, the effect of these measures on hypothetically selected THV size was evaluated against the implanted size, as well as with respect to manually-derived sizes. ResultsFA analysis was feasible in 92.3% of the cases, increasing to 100% if using the SA approach. Automatically-extracted measurements showed excellent agreement with manually-derived ones, with small biases and narrow limits of agreement, and comparable to the interobserver agreement. The SA approach presented a statistically lower IOV than manual analysis, showing the potential to reduce interobserver sizing disagreements. Moreover, the automated approaches displayed close agreement with the implanted sizes, similar to the ones obtained by the experts. ConclusionThe proposed automatic framework provides an accurate and robust tool for AoA measurements and THV sizing in patients undergoing TAVI.