MDCT Scan Research Articles

CT Findings of Gastrointestinal Stromal Tumor in Meckel’s Diverticulum - a Case Report

Although the small bowel constitutes about 75% of the gastrointestinal (GI) tract, primary tumors in it are relatively rare, making up only a small percentage of all GI neoplasms. Neoplasms of Meckel's diverticulum are rare and gastrointestinal stromal tumors are very uncommon malignant tumors occurring in this site. We report a case of a small-bowel tumor with an extremely rare histological type and uncommon location which was diagnosed on 64 MDCT scan and subsequently confirmed at surgery and histopathology. A 46-year-old male nonsmoker and nondiabetic presented to the emergency department with 3 massive gastrointestinal bleeding episodes in the form of melena. On examination, the patient was apyrexial and was having tachycardia and pallor with a blood pressure of 80/30mmHg. He had no past history of hematemesis or melena. The patient was resuscitated by 6 fresh blood transfusions and underwent abdominal x-ray and ultrasonography which were unremarkable. In 24 hours, the patient underwent three EGDs which failed to reveal any cause of bleeding from upper gut. Next day, colonoscopy was done which showed colon smeared with altered blood; however, no mucosal abnormality was visualized up to the ileocecal valve. In addition, however, blood was seen pouring out through the ileocecal valve and about 10cm of terminal ileum were filled with blood. No mucosal lesion was seen. On the second day in evening, the patient again had two massive bleeding episodes, again went into shock and four more blood transfusions were given to combat shock. The patient was send to the department of radiodiagnosis for CT scan which was done by Siemens Somotom Sensation 64 Multislice CT and showed a highly enhancing pelvic mass, exophytic, projecting from the small-gut wall, likely arising from a Meckel’s diverticulum (figures 1, 2 and 3). Figure 1 Figure 1: Axial MDCT image showing an exophytic, briskly enhancing pelvic mass arising eccentrically from the small gut. CT Findings of Gastrointestinal Stromal Tumor in Meckel’s Diverticulum a Case Report

Isolated granulocytic sarcoma presenting as a large lung mass

We report a unique histologically proven case of isolated intrathoracic granulocytic sarcoma in a 37-year-old man who had sustained complete remission for 45 months after receiving allogeneic bone marrow transplantation for acute myeloid leukemia. Chest MDCT scan showed a large lung mass with atelectasis in the right middle lobe and hilar and mediastinal lymphadenopathy which mimicked advanced bronchogenic carcinoma.

Radiation doses from small-bowel follow-through and abdomen/pelvis MDCT in pediatric Crohn disease

The onset of Crohn disease (CD) can occur in childhood. Imaging, which often involves radiation, is frequent in CD both for disease diagnosis and follow-up. However, information regarding radiation dose for contemporary CT and fluoroscopy is not available for determining the cost/benefit ratio for imaging strategies. To compare effective dose (ED) for small-bowel follow-through (SBFT) and abdomen/pelvis MDCT in pediatric CD. Average fluoroscopic time and number of radiographs were obtained for 30 consecutive pediatric SBFTs. The numbers of SBFTs and CT scans performed per child among children with CD (1990-2005) were determined. The ED was determined (ICRP 60, 10-year-old phantom, MOSFET) for a 5-min fluoroscopy examination of the central abdomen and right lower quadrant (110 kVp, 0.3 mA) and pelvis (110 kVp, 0.35 mA). The ED for a 16-slice abdomen/pelvis MDCT scan was determined using the 10-year-old protocol: 16 x 1.25 mm, pitch 1.375, 27.5 mm/rotation, 0.5 s, 140 kVp, 85 mA. A total of 176 children with CD underwent imaging, averaging 1.2 SBFTs and 1.1 CT scans. On average SBFT took 5.1 min with 3.3 abdominal radiographs. The EDs (mSv) for a 5-min fluoroscopy were 0.15 for the central abdomen, 0.35 for the right lower quadrant, and 0.56 for the pelvis, yielding an average ED for SBFT (5-min fluoroscopy, 3.3 abdominal radiographs) of 1.8-2.2 mSv. The ED for MDCT was 3.48 mSv. Although the ED for MDCT might be up to twice that for SBFT, excessive fluoroscopy time and number of abdominal radiographs can result in actual EDs that are equivalent. Attention must be paid to SBFT technique to minimize radiation dose and to the indication to determine the appropriate examination.

Aortic Arch Calcification and Arterial Stiffness are Independent Factors for Diastolic Left Ventricular Dysfunction in Chronic Hemodialysis Patients

Because cardiovascular disease is the major cause of death in dialysis patients, the correlation between diastolic left ventricular (LV) dysfunction and arterial sclerosis, including thoracic aortic calcification, was studied in chronic hemodialysis (HD) patients. The enrolled study subjects were 142 (73 men, 69 women) maintenance HD patients. Aortic arch calcification volume (AoACV) was measured by MDCT scan, arterial stiffness was estimated by brachial-ankle pulse wave velocity (PWV) and diastolic LV function was estimated as E/E' by tissue Doppler imaging with cardiac ultrasonography. E/E' correlated significantly with systolic blood pressure (r=0.29, p=0.037), age (r=0.19, p=0.02), LV mass index (r=0.18, p=0.036), dialysis vintage (r=0.19, p=0.037), AoACV (r=0.37, p<0.0001) and PWV (r=0.33, p=0.0002). Multiple regression analysis indicated that AoACV (beta=0.26, p=0.005) and PWV (beta=0.22, p=0.03) were independent determinants of E/E'. Diastolic LV dysfunction may be induced by increased vascular calcification and reduced arterial stiffness in chronic HD patients.

A stochastic approach for automatic registration and fusion of left atrial electroanatomic maps with 3D CT anatomical images

The integration of electroanatomic maps with highly resolved computed tomography cardiac images plays an important role in the successful planning of the ablation procedure of arrhythmias. In this paper, we present and validate a fully-automated strategy for the registration and fusion of sparse, atrial endocardial electroanatomic maps (CARTO maps) with detailed left atrial (LA) anatomical reconstructions segmented from a pre-procedural MDCT scan. Registration is accomplished by a parameterized geometric transformation of the CARTO points and by a stochastic search of the best parameter set which minimizes the misalignment between transformed CARTO points and the LA surface. The subsequent fusion of electrophysiological information on the registered CT atrium is obtained through radial basis function interpolation. The algorithm is validated by simulation and by real data from 14 patients referred to CT imaging prior to the ablation procedure. Results are presented, which show the validity of the algorithmic scheme as well as the accuracy and reproducibility of the integration process. The obtained results encourage the application of the integration method in post-intervention ablation assessment and basic AF research and suggest the development for real-time applications in catheter guiding during ablation intervention.

Letter by Gaibazzi Regarding Article, “Usefulness of 64-Slice Cardiac Computed Tomographic Angiography for Diagnosing Acute Coronary Syndromes and Predicting Clinical Outcome in Emergency Department Patients With Chest Pain of Uncertain Origin”

HomeCirculationVol. 116, No. 12Letter by Gaibazzi Regarding Article, “Usefulness of 64-Slice Cardiac Computed Tomographic Angiography for Diagnosing Acute Coronary Syndromes and Predicting Clinical Outcome in Emergency Department Patients With Chest Pain of Uncertain Origin” Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessLetterPDF/EPUBLetter by Gaibazzi Regarding Article, “Usefulness of 64-Slice Cardiac Computed Tomographic Angiography for Diagnosing Acute Coronary Syndromes and Predicting Clinical Outcome in Emergency Department Patients With Chest Pain of Uncertain Origin” Nicola Gaibazzi, MD Nicola GaibazziNicola Gaibazzi Cardiology Unit, Parma University Hospital, Parma, Italy Search for more papers by this author Originally published18 Sep 2007https://doi.org/10.1161/CIRCULATIONAHA.107.705426Circulation. 2007;116:e354To the Editor:I congratulate the authors of the interesting article, “Usefulness of 64-Slice Cardiac Computed Tomographic Angiography for Diagnosing Acute Coronary Syndromes and Predicting Clinical Outcome in Emergency Department Patients With Chest Pain of Uncertain Origin,” for their well-conducted study.1In the Clinical Implications section, the authors state “MDCT [multidetector computed tomographic] scanning has the potential to change clinical practice with respect to ED [emergency department] triage in patients with chest pain of uncertain origin.” I hope this is not going to happen, since my point is that it would be very unfortunate.The interest in clinical use of MDTC for coronary artery disease detection has been overinflated in the last few years, driven by equipment vendors for obvious, nonscientific reasons, as is typical for any new technology. MDCT is able to show nice-looking pictures of the coronaries, and a negative scan can approximate 100% of negative predictive power for coronary artery disease, but when used in chest pain units, the information it adds is trivial in comparison with low-cost, well-established imaging modalities.In fact, stress echocardiography has demonstrated exceptionally high negative predictive power in multicenter studies with large samples, such as the Stress Pharmacological Echocardiography in Emergency Department (SPEED) trial,2 with negative predictive power of 98.8% for all cardiovascular events and 99.6% for “hard” cardiovascular events. Conversely, a positive MDCT scan (presence of >50% coronary stenosis) often presents a diagnostic dilemma in that MDCT is not able to address the functional significance of a stenosis. In case of a positive result, a stress test becomes mandatory before or after diagnostic coronary angiography, making the initial MDCT scan once again redundant (“a costly picture”).Even more important, patient radiation exposure tends to be understated or “forgotten” in clinical studies and in clinical practice. This exposure represents a serious downside to this imaging modality, with the 10 to 20 mSv exposure dose of the scan corresponding to 1 new (fatal or nonfatal) cancer for every 1000 to 500 scans, according to the latest estimate of the authoritative Biological Effects of Ionizing Radiation Seventh Committee, released in 2005 from the US National Research Council.3So what is the role of MDCT scanning in the chest pain unit? Do we need a 1% gain in negative predictive power (from 99% to 100%) paid for by radiation exposure and unbelievably higher financial costs? Long-term risks should be included in the risk–benefit assessment of our procedures.DisclosuresNone.1 Rubinshtein R, Halon DA, Gaspar T, Jaffe R, Karkabi B, Flugelman MY, Kogan A, Shapira R, Peled N, Lewis BS. Usefulness of 64-slice cardiac computed tomographic angiography for diagnosing acute coronary syndromes and predicting clinical outcome in emergency department patients with chest pain of uncertain origin. Circulation. 2007; 115: 1762–1768.LinkGoogle Scholar2 Bedetti G, Pasanisi EM, Tintori G, Fonseca L, Tresoldi S, Minneci C, Jambrik Z, Ghelarducci B, Orlandini A, Picano E. Stress echo in chest pain unit: the SPEED trial. Int J Cardiol. 2005; 102: 461–7.CrossrefMedlineGoogle Scholar3 Health Risks From Exposure to Low Levels of Ionizing Radiation: Biological Effects of Ionizing Radiation Seventh Committee, Phase 2 (2006). Available at: http://books.nap.edu/openbook.php?isbn=030909156X. Accessed August 18, 2007.Google Scholar Previous Back to top Next FiguresReferencesRelatedDetails September 18, 2007Vol 116, Issue 12 Advertisement Article InformationMetrics https://doi.org/10.1161/CIRCULATIONAHA.107.705426PMID: 17875977 Originally publishedSeptember 18, 2007 PDF download Advertisement SubjectsAcute Coronary SyndromesComputerized Tomography (CT)Echocardiography

Accessory Epiploic Artery Originating from the VIII Segment Branch of the Right Hepatic Artery Discovered During Hepatic Chemoembolization

Knowledge of the standard anatomy and anomalies of the hepatic vessels is mandatory to obviate complications secondary to hepatic surgery, especially in liver transplantation, as well as in many radiological procedures such as transarterial chemoembolization for hepatic tumors. An international classification of the main variations in the vascular anatomy of the liver was proposed by Michels [1] in 1966 and modified by Hiatt et al. [2] in 1994. A standard finding, in 52–79% of cases, is the common hepatic artery arising from the celiac trunk, becoming the proper hepatic artery, and thus giving off the left and right hepatic arteries. Many other articles, in particular those concerned with living related liver transplant donor candidates, have tried to describe any unreported variations in direct relation to the potential surgical risk [3, 4]. Another large series was recently published by Song and colleagues [5], who did an angiographic analysis of nonhepatic arteries originating from the hepatic arteries in 250 patients. They found the right gastric artery to be the most common of these nonhepatic arteries, followed by the hepatic falciform artery, accessory left gastric artery, posterior superior pancreaticoduodenal artery, and left inferior phrenic artery; furthermore the left hepatic artery was the most frequent origin of nonhepatic arteries. We present a case of an accessory epiploic artery originating from a segmental branch of the right hepatic artery, also supplying a hepatocellular carcinoma located at the hepatic dome. The anomaly was discovered on the MDCT scan (Fig. 1) in association with a Michels type V variation (accessory right hepatic artery arising from the superior mesenteric artery) [1] (Fig. 2). The MDCT finding was subsequently confirmed at selective segmental arteriography of the VIII segment (Fig. 3) done before chemoembolization. The treatment was subsequently safely performed by positioning a microcatheter distal to the origin of this accessory epiploic artery. To our knowledge this anatomic variation of the hepatic vasculature has not been described previously.

Noninvasive Analysis of Coronary Artery Disease with Combination of MDCT and Functional MRI

We evaluated the diagnostic accuracy of an eight-row multidetector computed tomography coronary angiography (MDCT-CA) in detecting high-grade (>50%) stenoses in the three main coronary arteries in patients with coronary artery disease (CAD). Side branches were excluded. We correlated magnetic resonance imaging (MRI) findings of the myocardium with MDCT-CA of the coronary arteries. Fourteen CAD patients underwent conventional coronary angiography (CCA), MDCT-CA, and MRI. We determined the calcium burden with non-enhanced MDCT scan. Then MDCT-CA was performed after intravenous contrast injection during a single breathhold. The left ventricular (LV) MR cine imaging was assessed at rest and perfusion defects were observed during pharmacologic stress after contrast administration. Delayed contrast-enhanced MRI was performed to picture infarctions. MDCT-CA had sensitivity 82%, specificity 94%, positive predictive value 79%, and negative predictive value 95% of stenoses of more than 50% in the main coronary arteries when compared with CCA. LV wall dysfunction, perfusion defects, and infarctions were detected in 50%-78% of sectors assigned to calcifications or stenoses, but also in sectors supplied by normally perfused coronary arteries. CCA and MDCT-CA revealed comparable results in evaluating stenotic lesions above 50% in the main subepicardial coronary branches. There were no significant correlations between the degree of stenosis or calcification at MDCT-CA and the MR findings, but the combined information of MDCT-CA and MRI showed the variability of myocardial changes in regions perfused by significantly stenosed, calcified, and normal main coronary arteries.

Occlusive Acute Myocardial Infarct on 16 Multidetector-row Helical CT: An Experimental Study in Rabbits

Purpose: We wanted to evaluate the findings and diagnostic accuracy of MDCT for diagnosing occlusive acute myocardial infarction in rabbits. Materials and Methods: Myocardial infarction was induced in 14 rabbits. MDCT was performed in the early and delay phases at 1 minute and 6 minutes, respectively, after intravenous contrast injection. The rabbits were sacrificed after scanning. The cardiac specimens were sliced and then stained with triphenyltetrazolium chloride (TTC). The agreement in the transmural extent of infarction between the MDCT scans and the TTCstained specimens were analyzed by using kappa values. Results: Acute myocardial infarction was found in 9 of 14 rabbits on the TTC-stained specimens and MDCT. The infarcted myocardium was demonstrated as a low-attenuation area on the early phase and as a central low-attenuation area with rim-like enhancement along the endocardial and pericardial sides of the myocardial wall on the delay phase. There was excellent agreement in the scores of the transmural extent of myocardial infarction between the TTC-stained specimens and the early phase scan (kappa value = 0.882, p = 0.000), and there was fair to good agreement between the TTC-stained specimens and the delay phase scan (kappa value = 0.439, p = 0.000). Microscopic examination of the cardiac specimens revealed necrosis of myocardial cells in the central portion and granulation tissue along the endocardial and pericardial sides of the necrotic myocardium. Conclusion: 16 slice MDCT scan was useful for the diagnosis of acute myocardial infarction. The early phase scan was more accurate than the delay phase scan for evaluating the transmural extent of myocardial infarction. Histopathologic examination suggested that the low-attenuation area on the delay phase might correspond to necrotic myocardium and the enhanced area might correspond to granulation tissue.

A Novel Model to Test Accuracy and Reproducibility of MDCT Scan Protocols for Coronary Calcium in Vivo

We compared the accuracy and reliability of prospectively triggered, retrospectively ECG gated, and non-gated CT image reconstruction for measurements of coronary artery calcification (CAC) in vivo using a novel animal model. In six Yorkshire farm pigs, prefabricated chains of cortical bone fragments were sutured over the epicardial bed of the major coronary arteries. Using a 4-slice MDCT scanner, each animal was imaged with two different protocols: sequential acquisition with prospective ECG triggering, and spiral acquisition with retrospectively ECG gated image reconstruction- non-gated reconstructions were also generated from these latter scans. Two independent observers measured the 'Agatston score' (AS), the calcified volume (CV), and mineral mass (MM). To calculate accuracy of MM measurements the ash weight of the burned bone fragments was compared to MDCT derived MM. Six pigs successfully underwent surgery and CT imaging (mean heart rate: 86+/-12 bpm). MM measurements from prospectively ECG triggered CT sequential scans were more accurate (p<0.02) and reproducible (p=0.05) than sequential CT scans without ECG triggering or spiral acquisition using retrospective ECG gating. At high heart rates prospective ECG triggered image reconstruction is more accurate and reproducible for CAC scoring than retrospective ECG gated reconstruction and non-gated reconstruction.

An Unusual Case of Systemic Arterial Supply to the Lung with Bronchial Atresia

2Division of Thoracic Surgery, The Ottawa Hospital, Civic Campus, Ottawa, ON, Canada K1Y 4E9. e wish to report an unusual case of systemic arterial supply to the lung with coexistent congenital bronchial atresia identified on a contrast-enhanced MDCT scan. This is a rare and interesting anomaly within the pulmonary sequestration spectrum that differs considerably from the classic description of sequestration. A confident diagnosis on CT scan allowed for nonoperative treatment with embolization of the systemic artery. This case also highlights the utility of the alternative classification of bronchopulmonary-vascular malformations (BPVM) described by Clements and Warner [1].

"Evaluation of Mandibular Pathologies By MDCT and Denta Scan Software"

"Evaluation of Mandibular Pathologies By MDCT and Denta Scan Software"