Coronary arterial bypass graft patency evaluated by multi-detector computed tomography and magnetic resonance imaging

The progression of atherosclerosis of the coronary artery does not stop after coronary arterial bypass grafting (CABG) surgery. In contrary, new stenotic lesions or even     

Invasive angiography, computed tomography or magnetic resonance imaging for coronary imaging and cardiovascular risk stratification? Regulatory and practical considerations

In 2003, risk stratification in coronary heart disease is routinely performed by the results of coronary angiogram, the invasive gold standard angiography. Combined with the left ventricular ejection fraction assessment, the classification in one, two or three vessel disease remain the cornerstone of the revascularization strategy despite well-known limitations of this approach. Invasive coronary angiography is a mature technic with recommendations for training program and guidelines for indications. By comparison, the new noninvasive coronary imaging tools, computed tomography (CT) and magnetic resonance (MR) imaging, are just emerging. Coronary artery MR angiography is one of the most challenging areas because of the size and topology of the coronary arteries, as well as cardiac and respiratory motion. Multidetector-row and multisclice spiral computed tomography appear of most value for the detection of coronary artery disease with an excellent negative predictive value for proximal and middle main branches. Together, MR and CT, provide unique information that may predict cardiovascular risk. They identify flow-limiting coronary stenoses and calcified plaques, directly image the atherosclerotic lesions, measure atherosclerotic burden and characterize plaque components. Nevertheless, invasive coronary angiography still remain the first step of percutaneous coronary intervention. Therefore, one of the ultimate goals for the clinicians is the identification of the high-risk patient through a combination of strategies such as assessment of conventional risk factors, blood markers, and imaging. Indifferently to the imaging tool, the treatment should consider a human being and not only a picture.     

Quantitative analysis of skeletal muscle mass in patients with rheumatic diseases under glucocorticoid therapy – Comparison among bioelectrical impedance analysis,computed tomography,and magnetic resonance imaging

Abstract

Objectives. To determine the availability of bioelectrical impedance analysis (BIA), computed tomography (CT), and magnetic resonance imaging (MRI) for measurement of skeletal muscle mass in patients with rheumatic diseases and quantitatively assess skeletal muscle loss after glucocorticoid (GC) treatment.

Methods. The data from 22 patients with rheumatic diseases were retrospectively obtained. The muscle mass of body segments was measured with a BIA device in terms of skeletal muscle mass index (SMI). Cross-sectional area (CSA) was obtained from CT and MRI scans at the mid-thigh level using the image analysis program. We further assessed the data of three different measurements before and after GC treatment in 7 patients with rheumatic diseases.

Results. SMI of whole body was significantly correlated with estimated muscle volume and mid-thigh muscle CSA with CT and MRI (p < 0.01). Significant correlations between SMI and mid-thigh muscle CSA of each leg were also found (p < 0.01). All the three measurements were negatively correlated with GC dosage (p < 0.01). Significant decline in mid-thigh muscle CSA with CT and MRI was found after GC treatment in 7 patients (p < 0.02). Those patients showed significant decline in SMI of whole body after GC treatment, but not in SMI of each leg. On the other hand, significant correlations between mid-thigh muscle CSA with CT and MRI were found before and after GC treatment (p < 0.01).

Conclusions. GC-related skeletal muscle loss could be quantitatively assessed with BIA, CT, or MRI in patients with rheumatic diseases, and CT and MRI appeared to be more accurate than BIA.     

Does the type of prosthesis influence early left ventricular mass regression after aortic valve replacement? Assessment with magnetic resonance imaging

Background

Debate exists regarding selection of the prosthesis type most likely to maximize early left ventricular (LV) mass regression after aortic valve replacement (AVR) for stenotic valvular disease. The aim of this study was to compare the degree of LV mass regression measured by MRI 6 months after prospectively randomized valve implantation for two biological prostheses, stented and stentless, and for two mechanical valves, tilting disc and bileaflet.

Methods

Thirty-nine consecutive patients with predominant aortic stenosis accepted for elective AVR were studied. Twenty patients requiring a tissue prosthesis were randomly assigned to receive either a Freestyle or Mosaic valve. The remaining 19 patients in whom mechanical prosthesis was indicated were randomly assigned to receive either an Ultracor or an ATS valve.

Results

There was no difference in valve size implanted between the compared groups. LV mass measurements were performed with MRI (1.5-T Vision, Siemens, Germany) immediately before and 6 months after surgery. All valve types produced significant postoperative reduction in LV mass compared with preoperative values (P < .01). Percent change in LV mass regression was similar between the two porcine valve types, Mosaic (24.4% ± 11.1%) and Freestyle (21.1% ± 16.7%), and between the two mechanical valve designs, Ultracor (19.3% ± 9.5%) and ATS (26.3% ± 10.8%), respectively.

Conclusions

Significant LV remodeling occurs early after AVR for aortic stenosis. The degree of regression in LV mass is independent of prosthesis type implanted.     

Imaging in the diagnosis and management of peripheral psoriatic arthritis—The clinical utility of magnetic resonance imaging and ultrasonography

Psoriatic arthritis (PsA) is an inflammatory joint disease characterised by the presence of arthritis and often enthesitis and/or spondylitis in patients with psoriasis. However, it presents a wide range of disease manifestations in various patterns. Imaging is an important part of management of PsA, and is used for multiple reasons including establishing/confirming a diagnosis of inflammatory joint disease, determining the extent of disease, monitoring activity and damage, assessing therapeutic efficacy, and identifying complications of disease or treatment, in the setting of clinical practice or clinical studies. Magnetic resonance imaging (MRI) allows detailed assessment of all peripheral and axial joints involved in PsA, and can visualise both inflammation and structural changes. Ultrasonography (US) can visualise many of the peripheral heterogeneous tissue compartments affected by PsA. In contrast to MRI, US is not useful for assessing axial involvement in the spine and sacroiliac joints. In this paper, we will provide an overview of the status, strengths and limitations of MRI and US in peripheral PsA in routine clinical practice and clinical trials.     

Comparison of 16 slice multi-detector computed tomography and breath hold 3D magnetic resonance angiography in the detection of coronary stenosis

Objective To compare 16-slice multi-detector spiral computed tomography (MDCT) and breathhold 3D magnetic resonance (MR) coronary angiography in the visualization of coronary arteries and the accuracy of detecting significant (> 50%) coronary stenoses in patients with suspected coronary artery disease. Methods Forty patients were examined by 16-slice CT (GE, Lightspeed 16) and MR (GE,Twinspeed) within 3 days; 31 of them underwent conventional coronary angiography (CAG) within 2 weeks after CT and MR scan. CT was performed with 16×1.25 mm detector collimation, 0.5 s rotation time and images were reconstructed at 60%-75% of the cardiac cycle. MR was performed with breath hold 3D FIESTA (TR4.0 ms, TE1 .7 ms, flip angle 65, slice thickness 3 mm, FOV 280 mm, matrix 256×192). Mean heart rate was 63±5.8 bpm andβ-blocker was used in 24 patients. MR and CT image quality was evaluated in 9 coronary segments (RCA1, RCA2, RCA3, LM, LAD1, LAD2, LAD3, LCX1, LCX2) using a four-point grading scale. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated for detection of significant stenosis using CAG as the gold standard. Results 16-slice CT showed higher image quality in most coronary segments except RCA2. Forty-three segments were diagnosed as significant stenosis by CAG, 36 and 27 of these were correctly detected by CT and MR respectively. Sensitivity, specificity, positive predictive value, and negative predictive value of 16-slice CT and MR for detecting significant stenosis were 83%, 84%. 49%, 97%. and 63%, 90%, 55%, 93%, respectively. Conclusion Sixteen-slice CT showed higher image quality in most coronary segments excepted for middle RCA. 16-slice CT had higher sensitivity than MR for detection of coronary significant stenosis, whereas MR had higher specificity than CT. Both CT and MR showed high negative predictive value, which is useful for excluding coronary stenosis in symptomatic patients. (J Geriatr Cordial 2006; 3(1): 24-28)     

Intraductal papillary mucinous neoplasm of the pancreas – epidemiology,risk factors,diagnosis, and management

Intraductal papillary mucinous neoplasm (IPMN) is one of the most common cystic neoplasms of the pancreas. It is a heterogeneous disease and can be divided into ductal types and morphological subtypes. The incidence of IPMN is increasing, likely due to the widespread use of cross-sectional imaging and a growing elderly population. IPMN poses an increasing demand on the health care system. Current guidelines provide indications for surgery and recommendations for surveillance, but management of IPMN is still challenging in routine clinical practice. In this article, we review current knowledge about IPMN and provide future directions for improving diagnosis and management.     

A rare case of retro-hepatic inferior vena caval leiomyosarcoma – Computed tomography,surgical and intraoperative echocardiography imaging

Leiomyosarcoma of retro-hepatic portion of inferior vena cava (IVC) is a rare vascular tumor with poor prognosis if adequate surgical resection is not achieved. Surgical repair includes dissection of the tumor and reconstruction of the IVC with a tube graft. Establishing a normal flow and gradient in IVC and hepatic veins is imperative for a successful repair. We report a case of retro hepatic IVC leiomyosarcoma where the preoperative computed tomography described the anatomy and extension of the tumor whereas intraoperative transesophageal echocardiography helped in the assessment of adequacy of surgical repair.     

Clinicopathological study of solid and pseudopapillary tumor of pancreas： Emphasis on magnetic resonance imaging findings

AIM: To report the clinicopathological features and magnetic resonance imaging (MRI) findings of solid and pseudopapillary tumor (SPT) of pancreas.METHODS: From 1981 to 2005, 26 surgically treated cases of SPT were retrospectively reviewed. MRI findings of the latest 11 consecutive SPT cases were investigated.RESULTS: There were 25 women and one man having SPT (median age: 23 year) with a median tumor size of 7.5 cm. Among them, nine patients developed solid pseudopapillary carcinoma. During the median follow-up period of 66 mo, the 5-year survival rate of the 26 SPT patients was 96.2%. Three MRI features were proposed including Type 1 image, displaying SPT with completely solid part. All SPT patients with type 1 image were detected incidentally. Type 2 image displays of SPT with solid mass hemorrhage and type 3 image with massive hemorrhage. All the eight SPT patients with type 2 and 3 images suffered abdominal pain due to hemorrhage from SPT.CONCLUSION: SPT had a favorable survival rate irrespective of surgical procedures, malignancy, and MRI findings, however, MRI could reliably correlate with its clinicopathological features.     

Is combined 18F-fluorodeoxyglucose-positron emission tomography/computed tomography superior to positron emission tomography or computed tomography alone for diagnosis, staging and restaging of pancreatic lesions?

BACKGROUND AND STUDY AIMS: To evaluate whether combined 18F-FDG PET/CT has an additive value over 18F-FDG-PET or CT alone for diagnosis, staging and restaging of pancreatic lesions. PATIENTS AND METHODS: Forty-six consecutive patients (23 women, 23 men; median age 62.5 years) underwent FDG-PET/CT. Analysis of PET, CT and fused PET/CT images was performed by 2 readers. Patients were divided into 2 groups: diagnosis and staging of primary tumours (n=34) and restaging: screening for recurrent or progressive pancreatic cancer (n=12). Accuracy analysis was performed lesion-by-lesion and patient-by-patient. Results were correlated with histopathology or clinical follow-up. RESULTS: Ninety-five foci were identified on PET, 140 lesions on CT and 119 on PET/CT. Thirty-four lesions were defined as 'definitely pathologic' and localised in pancreas, liver, lung or bone by all 3 techniques with equal certainty. In 11 patients malignancy was ruled out with the highest certainty by PET/CT. All 3 modalities made 2 false positive diagnoses of malignancy and missed metastases or vascular ingrowth in 7 patients. The accuracy rate of PET/CT (91.2%) for diagnosis of primary pancreatic lesions is higher compared to CT (88.2%) and PET alone (82.3%). Also for locoregional staging PET/CT has a higher accuracy rate (85.3%) compared to CT (83.8%) and PET (79.4%). When used for restaging, sensitivity (90.0%) and accuracy rate (91.6%) were highest for PET and PET/CT. CT had a lower sensitivity (80.0%). CONCLUSIONS: Topographical assignment of 'spots' with high FDG uptake is superior with PET/CT compared to PET alone. Fused PET/CT has a slightly higher sensitivity and accuracy rate for diagnosis and locoregional staging of primary pancreatic lesions compared to CT alone. PET and PET/CT perform equally well in screening for recurrent or progressive pancreatic cancer, with high accuracy. Due to its unlimited access, lower radiation exposure and cost, multidetector row CT remains the imaging technique of choice for diagnosis, staging and screening for recurrent pancreatic cancer.     

Detection of nodules in liver cirrhosis: spiral computed tomography or magnetic resonance imaging? A prospective study of 88 nodules in 34 patients

Detection and characterization of all focal lesions in the liver are critical for screening patients with chronic liver disease. The aim of this prospective study was to investigate the accuracy of magnetic resonance imaging (MRI) and spiral computed tomography for the diagnosis of hepatic nodules in cirrhotic patients when compared with pathological findings of the explanted liver. From February 1997 to July 1999, 34 cirrhotic patients waiting for orthotopic liver transplantation (OLT) (mean age, 53.5 +/- 9.3 years; 24 males) were included. All patients had MRI and spiral computed tomography examinations, and findings were matched with the histological findings. Data analyses were made using the McNemar chi-square test. Mean time between radiological examination (MRI or spiral computed tomography) and OLT was 43.8 +/- 39 days. A total of 88 nodules were found in the 34 patients: 54 hepatocellular carcinoma (HCC) (mean size, 18 +/- 10 mm) in 21 patients, 22 dysplastic nodules (mean size, 10.7 +/- 4.3 mm) in 11 patients, and 12 macroregenerative nodules in 13 patients. Lesion-by-lesion analyses showed that sensitivity of MRI and spiral computed tomography for nodule, HCC or dysplastic nodule diagnosis was 44.3 and 31.8% (P = 0.02), 61.1 and 51.9% (P = 0.2), and 27.3 and 0% (P = 0.04), respectively. Patient-by-patient analyses showed no statistical difference between spiral computed tomography and MRI for nodule diagnosis. In conclusion, in patients with liver cirrhosis, MRI is more accurate than spiral computed tomography for the detection of liver nodules and dysplastic nodules. However, tumour size is always a restricting factor for these two techniques, which are unable to detect small HCC in more than 60% of cases.     

Magnetic resonance imaging versus computed tomography for the detection of coronary stenosis: do we really have to focus on “stenoses”?

See article on page 1381     

A comparative study between computed tomography and endoscopic ultrasound in the detection of a mural nodule in intraductal papillary mucinous neoplasm –Multicenter observational study in Japan

Background/objectivesThe detection of malignancy is a major concern in the management of intraductal papillary mucinous neoplasm (IPMN). The height of the mural nodule (MN), estimated using endoscopic ultrasound (EUS) and computed tomography (CT), has been considered crucial for predicting malignant IPMN. Currently, whether surveillance using CT or EUS alone is sufficient for detecting MNs remains unclear. This study aimed to compare the ability of CT and EUS to detect MNs in IPMN.MethodsThis multicenter, retrospective observational study was conducted in 11 Japanese tertiary institutions. Patients who underwent surgical resection of IPMN with MN after CT and EUS examinations were eligible to participate. The MN detection rates between CT and EUS were examined.ResultsTwo-hundred-and-forty patients who underwent preoperative EUS and CT had pathologically confirmed MNs. The MN detection rates of EUS and CT were 83% and 53%, respectively (p < 0.001). Additionally, the MN detection rate of EUS was significantly higher than that of CT regardless of morphological type (76% vs. 47% in branch-duct-type IPMN; 90% vs. 54% in mixed IPMN; 98% vs. 56% in main-duct-type IPMN; p < 0.001). Further, pathologically confirmed MNs ≥5 mm were more frequently observed on EUS than on CT (95% vs. 76%, p < 0.001).ConclusionsEUS was superior to CT for the detection of MN in IPMN. EUS surveillance is essential for the detection of MNs.