The Assessment of Cardiac Masses by Cardiac CT and CMR Including Pre-op 3D Reconstruction and Planning.

PURPOSE OF REVIEW: The purpose of this review is to (1) review the recent evidence examining the use of CT and CMR in the assessment of a suspected cardiac mass, (2) summarize the typical imaging features of the most common cardiac masses, and (3) examine the latest developments in the use of three-dimensional reconstructions and models in the preoperative assessment of a cardiac mass. RECENT FINDINGS: CMR can distinguish between tumors and non-tumor masses and between benign and malignant mass with a high degree of accuracy. CT and CMR are complementary tools in the evaluation of cardiac masses. CMR is the preferred initial imaging modality due to its versatile imaging planes and superior tissue characterization. CT better depicts calcification and has a higher spatial resolution compared with CMR, which is of particular importance in preoperative planning. CT also offers a valuable alternative in those with contraindications to CMR. Three-dimensional reconstructions, particularly of CT datasets, are a valuable adjunct in the preoperative assessment of a cardiac mass and may allow a better appreciation of the margins of the mass and its relationship with surrounding structures. Three-dimensional printing is an emerging technology which may be of additional value in selected patients with a cardiac mass.

To investigate dose reduction and comparability of standard dose CT vs Ultra low dose CT in evaluating pulmonary emphysema.

OBJECTIVES: The aim of this study was to investigate the extent of dose reduction and comparability of standard dose CT vs Ultra low dose CT in evaluating pulmonary emphysema. METHODS: Forty-nine patients with emphysema were recruited from a tertiary referral respiratory clinic. Each patient had a non-contrast Standard Dose (SD) and Ultra Low Dose (ULD) thoracic CT. The images were reconstructed using contemporary iterative reconstruction with a standard lung kernel. Lung volumes and emphysema severity was calculated using a commercially available automated densitometry segmentation package. The effective dose was calculated for both CT protocols. RESULTS: Automated densitometry calculated the total lung volume and percentage lung area of emphysema. The findings were highly comparable between ULD and SD protocols. A strong correlation was seen between ULD and SD images in measurement of total lung volume (R = 0.925, p < 0.001) and percentage lung involvement by densitometry (R = 0.940, p < 0.001). There is a 95% dose reduction with the ULD protocol, the mean effective dose is 0.12 ±â€¯0.09 mSv versus 2.33 ±â€¯1.54 mSv for the SD protocol. CONCLUSIONS: ULD thoracic CT is a comparable protocol for the assessment of emphysema severity relative to standard dose CT. ULD CT is performed at a 95% dose reduction compared to SD CT.

Out of Hours Emergency Computed Tomography Brain Studies: Comparison of Standard 3 Megapixel Diagnostic Workstation Monitors With the iPad 2.

PURPOSE: The purpose was to compare performance of diagnostic workstation monitors and the Apple iPad 2 (Cupertino, CA) in interpretation of emergency computed tomography (CT) brain studies. METHODS: Two experienced radiologists interpreted 100 random emergency CT brain studies on both on-site diagnostic workstation monitors and the iPad 2 via remote access. The radiologists were blinded to patient clinical details and to each other's interpretation and the study list was randomized between interpretations on different modalities. Interobserver agreement between radiologists and intraobserver agreement between modalities was determined and Cohen kappa coefficients calculated for each. Performance with regards to urgent and nonurgent abnormalities was assessed separately. RESULTS: There was substantial intraobserver agreement of both radiologists between the modalities with overall calculated kappa values of 0.959 and 0.940 in detecting acute abnormalities and perfect agreement with regards to hemorrhage. Intraobserver agreement kappa values were 0.939 and 0.860 for nonurgent abnormalities. Interobserver agreement between the 2 radiologists for both diagnostic monitors and the iPad 2 was also substantial ranging from 0.821-0.860. CONCLUSIONS: The iPad 2 is a reliable modality in the interpretation of CT brain studies in them emergency setting and for the detection of acute and chronic abnormalities, with comparable performance to standard diagnostic workstation monitors.

Incidental cardiac findings on thoracic imaging.

The cardiac structures are well seen on nongated thoracic computed tomography studies in the investigation and follow-up of cardiopulmonary disease. A wide variety of findings can be incidentally picked up on careful evaluation of the pericardium, cardiac chambers, valves, and great vessels. Some of these findings may represent benign variants, whereas others may have more profound clinical importance. Furthermore, the expansion of interventional and surgical practice has led to the development and placement of new cardiac stents, implantable pacemaker devices, and prosthetic valves with which the practicing radiologist should be familiar. We present a collection of common incidental cardiac findings that can be readily identified on thoracic computed tomography studies and briefly discuss their clinical relevance.

The relationship of body mass index and abdominal fat on the radiation dose received during routine computed tomographic imaging of the abdomen and pelvis.

PURPOSE: To determine the relationship of increasing body mass index (BMI) and abdominal fat on the effective dose acquired from computed tomography (CT) abdomen and pelvis scans. METHODS: Over 6 months, dose-length product and total milliamp-seconds (mAs) from routine CT abdomen and pelvis scans of 100 patients were recorded. The scans were performed on a 64-slice CT scanner by using an automatic exposure control system. Effective dose (mSv) based on dose-length product, BMI, periumbilical fat thickness, and intra-abdominal fat were documented for each patient. BMI, periumbilical fat thickness, and intra-abdominal fat were compared with effective dose. RESULTS: Thirty-nine men and 61 women were included in the study (mean age, 56.3 years). The mean BMI was 26.2 kg/m(2). The mean effective dose was 10.3 mSv. The mean periumbilical fat thickness was 2.4 cm. Sixty-five patients had a small amount of intra-abdominal fat, and 35 had a large amount of intra-abdominal fat. The effective dose increased with increasing BMI (P < .001) and increasing amounts of intra-abdominal fat (P < .001). For every kilogram of weight, there is a 0.13 mSv increase in effective dose, which is equal to 6.5 chest radiographs per CT examination. For an increase in BMI by 5 kg/m(2), there is a 1.95 mSv increase in effective dose, which is equal to 97.5 chest radiographs per CT examination. CONCLUSION: Increasing BMI and abdominal fat significantly increases the effective dose received from CT abdomen and pelvis scans.

Cardiac masses, part 1: imaging strategies and technical considerations.

OBJECTIVE: The objective of this article is to discuss optimal imaging strategies for the evaluation of cardiac masses. The advantages and disadvantages of echocardiography, cardiac MRI, gated cardiac CT, and nuclear imaging will be discussed and specific techniques presented. CONCLUSION: Multimodality imaging plays a pivotal role in the diagnosis and surgical planning of cardiac masses. Clinical features, such as patient age, location, and imaging characteristics of the mass will determine the likely differential diagnosis.

Cardiac masses, part 2: key imaging features for diagnosis and surgical planning.

OBJECTIVE: The objectives of this article are to discuss key radiologic features that differentiate primary and secondary cardiac masses. Clinical scenarios are included to highlight stepwise radiologic workup of tumors of the pericardium, epicardium, myocardium, valves, and chambers. The involvement of key cardiac anatomic structures will also be emphasized to determine resectability and guide surgical planning. CONCLUSION: Multimodality imaging plays a pivotal role in diagnosis and surgical planning of cardiac masses. Clinical features, such as patient age, location, and imaging characteristics of the mass will determine the likely differential diagnosis. In addition to radiologic evaluation of the mass itself, involvement of valvular apparatus, extent of myocardial involvement, or presence of associated coronary artery involvement is necessary to determine resectability and surgical technique.

Iodinated contrast opacification gradients in normal coronary arteries imaged with prospectively ECG-gated single heart beat 320-detector row computed tomography.

BACKGROUND: To define and evaluate coronary contrast opacification gradients using prospectively ECG-gated single heart beat 320-detector row coronary angiography (CTA). METHODS AND RESULTS: Thirty-six patients with normal coronary arteries determined by 320 x 0.5-mm detector row coronary CTA were retrospectively evaluated with customized image postprocessing software to measure Hounsfield Units at 1-mm intervals orthogonal to the artery center line. Linear regression determined correlation between mean Hounsfield Units and distance from the coronary ostium (regression slope defined as the distance gradient G(d)), lumen cross-sectional area (G(a)), and lumen short-axis diameter (G(s)). For each gradient, differences between the 3 coronary arteries were analyzed with ANOVA. Linear regression determined correlations between measured gradients, heart rate, body mass index, and cardiac phase. To determine feasibility in lesions, all 3 gradients were evaluated in 22 consecutive patients with left anterior descending artery lesions > or =50% stenosis. For all 3 coronary arteries in all patients, the gradients G(a) and G(s) were significantly different from zero (P<0.0001), highly linear (Pearson r values, 0.77 to 0.84), and had no significant difference between the left anterior descending, left circumflex, and right coronary arteries (P>0.503). The distance gradient G(d) demonstrated nonlinearities in a small number of vessels and was significantly smaller in the right coronary artery when compared with the left coronary system (P<0.001). Gradient variations between cardiac phases, heart rates, body mass index, and readers were low. Gradients in patients with lesions were significantly different (P<0.021) than in patients considered normal by CTA. CONCLUSIONS: Measurement of contrast opacification gradients from temporally uniform coronary CTA demonstrates feasibility and reproducibility in patients with normal coronary arteries. For all patients, the gradients defined with respect to the coronary lumen cross-sectional area and short-axis diameters are highly linear, not significantly influenced by the coronary artery (left anterior descending artery versus left circumflex versus right coronary artery), and have only small variation with respect to patient parameters. Preliminary evaluation of gradients across coronary artery lesions is promising but requires additional study.

Imaging features of intramural hematoma of the aorta.

Intramural hematoma (IMH) is defined as localized hemorrhage within the aortic wall and is included in the acute aortic syndrome spectrum with aortic dissection and penetrating aortic ulcer. The mortality from IMH is similar to classic aortic dissection (21%). 16% of patients with IMH will evolve to classic aortic dissection over time. Despite this confusion exists regarding the precise definitions and radiologic features of IMH versus penetrating ulcers with mural thrombus and overt aortic dissection.

Dual-source CT coronary angiography without heart rate or rhythm control in comparison with conventional coronary angiography.

To explore the value of dual-source CT angiography (DSCTA) in diagnosing coronary artery stenosis (CAS) without heart rate or rhythm control. Eighty-nine patients with different heart rates/rhythms underwent both DSCTA and conventional coronary angiography (CCA) in 1 week. The diagnostic quality of normal coronary arteries and stenosed segments using DSCTA and CCA were analyzed, respectively, with CCA as the gold standard. Kappa test was used to assess the intermodality agreement between DSCTA and CCA in grading CAS. The value of DSCTA in diagnosing CAS (> 50% stenoses) were analyzed as well. The total evaluable rate of DSCTA in detecting coronary arteries was 98.8%. No significant difference between evaluable rates from different groups of heart rate (chi(2) = 1.745, P > 0.05) was found. Sensitivity, specificity, positive and negative predictive values of DSCTA in detecting CAS and > 50% stenoses were 97.9, 96.8, 89.5, 99.4 and 97.2, 95.5, 80.3, 99.4%, respectively; The inter-modality agreement between DSCTA and CCA in grading CAS was found to be excellent (k = 0.856, P < 0.01). DSCTA provides high accuracy and reliability for evaluation of CAS in a high suspected patient group without heart rate/rhythm control. It can be used as a powerful primary tool for the detection of CAS and a potential substitute of CCA.

Malignant peripheral nerve sheath tumour of the bladder associated with neurofibromatosis I.

Neurofibromatosis is a hamartomatous disorder of autonomic peripheral nerve sheaths associated with peripheral nerve sheath tumours. Most tumours are neurofibromas; however, the genitourinary system is rarely involved. We present a rare case of a nerve sheath tumour of the bladder in a young patient, which was discovered to be malignant.