Is there a relation between non-calcifying coronary plaques and acute coronary syndromes? A retrospective study using multislice computed tomography.

OBJECTIVES: The purpose of this study was to assess whether different coronary plaque types as classified by multislice computed tomography (CT) are retrospectively correlated with acute coronary syndromes (ACS) in an unselected study population. METHODS: Sixty-three consecutive patients were examined with 16-slice CT coronary angiography. Coronary plaque types were classified as calcifying type 1, mixed (calcifying > non-calcifying) type 2, mixed (non-calcifying > calcifying) type 3, and non-calcifying type 4. Patients who had an ACS within 17 days were included. All patients underwent invasive coronary angiography. RESULTS: Fifty-eight patients (92%) had coronary plaques evaluated by CT: 18 type 1 (31%), 10 type 2 (17%), 16 type 3 (28%) and 14 type 4 (24%). The presence of a non-calcifying plaque component (types 2-4; 40 of 63 patients, 63%) was correlated with ACS (n = 15; 24%) (p < 0.001). Only type 3 was significantly correlated with ACS (p = 0.01), but plaque types 2 and 4 were not. The diagnostic accuracy of CT for detection of stenosis >50% in proximal segments was: sensitivity 98%, specificity 90%, negative predictive value 97%, positive predictive value 97% per patient. CONCLUSIONS: Mixed calcifying/non-calcifying plaques with a predominantly non-calcifying component (type 3) as classified by multislice CT are retrospectively correlated with ACS.

Ultrasound of prostate cancer: recent advances.

Prostate cancer is the most common cancer in men. In the future, a significant further increase in the incidence of prostate cancer is expected. Therefore, improvement of prostate cancer diagnosis is a main topic of diagnostic imaging. The systematic prostate biopsy ("ten-core biopsy") is now the "gold standard" of prostate cancer diagnosis but may miss prostate cancer. Contrast-enhanced colour Doppler ultrasound (US) and elastography are evolving methods that may dramatically change the role of US for prostate cancer diagnosis. Contrast-enhanced colour Doppler US allows for investigations of the prostate blood flow and consequently for prostate cancer visualization and therefore for targeted biopsies. Comparisons between systematic and contrast-enhanced targeted biopsies have shown that the targeted approach detects more cancers and cancers with higher Gleason scores with a reduced number of biopsy cores. Furthermore, elastography, a new US technique for the assessment of tissue elasticity has been demonstrated to be useful for the detection of prostate cancer, and may further improve prostate cancer staging. Therefore, contrast-enhanced colour Doppler US and elastography may have the potential to improve prostate cancer detection, grading and staging. However, further clinical trials will be needed to determine the promise of these new US advances.

Fusion of multislice computed tomography and electroanatomical mapping data for 3D navigation of left and right atrial catheter ablation.

PURPOSE: To assess whether fusion of multislice computed tomography (CT) images with electroanatomical (EA)-mapping data using a new image integration module (CartoMerge) is feasible and accurate to navigate ablation catheters in right and left atrial catheter ablation. MATERIAL AND METHODS: Twenty-four patients were examined with ECG-gated cardiac multislice CT (64 mm x 0.6mm, 0.33 s) 1 day before left atrial (LA) (15 patients) radiofrequency or right atrial cavotricuspid isthmus ablation (9 patients). CT data were fused with the non-fluoroscopic EA-mapping data by using dedicated software (CartoMerge) and the value of CT was analysed. RESULTS: In 23/24 (96%) patients, CT images could be fused with the EA-map. The alignment error was 2.16+/-0.35 mm. In 15/15 (100%) patients, CT added relevant anatomical information regarding the course of the esophagus or the pulmonary veins before LA-ablation. CT added useful information in only 3/8 (37.5%) of patients undergoing right atrial cavotricuspid isthmus ablation. CONCLUSION: 3D-navigation of RF-ablation catheters in the atria assisted by image fusion of multislice CT with EA-mapping data is feasible and accurate. CT added relevant anatomical information about the left atrium and the pulmonary veins before LA-ablation, CT also provided information about the course of the esophagus which might help to avoid thermal injury. CT image fusion might be of minor value before right atrial cavotricuspid isthmus catheter ablation.

Diagnostic performance of 64-slice computed tomography in evaluation of coronary artery bypass grafts.

OBJECTIVE: The purpose of this study was to compare the diagnostic accuracy of 64-slice CT with that of invasive angiography in the detection of greater than 50% graft stenosis within 2 weeks of coronary artery bypass grafting and to investigate the clinical value of 64-slice CT. SUBJECTS AND METHODS: Forty-one patients (70 grafts, 46 arterial and 24 venous) underwent 64-slice CT a mean of 2.6 years after minimally invasive or conventional coronary artery bypass surgery. RESULTS: All 70 grafts were assessable, and none of the grafts was excluded from analysis. For the detection of 50-90% graft stenosis, the sensitivity of CT was 75%, the specificity was 95%, the positive predictive value was 67%, and the negative predictive value was 97% (true disease prevalence, 8/70 grafts; 11%). Greater than 50% graft stenosis and occlusion pooled together (prevalence, 14/70; 20%) were detected with a sensitivity of 85%, specificity of 95%, positive predictive value of 80%, and negative predictive value of 96%. Vein graft disease was found in eight (42%) of 19 patent vein grafts (graft age, 15.6 +/- 2.3 years). The disease was nonobstructive in three (16%) of the 19 grafts. The course of the left internal mammary artery was median retrosternal (< 1 cm deep) in 33.3% of conventionally sutured grafts. CONCLUSION: Sixty-four-slice CT angiography can be used for accurate exclusion of greater than 50% graft stenosis, but detection of distal anastomotic stenosis is limited, and the degree of stenosis can be overestimated. The advantages of CT, however, are that it is noninvasive, vein graft disease can be diagnosed at an early stage, and complementary evaluation of extracardiac anatomic features provides useful information before coronary artery bypass grafting is redone.

Value of contrast-enhanced ultrasound and elastography in imaging of prostate cancer.

PURPOSE OF REVIEW: Prostate cancer is the most commonly diagnosed malignancy in men. Gray-scale ultrasound-guided systematic biopsy is the standard of care for prostate cancer detection in men with an elevated prostate-specific antigen or an abnormal digital rectal examination. Systematic biopsy may miss up to 35% of clinically relevant cancers. Color and power Doppler ultrasound, ultrasound contrast agents, and elastography have and will dramatically change the role of ultrasound in prostate cancer diagnosis. RECENT FINDINGS: Several reports have demonstrated that contrast-enhanced ultrasound investigations of the blood flow of the prostate allow for prostate cancer visualization and therefore, for targeted biopsies. Comparisons between systematic and contrast-enhanced ultrasound-targeted biopsies have shown that the targeted approach detects more cancers with a lower number of biopsy cores. Furthermore, contrast-enhanced ultrasound has been shown to detect cancers with higher Gleason scores compared with the systematic approach, which seems to improve prostate cancer grading. In addition, elastography is a new ultrasound technique that allows for the assessment of tissue elasticity. SUMMARY: Contrast-enhanced ultrasound and elastography improve prostate cancer detection and may be useful for prostate cancer grading and staging. Future clinical trials will be needed to determine the promise of these new advances for ultrasound of the prostate evolving into clinical applications.

Aortic valve calcification as quantified with multislice computed tomography predicts short-term clinical outcome in patients with asymptomatic aortic stenosis.

BACKGROUND AND AIM OF THE STUDY: Aortic valve calcification may be an independent risk factor for adverse clinical outcome. The study aim was to assess the predictive value of possible risk factors, including the severity of aortic valve calcification as quantified with 16-multislice computed tomography (MSCT) for adverse short-term clinical outcome in patients with asymptomatic, degenerative aortic stenosis (AS). METHODS: Possible risk factors for adverse short-term clinical outcome were prospectively tested in 34 consecutive patients with asymptomatic AS as follows: (i) aortic valve calcium (AVC) score as quantified with MSCT; (ii) echocardiographic parameters--aortic valve area (AVA) calculated with continuity equation, mean and maximal transvalvular pressure gradients, end-diastolic septal wall diameter; and (iii) laboratory tests (brain natriuretic peptide (BNP), C-reactive protein (CRP)). RESULTS: Within 18-24 months of follow up, 11 of 34 patients developed a major adverse clinical outcome. Ten patients suffered from onset of symptoms accompanied by hemodynamic progression, and one patient died from sudden cardiac death. Six of these 10 patients underwent aortic valve replacement, one patient declined surgery, and three patients were not accepted for surgery (one of these died suddenly shortly afterwards). The aortic valve calcium score was the strongest predictor of a major adverse clinical event (p < 0.001) among all parameters assessed (1,928 +/- 789 versus 5,111 +/- 2,409 Agatston units). The plasma level of BNP (p = 0.003), mean transvalvular pressure gradient (p = 0.002) and AVA (p = 0.003) were also risk factors for adverse clinical outcome. CONCLUSION: The AVC score as quantified with MSCT predicted adverse short-term clinical outcome in patients with asymptomatic AS. In patients with severe aortic valve calcification, close follow up examinations are mandatory, and early elective surgery may be considered even in the absence of symptoms. MSCT provides a comprehensive non-invasive imaging approach for risk stratification in patients with asymptomatic AS.

Evaluation of ascending aortic atherosclerosis with 16-multidetector computed tomography is useful before total endoscopic coronary bypass surgery.

BACKGROUND: The purpose of this study was to investigate the assessment of ascending aortic atherosclerosis with 16-multidetector computed tomography (16-MDCT) angiography prior to total endoscopic coronary artery bypass (TECAB) surgery. METHODS: Forty-five patients were examined with electrocardiogram-gated, 16-MDCT angiography. The presence of atherosclerosis at the ascending aorta was graduated as severe (>50% of circumference) or as mild (<50% of circumference). Ascending aortic plaque composition was evaluated based on CT densities expressed as Hounsfield units (HU). TECABs using the Da Vinci telemanipulator were performed either on the arrested heart (n = 39) with an intra-aortic cardiopulmonary bypass (CPB) perfusion device or on the beating heart (n = 6) in patients with severe atherosclerosis. RESULTS: The presence of mild atherosclerosis at the ascending aorta (11/39) was associated with intra-aortic CPB perfusion device-related difficulties such as intra-aortic balloon migration (BM) or balloon rupture (P = .007) in arrested heart TECABs. The CT density of atherosclerotic plaque in patients with BM was mean 58 HU +/- 51 standard deviation (SD), suggesting noncalcifying plaque. In patients without BM, CT density of plaque was mean 526 HU +/- 306 SD corresponding to calcifying plaque (P < .001). Balloon rupture occurred in 2 patients who had calcifying plaque at the ascending aorta. CONCLUSION: Evaluation of ascending aortic atherosclerosis with 16-MDCT angiography is useful prior to TECAB surgery. Even mild atherosclerosis of the ascending aorta is associated with intraoperative difficulties regarding the remote-access perfusion system that is used for arrested heart TECAB surgery.

High-resolution 16-MDCT evaluation of radial artery for potential use as coronary artery bypass graft: a feasibility study.

OBJECTIVE: The objective of our study was to assess the feasibility of using 16-MDCT angiography for the preoperative assessment of the radial and ulnar arteries and the palmar arches in patients scheduled for radial artery harvesting for coronary artery bypass graft (CABG) surgery. CONCLUSION: Sixteen-MDCT angiography shows promise for the noninvasive preoperative assessment of the radial artery as a CABG donor site.

Power Doppler ultrasound imaging for quantification of urinary bladder neck blood flow changes.

This study was designed to evaluate power Doppler imaging for assessment of urinary bladder neck blood flow in comparison with laser Doppler flowmetry (LDF) in an animal model. Transrectal power Doppler ultrasound (US) and LDF of the urinary bladder neck were performed in three anesthetized pigs during comparative cystometry. Normal saline (NaCl) was used for the first run, followed by a second run with 0.2 mol/L potassium chloride (KCl). Standardized sonographic equipment settings (Acuson Sequoia 512); MountainView, CA) were used for power Doppler imaging. Computer-assisted calculation of color pixel density (CPD) of power Doppler images was performed using Scion Image) software image analysis. Tissue perfusion units (TPU) were measured using a BLF21 laser Doppler flowmeter (Transonic Systems Inc., Ithaca, NY, USA). The power Doppler results were compared with the findings obtained by LDF. NaCl filling resulted in a mean CPD increase at the bladder neck from 18.65 (+/- 1.78) at empty bladder to 37.8 (+/- 1.84) at 100 mL and to 88.32 (+/- 1.35) at full bladder capacity (C(max)) of 270 mL, respectively. With KCl filling, a mean CPD increase from 18.65 (+/- 1.78) to 59.63 (+/- 0.5) at 100 mL and 110.82 (+/- 2.98) at full bladder capacity (270 mL) was observed. The CPD increase was significantly higher for KCl than with NaCl (p < 0.001). With NaCl filling, bladder neck blood flow increased from 22 TPU (empty) to 46 TPU (100 mL) and 62.5 TPU at C(max), compared to 22 TPU, 50 TPU and 102.5 TPU with KCl. CPD and TPU measurements showed a strong correlation at p = 0.01. In conclusion, transrectal power Doppler US image quantification is a feasible and accurate method for assessing blood flow changes in the urinary bladder neck.

Schwannoma of the brachial plexus: cross-sectional imaging diagnosis using CT, sonography, and MR imaging.

Primary brachial plexus tumors are rare, usually benign, and in general have a good prognosis after surgical excision. We present a case of a schwannoma in which sonography enabled the correct diagnosis of a probably benign brachial plexus tumor. Key to the diagnosis was the demonstration of a smooth-bordered, longish, and well-defined nodule along a brachial plexus nerve root. Cross-sectional imaging modalities that provide a high degree of soft tissue contrast and spatial resolution, such as sonography and MR imaging, were suitable methods to establish the correct preoperative diagnosis. Findings at CT, sonography, MR imaging, and surgery are discussed.

Ovoid shape of the vermiform appendix: a criterion to exclude acute appendicitis--evaluation with US.

PURPOSE: To investigate whether the shape of the appendix in transverse section may be considered an ultrasonographic (US) criterion to exclude or confirm acute appendicitis. MATERIALS AND METHODS: The shapes of appendices of 100 control subjects, of 174 patients with clinical suspicion of acute appendicitis but without acute appendicitis, and of 108 patients with acute appendicitis were prospectively evaluated with US. Definite diagnoses in patients with clinical suspicion of acute appendicitis were established and confirmed either with surgery and histologic examination in 161 patients or with clinical follow-up in 121 patients. Statistical measures such as sensitivity, specificity, positive and negative predictive values, and accuracy were assessed for the appendiceal shape as a diagnostic US criterion for acute appendicitis. RESULTS: An at least partly round appendix indicated acute appendicitis with a sensitivity of 100%; specificity of 37%; positive and negative predictive values of 50% and 100%, respectively; and accuracy of 61%. In 67 of 174 patients with clinical suspicion of acute appendicitis but without acute appendicitis, the partly ovoid appendiceal shape aided in the exclusion of acute appendicitis, since it indicated a normal appendix with a probability of 86%. In 65 of 174 patients with clinical suspicion of acute appendicitis but without acute appendicitis, the ovoid shape over the entire appendiceal length excluded acute appendicitis with confidence. CONCLUSION: The shape of the appendix in transverse section is a useful US criterion, since an ovoid shape over the entire appendiceal length reliably rules out acute appendicitis.

Laparoscopic pyeloplasty for UPJ obstruction with crossing vessels: contrast-enhanced color Doppler findings and long-term outcome.

OBJECTIVES: To evaluate, in the present long-term follow-up study, contrast-enhanced color Doppler imaging (CDI) findings and the clinical outcome of patients with crossing vessels at the obstructed ureteropelvic junction (UPJ), who underwent laparoscopic pyeloplasty. In a previous study, contrast-enhanced CDI proved capable of detecting crossing vessels at the UPJ. METHODS: A total of 23 patients, who had undergone laparoscopic pyeloplasty and displacement of crossing vessels for UPJ obstruction at least 2 years before this study (mean 27 months), underwent contrast-enhanced CDI, intravenous urography, and renography. Contrast-enhanced CDI was performed using intravenously administered Levovist to assess the displacement of the vessels relative to the UPJ. All patients completed analog follow-up pain scales and quality-of-life assessment questionnaires. RESULTS. Contrast-enhanced CDI revealed a cranial displacement (mean 1.3 cm) of the crossing vessels from the UPJ in all 23 cases. Intravenous urography showed a decrease in the degree of hydronephrosis, with a success rate of 100% in low-grade and 86% in high-grade hydronephrosis. The split renal function improved from 39.7% to 48.1%. Analog pain scale measurements demonstrated a mean improvement in pain of 92% (range 73% to 100%) and a mean quality-of-life score of 94 (range 78 to 100). CONCLUSIONS: Our series of patients with crossing vessels at the UPJ treated by laparoscopic pyeloplasty showed an excellent long-term successful outcome. Contrast-enhanced CDI allows for preoperative detection, as well as postoperative assessment, of the displacement of the crossing vessel. We recommend that the presence of a crossing vessel be routinely determined preoperatively, because it may influence the choice of treatment modality and thereby the clinical outcome.