Stent-protected angioplasty versus carotid endarterectomy in patients with carotid artery stenosis: meta-analysis of randomized trial data

Stent-protected angioplasty of carotid artery stenosis may be an alternative to surgical endarterectomy. Results published so far are indecisive, with evidence both in favour of and against this procedure. After the recent publication of two large European multicentre trials (SPACE and EVA-3S) almost 3,000 patients have been included in randomized studies. For this report, we therefore conducted a systematic review of randomized studies that compared endovascular treatment with surgery for carotid stenosis. We evaluated seven trials including 2,973 patients. In our meta-analysis endovascular treatment seemed to carry a slightly higher risk for stroke or death within 30 days after the procedure as compared with surgery (8.2% vs. 6.2%; p = 0.04; OR 1.35), whereas the rates of disabling stroke or death within 30 days did not differ significantly (p = 0.47; n.s.). On the other hand, surgery carried a significantly higher risk for cranial nerve palsy (4.7% vs. 0.2%; p < 0.0001; OR 0.17) and myocardial infarction (2.3% vs. 0.9%; p = 0.03; OR 0.37). Long-term effects of both methods still need to be evaluated. Two other large multicentre trials (ICSS and CREST) are ongoing. Results of these studies will increase the database to about 7,000 randomized patients. Future meta-analyses should then allow definitive treatment recommendations. The publication of first results from the SPACE study [1] has fuelled a controversial debate as to whether endovascular treatment of severe carotid artery stenosis constitutes an alternative to surgical endarterectomy—the gold-standard method so far. This article first reviews all randomized trials comparing endovascular treatment of carotid artery stenosis with surgery. In a meta-analysis the safety and efficacy of both methods are compared. Some questions arising from SPACE are then discussed separately.     

Hyperperfusion syndrome after carotid stent angioplasty

Introduction  This study assesses the incidence and causes of hyperperfusion syndrome occurring after carotid artery stenting (CAS). Materials and methods  We retrospectively reviewed the clinical database of 417 consecutive patients who were treated with CAS in our department to identify patients who developed hyperperfusion syndrome and/or intracranial hemorrhage. Magnetic resonance imaging (MRI) including fluid-attenuated inversion recovery and diffusion-weighted imaging was performed before and after CAS in 269 cases. A Spearman’s rho nonparametric correlation was performed to determine whether there was a correlation between the occurrence/development of hyperperfusion syndrome and the patient’s age, degree of stenosis on the stented and contralateral side, risk factors such as diabetes, smoking, hypertension, adiposity, gender and fluoroscopy time, and mean area of postprocedural lesions as well as preexisting lesions. Significance was established at p < 0.05. Results  Of the 417 carotid arteries stented and where MRI was also completed, we found hyperperfusion syndrome in 2.4% (ten cases). Patients who had preexisting brain lesions (previous or acute stroke) were at a higher risk of developing hyperperfusion syndrome (p = 0.022; Spearman’s rho test). We could not validate any correlation with the other patient characteristics. Conclusion  Extensive microvascular disease may be a predictor of hyperperfusion syndrome after carotid stent placement. We believe that further studies are warranted to predict more accurately which patients are at greater risk of developing this often fatal complication. I. Q. Grunwald and M. Politi contributed equally to this study.     

Structural alterations of the coronary arterial wall are associated with myocardial flow heterogeneity in type 2 diabetes mellitus

Purpose  To determine the relationship between carotid intima–media thickness (IMT), coronary artery calcification (CAC), and myocardial blood flow (MBF) at rest and during vasomotor stress in type 2 diabetes mellitus (DM). Methods  In 68 individuals, carotid IMT was measured using high-resolution vascular ultrasound, while the presence of CAC was determined with electron beam tomography (EBT). Global and regional MBF was determined in milliliters per gram per minute with ¹³N-ammonia and positron emission tomography (PET) at rest, during cold pressor testing (CPT), and during adenosine (ADO) stimulation. Results  There was neither a relationship between carotid IMT and CAC (r = 0.10, p = 0.32) nor between carotid IMT and coronary circulatory function in response to CPT and during ADO (r = −0.18, p = 0.25 and r = 0.10, p = 0.54, respectively). In 33 individuals, EBT detected CAC with a mean Agatston-derived calcium score of 44 ± 18. There was a significant difference in regional MBFs between territories with and without CAC at rest and during ADO-stimulated hyperemia (0.69 ± 0.24 vs. 0.74 ± 0.23 and 1.82 ± 0.50 vs. 1.95 ± 0.51 ml/g/min; p ≤ 0.05, respectively) and also during CPT in DM but less pronounced (0.81 ± 0.24 vs. 0.83 ± 0.23 ml/g/min; p = ns). The increase in CAC was paralleled with a progressive regional decrease in resting as well as in CPT- and ADO-related MBFs (r = −0.36, p ≤ 0.014; r = −0.46, p ≤ 0.007; and r = −0.33, p ≤ 0.041, respectively). Conclusions  The absence of any correlation between carotid IMT and coronary circulatory function in type 2 DM suggests different features and stages of early atherosclerosis in the peripheral and coronary circulation. PET-measured MBF heterogeneity at rest and during vasomotor stress may reflect downstream fluid dynamic effects of coronary artery disease (CAD)-related early structural alterations of the arterial wall.     

Lower fractional anisotropy at the anterior body of the normal-appearing corpus callosum in multiple sclerosis versus symptomatic carotid occlusion

Introduction  Not uncommonly, differentiating multiple sclerosis (MS) from ischemic cerebral vascular disease is difficult based on conventional magnetic resonance imaging (MRI). We aim to determine whether preferential occult injury in the normal-appearing corpus callosum (NACC) is more severe in patients with MS than symptomatic carotid occlusion by comparing fractional anisotropy (FA) from diffusion tensor imaging (DTI). Methods  Eighteen patients (eight men, ten women; mean age, 38.6 years) with MS and 32 patients (24 men, eight women; mean age, 64.0 years) with symptomatic unilateral internal carotid occlusion were included. DTI (1.5 T) were performed at corpus callosum which were normal-appearing on fluid-attenuated inversion recovery MRI. Mean FA was obtained from the genu, anterior body, posterior body, and splenium of NACC. Independent-sample t test statistical analysis was performed. Results  The FA values in various regions of NACC were lower in the MS patients than symptomatic carotid occlusion patients, which was statistically different at the anterior body (0.67 ± 0.12 vs 0.74 ± 0.06, P = 0.009), but not at genu, posterior body, and splenium (0.63 ± 0.09 vs 0.67 ± 0.07, P = 0.13; 0.68 ± 0.09 vs 0.73 ± 0.05, P = 0.07; 0.72 ± 0.09 vs 0.76 ± 0.05, P = 0.13). Conclusion  MS patients have lower FA in the anterior body of NACC compared to patients with symptomatic carotid occlusion. It suggests that DTI has potential ability to differentiate these two conditions due to the more severe preferential occult injury at the anterior body of NACC in MS.     

Long-term outcome after angioplasty of symptomatic internal carotid artery stenosis with and without stent

Introduction Carotid angioplasty and stenting (CAS) has widely replaced balloon angioplasty (percutaneous transluminal angioplasty, PTA) in the treatment of internal carotid artery stenosis (ICAS). Here we assess whether the use of stents increases the safety and long-term efficacy of angioplasty in patients with ICAS. Our aim was to test the hypothesis that the long-term efficacy of CAS is superior to that of PTA. Methods At the University Medical Center Hamburg-Eppendorf, PTA was performed from 1990 to 1997 and CAS was performed from 1998 to 2006. All patients undergoing these procedures were symptomatic. Selection and follow-up examinations were performed by independent vascular neurologists. Follow-up terms were 1, 3, 6 and 12 months, then annually. Results In the PTA group (n = 71), 2.8% of the patients showed severe periinterventional complications (i.e. lasting neurological deficits). Of these 71 patients, 57.7% were followed up for an average period of 51 months. Stenois >70% was observed in 9.8% of the PTA patients, while 4.9% of the patients had ipsilateral occlusions. In the CAS group (n = 354), 4.2% of the patients showed severe periinterventional complications. In total, 61% of the CAS patients were followed up for an average period of 25 months, of whom 4.6% showed stenosis of >70% and 1.9% had ipsilateral occlusions. Periprocedural complications and new symptoms that appeared during follow-up occurred at a rate of 5.6% (PTA) and 5.9% (CAS). There was no difference in the rate of annual ipsilateral events (1.1% in PTA vs. 1.3% in CAS, p = 1.000) Conclusion Overall, the use of stents, rather than PTA only, shows no beneficial clinical effect in the treatment of ICA stenosis. While the rate of restenosis may be significantly reduced, this merely suggests that the impact of restenosis is less apparent than expected.     

High-resolution MR imaging of periarterial edema associated with biological inflammation in spontaneous carotid dissection

It has been suggested that spontaneous cervical carotid artery dissection (sCAD) may result from arterial inflammation. Periarterial edema (PAE), occasionally described in the vicinity of the mural hematoma in patients with sCAD, may support this hypothesis. Using cervical high-resolution magnetic resonance imaging, three readers, blinded to the mechanism of carotid artery dissection, searched for PAE, defined as periarterial T2-hyperintensity and T1-hypointensity, in 29 consecutive CAD patients categorized as spontaneous CAD (sCAD, n = 18) or traumatic CAD (tCAD, n = 11; i.e., major head or neck trauma within 2 weeks before the clinical onset). The relationships between PAE, inflammatory biological markers, history of infection and CAD mechanism were explored. Multiple CADs (n = 8) were found only in sCAD patients. Compared with tCAD, patients with sCAD were more likely to have a recent history of infection (OR = 12.5 [_95%CI = 1.3–119], p = 0.03), PAE (83% vs. 27%; OR = 13.3 [_95%CI = 2.2–82.0], p = 0.005) and to have elevated CRP (OR = 6.1 [_95%CI = 1.2–32.1], p = 0.0002) or ESR (OR = 8.8 [_95%CI = 1.5–50.1], p = 0.002) values. Interobserver agreement was 0.84 or higher for PAE identification. sCAD was associated with PAE and biological inflammation. Our results support the hypothesis of an underlying arterial inflammation in sCAD.     

Preoperative cerebrovascular reactivity to acetazolamide measured by brain perfusion SPECT predicts development of cerebral ischemic lesions caused by microemboli during carotid endarterectomy

Purpose  The aim of the present study was to determine whether preoperative cerebrovascular reactivity (CVR) to acetazolamide measured by quantitative brain perfusion single-photon emission computed tomography (SPECT) predicts development of cerebral ischemic lesions on postoperative diffusion-weighted magnetic resonance imaging (DWI) that are caused by microemboli during carotid endarterectomy (CEA). Materials and methods  One hundred and fifty patients with ipsilateral internal carotid artery stenosis (>70%) underwent CEA under transcranial Doppler monitoring of microembolic signals (MES) in the ipsilateral middle cerebral artery (MCA). Preoperative CVR to acetazolamide was measured using [¹²³I]N-isopropyl-p-iodoamphetamine SPECT, and region of interest (ROI) analysis in the ipsilateral MCA territory was performed using a three-dimensional stereotaxic ROI template. DWI was performed within 3 days before and 24 h after surgery. Results  Twenty-six patients (17.3%) developed new postoperative ischemic lesions on DWI. Logistic regression analysis demonstrated that, among the variables tested, a high number of MES during carotid dissection (95% CIs, 1.179 to 1.486; P < 0.0001) and preoperative reduced CVR to acetazolamide (95% CIs, 0.902 to 0.974; P = 0.0008), which were significantly associated with the development of new postoperative ischemic lesions on DWI. In 47 patients with MES during carotid dissection, the combination of number of MES during carotid dissection and CVR to acetazolamide identified development of new postoperative ischemic lesions on DWI with a positive predictive value of 100% or zero. Conclusions  Preoperative CVR to acetazolamide measured by quantitative brain perfusion SPECT predicts development of cerebral ischemic lesions on postoperative DWI that are caused by microemboli during CEA.     

Evaluation of the effectiveness of CT-guided infiltration in the treatment of Arnold’s neuralgia

Introduction  The aim of this study was to evaluate the effectiveness of computed tomography (CT)-guided infiltration in the treatment of Arnold's neuralgia. Methods  A retrospective study included 31 patients suffering from Arnold's neuralgia and having undergone a total of 45 CT-guided infiltrations of the greater occipital nerve (GON), in a proximal site (emergence of the GON, technique 1, n = 24) or in two proximal sites (emergence of the GON and at the site of the first bend of the GON drawn by the GON, technique 2, n = 21). Infiltration was considered to be effective when pain relief was equal to or greater than 50% for at least 1 month. Results  There was no significant difference between the two techniques regarding immediate pain relief effect (53.3% for technique 1 vs. 60.5% for technique 2, p = 0.5), but technique 2 yielded better persistence of pain relief effect (p = 0.01), leading to a significantly higher percentage of effective infiltrations with technique 2 (p = 0.03). Conclusion  Infiltrations carried out in a single site yield results that are comparable to those previously published. Infiltrations in two sites provide significantly better results and should now be preferred to other single-site techniques in order to reduce the rate of failure or recurrence of Arnold's neuralgia.     

Whole-body CT in polytrauma patients: effect of arm positioning on thoracic and abdominal image quality

The purpose of this study is to assess the influence of different arm positioning techniques on thoracic and abdominal image quality and radiation dose of whole-body trauma CT (wbCT). One hundred and fifty polytrauma patients (104 male, mean age 47 ± 19) underwent wbCT with arms elevated above the head (group A, n = 50), alongside the abdomen (group B, n = 50), and on a pillow ventrally to the chest with both arms flexed (group C, n = 50). Two blinded, independent observers measured image noise and rated image quality (scores 1–3) of the liver, aorta, spleen, spine, and lower lungs. Radiation dose parameters were noted, and the abdomens’ anterior–posterior diameter and scan lengths were measured. Interreader agreements for image noise (r = 0.86; p < 0.001) and subjective image quality (k = 0.71–0.84) were good. Noise was lower (p < 0.05), image quality of the liver, aorta, spleen, and spine was higher, and radiation dose lower in group A than in groups B and C (p < 0.001, each). Image quality of the spleen, liver, and aorta were higher in group C than in group B (p < 0.05, each). No significant differences in scan length (p = 0.61) were found among groups. Abdominal anterior–posterior diameter correlated significantly with noise (r = 0.82; p < 0.01) and dose (r = 0.47; p < 0.001). Estimated effective radiation doses were significantly (p < 0.001) higher in groups B (21.2 mSv) and C (21.9 mSv) as compared to A (16.1 mSv). In wbCT for polytrauma patients, positioning of the arms above the head results in better image quality and lower radiation dose. Placing the flexed arms on a large pillow ventrally to the chest significantly improves image quality as compared to positioning alongside the abdomen.     

Infarct size in primary angioplasty without on-site cardiac surgical backup versus transferal to a tertiary center: a single photon emission computed tomography study

Background  Primary percutaneous coronary intervention (PCI) performed in large community hospitals without cardiac surgery back-up facilities (off-site) reduces door-to-balloon time compared with emergency transferal to tertiary interventional centers (on-site). The present study was performed to explore whether off-site PCI for acute myocardial infarction results in reduced infarct size. Methods and results  One hundred twenty-eight patients with acute ST-segment elevation myocardial infarction were randomly assigned to undergo primary PCI at the off-site center (n = 68) or to transferal to an on-site center (n = 60). Three days after PCI, ^99mTc-sestamibi SPECT was performed to estimate infarct size. Off-site PCI significantly reduced door-to-balloon time compared with on-site PCI (94 ± 54 versus 125 ± 59 min, respectively, p < 0.01), although symptoms-to-treatment time was only insignificantly reduced (257 ± 211 versus 286 ± 146 min, respectively, p = 0.39). Infarct size was comparable between treatment centers (16 ± 15 versus 14 ± 12%, respectively p = 0.35). Multivariate analysis revealed that TIMI 0/1 flow grade at initial coronary angiography (OR 3.125, 95% CI 1.17–8.33, p = 0.023), anterior wall localization of the myocardial infarction (OR 3.44, 95% CI 1.38–8.55, p < 0.01), and development of pathological Q-waves (OR 5.07, 95% CI 2.10–12.25, p < 0.01) were independent predictors of an infarct size > 12%. Conclusions  Off-site PCI reduces door-to-balloon time compared with transferal to a remote on-site interventional center but does not reduce infarct size. Instead, pre-PCI TIMI 0/1 flow, anterior wall infarct localization, and development of Q-waves are more important predictors of infarct size.     

Comparison of MRI (including SS SE-EPI and SPIO-enhanced MRI) and FDG-PET/CT for the detection of colorectal liver metastases

Fluoro-18-deoxyglucose positron emission tomography computed tomography (FDG-PET/CT) and magnetic resonance imaging (MRI), including unenhanced single-shot spin-echo echo planar imaging (SS SE-EPI) and small paramagnetic iron oxide (SPIO) enhancement, were compared prospectively for detecting colorectal liver metastases. Twenty-four consecutive patients suspected for metastases underwent MRI and FDG-PET/CT. Fourteen patients (58%) had previously received chemotherapy, including seven patients whose chemotherapy was still continuing to within 1 month of the PET/CT study. The mean interval between PET/CT and MRI was 10.2 ± 5.2 days. Histopathology (n = 18) or follow-up imaging (n = 6) were used as reference. Seventy-seven metastases were detected. In nine patients, MRI and PET/CT gave concordant results. Sensitivities for unenhanced SS SE-EPI, MRI without SS SE-EPI and FDG-PET/CT were, respectively, 100% (p = 9 × 10⁻¹⁰ vs PET, p = 8 × 10⁻³ vs MRI without SS SE-EPI), 90% (p = 2 × 10⁻⁷ vs PET) and 60%. PET/CT sensitivity dropped significantly with decreasing size, from 100% in lesions larger than 20 mm (identical to MRI), over 54% in lesions between 10 and 20 mm (p = 3 × 10⁵ versus unenhanced SS SE-EPI), to 32% in lesions under 10 mm (p = 6 × 10⁻⁵ versus unenhanced SS SE-EPI). Positive predictive value of PET was 100% (identical to MRI). MRI, particularly unenhanced SS SE-EPI, has good sensitivity and positive predictive value for detecting liver metastases from colorectal carcinoma. Its sensitivity is better than that of FDG-PET/CT, especially for small lesions.     

Evaluation of right ventricular function with multidetector computed tomography: comparison with magnetic resonance imaging and analysis of inter- and intraobserver variability

This study was performed to prospectively compare multidetector computed tomography (MDCT) with 16 simultaneous sections and magnetic resonance imaging (MRI) for the assessment of global right ventricular function in 50 patients. MDCT using a semiautomatic analysis tool showed good correlation with MRI for end-diastolic volume (EDV, r = 0.83, p < 0.001), end-systolic volume (ESV, r = 0.86, p < 0.001) and stroke volume (SV, r = 0.74, p < 0.001), but only a moderate correlation for the ejection fraction (EF, r = 0.67, p < 0.001). Bland Altman analysis revealed a slight, but insignificant overestimation of EDV (4.0 ml, p = 0.08) and ESV (2.4 ml, p = 0.07), and underestimation of EF (0.1%, p = 0.92) with MDCT compared with MRI. All limits of agreement between both modalities (EF: ±15.7%, EDV: ±31.0 ml, ESV: ±18.0 ml) were in a moderate but acceptable range. Interobserver variability of MDCT was not significantly different from that of MRI. For MDCT software, the post-processing time was significantly longer (19.6 ± 5.8 min) than for MRI (11.8 ± 2.6 min, p < 0.001). Accurate assessment of right ventricular volumes by 16-detector CT is feasible but still rather time-consuming.     

Comprehensive assessment of the severity and mechanism of aortic regurgitation using multidetector CT and MR

Recent studies have suggested that both cardiac magnetic resonance (MR) and multidetector computed tomography (MDCT) can quantify aortic regurgitation (AR) by planimetry of the anatomical regurgitant orifice (ARO). However, this measurement was not compared with quantitative assessment of AR such as the effective regurgitant orifice (ERO) by proximal isosurface area (PISA) transthoracic echocardiography (TTE) or phase contrast MR. In 42 patients (34 men, age 54 ± 11 years) we compared planimetered ARO by MDCT and MR with ERO and regurgitant volume by PISA TTE and phase contrast MR. ARO by MDCT (r = 0.87, p < 0.001) and MR (r = 0.81, p < 0.001) correlated highly with ERO by TTE. However, ARO by MDCT (27 ± 15 mm², p < 0.001), but not by MR (23 ± 13 mm², p = 0.58), were larger than PISA ERO (22 ± 11 mm²). ARO by MDCT (r = 0.78, p < 0.001; r = 0.85, p < 0.001) and MR (r = 0.85, p < 0.001; r = 0.87 p < 0.001) correlated well with regurgitant volume by PISA and phase contrast MR. Both MDCT (к = 0.80, p < 0.001) and MR (к = 0.84, p < 0.001) demonstrated excellent agreement in correctly assessing the mechanisms of AR, i.e. aortic root dilatation (type I), cusp prolapse (type II) and restrictive cusp motion (type III), using surgical inspection as a reference. Measurement of ARO by both MDCT and MR allows accurate quantitative assessment of AR. Both techniques can also accurately determine the mechanism of AR.     

Incidental head and neck <Superscript>18</Superscript>F-FDG uptake on PET/CT without corresponding morphological lesion: early predictor of cancer development?

Purpose  To retrospectively determine whether increased/asymmetric FDG uptake on PET without a correlating morphological lesion on fully diagnostic CT indicates the development of a head and neck malignancy. Methods  In 590 patients (mean age 55.4 ± 13.3 years) without a head and neck malignancy/inflammation FDG uptake was measured at (a) Waldeyer’s ring, (b) the oral floor, (c) the larynx, and (d) the thyroid gland, and rated as absent (group A), present (group B), symmetric (group B1) or asymmetric (group B2). Differences between groups A and B and between B1 and B2 were tested for significance with the U-test (p < 0.05). An average follow-up of about 2.5 years (mean 29.5 ± 13.9 months) served as the reference period to determine whether patients developed a head and neck malignancy. Results  Of the 590 patients, 235 (40%) showed no evidence of enhanced FDG uptake in any investigated site, and 355 (60%) showed qualitatively elevated FDG uptake in at least one site. FDG uptake values (SUV_max, mean±SD) for Waldeyer’s ring were 3.0 ± 0.89 in group A (n = 326), 4.5 ± 2.18 in group B (n = 264; p < 0.01), 5.4 ± 3.35 in group B1 (n = 177), and 4.1 ± 1.7 in group B2 (n = 87; p < 0.01). Values for the oral floor were 2.8 ± 0.74 in group A (n = 362), 4.7 ± 2.55 in group B (n = 228; p < 0.01), 4.4 ± 3.39 in group B1 (n = 130), and 5.1 ± 2.69 in group B2 (n = 98, p = 0.01). Values for the larynx were 2.8 ± 0.76 in group A (n = 353), 4.2 ± 2.05 in group B (n = 237; p < 0.01), 4.0 ± 2.02 in group B1 (n = 165), and 4.6 ± 2.8 in group B2 (n = 72; p = 0.027). Values for the thyroid were 2.4 ± 0.63 in group A (n = 404), 3.0 ± 1.01 in group B (n = 186; p < 0.01), 2.6 ± 0.39 in group B1 (n = 130), and 4.0 ± 1.24 in group B2 (n = 56; p < 0.01). One patient developed a palatine tonsil carcinoma (group B1, SUV_max 3.2), and one patient developed an oral floor carcinoma (group B1, SUV_max 3.7). Conclusion  Elevated/asymmetric head and neck FDG accumulation without a correlating morphological lesion can frequently be found and does not predict cancer development. In populations in which goitre is endemic, FDG uptake by the thyroid is common and not associated with thyroid cancer.     

Contrast-enhanced magnetic resonance angiography in carotid artery disease: does automated image registration improve image quality?

Contrast-enhanced magnetic resonance angiography (MRA) is a noninvasive imaging alternative to digital subtraction angiography (DSA) for patients with carotid artery disease. In DSA, image quality can be improved by shifting the mask image if the patient has moved during angiography. This study investigated whether such image registration may also help to improve the image quality of carotid MRA. Data from 370 carotid MRA examinations of patients likely to have carotid artery disease were prospectively collected. The standard nonregistered MRAs were compared to automatically linear, affine and warp registered MRA by using three image quality parameters: the vessel detection probability (VDP) in maximum intensity projection (MIP) images, contrast-to-noise ratio (CNR) in MIP images, and contrast-to-noise ratio in three-dimensional image volumes. A body shift of less than 1 mm occurred in 96.2% of cases. Analysis of variance revealed no significant influence of image registration and body shift on image quality (p > 0.05). In conclusion, standard contrast-enhanced carotid MRA usually requires no image registration to improve image quality and is generally robust against any naturally occurring body shift. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Diagnostic value of PET/CT for the staging and restaging of pediatric tumors

Objective  The objective of this retrospective study was to compare the diagnostic value of 2-[¹⁸F]fluoro-2-deoxy-d-glucose positron emission tomography (¹⁸F-FDG PET)/CT versus ¹⁸F-FDG PET and CT alone for staging and restaging of pediatric solid tumors. Methods  Forty-three children and adolescents (19 females and 24 males; mean age, 15.2 years; age range, 6–20 years) with osteosarcoma (n = 1), squamous cell carcinoma (n = 1), synovial sarcoma (n = 2), germ cell tumor (n = 2), neuroblastoma (n = 2), desmoid tumor (n = 2), melanoma (n = 3), rhabdomyosarcoma (n = 5), Hodgkin’s lymphoma (n = 7), non-Hodgkin-lymphoma (n = 9), and Ewing’s sarcoma (n = 9) who had undergone ¹⁸F-FDG PET/CT imaging for primary staging or follow-up of metastases were included in this study. The presence, location, and size of primary tumors was determined separately for PET/CT, PET, and CT by two experienced reviewers. The diagnosis of the primary tumor was confirmed by histopathology. The presence or absence of metastases was confirmed by histopathology (n = 62) or clinical and imaging follow-up (n = 238). Results  The sensitivities for the detection of solid primary tumors using integrated ¹⁸F-FDG PET/CT (95%), ¹⁸F-FDG PET alone (73%), and CT alone (93%) were not significantly different (p > 0.05). Seventeen patients showed a total of 153 distant metastases. Integrated PET/CT had a significantly higher sensitivity for the detection of these metastases (91%) than PET alone (37%; p < 0.05), but not CT alone (83%; p > 0.05). When lesions with a diameter of less than 0.5 cm were excluded, PET/CT (89%) showed a significantly higher specificity compared to PET (45%; p < 0.05) and CT (55%; p < 0.05). In a sub-analysis of pulmonary metastases, the values for sensitivity and specificity were 90%, 14%, 82% and 63%, 78%, 65%, respectively, for integrated PET/CT, stand-alone PET, and stand-alone CT. For the detection of regional lymph node metastases, ¹⁸F-FDG PET/CT, ¹⁸F-FDG PET alone, and CT alone were diagnostically correct in 83%, 61%, and 42%. A sub-analysis focusing on the ability of PET/CT, PET, and CT to detect osseous metastases showed no statistically significant difference between the three imaging modalities (p > 0.05). Conclusion  Our study showed a significantly increased sensitivity of PET/CT over that of PET for the detection of distant metastases but not over that of CT alone. However, the specificity of PET/CT for the characterization of pulmonary metastases with a diameter > 0.5 cm and lymph node metastases with a diameter of <1 cm was significantly increased over that of CT alone.     

Can T2 relaxation values and color maps be used to detect chondral damage utilizing subchondral bone marrow edema as a marker?

Objective  This study aimed to investigate whether a commercially available time-efficient T2 mapping sequence will demonstrate findings of articular cartilage degeneration based on T2 relaxation values (RV) and color maps, using subchondral bone marrow edema (BME) as a marker for chondral damage. Materials and methods  The patient group consisted of 88 subjects who underwent knee magnetic resonance imaging at 1.5 T who had subchondral BME evident on fat-suppressed T2-weighted sequences. The control group was comprised of 60 subjects with no evidence of subchondral BME. A commercially available eight echo T2 relaxation sequence (acquisition time 8:36 min) was used to construct a T2 color map and to determine T2 RVs. T2 RVs were determined on cartilage overlying subchondral BME in patients and in eight pre-determined anatomical regions in controls. T2 color maps in the patient and control groups were analyzed for degree of color stratification (presence = two or more colors) at the same anatomic site as that used for T2 RV determination. Results  T2 RVs were significantly increased in patients compared to controls for the medial femoral condyle (MF; p < 0.01), medial patellar facet (MP; p < 0.01), lateral patellar facet (LP; p < 0.01), lateral femoral condyle (LF; p < 0.01) and lateral tibial plateau (LT; p < 0.01). Loss of color stratification was noted in patients compared to controls in the medial tibial plateau (MT; p = 0.01), LF (p < 0.01), and LT (p < 0.01). In the patient group, increase in T2 RVs was associated with corresponding decrease in color stratification in MF (p < 0.01), MT (p < 0.01), MP (p < 0.01), medial femoral trochlear groove (p = 0.02), and lateral femoral trochlear groove (p < 0.01). Conclusion  Subchondral BME was associated with an increase in adjacent articular cartilage T2 RVs at some sites. Also, elevated T2 RVs were associated with loss of color stratification.     

Percutaneous interventions for treating ischemic complications of aortic dissection

The aim of this study was to evaluate the role of percutaneous interventions in treating ischemia complicating aortic dissection. Forty-five patients with ischemia complicating aortic dissection were treated by balloon fenestration, true lumen stenting, angioplasty, or thrombolysis. Clinical and laboratory examinations were performed before and after intervention, and at the end of follow-up (median 37 months). Eighteen dissections were acute, 9 sub-acute, and 18 chronic. Mesenterohepatic ischemia resolved in 16 of 18 patients; lactate and SGOT values fell from 2.89 to 1.23 mmol/L (p = 0.006) and from 165.9 to 59.7 U/L (p = 0.034), respectively. In patients with renal ischemia, creatinine levels fell from 360.1 to 196.3 μmol/L (p = 0.007) accompanied by a significant reduction in blood pressure. Limb-threatening ischemia resolved in three of four patients; in 21 claudicants, the mean walking distance improved from 272 to 1,283 m (p = 0.001). Spinal ischemia resolved completely or partially in six of eight patients. Adjunctive surgical measures were necessary in six patients. Overall 30-day mortality in the 45 patients was 6.7%; all three deaths were in patients with acute dissections (mortality in this subgroup 16.7%). Ischemia complicating aortic dissection can be effectively treated by percutaneous interventions resulting in good early and mid-term outcomes.     

Dual-energy CT head bone and hard plaque removal for quantification of calcified carotid stenosis: utility and comparison with digital subtraction angiography

We evaluated quantification of calcified carotid stenosis by dual-energy (DE) CTA and dual-energy head bone and hard plaque removal (DE hard plaque removal) and compared the results to those of digital subtraction angiography (DSA). Eighteen vessels (13 patients) with densely calcified carotid stenosis were examined by dual-source CT in the dual-energy mode (tube voltages 140 kV and 80 kV). Head bone and hard plaques were removed from the dual-energy images by using commercial software. Carotid stenosis was quantified according to NASCET criteria on MIP images and DSA images at the same plane. Correlation between DE CTA and DSA was determined by cross tabulation. Accuracies for stenosis detection and grading were calculated. Stenosis could be evaluated in all vessels by DE CTA after applying DE hard plaque removal. In contrast, conventional CTA failed to show stenosis in 13 out of 18 vessels due to overlapping hard plaque. Good correlation between DE plaque removal images and DSA images was observed (r ² = 0.9504) for stenosis grading. Sensitivity and specificity to detect hemodynamically relevant (>70%) stenosis was 100% and 92%, respectively. Dual-energy head bone and hard plaque removal is a promising tool for the evaluation of densely calcified carotid stenosis.     

Chronic thyroiditis in patients with advanced breast carcinoma: metabolic and morphologic changes on PET-CT

Purpose  To investigate clinical implications of FDG uptake in the thyroid glands in patients with advanced breast carcinoma by comparing metabolic and morphologic patterns on positron emission tomography (PET)/computed tomography (CT). Methods  The institutional review board waived the requirement for informed consent. A retrospective analysis was performed in 146 women (mean age 54 years) with advanced breast carcinoma who received systemic treatment. All patients underwent PET-CT before and after treatment. All PET-CT studies were reviewed in consensus by two reviewers. Morphologic changes including volume and mean parenchymal density of the thyroid glands were evaluated. Maximum standardized uptake value (SUVmax) and total lesion glycolysis (TLG) were determined to evaluate metabolic changes. These parameters were compared between patients with chronic thyroiditis who received thyroid hormone replacement therapy and those who did not. Results  Of the 146 patients, 29 (20%) showed bilaterally diffuse uptake in the thyroid glands on the baseline PET-CT scan. The SUVmax showed a linear relationship with volume (r = 0.428, p = 0.021) and the mean parenchymal density (r = −0.385, p = 0.039) of the thyroid glands. In 21 of the 29 patients (72%) with hypothyroidism who received thyroid hormone replacement therapy, the volume, mean parenchymal density, SUVmax, and TLG of the thyroid glands showed no significant changes. In contrast, 8 of the 29 patients (28%) who did not receive thyroid hormone replacement therapy showed marked decreases in SUVmax and TLG. Conclusion  Diffuse thyroid uptake on PET-CT represents active inflammation caused by chronic thyroiditis in patients with advanced breast carcinoma. Diffuse thyroid uptake may also address the concern about subclinical hypothyroidism which develops into overt disease during follow-up.