The risk of delayed spinal cord injury in pediatric spinal deformity surgery.

Delayed spinal cord injury (SCI) hours or days after surgery, with uneventful monitoring and initial normal postoperative neurological examination, is a rare complication. Based on anecdotal evidence, the risk of delayed spinal cord injury might be higher than previously assumed. Therefore the aim of this study was to determine the risk of delayed SCI after pediatric spinal deformity surgery between 2013-2019 in the Netherlands. The total number of pediatric spinal deformity surgeries performed for scoliosis or kyphosis between 2013-2019 was obtained from the Dutch National Registration of Hospital Care. All eleven Dutch hospitals that perform pediatric spinal deformity surgery were contacted for occurrence of delayed SCI. From the identified patients with delayed SCI, the following data were collected: patient characteristics, details about the SCI, the surgical procedure, management and degree of improvement.2884 pediatric deformity surgeries were identified between 2013-2019. Seven patients (0.24%) with delayed SCI were reported: 3 idiopathic, 2 neuromuscular (including 1 kypho-scoliosis) and 2 syndromic scoliosis. The risk of delayed SCI after pediatric deformity surgery was 1:595 in idiopathic scoliosis, 1:214 in syndromic scoliosis, 1:201 in neuromuscular scoliosis. All seven patients had a documented normal neurological examination in the first postoperative period; neurological deficits were first diagnosed at a median 16h (range 2.5-40) after surgery. The risk of delayed SCI after pediatric deformity surgery is higher than previously reported, especially in patients with non-idiopathic scoliosis. Regular postoperative testing for late neurologic deficit should be performed for timely diagnosis and management of this devastating complication.

Did the dislocation risk after primary total hip arthroplasty decrease over time? A meta-analysis across six decades.

BACKGROUND: While continuous optimization is attempted to decrease the incidence of dislocation after total hip arthroplasty (THA), dislocation remains a major complication. This meta-analysis aims to analyze the evolution of the dislocation risk after primary THA over the decades and to evaluate its potential publication bias. PATIENTS AND METHODS: A systematic search was performed according to the PRISMA guidelines for this meta-analysis in the literature published between 1962 and 2020. MEDLINE, Cochrane and Embase databases were searched for studies reporting the dislocation risk and length of follow-up. Studies that reported on revision rates only and did not mention separate dislocations were excluded. All study designs were eligible. Study quality was assessed by existing quality assessment tools adjusted for arthroplasty research. Overall risk and yearly dislocation rates were calculated and related to historical time frame, study design, sample size and length of follow-up. RESULTS: In total, 174 studies were included with an overall moderate quality. In total there were 85.209 dislocations reported in 5.030.293 THAs, showing an overall dislocation risk of 1.7%, with a median follow-up of 24 months. The overall dislocation risk classified per decade decreased from 3.7% in 1960-1970 to 0.7% in 2010-2020. The yearly dislocation rate decreased from 1.8 to 0.7% within these same decades. There was no significant correlation between the reported dislocation risk and the duration of follow-up (p = 0.903) or sample size (p = 0.755). The reported dislocation risk was higher in articles with registry data compared to other study designs (p = 0.021). CONCLUSION: The dislocation risk in THA has been decreasing over the past decades to 0.7%. Non-selective registry studies reported a higher dislocation risk compared to studies with selective cohorts and RCTs. This indicates that the actual dislocation risk is higher than often reported and 'real-world data' are reflected better in large-scale cohorts and registries.

CT analysis of the posterior anatomical landmarks of the scoliotic spine.

AIM: To use computed tomography (CT) to assess the validity and reliability of the posterior landmarks, spinous processes (SP), transverse processes (TP), and centre of lamina (COL), as compared to the Cobb angle to assess the curve severity and progression of adolescent idiopathic scoliosis (AIS). MATERIALS AND METHODS: A consecutive series of CT examinations of severe AIS patients were included retrospectively. SP, TP, and COL angles were measured for all curves and compared to the Cobb angle. RESULTS: One hundred and five patients were included. The mean Cobb versus SP, TP, and COL angles were, 54° versus 37°, 49°, and 51° in the thoracic curves and 34° versus 26°, 31°, and 34° in the (thoraco)lumbar curves. Intraclass correlation coefficient values for intra-rater measurements of the SP, TP, and COL angles were 0.93, 0.97, and 0.95 and 0.70, 0.90, and 0.88 for inter-rater measurements. The correlations between the Cobb angle and SP, TP, and COL angles in thoracic and (thoraco)lumbar curves were 0.79 and 0.66, 0.87 and 0.84, and 0.80 and 0.70. CONCLUSIONS: The posterior spinal landmarks can be used for assessment of scoliosis severity in AIS; however, they show a systematic underestimation, but a strong correlation with the coronal Cobb angle. TP and COL angles had the highest validity.

Current Evidence for Spinopelvic Characteristics Influencing Total Hip Arthroplasty Dislocation Risk.

BACKGROUND: Decreased pelvic mobility and pelvic retroversion may result from spinal degeneration and lead to changes in the orientation of the acetabular implant after total hip arthroplasty (THA). While multiple patient and surgery-related factors contribute to THA dislocations, there is increasing evidence that sagittal spinopelvic dynamics are relevant for THA stability. The aim of this systematic review was to assess the relationship between previously described sagittal spinopelvic characteristics and implant dislocations after primary THA. METHODS: A comprehensive literature search in the PubMed and Embase databases was conducted for studies reporting on spinopelvic morphology, alignment, pathology, or surgery and THA dislocations. Risk of bias was assessed using the MINORS criteria. Because of high heterogeneity in study methodology, a synthesis of best evidence was performed. Odds ratios (ORs), relative risks (RRs), and effect sizes (g) were calculated. RESULTS: Fifteen studies (1,007,900 THAs) with quality scores of 15 to 23 out of 24 were included. Nine different spinopelvic alignment parameters (8 studies, g = 0.14 to 2.02), spinal pathology (2 studies, OR = 1.9 to 29.2), and previous spinal fusion surgery (8 studies, OR = 1.59 to 23.7, RR = 3.0) were found to be related to THA dislocation. Conflicting results were found for another sagittal pelvic morphology parameter, pelvic incidence. CONCLUSIONS: Several sagittal spinopelvic patient characteristics were found to be related to THA dislocation, and the associated risks were greater than for other patient and surgery-related factors. Future research is needed to determine which of those characteristics and parameters should be taken into account in patients undergoing primary THA. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

[Treatment recommendations for early esophageal cancer : Endoscopic and surgical options]. / Therapieempfehlungen beim Frühkarzinom des Ösophagus : Endoskopische und chirurgische Optionen.

BACKGROUND: Esophageal cancer represents a complex tumor entity with an increasing proportion of adenocarcinomas. Early esophageal cancer is staged as m1-m3 depending on the depth of infiltration into the mucosa and as sm1-sm3 depending on invasion into the submucosa. The risk of lymph node metastasis is strongly correlated with the depth of invasion and increases by leaps and bounds with submucosal infiltration. MATERIAL AND METHODS: This review is based on publications retrieved by a selective database search (MEDLINE, PubMed, Cochrane Library, International Standard Randomised Controlled Trial Number, ISRCTN, registry) on the current management of early esophageal cancer. RESULTS: The endoscopic diagnostics and evaluation of the dignity of superficial esophageal cancer by traditional staining techniques have been expanded by virtual chromoendoscopy. Endoscopic resection is the diagnostic and therapeutic procedure of choice for mucosal low risk adenocarcinomas (grade 1 or 2, no blood or lymph vessel invasion). Under certain prerequisites adenocarcinomas of the upper submucosa (sm1) can also be endoscopically removed. All other stages necessitate surgical treatment. In squamous cell carcinoma without risk factors a surgical oncological esophageal resection is indicated after infiltration of the third mucosal layer (m3). Endoscopic submucosal dissection (ESD) shows high rates of en bloc and R0 (curative) resections even with large lesions. CONCLUSION: Borderline cases between endoscopic and surgical treatment of early esophageal cancer necessitate an interdisciplinary approach and individually adapted management, which in the locally advanced stage are always embedded in a multimodal concept.

Cardiac fibroblast activation detected by Ga-68 FAPI PET imaging as a potential novel biomarker of cardiac injury/remodeling.

BACKGROUND: Fibroblast activation protein (FAP) as a specific marker of activated fibroblasts can be visualized by positron emission tomography (PET) using Ga-68-FAP inhibitors (FAPI). Gallium-68-labeled FAPI is increasingly used in the staging of various cancers. In addition, the first cases of theranostic approaches have been reported. In this work, we describe the phenomenon of myocardial FAPI uptake in patients who received a Ga-68 FAPI PET for tumor staging. METHOD AND RESULTS: Ga-68 FAPI PET examinations for cancer staging were retrospectively analyzed with respect to cardiac tracer uptake. Standardized uptake values (SUV) were correlated to clinical covariates in a univariate regression model. From 09/2018 to 11/2019 N = 32 patients underwent FAPI PET at our institution. Six out of 32 patients (18.8%) demonstrated increased localized myocardial tracer accumulation, with remote FAPI uptake being significantly higher in patients with vs without localized focal myocardial uptake (SUVmax 2.2 ± .6 vs 1.5 ± .4, P < .05 and SUVmean 1.6 ± .4 vs 1.2 ± .3, P < .05, respectively). Univariate regression demonstrated a significant correlation of coronary artery disease (CAD), age and left ventricular ejection fraction (LVEF) with remote SUVmean uptake, the latter with a very strong correlation with remote uptake (R2 = .74, P < .01). CONCLUSION: Our study indicates an association of CAD, age, and LVEF with FAPI uptake. Further studies are warranted to assess if fibroblast activation can be reliably measured and may be used for risk stratification regarding early detection or progression of CAD and left ventricular remodeling.

ANTECEDENTES: Proteína de activación de fibroblastos (FAP) como marcador específico de fibroblastos maduros activados se puede visualizar mediante tomografía por emisión de positrones (PET) usando inhibidores de Ga-68-FAP (FAPI). El FAPI marcado con galio 68 se usa cada vez más en la estatificación de varios tipos de cáncer.Además, se han reportado los primeros casos de abordajes teranósticos. En este trabajo describimos el fenómeno de la captación de FAPI miocárdica en pacientes que recibieron Ga-68 FAPI PET para estatificación tumoral. MéTODO Y RESULTADOS: Los exámenes de PET Ga-68 FAPI para estadificación de cáncer se analizaron retrospectivamente con respecto a la captación del marcador cardíaco. Los valores de absorción estandarizados (SUV) se correlacionaron con covariables clínicas en un modelo de regresión univariante. Del 09/2018 al 11/2019 con una n = 32 pacientes fueron sometidos a PET FAPI en nuestra institución. Seis de 32 pacientes (18.8%) demostraron un aumento de acumulación del marcador localizado en el miocardio, con la captación remota de FAPI siendo significativamente mayor en pacientes con aumento de la captación vs sin captación focalizada de miocardio (SUVmax 2.2 ± 0.6 vs. 1.5 ± 0.4, p <0.05 y SUV mean 1.6 ± 0.4 vs. 1.2 ± 0.3, p <0.05, respectivamente). La regresión univariante demostró una correlación significativa de la enfermedad de la arteria coronaria (CAD), la edad y la fracción de eyección ventricular izquierda (FEVI) con absorción SUV remota, esta última con una muy fuerte correlación con la captación remota (R² = 0.74, p <0.01). CONCLUSIóN: Nuestro estudio indica una asociación de CAD, edad y FEVI con la captación de FAPI. Se necesitan más estudios para evaluar si la activación de fibroblastos se puede medir de manera confiable y se puede usar para la estratificación de riesgo con respecto a la detección temprana o la progresión de la CAD y la remodelación ventricular izquierda.

CONTEXTE: La protéine d'activation des fibroblastes (FAP) activés et matures peut être visualisée par tomographie à émission de positons (TEP) à l'aide d'inhibiteurs de l'activation des fibroblastes (FAPI). FAPI marqué au gallium 68 est de plus en plus utilisé dans la stratification de divers cancers. De plus, les premiers exemples d'approches théranostiques ont été rapportés. Dans ce travail nous décrivons la captation myocardique de FAPI chez les patients qui bénéficié d'une TEP au Ga-68 FAPI pour stratification tumorale. MéTHODE ET RéSULTATS: Les examens TEP Ga-68 FAPI pour la stratification oncologique ont été analysés rétrospectivement pour l'absorption du traceur au niveau cardiaque. Les valeurs d'absorption normalisées (SUV) font été corrélées aux variables cliniques selon un modèle de régression univarié. A partir de septembre 2018 jusqu'en novembre 2019, 32 patients ont bénéficié d'une TEP FAPI dans notre établissement. Six de nos 32 patients (18,8%) ont démontré une augmentation focale de captation du tracer au niveau myocardique. Les foyers systémiques se sont révélés significativement plus élevé chez les patients avec foyers myocardiques localisés (SUV max 2,2 ± 0,6 vs 1,5 ± 0,4, p <0,05 et SUV mean 1,6 ± 0,4 vs 1,2 ± 0,3, p <0,05, respectivement). Nous avons observé une corrélation significative entre la maladie coronarienne, l'âge, la fraction d'éjection du ventricule gauche et la présence de foyer myocardiques FAPI (R² = 0,74, p <0,01) CONCLUSION: Notre étude indique une association entre la maladie cardiovasculaire coronarienne, l'âge et la FEVG et la captation myocardique de FAPI. Des études additionnelles sont nécessaires pour déterminer si l'activation des fibroblastes peut être mesurée de manière fiable et utilisée pour la détection et la progression de la maladie coronarienne et le remodelage du ventricule gauche.

[What actually happens in hybrid imaging?] / Was passiert eigentlich in der Hybridbildgebung?

CLINICAL/METHODOLOGICAL ISSUE: The goal of this article is to shed light on innovations in perfusion imaging and the fields of application that have opened up in hybrid imaging of the heart. STANDARD RADIOLOGICAL METHODS: As before, the most commonly used modalities in hybrid imaging are single photon emission computed tomography (SPECT) and positron emission tomography/computed tomography (PET/CT). Perfusion tracers and the radioactively labeled glucose analog 18F­fluorodeoxyglucose (FDG) are commonly used for vitality imaging. METHODICAL INNOVATIONS: Use of PET/MRI (magnetic resonance imaging) is becoming increasingly widespread. In addition, FDG is also increasingly applied in imaging infectious and inflammatory myocardial diseases. Furthermore, novel tracers are used, such as the amyloid-specific tracers in cardiac amyloidosis. PERFORMANCE: Overall, this development has led to an increasing use of hybrid imaging techniques. These still include myocardial perfusion imaging, but are also used in inflammatory and infectious diseases such as endocarditis, myocarditis and sarcoidosis, as well as in underestimated diseases such as cardiac amyloidosis. The use of tracers has led to the creation of new fields of application in hybrid imaging. PRACTICAL RECOMMENDATIONS: Hybrid imaging combining myocardial perfusion and coronary visualization seems to be particularly advantageous in complex cases such as multivessel disease. In infectious and inflammatory myocardial diseases, FDG PET/CT or PET/MRI has clearly demonstrated its added value. New fields of application are very promising, but their significance has yet to be clearly demonstrated.

Trigonometric Algorithm Defining the True Three-Dimensional Acetabular Cup Orientation: Correlation Between Measured and Calculated Cup Orientation Angles.

BACKGROUND: Acetabular cup orientation plays a key role in implant stability and the success of total hip arthroplasty. To date, the orientation has been measured with different imaging modalities and definitions, leading to lack of consensus on optimal cup placement. A 3-dimensional (3D) concept involving a trigonometric description enables unambiguous definitions. Our objective was to test the validity and reliability of a 3D trigonometric description of cup orientation. METHODS: Computed tomographic scans of the pelvis, performed for vascular assessment of 20 patients with 22 primary total hip replacements in situ, were systematically collected. On multiplanar reconstructions, 3 observers independently measured cup orientation retrospectively in terms of coronal inclination, sagittal tilt, and transverse version. The angles measured in 2 planes were used to calculate the angle in the third plane via a trigonometric algorithm. For correlation and reliability analyses, intraobserver and interobserver differences between measured and calculated angles were evaluated with use of the intraclass correlation coefficient (ICC). RESULTS: Measured and calculated angles had ICCs of 0.953 for coronal inclination, 0.985 for sagittal tilt, and 0.982 for transverse version. Intraobserver and interobserver reliability had ICCs of 0.987 and 0.987, respectively, for coronal inclination; 0.979 and 0.981, respectively, for sagittal tilt; and 0.992 and 0.978, respectively, for transverse version. CONCLUSIONS: The 3D concept with its trigonometric algorithm is a valid and reliable tool for the measurement of cup orientation. CLINICAL RELEVANCE: By calculating the transverse version of cups from coronal inclination and sagittal tilt measurements, the trigonometric algorithm enables a 3D definition of cup orientation, regardless of the imaging modality used. In addition, it introduces sagittal tilt that, like pelvic tilt, rotates around the transverse axis.

Evaluation of a low-carbohydrate diet-based preparation protocol without fasting for cardiac PET/MR imaging.

OBJECTIVE: Assessment of increased glucose uptake in inflammatory or malignant myocardial disease using PET/MRI relies on uptake suppression in normal myocardium. We evaluated the efficacy of a ≥24 hours high-fat, low-carbohydrate, and protein-permitted diet (HFLCPP) in combination with unfractionated heparin for suppression of "physiologic" myocardial glucose uptake. METHODS: PET/MRI was successfully performed in 89 patients. HFLCPP was started ≥24 hours prior to PET/MRI. All patients received i.v. injection of unfractionated heparin (50 IU·kg-1) 15 minutes prior to FDG administration. Left ventricular FDG uptake was visually evaluated by two readers. Diffuse myocardial uptake exceeding liver uptake, isolated uptake in the lateral wall, or diffuse uptake in the entire circumference of the heart base were defined as failed suppression. Homogeneous myocardial uptake below liver uptake with/without focal uptake was defined as successful suppression. RESULTS: Success rate was 84%. Suppression was unsuccessful in 14 patients. No significant influence of gender (P = .40) or age (P = .21) was found. However, insufficient suppression was more common in patients younger than 45 years (20% vs 7%). PET/MR imaging completion rate was >97%. CONCLUSION: A HFLCPP diet in combination with unfractionated heparin was successfully implemented for cardiac PET/MRI and resulted in a sufficient suppression of myocardial FDG uptake in 84% of patients.

Impact of the scout view orientation on the radiation exposure and image quality in thoracic and abdominal CT.

OBJECTIVES: To assess the impact of the scout view orientation on radiation exposure and image quality in thoracoabdominal CT, when automated tube voltage selection (ATVS) and automated tube current modulation (ATCM) are used in combination with scan planning on a single scout view. METHODS: Fifty patients underwent two thoracoabdominal CT examinations, one planned on an anteroposterior scout view, one planned on a lateral scout view. Both examinations included contrast-enhanced imaging of chest (CH) and abdomen (AB) and non-contrast-enhanced imaging of the liver (LI). For all examinations the same imaging protocol was used on the same dual-source CT scanner. The radiation exposure was recorded and objective as well as visual image quality was assessed for all examinations. RESULTS: The median dose-length product was significantly lower in scans planned on a lateral scout view (CH: 179 vs. 218 mGy*cm, LI: 148 vs. 178 mGy*cm, AB: 324 vs. 370 mGy*cm, p < 0.0001). Objective image quality was marginal lower in scans planned on a lateral scout view, whereas the visual image quality was rated as equal. CONCLUSION: At the tested radiation doses, the orientation of the scout view has a significant impact on the radiation exposure but no clinically relevant impact on the image quality. KEY POINTS: • The scout view orientation has a significant impact on the radiation exposure. • The scout view orientation has no clinically relevant impact on image quality. • A lateral scout view should be preferred with regard to radiation exposure.

[Noncompaction cardiomyopathy]. / "Non-compaction"-Kardiomyopathie.

Noncompaction cardiomyopathy (NCCM) is a genetic myocardial disorder, which is characterized by a two-layered ventricle wall with a thin compact outer layer and a noncompacted inner layer, with prominent trabeculations and deep intratrabecular recesses communicating with the ventricle cavity without any contact to the coronary system. Before the initial description as isolated left ventricle cardiomyopathy (ILVCN) in 1984 by Engberding and Bender, the morphological characteristics had been described only in association with other congenital cardiac disorders, such as atresia of the semilunar valves. The disease usually involves the myocardium of the left ventricle but involvement of the right ventricular has recently been shown. Due to delayed diagnosis and therapy, in advanced stages NCCM can result in heart failure. Life-threatening complications, such as malignant arrhythmia with sudden cardiac death and embolic events have been observed in patients with NCCM. A multimodal investigation including echocardiography and cardiac magnet resonance tomography (CMR) as well as a focused analysis of symptoms can allow a valid diagnosis.

Cardiac MRI: T2-Mapping Versus T2-Weighted Dark-Blood TSE Imaging for Myocardial Edema Visualization in Acute Myocardial Infarction.

PURPOSE: To assess the diagnostic accuracy of T2 mapping for the detection of myocardial edema in acute myocardial infarction (AMI), and to compare this diagnostic accuracy with that of the current standard for myocardial edema imaging, which is T2w dark-blood TSE imaging. MATERIALS AND METHODS: 29 patients with AMI were examined at 1.5 T. For the visualization of myocardial edema, T2 maps, calculated from three T2w SSFP images, and T2w dark-blood TSE images were acquired in standard short- and long-axis views. Cine SSFP images were acquired for the analysis of left ventricular (LV) function and late gadolinium enhancement images (LGE) for the visualization of myocardial necrosis. The T2 maps as well as the T2w dark-blood TSE images were evaluated twice independently from the cine SSFP and LGE images. The presence or absence of myocardial edema was rated visually for each LV segment. As the standard of reference, the infarct zone was defined based on the cine SSFP and the LGE images. RESULTS: In this segment-based analysis, T2 mapping showed a sensitivity of 82 % and a specificity of 94 % for the detection of edema in the infarct zone. T2w dark-blood TSE imaging revealed a sensitivity of 50 % and a specificity of 98 %. T2 mapping showed a higher intra-rater agreement compared to T2w dark-blood TSE imaging (κ: 0.87 vs. 0.76). CONCLUSIONS: T2 mapping allows for the visualization of myocardial edema in AMI with a high sensitivity and specificity, and features better diagnostic accuracy in terms of a higher sensitivity compared to T2w dark-blood TSE imaging. Citation Format: • Naßenstein K, Nensa F, Schlosser T et al. Cardiac MRI: T2-Mapping Versus T2-Weighted Dark-Blood TSE Imaging for Myocardial Edema Visualization in Acute Myocardial Infarction. Fortschr Röntgenstr 2014; 186: 166 - 172.

[Percutaneous arteriovenous shunting in patients with severe COPD: a new interventional radiological treatment]. / Perkutane arteriovenöse Shuntanlage bei Patienten mit schwerer COPD: eine neue interventionelle radiologische Technik.

PURPOSE: The aim of this study was to evaluate the technical feasibility and safety of a new interventional radiological technique to create a shunt percutanously between the external iliac vein and artery in patients with severe COPD. MATERIALS AND METHODS: 40 patients were included in this multicenter trial. In 38 patients the artery was punctured from the vein using a novel crossing needle. A special delivery system was used to implant a novel nitinol device (ACS, ROX Medical) between the artery and the vein to maintain a 4 mm calibrated and structured fistula between the two vessels. RESULTS: Shunt implantation was successful in 38 patients. The perfused arteriovenous shunts could be well documented in DSA and the diameter was measured between 3 and 4 mm in all cases. Peri-interventional non-flow-limiting dissection of the iliac artery occurred in one patient. Post-interventional venous bleeding in two patients was treated successfully by local compression. In one patient a peripheral artery thrombembolism was successfully treated by thrombolysis. CONCLUSION: The new interventional radiological technique to create an arteriovenous shunt in the iliac vessels presented in this study has proven to be feasible and safe.

Cardiac MRI: estimation of changes in normalized myocardial gadolinium accumulation over time after contrast injection in patients with acute myocarditis and healthy volunteers.

PURPOSE: An increased normalized gadolinium accumulation (NGA) in the myocardium during early washout has been used for the diagnosis of acute myocarditis (AM). Due to the fact that the pharmacokinetics of contrast agents are complex, time-related changes in NGA after contrast injection are likely. Because knowledge about time-related changes of NGA may improve the diagnostic accuracy of MR, our study aimed to estimate the time course of NGA after contrast injection in patients as well as in healthy volunteers. MATERIALS AND METHODS: An ECG-triggered inversion recovery SSFP sequence with incrementally increasing inversion times was repetitively acquired over the 15 minutes after injection of 0.2 Gd-DTPA per kg body weight in a 4-chamber view in 15 patients with AM and 20 volunteers. The T 1relaxation times and the longitudinal relaxation rates (R1) of the myocardium and skeletal musculature were calculated for each point in time after contrast injection. The time course of NGA was estimated based on the linear relationship between R1 and tissue Gd concentration. RESULTS: NGA decreased over time in the form of a negative power function in patients with AM and in healthy controls. NGA in AM tended to be higher than in controls (p > 0.05). CONCLUSION: NGA rapidly changes after contrast injection, which must be considered when measuring NGA. Although we observed a trend towards higher NGA values in patients with AM with a maximum difference one minute after contrast injection, NGA did not allow us to differentiate patients with AM from healthy volunteers, because the observed differences did not reach a level of significance.

Coronary artery calcium score: influence of the reconstruction interval on cardiac risk stratification in asymptomatic patients using dual-source computed tomography.

PURPOSE: To evaluate the impact of the reconstruction interval on coronary calcium score and cardiac risk stratification using dual-source computed tomography (DSCT). MATERIALS AND METHODS: DSCT coronary calcium scoring was performed in 61 consecutive patients, and five data sets per patient were reconstructed within diastole (50 - 70 % of the R-R interval). The Agatston score, volumetric score and the relative variability were assessed for all reconstructions. To assess the individual cardiovascular risk, patients were assigned to risk groups based on age and gender-matched percentile ranks. RESULTS: The mean Agatston score was 184.8 ± 377.9 (relative variability 47 % ± 52 %). The mean volumetric score was 164.4 ± 310.1 (relative variability 49 % ± 58 %). There was a negative correlation between the total Agatston score and the relative variability (r = -0.37; p < 0.01). Depending on the reconstruction interval used, 18 predominantly young patients were assigned to more than one risk group. CONCLUSION: Despite the increased temporal resolution of DSCT examinations, the Agatston and volumetric scores depend on the reconstruction time within the cardiac cycle. The fact that the greatest relative variability for both the Agatston score and the volumetric score was found in young patients with small amounts of coronary calcium may result in different treatment strategies for young patients depending on the reconstruction used. Therefore, more accurate risk stratification may require the analysis of multiple reconstruction intervals.

Comparison of a multi-breath-hold and a single breath-hold cine imaging approach for 4D guide-point modeling of the left ventricle.

PURPOSE: Guide-point modeling (GPM) enables reliable and time-efficient assessment of left ventricular (LV) volumes when using sequences that allow acquisition of short- and long-axis scans within a single breath-hold. Slice misalignment may influence GPM analysis of standard multi-breath-hold images due to image acquisition in different breath-holds. Thus, our study aimed to assess if such an approach allows for reliable volumetric calculations in the clinical routine. MATERIALS AND METHODS: 52 patients were examined on a 1.5 T scanner with multi-breath-hold acquisitions on the standard short- and long-axis using an SSFP (TR 3 ms, TE 1.5 ms, FA 60 degrees ) sequence and a TPAT accelerated SSFP (TR 4.6 msec, TE 1.1msec, FA 60 degrees , acceleration factor 3) sequence that covered the LV in 3 short- and 2 long-axis slices within a single breath-hold. For both datasets GPM was used to assess LV volumes. In addition, LV parameters were calculated by applying the summation of slices (SoS) approach (standard of reference) with the short-axis views of the multi-breath-hold dataset. RESULTS: The post-processing times were shorter with both GPM approaches (both, p < 0.001). No significant difference between the 3 methods for the calculation of the ejection fraction was observed. However, end-diastolic, end-systolic and stroke volumes yielded higher results than the standard of reference if the GPM technique was employed. Excellent correlations were observed for all volumetric parameters derived from both GPM evaluations (all r > 0.97). CONCLUSION: Cine short- and long-axis images that had been acquired in different breath-holds can be reliably evaluated by the GPM approach.

Concomitant atherosclerotic disease detected by whole-body MR angiography in relation to coronary artery calcification in patients with coronary artery disease.

PURPOSE: Patients with coronary artery disease (CAD) show a high prevalence for concomitant atherosclerotic peripheral arterial disease (PAD). On the other hand, PAD seems to be an additional risk factor for cardiac events. We evaluated the correlation between arterial pathologies as found in whole-body MR angiography and coronary artery calcification (CAC) detected by electron beam computed tomography (EBCT) and multislice CT (MSCT). MATERIALS AND METHODS: Two hundred and twenty-eight patients (161 men; 67 women) with suspicion for CAD/known CAD underwent whole-body contrast-enhanced MR angiography (wb-ce-MRA) and EBCT/MSCT. An atherosclerosis index was calculated for each patient Index = (40)Sigma(n=1) w(i) with w(i) being the grading of the stenosis of the i (ten) of 40 arteria segments (grade: 0 - no plaque; 1 - plaque - < or = 50 % stenosis; 2 - > 50 % stenosis - < or = 90 % stenosis; 3 - > 90 % stenosis - < 100 % stenosis; 4 - occlusion). Correlations between CAC and atherosclerosis index were performed. RESULTS: Wb-ce MRA and CAC correlate only moderately in this population. An atherosclerosis index 8 renders a positive predictive value for a CAC 100 of 63.3 %. CONCLUSION: An atherosclerosis index as defined in this study does not fully correlate with the extent of CAD as revealed by catheter angiography or EBCT/MSCT, but it might theoretically mirror the increased risk by PAD. It thus might be a promising complementary parameter for the prediction of cardiac events. Future studies need to show its possible additional predictive impact.