Benjamin Henninger

Bone Metastases in Patients with Neuroendocrine Tumor: 68Ga-DOTA-Tyr3-Octreotide PET in Comparison to CT and Bone Scintigraphy

Somatostatin receptor scintigraphy is an accurate imaging modality for the diagnosis of neuroendocrine tumor. Because detection of distant metastases has a major impact on treatment, early diagnosis of metastatic spread is of great importance. So far, no standard procedure has become established for the early diagnosis of bone metastases from neuroendocrine tumor. We compared the diagnostic value of CT with that of the novel somatostatin analog 68Ga-1,4,7,10-tetraazacyclododecane-N,N′,N″,N′′′-tetraacetic acid-d-Phe1-Tyr3-octreotide (68Ga-DOTATOC) in the detection of such metastases. Methods: Fifty-one patients (22 women and 29 men; age range, 32–87 y) with histologically verified neuroendocrine tumor were included in this study. PET scans were fused with CT scans using a vacuum fixation device. 18F-NaF or 99mTc-dicarboxypropane diphosphonate bone scans or clinical follow-up served as the reference standard. Results: Twelve of the 51 patients had no evidence of bone metastases on any of the available imaging modalities, and 37 patients had 68Ga-DOTATOC PET results true-positive for bone metastases. 68Ga-DOTATOC PET results were true-negative for 12 patients, false-positive for one, and false-negative for another, resulting in a sensitivity of 97% and a specificity of 92%. 68Ga-DOTATOC PET detected bone metastases at a significantly higher rate than did CT (P < 0.001). Furthermore, conventional bone scans confirmed the results of somatostatin receptor PET but did not reveal additional tumors in any patients. Conclusion: 68Ga-DOTATOC PET is a reliable, novel method for the early detection of bone metastases in patients with neuroendocrine tumor. Our results show that CT and conventional bone scintigraphy are less accurate than 68Ga-DOTATOC PET in the primary staging or restaging of neuroendocrine tumor.

High-sensitivity troponin T for prediction of left ventricular function and infarct size one year following ST-elevation myocardial infarction

BACKGROUND Data relating high-sensitivity cardiac troponin T (hs-cTnT) to long-term myocardial function and infarct size in patients after ST-elevation myocardial infarction (STEMI) are lacking. We aimed to evaluate the use of early hs-cTnT concentrations for prediction of myocardial function and infarct size assessed by cardiac magnetic resonance imaging (CMR) one year following STEMI. METHODS Sixty-six patients, revascularized by primary percutaneous coronary intervention (PCI) for first-time STEMI, were enrolled in this observational study. Serial hs-cTnT, creatine kinase (CK), high-sensitivity C-reactive protein (hs-CRP) and lactate dehydrogenase (LDH) levels were measured on admission, 6 h, 12 h, and 24 h post-PCI. Patients underwent CMR within the first week and 12months thereafter. RESULTS Except for admission hs-cTnT, all single time point and peak hs-cTnT concentrations showed significant correlations with left ventricular ejection fraction (LVEF: r=-0.404 to -0.517, all ps<0.01) and infarct size (IS: r=0.421 to 0.700, all ps<0.01) at baseline and follow-up. The area under the curve (AUC) of peak hs-cTnT was 0.82 (95% CI 0.71-0.92) for the prediction of decreased LVEF (<55%) and 0.89 (95% CI 0.81-0.97) for the prediction of large IS (>8%) at 12months. The combination of all four biomarkers resulted in an AUC of 0.82 and 0.92 for the prediction of reduced LVEF and large IS at 12months, respectively (both ps>0.05). CONCLUSION In stable STEMI patients successfully revascularized by primary PCI, serial and peak concentrations of hs-cTnT are closely correlated to long-term LVEF and IS. Combination of hs-cTnT with CK, hs-CRP, or LDH did not add any significant prognostic value as compared with hs-cTnT alone.

R2* Relaxometry for the Quantification of Hepatic Iron Overload: Biopsy-Based Calibration and Comparison with the Literature

PURPOSE We compared the calibration of hepatic iron based on R2* relaxometry and liver biopsy with similar studies that have already been published to investigate the transferability of published calibration curves. MATERIALS AND METHODS 17 patients with clinically suspected hepatic iron overload (HIO) were enrolled. All patients underwent liver biopsy and MRI of the liver using a multi-echo gradient echo sequence (TR = 200 ms; TE-initial 0.99 ms; Delta-TE 1.41 ms; 12 echos; flip-angle: 20 °). R2* parameter maps were analyzed using manually placed regions of interest and R2* values were correlated with liver iron concentration (LIC) obtained from liver biopsy. In addition, the results of our study were compared with 6 similar, already published studies. RESULTS A linear relationship between R2* and LIC was found. Regression analysis yielded a correlation coefficient of 0.926, a slope of 0.024 (s mg/g) [95 % CI 0.013 - 0.024] and an intercept of 0.277 (mg/g) [95 % CI -0.328 - 2.49]. We found a significant correlation between the calibration curves obtained from our study in comparison to 3/6 similar studies. The other 3 studies used a different reference standard or sequence parameters which lead to a significant difference for slope, intercept or both in comparison to our data. CONCLUSION Calibration curves from published studies that are based on a correlation of liver biopsy and R2* can be used for the estimation of liver iron concentration, although different scanning parameters and post-processing protocols were used. Low initial TEs might be a prerequisite for pooling data for liver iron quantification. KEY POINTS • Calibration curves from different studies can be used for liver iron quantification• For that purpose calibration curves from published studies should be based on liver biopsy• Low initial TEs might be a prerequisite for pooling data for liver iron quantification.

[18F]choline positron emission tomography in prostate cancer patients with biochemical recurrence after radical prostatectomy: influence of antiandrogen therapy - a preliminary study.

ObjectiveOur purpose was to evaluate whether antiandrogen therapy (AAT) influences [18F]choline PET results in patients with biochemical recurrence after radical prostatectomy (RPE). MethodsThrough a retrospective study we evaluated two groups of patients, both with histologically proven carcinoma of the prostate, who had undergone RPE and a subsequent [18F]choline PET because of biochemical failure (<4 ng/dl). One group consisted of 13 patients under AAT at the time of the PET examination (age range, 55–80 years; median, 68). The other group who had not undergone AAT consisted of 22 patients (age range, 48–72 years; median, 67). Our results were correlated with follow-up information related to histopathology, changes in prostate-specific antigen levels, other imaging modalities and clinical examination. Mean follow-up was 27 months. ResultsIn patients who had undergone AAT, [18F]choline PET was true positive in eight out of 10 patients. The overall sensitivity in this group was 80%. In two cases [18F]choline PET turned out to be false negative, missing local relapse. Of the patients treated only with RPE, 10 out of 20 turned out to be true positive, resulting in a sensitivity of 50%.In all, in four patients biochemical recurrence could not be correlated to pathological findings in any of the available modalities. The difference in sensitivity between patients with and without AAT was statistically not significant (P=0.235). ConclusionIn patients with biochemical recurrence during AAT after RPE, [18F]choline PET can yield true-positive findings, even at prostate-specific antigen values of less than 4 ng/dl, and is an accurate technique for the detection of recurrence.

Improving visualization of the central compartment of the hip with direct MR arthrography under axial leg traction: a feasibility study.

RATIONALE AND OBJECTIVES To evaluate the feasibility of a modified approach for direct magnetic resonance (MR) arthrography of the hip under leg traction in achieving a sufficient femoroacetabular interface and improving the visualization of the ligamentum teres. MATERIALS AND METHODS Forty-six MR arthrograms of 44 patients who underwent MR arthrography with and without leg traction were included into the study. Traction approach included injection of 18-27 mL of fluid (local anesthetic, contrast agent), application of weight-adapted traction load (15-23 kg), and the use of a supporting plate. Patients were instructed to report on pain and complications with an integer pain scale. Joint distraction was measured on coronal images obtained with and without traction, and two radiologists independently evaluated whether femoroacetabular cartilage layers and the ligamentum teres could be seen as distinct entities. McNemar test was used and interobserver agreement was assessed. RESULTS No patient asked for termination of the examination. There were no cases of neuropraxia. Mean difference in distraction was 3.7 mm/3.6 mm (reader 1/reader 2). Cartilage layers could be seen as distinct entities in 43/43 (93.5%/93.5%) and 6/8 (13%/17.4%) of the joints with/without traction (P < .001/P < .001), respectively. The ligamentum teres could be differentiated in 33/30 (71.7%/65.2%) cases with traction, in 33/30 (71.7%/65.2%) cases without traction (P < .999/P < .999), and in 40/37 (87%/80.4%) cases with both the techniques combined. CONCLUSIONS Traction MR arthrography is safe and technically feasible. It enabled the differentiation between femoroacetabular cartilage layers in most cases. Visualization of the ligamentum teres was optimal by combining imaging with both modalities.

Prognostic value of left ventricular global function index in patients after ST-segment elevation myocardial infarction

AIMS The left ventricular global function index (LVGFI) is a novel indicator of left ventricular performance. Its prognostic value in patients after ST-segment elevation myocardial infarction (STEMI) is unknown. We sought to evaluate the prognostic significance of LVGFI measured by cardiovascular magnetic resonance (CMR) imaging after STEMI. METHODS AND RESULTS Two hundred eligible STEMI patients (56 ± 11 years, 16% female) revascularized by primary percutaneous coronary intervention were followed-up for 3.1 [2-4.1] years for major adverse cardiac events (MACE). MACE was defined as a composite of death, non-fatal myocardial re-infarction, and new congestive heart failure. All patients underwent CMR imaging within 2 [2-4] days after STEMI. Late enhancement and cine images were acquired to assess myocardial injury as well as myocardial function, including LVGFI. Patients suffering a MACE event (n = 20, 10%) had a significantly lower LVGFI (P = 0.001). In Kaplan-Meier analysis, a decreased LVGFI was associated with a reduced MACE-free survival (P < 0.001). Multivariate Cox regression analysis revealed a decreased LVGFI as a predictor for MACE [hazard ratio = 4.79, 95% confidence interval (CI) 1.46-15.67, P = 0.010] after adjusting for microvascular obstruction, left ventricular mass, and multivessel disease. In receiver operating characteristic analysis, LVGFI was a strong predictor for MACE (area under the curve = 0.73, CI 0.61-0.85). However, c-statistics revealed that LVGFI does not provide incremental prognostic information over left ventricular ejection fraction (LVEF) (P = 0.38). CONCLUSION LVGFI assessed by CMR is a strong predictor of MACE within 3 years after first STEMI. A superior predictive value as compared with LVEF was not found in this study.

Automated two-point dixon screening for the evaluation of hepatic steatosis and siderosis: comparison with R2*-relaxometry and chemical shift-based sequences

ObjectivesTo evaluate the automated two-point Dixon screening sequence for the detection and estimated quantification of hepatic iron and fat compared with standard sequences as a reference.MethodsOne hundred and two patients with suspected diffuse liver disease were included in this prospective study. The following MRI protocol was used: 3D-T1-weighted opposed- and in-phase gradient echo with two-point Dixon reconstruction and dual-ratio signal discrimination algorithm (“screening” sequence); fat-saturated, multi-gradient-echo sequence with 12 echoes; gradient-echo T1 FLASH opposed- and in-phase. Bland–Altman plots were generated and correlation coefficients were calculated to compare the sequences.ResultsThe screening sequence diagnosed fat in 33, iron in 35 and a combination of both in 4 patients. Correlation between R2* values of the screening sequence and the standard relaxometry was excellent (r = 0.988). A slightly lower correlation (r = 0.978) was found between the fat fraction of the screening sequence and the standard sequence. Bland–Altman revealed systematically lower R2* values obtained from the screening sequence and higher fat fraction values obtained with the standard sequence with a rather high variability in agreement.ConclusionsThe screening sequence is a promising method with fast diagnosis of the predominant liver disease. It is capable of estimating the amount of hepatic fat and iron comparable to standard methods.Key points• MRI plays a major role in the clarification of diffuse liver disease.• The screening sequence was introduced for the assessment of diffuse liver disease.• It is a fast and automated algorithm for the evaluation of hepatic iron and fat.• It is capable of estimating the amount of hepatic fat and iron.

Primary mediastinal synovial sarcoma: a case report and review of the literature.

Primary mediastinal synovial sarcoma is a rare malignancy with only a few cases reported so far. A 56-year-old woman was admitted to our hospital for an investigation of a nodule in the left middle lung on chest radiography. Computed tomography revealed a mediastinal mass first described as a solitary fibrous tumor. The diagnosis of synovial sarcoma was established by computed tomography-guided percutaneous needle biopsy. Work up showed no metastasis to distant organs or contralateral pleural cavity. The mass was surgically resected; pathological and immunohistochemical analyses confirmed the diagnosis of a monophasic spindle cell synovial sarcoma probably originating from phrenic nerve. The patient received adjuvant chemotherapy and radiation and is free of recurrence after a follow up of 16 months.

Fetuin-A is related to infarct size, left ventricular function and remodelling after acute STEMI

Objective To investigate the relationship between plasma fetuin-A, an anti-inflammatory glycoprotein which might be involved in myocardial healing after acute infarction, and infarct size, left ventricular (LV) function and dimensions as well as the occurrence of adverse remodelling at 4 months after acute ST segment elevation myocardial infarction (STEMI). Methods In this single-centre prospective, observational study, 89 patients underwent cardiac MR within the first week and 4 months after mechanical reperfusion for first STEMI. Infarct size, LV function and dimensions were assessed at both time points. Fetuin-A levels were determined from blood samples drawn at a median of 49 h (IQR 30–59 h) after STEMI by an immunofluorescent assay. Results Fetuin-A levels (median 568 µg/mL, IQR 478–763 µg/mL) were significantly correlated with infarct size and LV ejection fraction at baseline and follow-up (all p<0.05). Moreover, fetuin-A was related to the increase in the end-diastolic volume index (r=−0.383, p<0.001). According to multivariate logistic regression analysis, fetuin-A concentrations (HR=0.17, 95% CI 0.03 to 0.89, p=0.036) besides the presence of late microvascular obstruction (HR=10.03, 95% CI 0.98 to 102.43, p=0.05) were significantly related to the occurrence of adverse LV remodelling at 4 months. Conclusions Circulating fetuin-A at day 2 after STEMI is related to acute and chronic infarct size, LV function and dimensions. In addition, it might be useful to identify patients at increased risk for adverse LV remodelling.

Erratum to: Evaluation of liver fat in the presence of iron with MRI using T2* correction: a clinical approach

Due to a transcription error, the author names in the article entitled “Evaluation of liver fat in the presence of iron with MRI using T2 correction: a clinical approach”, were incorrectly published. We would like to clarify that the author list should read as follows: Benjamin Henninger, Christian Kremser, Stefan Rauch, Robert Eder, Werner Judmaier, Heinz Zoller, Henrik Michaely, Michael Schocke We apologise for this error in the author list; the error was multifactorial.