-
[show abstract]
[hide abstract]
ABSTRACT: OBJECTIVE: While staging patients with malignant melanoma, cerebral susceptibility artefacts on T2*-weighted/susceptibility-weighted imaging (SWI) sequences without a correlate on contrast-enhanced T1-weighted images can be confusing. Without intravenous contrast enhancement, cavernomas, microhaemorrhages and melanin-containing metastases represent possible differential diagnoses for these findings. The purpose of this study was to find out, how often such lesions correspond to metastases. METHODS: Brain MR images (1.5 T) of 408 patients with malignant melanoma but without cerebral metastases in the initial staging by MRI were reviewed retrospectively. Eighteen patients (5 female, 13 male) with malignant melanoma and signal intensity loss on T2*/SWI were included in our study. The average observation period was 19.6 months (6-46 months, 2006-2009). RESULTS: In each of these 18 patients between one and seven hypointense lesions on T2*/SWI were found. None of these lesions developed into metastasis. CONCLUSION: Focal areas of susceptibility artefacts in the brain parenchyma without corresponding abnormalities in contrast-enhanced T1 weighted images are unlikely to represent brain metastases. KEY POINTS : • In melanoma patients early diagnosis of metastatic brain lesions is mandatory. • Melanin content and haemorrhage are potential reasons for MRI characteristics of melanoma metastases. • Susceptibility-weighted MRI visualises melanin and blood products. • Isolated cerebral susceptibility artefacts do not convert into melanoma metastases. • SWI/T2* sequences cannot replace Gd-enhanced sequences.
European Radiology 05/2013; · 3.22 Impact Factor
-
Felix Nensa,
Thorsten D Poeppel,
Karsten Beiderwellen,
Juliane Schelhorn,
Amir A Mahabadi,
Raimund Erbel,
Philipp Heusch,
Kai Nassenstein,
Andreas Bockisch, Michael Forsting,
Thomas Schlosser
[show abstract]
[hide abstract]
ABSTRACT: Purpose:To assess the feasibility of hybrid imaging of the heart with fluorine 18 fluorodeoxyglucose (FDG) on an integrated 3-T positron emission tomography (PET)/magnetic resonance (MR) imaging system.Materials and Methods:The present study was approved by the local institutional review board. Written informed consent was obtained from all patients before imaging. Twenty consecutive patients with myocardial infarction (n = 20) underwent cardiac PET/MR imaging examination. Ten patients underwent additional cardiac PET/computed tomography (CT) before PET/MR. Two-dimensional half-Fourier acquisition single-shot turbo spin-echo sequences, balanced steady-state free precession cine sequences, two-dimensional turbo inversion-recovery magnitude T2-weighted sequences, and late gadolinium-enhanced (LGE) segmented two-dimensional inversion-recovery turbo fast low-angle shot sequences were performed. According to the 17-segment model, PET tracer uptake, wall motion, and late gadolinium enhancement were visually assessed for each segment on a binary scale, and categorical intermethod agreement was calculated by using the Cohen κ. The maximum standardized uptake value was measured in corresponding myocardial locations on PET/CT and PET/MR images.Results:Agreement was substantial over all patients and segments between PET and LGE images (κ = 0.76) and between PET and cine images (κ = 0.78). In 306 segments, 97 (32%) were rated as infarcted on PET images, compared with 93 (30%) rated as infarcted on LGE images and with 90 (29%) rated as infarcted on cine images. In a subgroup of patients (n = 10) with an additional PET/CT scan, no significant difference in myocardial tracer uptake between PET/CT and PET/MR images was found (paired t test, P = .95).Conclusion:Cardiac PET/MR imaging with FDG is feasible and may add complementary information in patients with ischemic heart disease.© RSNA, 2013Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13130231/-/DC1.
Radiology 05/2013; · 5.73 Impact Factor
-
Lale Umutlu,
Oliver Kraff,
Anja Fischer,
Sonja Kinner,
Stefan Maderwald,
Kai Nassenstein,
Felix Nensa,
Johannes Grüneisen,
Stephan Orzada,
Andreas K Bitz, Michael Forsting,
Mark E Ladd,
Thomas C Lauenstein
[show abstract]
[hide abstract]
ABSTRACT: OBJECTIVES: The aim of this study was to investigate the feasibility of 7-T contrast-enhanced MR imaging of the female pelvis. METHODS: Ten healthy female volunteers were examined on a 7-T whole-body MR system utilising a custom-built eight-channel transmit/receive radiofrequency body coil. The examination protocol included (1) T1-weighted fat-saturated 2D spoiled gradient echo (FLASH), (2) dynamic T1-weighted fat-saturated 3D FLASH, and (3) T2-weighted TSE sequences. For qualitative image analysis pelvic anatomy, uterine zonal anatomy and image impairment due to artefacts was assessed using a five-point scale. For quantitative analysis contrast ratios between the junctional zone and myometrium were obtained for T2-weighted MRI. RESULTS: Two-dimensional FLASH MRI offered the best overall image quality (meancontrast-enhanced 4.9) and highest tissue contrast (meancontrast-enhanced 4.7). T2-weighted TSE imaging provided a moderate to high conspicuity of the uterine zonal anatomy with mean scores ranging from 3.5 for endometrium to 4.65 for myometrium. Overall image impairment was rated strongest for T2-weighted MRI (2.9) and least for 2D FLASH MRI (mean 4.2). CONCLUSION: This study demonstrated the feasibility of 7-T T1-weighted MRI of the female pelvis and current constraints associated with T2-weighted MRI. KEY POINTS: • Dynamic contrast-enhanced female pelvis MR imaging at 7 T is feasible. • Unenhanced T1-weighted MRI offers inherent hyperintense delineation of pelvic arterial vasculature. • Two-dimensional FLASH MRI provided best overall image quality and least artefact impairment.
European Radiology 05/2013; · 3.22 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Acute peripheral inflammation with corresponding increases in peripheral cytokines affects neuropsychological functions and induces depression-like symptoms. However, possible effects of increased immune responses on social cognition remain unknown. Therefore, this study investigated the effects of experimentally induced acute inflammation on performance and neural responses during a social cognition task assessing Theory of Mind (ToM) ability. In this double-blind, randomized crossover functional magnetic resonance imaging study, 18 healthy, right-handed male volunteers received an injection of bacterial lipopolysaccharide (LPS; 0.4 ng/kg) or saline, respectively. Plasma levels of pro- and anti-inflammatory cytokines as well as mood ratings were analyzed together with brain activation during a validated ToM task (i.e., Reading the Mind in the Eyes Test). LPS administration induced pronounced transient increases in pro- (IL-6, TNF-α) and anti-inflammatory (IL-10, IL-1ra) cytokines as well as decreases in mood. Social cognition performance was not affected by acute inflammation. However, altered neural activity was observed during the ToM task after LPS administration reflected by increased responses in the fusiform gyrus, temporo-parietal junction, superior temporal gyrus and precuneus. The increased task-related neural responses in the LPS condition may reflect a compensatory strategy or a greater social cognitive processing as a function of sickness.
Social Cognitive and Affective Neuroscience 04/2013; · 6.13 Impact Factor
-
Lale Umutlu,
Nina Theysohn,
Stefan Maderwald,
Sören Johst,
Thomas C Lauenstein,
Christoph Moenninghoff,
Sophia L Goericke,
Philipp Dammann,
Karsten H Wrede,
Mark E Ladd, Michael Forsting,
Marc Schlamann
[show abstract]
[hide abstract]
ABSTRACT: PURPOSE: To intraindividually compare the delineation of intracranial arterial vasculature in nonenhanced versus contrast-enhanced magnetization prepared rapid gradient echo (MPRAGE) imaging at 7 Tesla (T). MATERIALS AND METHODS: Sixteen subjects were examined on a 7 T whole-body magnetic resonance system (Magnetom 7T) equipped with a 32-channel transmit/receive head coil. MPRAGE imaging was performed pre- and postcontrast after the application of 0.1 mmol/kg bodyweight gadobutrol. For qualitative analysis, the delineation of the intracranial arteries, overall image quality, and image impairment were assessed in the nonenhanced and contrast-enhanced datasets using a 5-point scale (5 = excellent to 1 = nondiagnostic). Additionally, contrast ratios (CR) of the middle cerebral artery in correlation to surrounding gray matter in nonenhanced and postcontrast images were obtained. For statistical analysis a Wilcoxon signed-rank test was applied. RESULTS: Nonenhanced MPRAGE imaging offered an excellent delineation of the central vessel segments of the anterior circulation (mean anterior circulation 4.6) and a moderate- to high-quality assessment of the vessels of the posterior circulation (mean posterior circulation 3.9). Vessel delineation was improved in all assessed segments in the contrast-enhanced datasets, except for the cavernous segment of the internal carotid artery. Quantitative analysis revealed a mild, nonsignificant increase in CR mean values of the M1 segment (CRnonenhanced 0.67; CRcontrast-enhanced 0.69). CONCLUSION: Our results demonstrate the high diagnostic value of nonenhanced 7 T MPRAGE imaging for the assessment of the intracranial arterial vasculature, with improved assessment of the peripheral segments because of the application of a contrast agent.
Academic radiology 03/2013; · 2.09 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: RATIONALE AND OBJECTIVES: Workflow efficiency and workload of radiological technologists (RTs) were compared in head examinations performed with two 1.5 T magnetic resonance (MR) scanners equipped with or without an automated user interface called "day optimizing throughput" (Dot) workflow engine. MATERIALS AND METHODS: Thirty-four patients with known intracranial pathology were examined with a 1.5 T MR scanner with Dot workflow engine (Siemens MAGNETOM Aera) and with a 1.5 T MR scanner with conventional user interface (Siemens MAGNETOM Avanto) using four standardized examination protocols. The elapsed time for all necessary work steps, which were performed by 11 RTs within the total examination time, was compared for each examination at both MR scanners. The RTs evaluated the user-friendliness of both scanners by a questionnaire. Normality of distribution was checked for all continuous variables by use of the Shapiro-Wilk test. Normally distributed variables were analyzed by Student's paired t-test, otherwise Wilcoxon signed-rank test was used to compare means. RESULTS: Total examination time of MR examinations performed with Dot engine was reduced from 24:53 to 20:01 minutes (P < .001) and the necessary RT intervention decreased by 61% (P < .001). The Dot engine's automated choice of MR protocols was significantly better assessed by the RTs than the conventional user interface (P = .001). CONCLUSIONS: According to this preliminary study, the Dot workflow engine is a time-saving user assistance software, which decreases the RTs' effort significantly and may help to automate neuroradiological examinations for a higher workflow efficiency.
Academic radiology 03/2013; · 2.09 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: PURPOSE: Positron emission tomography/magnetic resonance imaging (PET/MRI) requires efficient scan protocols for whole-body cancer staging. The aim of this study was to evaluate if the application of diffusion-weighted MR imaging (DWI) results in a diagnostic benefit for lesion detection in oncologic patients if added to a whole-body [18F]-fluorodesoxyglucose ([18F]-FDG) PET/MRI protocol. METHODS: 25 consecutive oncologic patients (16 men, 9 women; age 57±12 years) prospectively underwent whole-body [18F]-FDG-PET/MRI including DWI on a hybrid PET/MRI scanner. A team of two readers assessed [18F]-FDG PET/MRI without DWI for primary tumors and metastases. In a second session, now considering DWI, readers reassessed [18F]-FDG PET/MRI accordingly. Additionally, the lesion-to-background contrast on [18F]-FDG PET and DWI was rated qualitatively (0, invisible; 1, low; 2, intermediate; 3, high). Wilcoxon's signed-rank test was performed to test for differences in the lesion-to-background contrast. RESULTS: 49 lesions were detected in 16 patients (5 primaries, 44 metastases). All 49 lesions were concordantly detected by [18F]-FDG PET/MRI alone and [18F]-FDG PET/MRI with DWI. The lesion-to-background contrast on DWI compared to [18F]-FDG PET was rated lower in 22 (44.9%) of 49 detected lesions resulting in a significantly higher lesion-to-background contrast on [18F]-FDG PET compared to DWI (P=0.001). CONCLUSIONS: DWI as part of whole-body [18F]-FDG PET/MRI does not benefit lesion detection. Given the necessity to optimize imaging protocols with regard to patient comfort and efficacy, DWI has to be questioned as a standard tool for whole-body staging in oncologic PET/MRI.
European journal of radiology 02/2013; · 2.65 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: PURPOSE: To compare maximum and mean standardized uptake values (SUVmax/mean) of normal organ tissues derived from [(18)F]-fluoro-desoxyglucose (FDG) positron emission tomography/magnetic resonance imaging (PET/MRI) using MR attenuation correction (MRAC) (DIXON-based 4-segment μ-map) with [(18)F]-FDG positron emission tomography/computed tomography (PET/CT) using CT-based attenuation correction (CTAC). METHODS AND MATERIALS: In 25 oncologic patients (15 men, 10 women; age 57±13 years) after routine whole-body FDG-PET/CT (60min after injection of 290±40 MBq [(18)F]-FDG) a whole-body PET/MRI was performed (Magnetom Biograph mMR™, Siemens Healthcare, Erlangen, Germany). Volumes of interest of 1.0cm(3) were drawn in 7 physiological organ sites in MRAC-PET and the corresponding CTAC-PET images manually. Spearman correlation coefficients were calculated to compare MRAC- and CTAC based SUV values; Wilcoxon-Matched-Pairs signed ranks test was performed to test for potential differences. RESULTS: The mean delay between FDG-PET/CT and PET/MRI was 92±18min. Excellent correlations of SUV values were found for the heart muscle (SUVmax/mean: R=0.97/0.97); reasonably good correlations were found for the liver (R=0.65/0.72), bone marrow (R=0.42/0.41) and the SUVmax of the psoas muscle (R=0.41). For subcutaneous fat, the correlation coefficient was 0.66 for SUVmean (p<0.05). Correlations between MRAC and CTAC were non-significant for SUVmean of the psoas muscle, SUVmax of subcutaneous fat, SUVmax and SUVmean of the lungs, SUVmax and SUVmean of the blood-pool. The median SUVmax and SUVmean in MRAC-PET were lower than the respective CTAC values in all organs (p<0.05) but heart (SUVmax) and the bone marrow (SUVmean). CONCLUSION: In conclusion, in oncologic patients examined with PET/CT and PET/MRI SUVmax and SUVmean values generally correlate well in normal organ tissues, except the lung, subcutaneous fat and the blood pool. SUVmax and SUVmean derived from PET/MRI can be used reliably in clinical routine.
European journal of radiology 02/2013; · 2.65 Impact Factor
-
Zsolt Kulcsár,
Sophia L Göricke,
Elke R Gizewski,
Marc Schlamann,
Ulrich Sure,
I Erol Sandalcioglu,
Susanne Ladd,
Petra Mummel,
Oliver Kastrup, Michael Forsting,
Isabel Wanke
[show abstract]
[hide abstract]
ABSTRACT: INTRODUCTION: Our purpose was to analyze the long-term evolution of wide neck cerebral aneurysms treated with stent assistance. METHODS: Data of consecutive patients treated with the Neuroform stent over 9 years were retrospectively analyzed with emphasis on periprocedural complications, aneurysm occlusion grade evolution, and in-stent stenosis rates. RESULTS: Altogether, 113 patients with 117 unruptured and ruptured aneurysms were subject of analysis. Mean aneurysm size was 9.4 mm, and mean neck size was 4.7 mm. Procedural thromboembolic and hemorrhagic complications affected eight (6.8 %) and four cases (3.4 %), respectively. Immediate complete occlusion and occlusion with residual neck was achieved in 85 % of cases, which at the first follow-up of 6 months, changed to 77 and 76 % at 36 months. Aneurysms ≥10 mm showed a higher tendency of recurrence. During the overall follow-up time ranging from 1 to 9 years, an in-stent stenosis of ≥50 % was observed only in three cases, all of them being asymptomatic. CONCLUSIONS: Stent-assisted coiling of wide neck aneurysms provided stable occlusion over the long-term follow-up, with very low and silent in-stent stenosis rates. Some incompletely occluded aneurysms showed a tendency of progressive occlusion; however, this was counterbalanced by the regrowth of others.
Neuroradiology 01/2013; · 2.82 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Fear conditioning is relevant for elucidating the pathophysiology of anxiety, but may also be useful in the context of chronic pain syndromes which often overlap with anxiety. Thus far, no fear conditioning studies have employed aversive visceral stimuli from the lower gastrointestinal tract. Therefore, we implemented a fear conditioning paradigm to analyze the conditioned response to rectal pain stimuli using fMRI during associative learning, extinction and reinstatement. In N = 21 healthy humans, visual conditioned stimuli (CS) were paired with painful rectal distensions as unconditioned stimuli (US), while different visual stimuli (CS) were presented without US. During extinction, all CSs were presented without US, whereas during reinstatement, a single, unpaired US was presented. In region-of-interest analyses, conditioned anticipatory neural activation was assessed along with perceived CS-US contingency and CS unpleasantness. Fear conditioning resulted in significant contingency awareness and valence change, i.e., learned unpleasantness of a previously neutral stimulus. This was paralleled by anticipatory activation of the anterior cingulate cortex, the somatosensory cortex and precuneus (all during early acquisition) and the amygdala (late acquisition) in response to the CS. During extinction, anticipatory activation of the dorsolateral prefrontal cortex to the CS was observed. In the reinstatement phase, a tendency for parahippocampal activation was found. Fear conditioning with rectal pain stimuli is feasible and leads to learned unpleasantness of previously neutral stimuli. Within the brain, conditioned anticipatory activations are seen in core areas of the central fear network including the amygdala and the anterior cingulate cortex. During extinction, conditioned responses quickly disappear, and learning of new predictive cue properties is paralleled by prefrontal activation. A tendency for parahippocampal activation during reinstatement could indicate a reactivation of the old memory trace. Together, these findings contribute to our understanding of aversive visceral learning and memory processes relevant to the pathophysiology of chronic abdominal pain.
PLoS ONE 01/2013; 8(2):e51149. · 4.09 Impact Factor
-
Christian Buchbender,
Verena Hartung-Knemeyer,
Philipp Heusch,
Till A Heusner,
Karsten Beiderwellen,
Hans-Joerg Wittsack,
Hilmar Kühl, Michael Forsting,
Andreas Bockisch,
Gerald Antoch,
Rotem S Lanzman
[show abstract]
[hide abstract]
ABSTRACT: OBJECTIVES: The purpose of this study was to test whether the acquisition of positron emission tomography (PET) does interfere with simultaneous diffusion weighted imaging (DWI) in an integrated whole-body PET/MRI system. MATERIAL AND METHODS: Fourteen consecutive oncological patients (9 men, 5 women; age 54±13 years ([mean±standard deviation]) scheduled for routine [(18)F]-FDG PET/CT were prospectively enrolled. For DWI, an echo planar imaging (EPI) sequence (b=0-500-1000s/mm(2)) was acquired twice on an integrated whole-body 3T PET/MRI system in each patient; first with simultaneous PET acquisition and a second time with the PET component switched off. The apparent diffusion coefficient (ADC) and the signal-to-noise ratio at b=1000s/mm(2) (SNR) of the myocardium, paraspinal muscle, liver, spleen, renal cortex and tumor tissue (if present) were measured. In addition, the coefficient of variation (CV) of ADC values was calculated. Student's t-test for paired samples was performed to test for differences of the mean ADC, ADC CV and SNR between DWI with and without simultaneous PET acquisition. RESULTS: There were no significant differences of the ADC [(mean±standard deviation)] between the DWI acquisitions with and without simultaneous PET acquisition for the myocardium (2572±441×10(-6)mm(2)/s and 2586±376×10(-6)mm(2)/s, respectively) (P=0.817), paraspinal muscle (1279±254×10(-6)mm(2)/s vs. 1219±181×10(-6)mm(2)/s) (P=0.318), liver (1245±158×10(-6)mm(2)/s vs. 1254±171×10(-6)mm(2)/s) (P=0.848), spleen (980±122×10(-6)mm(2)/s vs. 1000±187×10(-6)mm(2)/s) (P=0.676) and renal cortex (1951±226×10(-6)mm(2)/s vs. 1930±273×10(-6)mm(2)/s) (P=0.730). Mean ADC of lymph node metastases (n=6) did not differ between with PET acquisition (853±174×10(-6)mm(2)/s) and without simultaneous PET (865±170×10(-6)mm(2)/s) (P=0.675). There were no significant differences between the CV of ADC values or the SNR values measured in DWI datasets that were acquired with or without simultaneous PET for any evaluated organ site. CONCLUSION: The simultaneous acquisition of DWI and PET on an integrated PET/MRI system does not impact ADC quantification of normal and tumor tissue and does not alter SNR. This knowledge provides a basis for the use of simultaneous multiparametric PET/MRI comprising DWI in diagnostic imaging and quantitative tumor therapy monitoring using repeated ADC measurements.
European journal of radiology 12/2012; · 2.65 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Conduct disorder (CD) prior to age 15 is a precursor of schizophrenia in a minority of cases and is associated with violent behavior through adulthood, after taking account of substance misuse. The present study used structural magnetic imaging to examine gray matter (GM) volumes among 27 men with schizophrenia preceded by CD (SZ+CD), 23 men with schizophrenia but without CD (SZ-CD), 27 men with CD only (CD), and 25 healthy (H) men. The groups with schizophrenia were similar in terms of age of onset and duration of illness, levels of psychotic symptoms, and medication. The 2 groups with CD were similar as to number of CD symptoms, lifelong aggressive behavior, and number of criminal convictions. Men with SZ+CD, relative to those with SZ-CD, displayed (1) increased GM volumes in the hypothalamus, the left putamen, the right cuneus/precuneus, and the right inferior parietal cortex after controlling for age, alcohol, and drug misuse and (2) decreased GM volumes in the inferior frontal region. Men with SZ+CD (relative to the SZ-CD group) and CD (relative to the H group) displayed increased GM volumes of the hypothalamus and the inferior and superior parietal lobes, which were not associated with substance misuse. Aggressive behavior, both prior to age 15 and lifetime tendency, was positively correlated with the GM volume of the hypothalamus. Thus, among males, SZ+CD represents a distinct subtype of schizophrenia. Although differences in behavior emerge in childhood and remain stable through adulthood, further research is needed to determine whether the differences in GM volumes result from abnormal neural development distinct from that of other males developing schizophrenia.
Schizophrenia Bulletin 09/2012; · 8.80 Impact Factor
-
The Journal of clinical endocrinology and metabolism 09/2012; · 6.50 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: There is evidence to support that the cerebellum contributes to the neural processing of both emotions and painful stimuli. This could be particularly relevant in conditions associated with chronic abdominal pain, such as the irritable bowel syndrome (IBS), which are often also characterized by affective disturbances. We aimed to test the hypothesis that in IBS, symptoms of anxiety and depression modulate brain activation during visceral stimulation within the cerebellum. We reanalyzed a previous data set from N = 15 female IBS patients and N = 12 healthy women with a specific focus on the cerebellum using advanced normalization methods. Rectal distension-induced brain activation was measured with functional magnetic resonance imaging using non-painful and painful rectal distensions. Symptoms of anxiety and depression, assessed with the Hospital Anxiety and Depression scale, were correlated with cerebellar activation within IBS patients. Within IBS, depression scores were associated with non-painful distension-induced activation in the right cerebellum primarily in Crus II and lobule VIIIb, and additionally in Crus I. Depression scores were also associated with painful distension-induced activation predominantly in vermal lobule V with some extension to the intermediate cerebellum. Anxiety scores correlated significantly with non-painful induced activation in Crus II. Symptoms of anxiety and depression, which are frequently found in chronic pain conditions like IBS, modulate activation during visceral sensory signals not only in cortical and subcortical brain areas but also in the cerebellum.
The Cerebellum 08/2012; · 3.21 Impact Factor
-
Christian Buchbender,
Sherko Kuemmel,
Oliver Hoffmann,
Alexander R Stahl,
Rainer Kimmig,
Friedrich Otterbach,
Susanne Ladd,
Angela Koeninger, Michael Forsting,
Andreas Bockisch,
Gerald Antoch,
Till A Heusner
[show abstract]
[hide abstract]
ABSTRACT: Up to about one-quarter of patients treated with neoadjuvant chemotherapy do not adequately respond to the given treatment. By a differentiation between responders and non-responders ineffective toxic therapies can be prevented.
To retrospectively test if FDG-PET/CT is able to early differentiate between breast cancer lesions with pathological complete response (pCR) and lesions without pathological complete response (npCR) after two cycles of neoadjuvant chemotherapy (NACT).
In this retrospective study 26 breast cancer patients (mean age, 46.9 years ± 9.9 years) underwent a pre-therapeutic FDG-PET/CT scan and a subsequent FDG-PET/CT after the second cycle of NACT. Histopathology of resected specimen served as the reference standard. Maximum standardized uptake values (SUVmax) of cancer lesions before and after the second cycle of NACT were measured. Two evaluation algorithms were used: (a) pCR: Sinn Score 3 and 4, npCR: Sinn Score 0-2; (b) pCR: Sinn Score 4, npCR: Sinn Score 0-3. The absolute and relative decline of the SUVmax (ΔSUVmax, ΔSUVmax(%))was calculated. Differences of the SUVmax as well as of the SUVmax decline between pCR lesions and npCR lesions were tested for statistical significance P < 0.05. To identify the optimal cut-off value of ΔSUVmax(%) to differentiate between pCR lesions and npCR lesions a receiver-operating curve (ROC) analysis was performed.
Using evaluation algorithm A the ΔSUVmax was 13.5 (pCR group) and 3.9 (npCR group) (P = 0.006); the ΔSUVmax(%) was 79% and 47%, respectively (P = 0.001). On ROC analysis an optimal cut-off ΔSUVmax(%) of 66% was found. Using evaluation algorithm B the ΔSUVmax was 17.5 (pCR group) and 4.9 (npCR group) (P = 0.013); the ΔSUVmax(%) was 89% and 51%, respectively (P = 0.003). On ROC analysis an optimal cut-off ΔSUVmax(%) of 88% was found.
FDG-PET/CT may be able to early differentiate between pCR and npCR of primary breast cancer lesions after two cycles of NACT.
Acta Radiologica 07/2012; 53(6):628-36. · 1.37 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The aim of this study was to evaluate whether a virtual 3-D (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT panendoscopy is feasible and can be used for noninvasive imaging of the upper airways and pharyngeal/laryngeal tumours.
From (18)F-FDG PET/CT data sets of 40 patients (29 men, 11 women; age 61 ± 9 years) with pharyngeal or laryngeal malignancies virtual 3-D (18)F-FDG PET/CT panendoscopies were reconstructed and the image processing time was measured. The feasibility of assessing the oral cavity, nasopharynx, tongue base, soft palate, pharyngeal tonsils, epiglottis, aryepiglottic folds, piriform sinus, postcricoid space, glottis, subglottis, trachea, bronchi and oesophagus and of detecting primary tumours was tested. Results of fibre-optic bronchoscopy and histology served as the reference standard.
The nasopharynx, tongue base, soft palate, pharyngeal tonsils, epiglottis, subglottis and the tracheobronchial tree were accessible in all 40, and the aryepiglottic folds, posterior hypopharyngeal wall, postcricoid space, piriform sinus, glottis, oral cavity and oesophagus in 37, 37, 37, 37, 33, 16 and 0 patients, respectively. In all 12 patients with restricted fibre-optic evaluation due to being primarily intubated, the subglottis was accessible via virtual panendoscopy. The primary tumour was depicted in 36 of 40 patients (90 %). The mean processing time for virtual (18)F-FDG PET/CT panendoscopies was 145 ± 98 s.
Virtual (18)F-FDG PET/CT panendoscopy of the upper airways is technically feasible and can detect pharyngeal and laryngeal malignancies. This new tool can aid in the complete evaluation of the subglottic space in intubated patients and may be used for planning optical panendoscopies, biopsies and surgery in the future.
European Journal of Nuclear Medicine 06/2012; 39(9):1435-40. · 4.53 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: An increase of the magnetic field strength to ultrahigh-field yields advantageous as well as disadvantageous changes in physical effects. The beneficial increase in signal/noise ratio can be leveraged into higher spatiotemporal resolution, and an exacerbation of artifacts can impede ultrahigh-field imaging. With the successful introduction of intracranial and musculoskeletal imaging at 7 T, recent advances in coil design have created opportunities for further applications of ultrahigh-field magnetic resonance (MR) imaging in other parts of the body. Initial studies in 7 T neck and spine MR imaging have revealed promising insights and new challenges, demanding further research and methodological optimization.
Neuroimaging Clinics of North America 05/2012; 22(2):363-71, xii. · 1.51 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Virtual (18)F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) bronchoscopies provide virtually realistic, 3D endoscopic views of the airways combining anatomical and functional data at a high resolution. Today, even very small airways can be imaged by virtual bronchoscopy. (18)F-FDG PET/CT bronchoscopy images are generated from standard whole-body (18)F-FDG PET/CT scan source data without any additional radiation exposure. The purpose of this review was to give an overview over the studies that are currently available, to provide the technical background of (18)F-FDG PET/CT bronchoscopy and to explain the diagnostic accuracy of (18)F-FDG PET/CT bronchoscopy. Moreover, this manuscript highlights potential future applications of this promising new imaging technique.
Expert Review of Medical Devices 05/2012; 9(3):241-7. · 2.63 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The diagnostic accuracy of FDG-PET/CT for the detection of axillary lymph node metastases in breast cancer patients acquired 60 min after FDG administration is reported to be only moderate, especially due to low sensitivity.
To test whether a delayed scan 90 min after FDG administration could enhance the diagnostic accuracy of FDG-PET/CT for the detection of axillary lymph node metastases.
Thirty-eight women suffering from primary breast cancer (mean age 52 years; range 25-78 years; standard deviation 14 years) underwent a pre-therapeutic dual-time-point FDG-PET/CT scan. The maximum standardized uptake value (SUVmax) of axillary lymph nodes was measured at two different time points (time point T1: 60 min after FDG injection, time point T2: 90 min after FDG injection). SUVmax of axillary lymph nodes at T1 and T2 were assessed for statistical significance using a paired Wilcoxon-Test (P < 0.05). At T1 a qualitative analysis of the FDG-PET/CT scan was performed to define physiologic and metastatic lymph nodes. At T2 an increase of the SUVmax of at least 3.75% over time was rated as indicating malignancy. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and the accuracy of FDG-PET/CT for the detection of axillary lymph node metastases was calculated at time points T1 and T2. Statistically significant differences were determined using Fisher's exact test (P < 0.05). Histopathology served as the standard of reference. A compartment based analysis was done.
Axillary lymph nodes had a mean SUVmax of 1.6 (range 0.6-10.8; SD 1.9) at T1 and a mean SUVmax of 1.8 (range 0.5-17.9; SD 3.5) at T2. This difference was statistically significant (P = 0.047). The sensitivity, specificity, PPV, NPV, and accuracy of FDG-PET/CT for the detection of axillary lymph node metastases was 81%, 100%, 100%, 88%, and 92% at T1, and 88%, 50%, 56%, 85%, and 66% at T2, respectively. This difference was not statistically significant (P = 0.27).
There is a slight increase of the FDG accumulation of axillary lymph nodes between 60 and 90 min after FDG administration. This increase did not translate into a statistical significant enhancement of the diagnostic accuracy of FDG-PET/CT for the detection of axillary lymph nodes. Especially due to false-positive results a delayed FDG-PET/CT scan 90 min after FDG administration is not able to enhance the diagnostic accuracy for the detection of lymph node metastases.
Acta Radiologica 04/2012; 53(5):518-23. · 1.37 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: PurposeTo 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.
MethodsIn 590 patients (mean age 55.4 ± 13.3years) 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 2.5years (mean 29.5 ± 13.9months) served as the reference period to determine whether
patients developed a head and neck malignancy.
ResultsOf 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 (SUVmax, 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, SUVmax 3.2), and one patient developed an oral floor carcinoma (group B1, SUVmax 3.7).
ConclusionElevated/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.
European journal of nuclear medicine and molecular imaging 04/2012; 36(9):1397-1406. · 4.99 Impact Factor
