Christian Marx

Comprehensive Cardiac Magnetic Resonance for Short‐Term Follow‐Up in Acute Myocarditis

Background Cardiac magnetic resonance (CMR) can detect inflammatory myocardial alterations in patients suspected of having acute myocarditis. There is limited information regarding the degree of normalization of CMR parameters during the course of the disease and the time window during which quantitative CMR should be most reasonably implemented for diagnostic work‐up. Methods and Results Twenty‐four patients with suspected acute myocarditis and 45 control subjects underwent CMR. Initial CMR was performed 2.6±1.9 days after admission. Myocarditis patients underwent CMR follow‐up after 2.4±0.6, 5.5±1.3, and 16.2±9.9 weeks. The CMR protocol included assessment of standard Lake Louise criteria, T1 relaxation times, extracellular volume fraction, and T2 relaxation times. Group differences between myocarditis patients and control subjects were highest in the acute stage of the disease (P<0.001 for all parameters). There was a significant and consistent decrease in all inflammatory CMR parameters over the course of the disease (P<0.01 for all parameters). Myocardial T1 and T2 relaxation times—indicative of myocardial edema—were the only single parameters showing significant differences between myocarditis patients and control subjects on 5.5±1.3‐week follow‐up (T1: 986.5±44.4 ms versus 965.1±28.1 ms, P=0.022; T2: 55.5±3.2 ms versus 52.6±2.6 ms; P=0.001). Conclusions In patients with acute myocarditis, CMR markers of myocardial inflammation demonstrated a rapid and continuous decrease over several follow‐up examinations. CMR diagnosis of myocarditis should therefore be attempted at an early stage of the disease. Myocardial T1 and T2 relaxation times were the only parameters of active inflammation/edema that could discriminate between myocarditis patients and control subjects even at a convalescent stage of the disease.

3D-Dixon MRI based volumetry of peri- and epicardial fat

There is growing evidence that pericardial and epicardial fat volume (PFV, EFV) are associated with cardiovascular risk. We evaluated a novel method for accurate measurement of PFV and EFV using a 3D-Dixon based cardiac magnetic resonance (CMR) approach. An electrocardiography triggered and respiratory navigator gated 3D-gradient echo pulse sequence was used for cardiac Dixon imaging. Based on this sequence, voxels predominantly containing fat were identified and added up for volumetry. After accuracy assessment in phantoms, consisting of muscle tissue and seven different fat samples (50–200xa0ml), the sequence was acquired in 34 healthy volunteers (22 male, BMI range 14–42xa0kg/m2, age range 21–79xa0years) at 1.5xa0T. Analysis was performed independently by two readers who draw two 3D-regions of interest, one for EFV and one for PFV. Additionally, EFV and PFV were compared between overweighted and non-overweighted subjects. The phantom study showed an excellent agreement of measured and true fat volumes (maximum differencexa0=xa06xa0%, linear correlation coefficient Rxa0=xa01.00). PFV over all volunteers was 158.0xa0±xa0126.4xa0ml and EFV was 77.0xa0±xa055.3xa0ml. PFV and EFV were highly correlated (Rxa0=xa00.96). Inter-reader agreement was good with a mean difference of 0.2xa0±xa05.6 and 4.5xa0±xa04.2xa0ml for PFV/EFV, (Rxa0>xa00.99, each). EFV and PFV differed significantly between subjects with BMIxa0>xa025xa0kg/m2 and BMIxa0<xa025xa0kg/m2, nxa0=xa017 each (PFV 219.0xa0±xa0151.8 vs. 96.9xa0±xa044.7xa0ml and EFV 102.3xa0±xa066.3 vs. 51.7xa0±xa023.6xa0ml, pxa0<xa00.001, each). The proposed 3D-Dixon based method allows accurate measurement of cardiac fat volumes. It provides a valuable tool for cardiovascular risk stratification by CMR.

Differentiation of prostatitis and prostate cancer using the Prostate Imaging—Reporting and Data System (PI-RADS)

PURPOSEnTo determine if prostate cancer (PCa) and prostatitis can be differentiated by using PI-RADS.nnnMATERIALS AND METHODSn3T MR images of 68 patients with 85 cancer suspicious lesions were analyzed. The findings were correlated with histopathology. T2w imaging (T2WI), diffusion weighted imaging (DWI), dynamic contrast enhancement (DCE), and MR-Spectroscopy (MRS) were acquired. Every lesion was given a single PI-RADS score for each parameter, as well as a sum score and a PI-RADS v2 score. Furthermore, T2-morphology, ADC-value, perfusion type, citrate/choline-level, and localization were evaluated.nnnRESULTSn44 of 85 lesions showed PCa (51.8%), 21 chronic prostatitis (24.7%), and 20 other benign tissue such as hyperplasia or fibromuscular tissue (23.5%). The single PI-RADS score for T2WI, DWI, DCE, as well as the aggregated score including and not including MRS, and the PI-RADS v2-score were all significantly higher for PCa than for prostatitis or other tissue (p<0.001). The single PI-RADS score for MRS and the PI-RADS sum score including MRS were significantly higher for prostatitis than for other tissue (p=0.029 and p=0.020), whereas the other parameters were not different. Prostatitis usually presented borderline pathological PI-RADS scores, showed restricted diffusion with ADC≥900mm(2)/s in 100% of cases, was more often indistinctly hypointense on T2WI (66.7%), and localized in the transitional zone (57.1%). An ADC≥900mm(2)/s achieved the highest predictive value for prostatitis (AUC=0.859).nnnCONCLUSIONnProstatitis can be differentiated from PCa using PI-RADS, since all available parameters are more distinct in cases of cancer. However, there is significant overlap between prostatitis and other benign findings, thus PI-RADS is only suitable to a limited extent for the primary assessment of prostatitis. Restricted diffusion with ADC≥900mm(2)/s is believed to be a good indicator for prostatitis. MRS can help to distinguish between prostatitis and other tissue.

In-bore transrectal MRI-guided prostate biopsies: Are there risk factors for complications?

PURPOSEnTo systematically analyze risk factors for complications of in-bore transrectal MRI-guided prostate biopsies (MRGB).nnnMATERIALS AND METHODSn90 patients, who were scheduled for MRGB were included for this study. Exclusion criteria were coagulation disorders, therapy with anticoagulant drugs, and acute infections of the urinary and the lower gastrointestinal tract. Directly after, one week and one year after the biopsy, we assessed biopsy related complications (e.g. hemorrhages or signs of prostatitis). Differences between patients with and without complications were analyzed regarding possible risk factors: age, prostate volume, number of taken samples, biopsy duration, biopsy of more than one lesion, diabetes, arterial hypertension, hemorrhoids, benign prostate hyperplasia, carcinoma or prostatitis (according to histopathological analysis), and lesion localization. Complications were classified according to the Clavien-Dindo classification.nnnRESULTSnWe observed 15 grade I complications in 90 biopsies (16.7%) with slight hematuria in 9 cases (10%), minor vasovagal reactions in 4 cases (4.4%), and urinary retention and positioning-related facial dysesthesia in 1 case each (1.1%). One patient showed acute prostatitis requiring antibiotics as the only grade II complication (1.1%). There were no adverse events that occurred later than one week. Complications grade III or higher such as pelvic abscesses, urosepsis or severe hemorrhages were not seen. There were no significant associations between the assessed risk factors and biopsy-related complications.nnnCONCLUSIONnIn-bore transrectal MRI-guided prostate biopsies can be considered safe procedures in the diagnosis of prostate cancer with very low complication rates. There seem to be no risk factors for complications.

Spindle cell rhabdomyosarcoma of the prostate

The spindle cell rhabdomyosarcoma is a rare variant of the embryonal rhabdomyosarcoma, mostly occurring in childhood. Only a few cases are described in adults. To date, no case of the spindle cell subtype of the prostatic embryonal rhabdomyosarcoma has been published. We report on a 23‐year‐old man, initially presenting with obstructive micturition problems, perineal pain and night sweat. After diagnosis by transrectal biopsy of the prostate, radiochemotherapy within the CWS 2002 P study was applied: nine cycles of vincristine, doxorubicin, actinomycinu2009D, ifosfamide, and fractionated radiotherapy of the tumor and suspect lymph nodes (final dose 50.4u2009Gy). The tumor initially shrank, but an early local recurrence arose. Second‐line chemotherapy was applied, followed by a salvage radical cytoprostatectomy. The patient died of disseminated disease 14u2009months after diagnosis.

Evaluation of Exponential ADC (eADC) and Computed DWI (cDWI) for the Detection of Prostate Cancer

PURPOSEnTo directly compare different methods proposed for enhanced conspicuity and discriminability of prostate cancer on diffusion-weighted imaging (DWI) and to compare the results to original DWI images and conventional apparent diffusion coefficient (ADC) maps.nnnMATERIALS AND METHODSnClinical routine prostate DWI datasets (bu200a=u200a0, 50, 800u200as/mm², acquired at a field strength of 3u200aT) of 104 consecutive patients with subsequent MR-guided prostate biopsy were included in this retrospective study. For each dataset exponential ADC maps (eADC), computed DWI images (cDWI), and additionally eADC maps for computed b-values of 2000 and 3000u200as/mm² were generated (c_eADC). For each of 123 lesions, the contrast (CR) and contrast-to-noise ratio (CNR) were determined. Differences in the CR and CNR of malignant lesions (nu200a=u200a83) between the different image types and group differences between benign (nu200a=u200a40), low-risk (nu200a=u200a53) and high-risk (nu200a=u200a30) lesions were assessed by repeated measures ANOVA and one-way ANOVA with post-hoc tests. The ability to differentiate between benign and malignant and between low-risk and high-risk lesions was assessed by receiver operating characteristic (ROC) curve analyses.nnnRESULTSnThe CR and CNR were higher for computed DWI and related c_eADC at bu200a=u200a3000u200as/mm² and 2000u200as/mm² compared to original DWI, conventional ADC and standard eADC. For differentiation of benign and malignant lesions, conventional ADC and CR of conventional ADC were best suited. For discrimination of low-risk from high-risk lesions, the CR of c_eADC was best suited followed by the CR of cDWI.nnnCONCLUSIONnComputed cDWI or related c_eADC maps at b-values between 2000 and 3000u200as/mm2 were superior to the original DWI, conventional ADC and eADC in the detection of prostate cancer.nnnKEY POINTSn· Prostate cancer can appear inconspicuous on original DWI800 images. · Computed DWI images at bu200a=u200a2000u200a-u200a3000u200as/mm² improve lesion-to-normal-tissue contrast in prostate cancer. · Contrast in computed DWI is superior to ADC and eADC at bu200a=u200a800u200as/mm².nnnCITATION FORMATn· Sprinkart AM, Marx C, Träber F etu200aal. Evaluation of Exponential ADC (eADC) and Computed DWI (cDWI) for the Detection of Prostate Cancer. Fortschr Röntgenstr 2018; 190: 758u200a-u200a766.

Contrast Media in Time-Resolved MRA at 3T: A Systematic Quantitative and Qualitative Analysis of Concentration and Dose Effects on Image Parameters in Minipigs

PURPOSEnQuantitative and qualitative analysis of gadopentetate dimeglumine (GD) versus standard-dose (sGb) and half-dose (hGb) gadobutrol in thoracoabdominal time-resolved contrast-enhanced magnetic resonance angiography (4D-MRA) with dynamic computed tomography (dCT) as the quantitative reference in minipigs.nnnMATERIALS AND METHODSn7 anesthetized Goettingen minipigs received thoracoabdominal dCT (0.37u200as rotation time) and transverse 4D-MRA (0.3u200as/dynamic frame;) using sGb and hGb. 8 other minipigs received coronal 4D-MRA (1.3u200as/dynamic frame; sGb, hGb, SGD). dCT attenuation levels were converted into absolute gadolinium concentrations and compared to 4D-MRA peak signal intensities (SI). Bolus lengths were quantified by full width at half maximum (FWHM) measurements. After this comparison of dose effects on SI in transverse 4D-MRA, coronal 4D-MRAs were analyzed regarding both quantitative and qualitative parameters.nnnRESULTSnIn dCT (transverse 4D-MRA) hGb showed 39.0u200a% (14.5u200a%) lower arterial peak gadolinium concentrations (peak SIs) and 20.6u200a% (33.8u200a%) shorter FWHM compared to sGb. The difference was due to peak plateaus or reversals in 4D-MRA in 5/7 animals. While sGb led to the highest peak SIs, image quality ratings of arteries were rated similarly high with all contrast agent protocols despite a slightly higher SI with sGb. In contrast, venous peak SIs and image quality ratings were significantly higher when using sGb.nnnCONCLUSIONnPeak Gd concentrations and 4D-MRA peak SIs are highest with sGB. These differences are most evident in the venous phase leading to superior image quality in multi-phase 4D-MRA.nnnKEY POINTSn· Standard-dose gadobutrol offers high vascular gadolinium concentrations and 4D-MRA peak signals.. · Absolute vascular gadolinium concentrations and 4D-MRA peak signal intensities at 3u200aT diverge.. · Peak plateaus or reversals cause decreased arterial 4D-MRA peak signals at 3u200aT.. · Arterial image quality is rated similarly high using different contrast agent protocols.. · Venous vessel visibility in 4D-MRA is significantly better using standard dose gadobutrol..nnnCITATION FORMATn· Hadizadeh DR, Keil VC, Jost G etu200aal. Contrast Media in Time-Resolved MRA at 3T: A Systematic Quantitative and Qualitative Analysis of Concentration and Dose Effects on Image Parameters in Minipigs. Fortschr Röntgenstr 2018; 190: 747u200a-u200a757.

Primary Urethral Plasmacytoma Treated with High-Dose-Rate Brachytherapy: A Case Report

Primary urethral solitary plasmacytoma is a very rare variant of extramedullary plasmacytoma. In total, only 9 cases have been reported so far. Patients were treated either by surgery or by external radiation therapy. Here, we report on a 22-year-old man, initially presenting with a palpable induration at the penis, intermittent dysuria and haematospermia, which was due to histologically confirmed solitary urethral kappa-restricted plasmacytoma. The patient subsequently underwent percutaneous and endo-urethral high-dose-rate brachytherapy with a total dose of 42 Gy applied in 14 fractions. Besides an uncomplicated urinary tract infection and hyperpigmentation of the penis, the patient tolerated the radiotherapy well and is still free of disease after 15 months follow-up.

Association between early diastolic dysfunction and increased peri-/epicardial fat: A CMR based study

Background Previous studies have shown that increased periand epicardial fat volume (PFV, EFV) leads to pathological diastolic strain (DS) and thus to cardiovascular morbidity. The aim of this study was to investigate the association between diastolic strain and EFV/PFV in obese and non-obese individuals without previous history of cardiovascular disease or additional cardiovascular risk factors.

Quantitative assessment of diffuse myocardial fibrosis and edema in patients with and without cardiac involvement of sarcoidosis by cardiovascular magnetic resonance T1- and T2-mapping at 1.5T

Background Cardiac involvement of sarcoidosis hallmarked by inflammatory myocardial processes and subsequent fibrotic myocardial alterations is a life threatening condition that makes early diagnosis favorable. Native T1as well as T2-mapping have been proposed as reliable methods to non-invasively assess diffuse myocardial fibrosis and edema respectively. Our aim was to examine the value of both methods for the differentiation between healthy and diseased myocardium.