Quantitative and qualitative assessment of plasma cell dyscrasias in dual-layer spectral CT.

OBJECTIVES: Virtual non-calcium (VNCa) images could improve assessment of plasma cell dyscrasias by enhancing visibility of bone marrow. Thus, VNCa images from dual-layer spectral CT (DLCT) were evaluated at different calcium suppression (CaSupp) indices, correlating results with apparent diffusion coefficient (ADC) values from MRI. METHODS: Thirty-two patients with initial clinical diagnosis of a plasma cell dyscrasia before any chemotherapeutic treatment, who had undergone whole-body low-dose DLCT and MRI within 2 months, were retrospectively enrolled. VNCa images with CaSupp indices ranging from 25 to 95 in steps of 10, conventional CT images, and ADC maps were quantitatively analyzed using region-of-interests in the vertebral bodies C7, T12, L1-L5, and the iliac bone. Independent two-sample t-test, Wilcoxon-signed-rank test, Pearson's correlation, and ROC analysis were performed. RESULTS: Eighteen patients had a non-diffuse, 14 a diffuse infiltration in conventional MRI. A significant difference between diffuse and non-diffuse infiltration was shown for VNCa-CT with CaSupp indices from 55 to 95, for conventional CT, and for ADC (each p < 0.0001). Significant quantitative correlation between VNCa-CT and MRI could be found with strongest correlation at CaSupp index 65 for L3 (r = 0.68, p < 0.0001) and averaged L1-L5 (r = 0.66, p < 0.0001). The optimum CT number cut-off point for differentiation between diffuse and non-diffuse infiltration at CaSupp index 65 for averaged L1-L5 was -1.6 HU (sensitivity 78.6%, specificity 75.0%). CONCLUSION: Measurements in VNCa-CT showed the highest correlation with ADC at CaSupp index 65. VNCa technique may prove useful for evaluation of bone marrow infiltration if MRI is not feasible. KEY POINTS: • VNCa-CT images can support the evaluation of bone marrow infiltration in plasma cell dyscrasias. • VNCa measurements of vertebral bodies show significant correlation with ADC in MRI. • Averaging L1-L5 at CaSupp index 65 allowed quantitative detection of infiltration comparable to MRI ADC.

[Microvascular changes in COVID-19]. / Mikrovaskuläre Veränderungen bei COVID-19.

BACKGROUND: Clinically, coronavirus disease 2019 (COVID-19) is associated with a wide range of symptoms, which can range from mild complaints of an upper respiratory infection to life-threatening hypoxic respiratory insufficiency and multiorgan failure. OBJECTIVE: The initially identified pulmonary damage patterns, such as diffuse alveolar damage in acute lung failure, are accompanied by new findings that draw a more complex scenario. These include microvascular involvement and a wide range of associated pathologies of multiple organ systems. A back-scaling of microstructural vascular changes is possible via targeted correlation of pathological autopsy results with radiological imaging. MATERIAL AND METHODS: Radiological and pathological correlation as well as microradiological imaging to investigate microvascular involvement in fatal COVID-19. RESULTS: The cases of two COVID-19 patients are presented. Patient 1 showed a relative hypoperfusion in lung regions that did not have typical COVID-19 infiltrates; the targeted post-mortem correlation also showed subtle signs of microvascular damage even in these lung sections. Patient 2 showed both radiologically and pathologically advanced typical COVID-19 destruction of lung structures and the case illustrates the damage patterns of the blood-air barrier. The perfusion deficit of the intestinal wall shown in computed tomography of patient 2 could not ultimately clearly be microscopically attributed to intestinal microvascular damage. CONCLUSION: In addition to microvascular thrombosis, our results indicate a functional pulmonary vasodysregulation as part of the pathophysiology during the vascular phase of COVID-19. The clinical relevance of autopsies and the integration of radiological imaging findings into histopathological injury patterns must be emphasized for a better understanding of COVID-19.

[Extranodal abdominal lymphomas]. / Extranodale abdominale Lymphomerkrankungen.

BACKGROUND: Extranodal manifestations occur in up to 40% of non-Hodgkin lymphomas. The prevalence of extranodal involvement has increased. OBJECTIVES: A comprehensive overview on lymphoma involvement in the parenchymatous abdominal organs, the gastrointestinal tract, and the peritoneal cavity under due consideration of clinical implications is given. MATERIALS AND METHODS: A selective literature search with analysis of dedicated original research articles and reviews was carried out. Clinical guidelines are discussed. RESULTS: Extranodal abdominal lymphoma involvement usually occurs secondarily in advanced disease. Sites involved most frequently are the liver and the gastrointestinal tract. Extranodal abdominal lymphoma involvement is more common in the immunocompromised patient. CONCLUSION: Imaging findings of extranodal abdominal lymphoma are variable. Lymphoma is an important differential diagnosis to be considered in unclear tumor diseases.

[Durable remission under dual HER2 blockade with Trastuzumab and Pertuzumab in a patient with metastatic gallbladder cancer]. / Dauerhafte Remission unter dualer HER2-Blockade mit Trastuzumab und Pertuzumab bei metastasiertem Gallenblasenkarzinom.

Gallbladder cancer represents a rare but dismal disease. The only curative option is complete surgical resection, though patients often develop recurrent disease. In patients with advanced biliary tract cancer, the combination of cisplatin and gemcitabine showed a benefit in overall survival compared to gemcitabine alone. However, there is no standardized second-line regimen after treatment failure. We report on a young patient with early recurrence of a gallbladder cancer with cutaneous and peritoneal metastases. Upon identification of an ERBB2 gene amplification within the NCT MASTER (Molecularly Aided Stratification for Tumor Eradication Research) exome sequencing program with resulting overexpression of HER2 in the tumors cells, the patient received a targeted therapy with the HER2 antibodies pertuzumab and trastuzumab in combination with nab-paclitaxel, which led to a durable remission for more than one year. This case report underlines the potential of molecularly aided personalized targeted therapy for patients with biliary tract cancer and the need for respective clinical trials.

How to not miss alveolar echinococcosis in hepatic lesions suspicious for cholangiocellular carcinoma.

PURPOSE: Hepatic alveolar echinococcosis (AE) resembles intrahepatic cholangiocarcinoma (ICC) on radiological imaging. The purpose of this study was to identify criteria to discriminate AE from ICC with CT and MR Imaging. METHODS: One hundred and sixteen imaging studies of 94 patients (CT n = 65; MRI n = 51) diagnosed with AE (n = 55) or ICC (n = 39) were retrospectively reviewed by two blinded radiologists for lesion features including enhancement pattern and matrix composition. A consensus read was conducted in cases of disagreement. Uni- and multivariate logistic regression with bootstrapping were used for analysis. RESULTS: Using CT, no or septal enhancement and calcification yielded the highest values of sensitivity/specificity (90.9%/90.6% and 81.8%/96.9%) for AE. Using MRI, no or septal enhancement and cystic components achieved the highest sensitivity/specificity (90.9%/100.0% and 84.8%/66.7%) for AE. Multivariate logistic regression identified the following strong independent predictors for AE: for MRI, no or septal enhancement (odds ratio [OR] 322.4; p < 0.001); for CT, no or septal enhancement and calcification (OR 35.9 and 42.5; p < 0.001 and p < 0.01, respectively). No or septal enhancement and calcification demonstrated the highest interreader agreement (>90%). CONCLUSION: Enhancement characteristics and matrix calcifications offer the strongest discriminating potential between AE and ICC with a high sensitivity, specificity, and interreader agreement.

Pitfalls in diagnosis and treatment of alveolar echinococcosis: a sentinel case series.

BACKGROUND: Alveolar echinococcosis (AE) is a neglected zoonosis presenting with focal liver lesions (FLL) with a wide range of imaging patterns resembling benign as well as malignant FLLs. Complementary serology and histopathology may be misleading. OBJECTIVE: The objective of our study is to highlight pitfalls leading to wrong diagnoses and harmful interventions in patients with AE. DESIGN: This retrospective sentinel case series analyses diagnostic and treatment data of patients with confirmed AE. RESULTS: 80 patients treated between 1999 and 2014 were included in the study. In 26/80 patients treatment decisions were based on a wrong diagnosis. AE was mistaken for cystic echinococcosis (CE) in 12/26 patients followed by cholangiocellular carcinoma (CCA) in 5/26 patients; 61/80 patients had predominantly infiltrative liver lesions and 19/80 patients had a predominantly pseudocystic radiological presentation. Serology correctly differentiated between Echinococcus multilocularis and Echinococcus granulosus in 53/80 patients. Histopathology reports attributed the right Echinococcus species in 25/58 patients but failed to differentiate E. multilocularis from E. granulosus in 25/58 patients. Although contraindicated in AE 8/25 patients treated surgically had instillation of a protoscolicidal agent intraoperatively. One of the eight patients developed toxic cholangitis and liver failure and died 1 year after liver transplantation. CONCLUSIONS: Misclassification of AE leads to a critical delay in growth inhibiting benzimidazole treatment, surgical overtreatment and bares the risk of liver failure if protoscolicidal agents are instilled in AE pseudocysts.

Accuracy and variability of semiautomatic centerline analysis versus manual aortic measurement techniques for TEVAR.

OBJECTIVES: This study aims to test whether inter-observer variability and time of diameter measurements for thoracic endovascular aortic repair (TEVAR) are improved by semiautomatic centerline analysis compared to manual assessment. METHODS: Preoperative computed tomography (CT) angiographies of 30 patients with thoracic aortic disease (mean age 66.8 ± 11.6 years, 23 males) were retrospectively analysed by two blinded experts in vascular radiology. Maximum aortic diameters at three positions relevant to TEVAR were assessed (P1, distal to left common carotid artery; P2, distal to left subclavian artery; and P3, proximal to coeliac trunk) using three measurement techniques: manual axial slices (axial), manual double-oblique multiplanar reformations (MPRs) and semiautomatic centerline analysis. RESULTS: Diameter measurements by both centerline analysis and the axial technique did not significantly differ from MPR (p = 0.17 and p = 0.37). Total deviation index for 0.9 was for P1 2.7 mm (axial), 3.7 mm (MPR), 1.8 mm (centerline); for P2 2.0 mm (axial), 3.6 mm (MPR), 1.8 mm (centerline); and for P3 3.0 mm (axial), 3.5 mm (MPR), 2.5 mm (centerline). Measurement time using centerline analysis was significantly shorter than for assessment by MPR. CONCLUSIONS: Centerline analysis provides the least variable and fast diameter measurements in TEVAR patients with the same accuracy as the current reference standard MPR.

Reliability of semiautomatic centerline analysis versus manual aortic measurement techniques for TEVAR among non-experts.

OBJECTIVES: The study aimed to test whether reliability and inter-observer variability of preoperative measurements for thoracic endovascular aortic repair (TEVAR) among non-experts are improved by semiautomatic centerline analysis compared with manual assessment. METHODS: Preoperative computed tomography (CT) angiographies of 30 patients with thoracic aortic disease (mean age 66.8 ± 11.6 years, 23 men) were retrospectively analysed in randomised order by one blinded vascular expert (reference standard) and three blinded non-expert readers. Aortic diameters were measured at four positions relevant to TEVAR using three measurement techniques (manual axial slices, manual multiplanar reformations (MPRs) and semiautomatic centerline analysis). Length measurements were performed using centerline analysis. Reliability was calculated as absolute measurement deviation (AMD) from reference standard and inter-observer variability as coefficient of variance (CV) among non-expert readers. RESULTS: For axial, MPR and centerline techniques, mean AMD was 7.3 ± 7.7%, 6.7 ± 4.5% and 4.7 ± 4.8% and mean CV was 5.2 ± 4.2%, 5.8 ± 4.8% and 3.9 ± 5.4%. Both AMD and CV were significantly lower for centerline analysis compared with axial technique (p = 0.001/0.042) and MPR (p = 0.009/0.003). AMD and CV for length measurements by centerline analysis were 3.2 ± 2.8% and 2.6 ± 2.4%, respectively. Centerline analysis was significantly faster than MPR (p < 0.001). CONCLUSIONS: Semiautomatic centerline analysis provides the most reliable and least variable diameter and length measurements among non-experts in candidates for TEVAR.

Hybrid approach for arch and thoracoabdominal pathologies.

The endovascular era began about 20 years ago and subsequently revolutionized vascular surgery as a less invasive treatment option, especially for high risk patients. In the late 1990s, a new hybrid approach for arch and thoracoabdominal pathologies was developed. Debranching and rerouting supra-aortic and visceral aortic branches with extra-anatomic bypass grafting was performed in order to achieve sufficient landing zones demanding for subsequent stent grafting. The initial single-center results of small series up to 20 patients were encouraging with acceptable complication rates. Hybrid arch procedures are feasible but seem to carry risks. However, the latest reports for thoracoabdominal hybrid procedures demand a word of caution due to high morbidity rates. The hybrid approach may be reserved for a selected comorbid patient cohort, which is regarded unfit for open reconstruction.

[Endovascular aortic surgery: management of secondary aortobronchial and aorto-enteral fistulas]. / Endovaskuläre Aortenchirurgie: Management sekundärer aortobronchialer und -enteraler Fisteln.

Secondary aortobronchial or aorto-enteral fistulas have an incidence of 0.36-4% and are a rare but life-threatening complication after endovascular aorta reconstruction. Due to the rarity of the disease and the heterogeneity of the patients (age, risk profile, localization) individual-specific solutions are necessary. The primary symptomatic, differential diagnosis and individual therapy concepts will be presented and discussed based of five case reports (2 aorto-esophageal fistulas, 2 aortobronchial fistulas and 1 aorto-duodenal fistula).

[Ultrafast MR sialography: comparison of two coil systems including an alternative surface coil]. / Ultraschnelle MR-Sialografie: Intraindividueller Vergleich einer Oberflächenempfangs- mit einer konventionellen Kopf-Hals-Spule.

PURPOSE: To compare the visualization of salivary ducts by ultrafast magnetic resonance sialography (MR sialography) using an alternative surface coil and a conventional head-neck coil. MATERIALS AND METHODS: In 11 healthy volunteers, ultrafast MR sialography (single shot turbo spin echo; acquisition time, 2.8 s) was performed before and after oral application of a sialogogue. Each subject received examinations with both a bilateral surface coil (SC) and a conventional head-neck coil (HNC). The depiction of parotideal and submandibular duct systems was graded from 1 to 5 (5 = poor) by four independent radiologists. ANOVA served for statistical analysis of duct rankings, and interobserver variability was determined by Intraclass Correlation Coefficient (ICC). RESULTS: With an excellent ICC of 0.96, both coil systems offered symmetric visualization of salivary ducts, and the image quality increased after oral application of sialogogue (p < 0.001). In total, the overall rating was worse for SC than for HNC (2.13 +/- 1.24 vs. 1.45 +/- 0.65, p < 0.001). SC was especially inferior in depiction of submandibular and extraglandular duct components compared to HNC (p < 0.001). CONCLUSION: Most notably due to the reduced visualization of extraglandular and submandibular ducts, the specific surface coil used in this study was inferior in image quality and does not constitute a reasonable alternative to conventional coil systems.

Imaging modalities for the thoracic aorta.

Almost 50 years after its introduction intra-arterial digital subtraction angiography (DSA) has been passed as the gold standard for diagnostic imaging of the aorta. Today's performance of multi-detector-row computed tomography angiography (CTA) as well as magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) offer remarkable improvements in the field of diagnostic cardiovascular imaging. The racy developments not only concerning image acquisition but also image postprocessing offer a multidimensional approach to assess anatomy and pathology of individual patients in a few minutes. Four-dimensional visualization assists us to select the ''adequate'' patient, quantify vascular and adjacent geometries, and select the appropriate device to realize even complex thoracic endovascular aortic reconstructions (TEVAR). There is still a discrepancy between perioperative and intraoperative imaging--but new technologies made also some progress in this field. Lifelong imaging surveillance of TEVAR and bypasses is still a critical component of patient care and requires comparable imaging and postprocessing capabilities as for the preoperative setting. Although is the most commonly used examination for imaging surveillance, MRA, chest x-ray and DSA all have their role in determining complications and their management.

[Integration of cardiac computed tomography into pulmonary vein isolation in patients with paroxysmal atrial fibrillation]. / Integration einer präinterventionellen Computertomografie des Herzens in die therapeutische Pulmonalvenenisolation bei Patienten mit paroxysmalem Vorhofflimmern.

PURPOSE: Detailed anatomic information of the left atrium is necessary for securely performing radiofrequency ablation of atrial fibrillation-triggering ectopies in the pulmonary vein ostia. In this study the impact of a preinterventionally acquired cardiac computed tomography (CT) on pulmonary vein isolation (PVI) was assessed. MATERIALS AND METHODS: Examinations of 54 patients with paroxysmal atrial fibrillation undergoing PVI were analyzed. In 27 patients a supplementary cardiac CT was obtained prior to PVI (CT group, 12 women, 15 men, 59.7+/-9.9 years of age): 16 x 1.5 mm collimation, 0.2 pitch, 120 kV tube voltage, 400 effective mAs. The fluoroscopy time, effective dose and quantity of radiofrequency (RF) pulses of the following catheter ablation were compared to 27 patients undergoing stand-alone PVI (11 women, 16 men, 62.0+/-9.9 years of age). Mann-Whitney tests served for statistical comparison. RESULTS: CT datasets were successfully integrated into the ablation procedure of each patient in the CT group. The mean quantity of RF pulses was significantly lower in the CT group (22.1+/-8.0 vs. 29.1+/-11.9, p=0.030), and a significant reduction of fluoroscopy time was found (41.8+/-12.0 min vs. 51.2+/-16.0 min, p=0.005). Effective doses of the catheter ablation differed in an equivalent dimension but altogether not significantly (14.9+/-10.0 mSv vs. 20.0+/-16.0 mSv, p=0.203). The mean additive effective dose of the cardiac CT was 8.5+/-0.3 mSv. CONCLUSION: CT-guided ablation of atrial fibrillation requires less fluoroscopy time than stand-alone PVI. Due to the multi-faceted dependency of individual fluoroscopy doses, a consistent reduction of the effective dose was not observed. Since supplementary CT constitutes an additive dose, optimized CT atriography needs to be designed in order to provide sufficient image quality while reducing X-ray exposure. The reduction in RF pulses implies an increase in the effectiveness and safety of catheter ablation.

[Image postprocessing of aortic CTA and MRA]. / Aktuelle Bildnachverarbeitung der aortalen CTA und MRA.

Multiplanar reformation (MPR) is the most relevant tool for patient selection and precise procedural planning and also for analyzing postinterventional complications. Curved MPR is used primarily for semiautomated or completely automated calculation of the centerline of the vascular lumen and to estimate the orthogonal vessel diameter and longitudinal extent. Reproducible and accurate measurement of complex pathologies and courses of vessels extends the range of diagnostic radiology. Contemporary scanner consoles allow automated processing of maximum intensity projections (MIP) and standard MPR and their storage in PACS. To improve patient selection, procedural planning, root-cause analysis postoperatively for assessment of treatment effects and to make better communication of findings to nonradiologists possible, volume rendering techniques (VRT) are a beneficial adjunct to source images. With current algorithms semiautomated segmentation is satisfactory for vessels and bones, but not for low-contrast structures (soft tissues), which still need to be segmented manually. In general, isotropic CT source data are preferable to MR images, which are often anisotropic. In many European countries image postprocessing is still not adequately reimbursed although the doctors making referrals often specifically and emphatically demand 3D visualization and measurements in daily practice.