[Relevant incidental findings and iatrogenic injuries : A retrospective analysis of 1165 resuscitation room patients]. / Relevante Zufallsbefunde und iatrogene Verletzungen : Eine retrospektive Analyse von 1165 Schockraumpatienten.

BACKGROUND: Whole-body computed tomography (CT) is increasingly being used as the diagnostic modality of choice in patients admitted to the resuscitation room. Beyond findings related to the suspected diagnosis it often additionally reveals incidental findings. The aim of this investigation was the evaluation of these findings in patients admitted via the emergency room after suffering potential major trauma or life-threatening medical conditions. Furthermore, the number of iatrogenic injuries as well as misplaced catheters and endotracheal tubes was investigated. METHODS: All patients admitted from 1 February 2012 to 31 January 2014 via the resuscitation area of the Mannheim University Medical Center, a tertiary care hospital and level 1 trauma center, were included in this study if they had undergone a whole-body CT scan at admission. Data from 1362 patients were collected retrospectively and 197 patients were excluded because of missing data so that the final cohort consisted of 1165 patients (1038 trauma and 127 internal neurological patients). Reports from the whole-body CT scans were screened for incidental findings. These findings were then classified as either clinically relevant or not. Furthermore, the reports were checked for iatrogenic injuries as well as misplaced catheters and endotracheal tubes. RESULTS: A total of 465 incidental findings were reported in 293 patients (25.1%) of the final cohort. In the synopsis of the radiological and clinical findings, 72 were rated as clinically relevant. In one patient two relevant incidental findings were reported and one patient presented with three incidental findings. In total, relevant incidental findings could be detected in 5.8% of the study patients (68/1165). In the discharge letters and/or the radiological report 16.2% of the incidental findings rated as clinically relevant were reported to be previously known, 66.2% were reported to be unknown and 17.6% could not be unequivocally classified as known or unknown due to missing references in the discharge letters. The group of internal neurological patients were clearly older than the trauma patients (61.6 years vs. 45.5 years). The rate of relevant incidental findings in the internal neurological group was more than twice as high as in the trauma group (11.0% vs. 5.2%); however, in the relatively young trauma group 1 in 20 patients showed an incidental finding classified as clinically relevant. In 43 (3.7%) patients a total of 46 iatrogenic injuries or misplaced catheters were reported. The most common finding was a too deeply placed endotracheal tube and five transurethral catheters placed in the emergency room were found to be blocked within the urethra. CONCLUSION: In addition to the main diagnosis, clinically relevant incidental findings were reported in nearly 25% of whole-body CT scans of patients admitted to the resuscitation room. Approximately 6% of patients had incidental findings rated as clinically relevant. In the internal neurological group of patients the rate of incidental findings was doubled compared to the trauma group; however, the latter were significantly younger. Whole-body CT was also useful for diagnosing iatrogenic injuries and misplaced catheters in approximately 4% of the study patients.

Diagnostic Performance of Contrast Enhanced Pulmonary Computed Tomography Angiography for the Detection of Angioinvasive Pulmonary Aspergillosis in Immunocompromised Patients.

Invasive pulmonary aspergillosis (IPA) is one of the major complications in immunocompromised patients. The mainstay of diagnostic imaging is non-enhanced chest-computed-tomography (CT), for which various non-specific signs for IPA have been described. However, contrast-enhanced CT pulmonary angiography (CTPA) has shown promising results, as the vessel occlusion sign (VOS) seems to be more sensitive and specific for IPA in hematologic patients. The aim of this study was to evaluate the diagnostic accuracy of CTPA in a larger cohort including non-hematologic immunocompromised patients. CTPA studies of 78 consecutive immunocompromised patients with proven/probable IPA were analyzed. 45 immunocompromised patients without IPA served as a control group. Diagnostic performance of CTPA-detected VOS and of radiological signs that do not require contrast-media were analyzed. Of 12 evaluable radiological signs, five were found to be significantly associated with IPA. The VOS showed the highest diagnostic performance with a sensitivity of 0.94, specificity of 0.71 and a diagnostic odds-ratio of 36.8. Regression analysis revealed the two strongest independent radiological predictors for IPA to be the VOS and the halo sign. The VOS is highly suggestive for IPA in immunocompromised patients in general. Thus, contrast-enhanced CTPA superior over non-contrast_enhanced chest-CT in patients with suspected IPA.

[Value of cardiac CT in the diagnostic work-up of coronary artery disease : Update 2017]. / Stellenwert der Herz-CT in der Diagnostik der koronaren Herzerkrankung : Update 2017.

The quantification of coronary calcifications using noncontrast-enhanced computed tomography (CT) as well as coronary CT angiography (cCTA) have rapidly evolved in the recent years. Nowadays, both techniques are increasingly clinically accepted regarding risk stratification and accurate exclusion of significant coronary artery disease (CAD). The higher acceptance of cCTA is mainly based on the higher robustness, lower radiation exposure through continuous technical innovations as well as by the growing scientific evidence. The poor predictive value of cCTA for predicting the hemodynamic significance of detected coronary artery stenosis may be improved by continuous technical developments in the area of functional imaging. The aim of this educational article is to summarize the current clinical status of calcium scoring and morphological cCTA and to provide an overview on novel functional CT techniques.

[Computed tomography in patients with chronic stable angina : Fractional flow reserve measurement]. / Computertomographie bei Patienten mit stabiler Angina Pectoris : Messung der fraktionellen Flussreserve.

Coronary computed tomography angiography (cCTA) has been established for the non-invasive diagnosis of coronary artery disease (CAD). Previous studies demonstrated the high diagnostic accuracy of cCTA, particularly for ruling out CAD. As a known limitation of cCTA a large number of visually significant coronary stenoses are found to be hemodynamically not relevant by invasive fractional flow reserve (FFR). CT-based FFR (CT-FFR) builds on recent advances in computational fluid dynamics and image simulation techniques. Along with CT myocardial perfusion imaging, CT-FFR is a promising approach towards a more accurate estimation of the hemodynamic relevance of coronary artery stenoses. CT-FFR is derived from regular CT datasets without additional image acquisitions, contrast material, or medication. Two CT-FFR techniques can be differentiated. The initial method requires external use of supercomputers and has gained approval for clinical use in the USA. Furthermore, a prototype-software has been introduced which is less computationally demanding via integration of reduced-order models for on-site calculation of CT-FFR. The present article reviews these methods in the context of available study results and meta-analyses. Furthermore, limitations and future concepts of CT-FFR are discussed.

[Acute pulmonary embolism and contraindication of anticoagulation : Bedside implantation of a new temporary vena cava inferior filter]. / Akute Lungenembolie und Kontraindikation für eine Antikoagulation : Bettseitige Implantation eines neuen passageren V.-cava-inferior-Filters.

Pulmonary embolism (PE), mostly caused by deep vein thrombosis, is a life-threatening complication in critically ill patients in the intensive care unit. A potential strategy to prevent PE in patients with contraindication for anticoagulant therapy is the implantation of a vena cava filter (VCF), to provide fast and safe PE protection against ascending thrombi. We report the case of a 56-year-old woman with an intracranial hemorrhage, who developed a PE. Because of acute contraindications for anticoagulant therapy, bedside implantation of a new VCF was performed to overcome the period of absolute contraindications for anticoagulation. After explanation, several thrombi were found on the filter.

Image quality of mean temporal arterial and mean temporal portal venous phase images calculated from low dose dynamic volume perfusion CT datasets in patients with hepatocellular carcinoma and pancreatic cancer.

PURPOSE: Dynamic volume perfusion CT (dVPCT) provides valuable information on tissue perfusion in patients with hepatocellular carcinoma (HCC) and pancreatic cancer. However, currently dVPCT is often performed in addition to conventional CT acquisitions due to the limited morphologic image quality of dose optimized dVPCT protocols. The aim of this study was to prospectively compare objective and subjective image quality, lesion detectability and radiation dose between mean temporal arterial (mTA) and mean temporal portal venous (mTPV) images calculated from low dose dynamic volume perfusion CT (dVPCT) datasets with linearly blended 120-kVp arterial and portal venous datasets in patients with HCC and pancreatic cancer. MATERIALS AND METHODS: All patients gave written informed consent for this institutional review board-approved HIPAA compliant study. 27 consecutive patients (18 men, 9 women, mean age, 69.1 years±9.4) with histologically proven HCC or suspected pancreatic cancer were prospectively enrolled. The study CT protocol included a dVPCT protocol performed with 70 or 80kVp tube voltage (18 spiral acquisitions, 71.2s total acquisition times) and standard dual-energy (90/150kVpSn) arterial and portal venous acquisition performed 25min after the dVPCT. The mTA and mTPV images were manually reconstructed from the 3 to 5 best visually selected single arterial and 3 to 5 best single portal venous phases dVPCT dataset. The linearly blended 120-kVp images were calculated from dual-energy CT (DECT) raw data. Image noise, SNR, and CNR of the liver, abdominal aorta (AA) and main portal vein (PV) were compared between the mTA/mTPV and the linearly blended 120-kVp dual-energy arterial and portal venous datasets, respectively. Subjective image quality was evaluated by two radiologists regarding subjective image noise, sharpness and overall diagnostic image quality using a 5-point Likert Scale. In addition, liver lesion detectability was performed for each liver segment by the two radiologists using the linearly blended120-kVp arterial and portal venous datasets as the reference standard. RESULTS: Image noise, SNR and CNR values of the mTA and mTPV were significantly higher when compared to the corresponding linearly blended arterial and portal venous 120-kVp datasets (all p<0.001) except for image noise within the PV in the portal venous phases (p=0.136). OBJECTIVE: image quality of mTA and mTPV were rated significantly better when compared to the linearly blended 120-kVp arterial and portal venous datasets. Both readers were able to detect all liver lesions found on the linearly blended 120-kVp arterial and portal venous datasets using the mTA and mTPV datasets. The effective radiation dose of the dVPCT was 27.6mSv for the 80kVp protocol and 14.5mSv for the 70kVp protocol. The mean effective radiation dose for the linearly blended 120-kVp arterial and portal venous CT protocol together of the upper abdomen was 5.60mSv±1.48mSv. CONCLUSION: Our preliminary data suggest that subjective and objective image quality of mTA and mTPV datasets calculated from low-kVp dVPCT datasets is non-inferior when compared to linearly blended 120-kVp arterial and portal venous acquisitions in patients with HCC and pancreatic cancer. Thus, dVPCT could be used as a stand-alone imaging technique without additionally performed conventional arterial and portal venous CT acquisitions.

Splenomegaly, elevated alkaline phosphatase and mutations in the SRSF2/ASXL1/RUNX1 gene panel are strong adverse prognostic markers in patients with systemic mastocytosis.

We evaluated the impact of clinical and molecular characteristics on overall survival (OS) in 108 patients with indolent (n=41) and advanced systemic mastocytosis (SM) (advSM, n=67). Organomegaly was measured by magnetic resonance imaging-based volumetry of the liver and spleen. In multivariate analysis of all patients, an increased spleen volume ⩾450 ml (hazard ratio (HR), 5.2; 95% confidence interval (CI), (2.1-13.0); P=0.003) and an elevated alkaline phosphatase (AP; HR 5.0 (1.1-22.2); P=0.02) were associated with adverse OS. The 3-year OS was 100, 77, and 39%, respectively (P<0.0001), for patients with 0 (low risk, n=37), 1 (intermediate risk, n=32) or 2 (high risk, n=39) parameters. For advSM patients with fully available clinical and molecular data (n=60), univariate analysis identified splenomegaly ⩾1200 ml, elevated AP and mutations in the SRSF2/ASXL1/RUNX1 (S/A/R) gene panel as significant prognostic markers. In multivariate analysis, mutations in S/A/R (HR 3.2 (1.1-9.6); P=0.01) and elevated AP (HR 2.6 (1.0-7.1); P=0.03) remained predictive adverse prognostic markers for OS. The 3-year OS was 76 and 38%, respectively (P=0.0003), for patients with 0-1 (intermediate risk, n=28) or 2 (high risk, n=32) parameters. We conclude that splenomegaly, elevated AP and mutations in the S/A/R gene panel are independent of the World Health Organization classification and provide the most relevant prognostic information in SM patients.

Comparison of organ-specific-radiation dose levels between 70 kVp perfusion CT and standard tri-phasic liver CT in patients with hepatocellular carcinoma using a Monte-Carlo-Simulation-based analysis platform.

PURPOSE: The aim of this study was to systematically compare organ-specific-radiation dose levels between a radiation dose optimized perfusion CT (dVPCT) protocol of the liver and a tri-phasic standard CT protocol of the liver using a Monte-Carlo-Simulation-based analysis platform. METHODS AND MATERIALS: The complete CT data of 52 patients (41 males; mean age 65 ± 12) with suspected HCC that underwent dVPCT examinations on a 3rd generation dual-source CT (Somatom Force, Siemens) with a dose optimized tube voltage of 70 kVp or 80 kVp were exported to an analysis platform (Radimetrics, Bayer). The dVPCT studies were matched with a reference group of 50 patients (35 males; mean age 65 ± 14) that underwent standard tri-phasic CT (sCT) examinations of the liver with 130 kVp using the calculated water-equivalent-diameter of the patients. The analysis platform was used for the calculation of the organ-specific effective dose (ED) as well as global radiation-dose parameters (ICRP103). RESULTS: The organ-specific ED of the dVPCT protocol was statistically significantly lower when compared to the sCT in 14 of 21, and noninferior in a total of 18 of 21 examined items (all p < 0.05). The EDs of the dVPCT examinations were especially in the dose sensitive organs such as the red marrow (17.3 mSv vs 24.6 mSv, p = < 0.0001) and the liver (33.3 mSv vs 46.9 mSv, p = 0.0003) lower when compared to the sCT. CONCLUSION: Our results suggest that dVPCT performed at 70 or 80 kVp compares favorably to sCT performed with 130 kVp with regard to effective organ dose levels, especially in dose sensitive organs, while providing additional functional information which is of paramount importance in patients undergoing novel targeted therapies.

[Advanced gastrointestinal stromal tumors : What role does surgery currently play in multimodal concepts?]. / Fortgeschrittene gastrointestinale Stromatumoren : Welche Rolle spielt die Chirurgie im multimodalen Konzept heute?

BACKGROUND: Gastrointestinal stromal tumors (GIST) have an incidence of 1-2/100,000 and thus constitute the most common mesenchymal neoplasm of the digestive tract. Their specific tumor biology with mutations in the protooncogenes c-KIT and PDGFR α acting as drivers of tumor growth facilitate targeted therapy with tyrosine kinase inhibitors. In this context, there are several specific indications for surgery in patients with advanced GIST. OBJECTIVE: This article discusses the importance of surgery within multimodal therapeutic concepts for advanced GIST. MATERIAL AND METHODS: The results of a selective literature search including own studies and case reports are presented. RESULTS: For large GIST at unfavorable anatomical locations, which are not amenable to organ-sparing resection, neoadjuvant imatinib therapy is the standard upfront treatment prior to surgery in the case of imatinib-sensitive mutations in the c-KIT protooncogene. This usually reduces the extent of resection without increasing perioperative morbidity. In the metastatic setting, surgery can constitute a significant part of multimodal therapy in patients with a generalized response to drug therapy by resection of residual tumor masses, although there are no prospective studies to prove a beneficial effect on overall survival. In patients with focal progression on anti-proliferative therapy, local therapeutic measures can make an important contribution to multimodal tumor control. In patients with generalized progression, an operation should only be performed in highly selected cases with the goal of symptom control. Local ablative therapies, such as radiofrequency ablation (RFA), irreversible electroporation (IRE) and selective internal radiotherapy (SIRT) are a therapeutic option particularly for liver metastases. CONCLUSION: Surgery plays an important role in the multimodal therapy of advanced GIST particularly in the neoadjuvant setting. Its role is more limited in metastatic stages where systemic treatment represents the frontline therapeutic approach.

[Injuries in children and adolescents in emergency services]. / Verletzungen bei Kindern und Jugendlichen im Bereitschaftsdienst.

BACKGROUND: A differentiated knowledge of trauma in children and adolescents is essential for the treatment of injured minors. The aim of this study was to present the focus of treatment in trauma emergency services. MATERIAL AND METHODS: Over a period of 2 years all acutely injured children and adolescents (n = 4784) in the emergency service were analyzed prospectively. The data were analyzed according to sex, age, date of examination, indications for x-ray imaging, diagnosis and therapy. RESULTS: Seasonal differences in the treatment spectrum were detected. In total 34.4 % of the patients presented with bruises/contusions, 23 % wounds, 19.9 % fractures, 14.9 % sprains/strains/ligament ruptures, 4.1 % craniocerebral trauma, 1.5 % dislocations, 1.1 % muscle/tendon injuries and 0.9 % burns. Of the patients 60 % underwent an x-ray examination and 8.3 % were hospitalized. Different injuries were found in the different age groups. Most fractures (25.7 %) were found at the distal forearm and most osteosyntheses (22.5 %) were also carried out at this anatomical location. CONCLUSION: Knowledge of the frequency and age dynamics is essential for competent treatment of injuries in children and adolescents. Analysis of the reality of the treatment in emergency services allows a much better evaluation of the requirements with respect to this clientele. The collected data can serve as a basis for the development of major capability foci, training concepts, treatment algorithms as well as prevention measures.

Fourier decomposition pulmonary MRI using a variable flip angle balanced steady-state free precession technique.

PURPOSE: Fourier decomposition (FD) is a noninvasive method for assessing ventilation and perfusion-related information in the lungs. However, the technique has a low signal-to-noise ratio (SNR) in the lung parenchyma. We present an approach to increase the SNR in both morphological and functional images. METHODS: The data used to create functional FD images are usually acquired using a standard balanced steady-state free precession (bSSFP) sequence. In the standard sequence, the possible range of the flip angle is restricted due to specific absorption rate (SAR) limitations. Thus, using a variable flip angle approach as an optimization is possible. This was validated using measurements from a phantom and six healthy volunteers. RESULTS: The SNR in both the morphological and functional FD images was increased by 32%, while the SAR restrictions were kept unchanged. Furthermore, due to the higher SNR, the effective resolution of the functional images was increased visibly. The variable flip angle approach did not introduce any new transient artifacts, and blurring artifacts were minimized. CONCLUSION: Both a gain in SNR and an effective resolution gain in functional lung images can be obtained using the FD method in conjunction with a variable flip angle optimized bSSFP sequence.

[Interdisciplinary treatment of soft tissue sarcoma of the extremities]. / Interdisziplinäre Behandlung der Weichgewebesarkome der Extremitäten.

Soft tissue sarcomas are a rare and heterogeneous group of tumors. Surgery clearly remains the standard therapy of non-metastatic soft tissue sarcoma. A pretreatment biopsy is necessary to determine the histology and grade of soft tissue sarcomas and to diagnose entities that can be treated by targeted therapies, such as dermatofibrosarcoma protuberans or alveolar soft tissue sarcoma once they are in a metastatic stage. Nevertheless, locally advanced disease requires multimodal treatment and interdisciplinary treatment decisions. Limb sarcoma of borderline resectability (encasement of vessels, invasion of joints or close proximity to motor nerves) may profit from isolated limb perfusion with recombinant tumor necrosis factor and melphalan. Preoperative chemotherapy may be applied in locally advanced high grade tumors when clear resection margins are difficult to achieve. Deep wave hyperthermia has proven to be a useful addition to systemic chemotherapy in such a neoadjuvant setting. Also preoperative radiation therapy has proven to be effective in controlling locally advanced sarcoma despite higher perioperative morbidity which pays off in the long run by better limb function. Postoperative adjuvant external beam irradiation therapy with the best available technique is recommended for any tumor larger than 5 cm with (FNLCC) grades 2 and 3 (American Joint Committee on Cancer stage IIb/III). Given all these therapeutic options, it is absolutely crucial that interdisciplinary decision-making starts early in the therapeutic process. Patients are often seen first by the surgeon. For an optimal treatment surgeons need to know the efficacy and toxicity of the multimodal treatment options described.

3 Tesla proton MRI for the diagnosis of pneumonia/lung infiltrates in neutropenic patients with acute myeloid leukemia: initial results in comparison to HRCT.

PURPOSE: To evaluate the diagnostic accuracy of 3 Tesla proton MRI for the assessment of pneumonia/lung infiltrates in neutropenic patients with acute myeloid leukemia. MATERIAL AND METHODS: In a prospective study, 3 Tesla MRI was performed in 19 febrile neutropenic patients (5 women, 14 men; mean age 61 years ± 14.2; range 23-77 years). All patients underwent high-resolution CT less than 24h prior to MRI. The MRI protocol (Magnetom Tim Trio, Siemens) included a T2-weighted HASTE sequence (TE/TR: 49 ms/∞, slice thickness 6mm) and a high-resolution 3D VIBE sequence with an ultra-short TE<1 ms (TE/TR 0.8/2.9 ms, slice thickness 2mm). The VIBE sequence was examined before and after intravenous injection of 0.1 mmol/kg gadoterate meglumine (Dotarem, Guerbet). The presence of pulmonary abnormalities, their location within the lung, and lesion type (nodules, consolidations, glass opacity areas) were analyzed by one reader and compared to the findings of HRCT, which was evaluated by a second independent radiologist who served as the reference standard. The findings were compared per lobe in each patient and rated as true positive (TP) findings if all three characteristics (presence, location, and lesion type) listed above were concordant to HRCT. RESULTS: Pulmonary abnormalities were characterized by 3 Tesla MRI with a sensitivity of 82.3% and a specificity of 78.6%, resulting in an overall accuracy of 88% (NPV/PPV 66.7%/89.5%). In 51 lobes (19 of 19 patients), pulmonary abnormalities visualized by MR were judged to be concordant in their location and in the lesion type identified by both readers. In 22 lobes (11 of 19 patients), no abnormalities were present on either MR or HRCT (true negative). In 6 lobes (5 of 19 patients), ground glass opacity areas were detected on MRI but were not visible on HRCT (false positives). In 11 lobes (7 of 19 patients), MRI failed to detect ground glass opacity areas identified by HRCT. However, since the abnormalities were disseminated in these patients, accurate treatment decisions were possible in every case based on MRI. In one case MRI showed a central area of cavitation, which was not visualized by HRCT. CONCLUSION: Infectious nodules and consolidations can be detected in neutropenic patients with acute myeloid leukemia with a sufficient diagnostic accuracy by 3 Tesla MRI. Detection of ground glass opacity areas is the main limitation of 3-Tesla MRI when compared to HRCT.

Whole-body CT for lymphoma staging: feasibility of halving radiation dose and risk by iterative image reconstruction.

OBJECTIVES: Patients with lymphoma are at higher-risk of secondary malignancies mainly due to effects of cancer therapy as well as frequent radiological surveillance. We thus aimed to investigate the objective and subjective image quality as well as radiation exposure and risk of full-dose standard (FDS), full-dose iterative (FDI), and half-dose iterative (HDI) image reconstruction in patients with lymphoma. MATERIAL AND METHODS: In 100 lymphoma patients, contrast-enhanced whole-body staging was performed on a dual-source CT. To acquire full-dose and half-dose CT data simultaneously, the total current-time product was equally distributed on both tubes operating at 120 kV. HDI reconstructions were calculated by using only data from one tube. Quantitative image quality was assessed by measuring image noise in different tissues of the neck, thorax, and abdomen. Overall diagnostic image quality was assessed using a 5-point Likert scale. Radiation doses and risks were estimated for a male and female reference person. RESULTS: For all anatomical regions apart from the lungs image noise was significantly lower and the overall subjective image quality significantly better when using FDI and HDI instead of FDS reconstruction (p<0.05). For the half-dose protocol, the risk to develop a radiation-induced cancer was estimated to be less than 0.11/0.19% for an adult male/female. CONCLUSIONS: Image quality of FDI and more importantly of HDI is superior to FDS reconstruction, thus enabling to halve radiation dose and risk to lymphoma patients.

Axillary lymph node characterization in breast cancer patients using magnetic resonance mammography: a prospective comparative study with FDG PET-CT and healthy women.

OBJECTIVE: The aim of this study was to evaluate the capability of dynamic contrast enhanced MR-mammography (MRM) for the interpretation of axillary lymph nodes (LNs) in patients with breast cancer. MATERIAL AND METHODS: 25 patients with breast cancer preoperatively underwent both FDG positron emission computed tomography (PET-CT) and dynamic contrast enhanced MRM. The maximum signal increase (SImax) and curve shape (types I-III) of contrast enhanced LNs ≥ 0.5 cm (short-axis) were analyzed in MRM and correlated to the maximum standard uptake value (SUVmax) of FDG PET-CT. 29 healthy women with MRM served as control group. Enhancement kinetics of all malignant LNs were compared to LN findings of the healthy control group. RESULTS: Overall 33 contrast enhanced LNs on preoperative MRM had a corresponding FDG uptake on PET-CT. 30 of the PET positive LNs were classified as surely malignant (mean SUVmax 7.3 (± 5.4)). The mean SImax of these LNs was not significantly different to the control group (222% vs 197%), but malignant LNs had a significantly higher rate of type III curves with rapid washout (93% vs 66%, p = 0.008). CONCLUSION: The maximum signal increase is not capable of differentiating malignant from benign axillary LNs. However, since malignant LNs showed a higher frequency of rapid washout curves (type III curves) on corresponding MRM future studies should concentrate on the analysis of this parameter. In clinical routine the curve shape still should be taken with care as there is a high overlap with benign LNs.

Predictive value of zero calcium score and low-end percentiles for the presence of significant coronary artery stenosis in stable patients with suspected coronary artery disease.

PURPOSE: To prospectively investigate the predictive value of a zero calcium score (CS) value as well as age- and sex-adjusted low-end CS percentiles for the presence of significant coronary artery stenosis in stable patients with suspected coronary artery disease (CAD). MATERIALS AND METHODS: In total, 87 consecutive stable patients with suspected CAD were prospectively enrolled in this study (33 women; 66 ± 10 years). All patients underwent non-enhanced CT for calcium scoring (CSCT) and contrast-enhanced coronary CT angiography (cCTA). Invasive coronary angiography (ICA) served as the reference standard in all patients. Diagnostic performance for the presence of significant stenosis (≥ 50% diameter) was calculated separately for CS in comparison to cCTA and ICA. RESULTS: ICA identified significant stenosis in 56/87 patients (64%). The mean CS was 571 ± 599. On a per patient based analysis, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for patients with a zero CS were 98.5%, 18.2%, 78.0% and 80.0%, respectively, compared to cCTA and 100%, 16.1%, 68.3% and 100%, respectively, compared to ICA. Low-end age- and sex-adjusted percentiles derived from asymptomatic Caucasian populations showed results comparable to a CS of zero. CONCLUSION: The prevalence of significant coronary artery stenosis is low in stable patients with suspected CAD and a CS of zero but also in patients below certain low-end age- and sex-adjusted percentile ranks. Thus, CS should be used as a gatekeeper prior to further diagnostic procedures in these patients. A CS value below certain age- and sex-adjusted percentile ranks seems to be of identical diagnostic value to a CS of zero in stable patients.

CT-based response assessment of advanced gastrointestinal stromal tumor: dual energy CT provides a more predictive imaging biomarker of clinical benefit than RECIST or Choi criteria.

OBJECTIVES: Dual-energy CT (DECT) allows quantification of intravenously injected iodinated contrast media in tumors, and therefore may be considered as a surrogate marker for perfusion and tumor vascularity. This study evaluated whether newly developed DECT response criteria allow better correlation with survival than established response criteria. METHODS: Seventeen patients with advanced GIST treated with tyrosine-kinase-inhibitors were assessed by contrast-enhanced DECT 2 and 6 months after beginning of treatment. Response to treatment of 165 tumor lesions was evaluated according to RECIST, Choi criteria and newly developed DECT criteria, defining non-responders as an increase of both tumor size >20% and iodine related attenuation or either a >50% increase of tumor size or iodine related attenuation. All other patients were classified as responders. Progression-free survival (PFS) and overall survival (OS) were calculated by Kaplan-Meier analysis. RESULTS: Choi criteria and DECT showed a significantly longer median PFS of patients rated as responders than patients rated as non-responders (9-29 months vs. 2-6 months; p<0.02) at follow-up. Only DECT analysis at 6 months follow-up allowed a valid prediction of OS. CONCLUSION: This study indicates that DECT allows a better prediction of therapeutic benefit in advanced GIST patients treated with tyrosine-kinase-inhibitors than established response criteria. However, the most important predictive biomarker of therapeutic benefit was absence of progression, no matter which response evaluation criteria were applied.