Impact of endobronchial coiling on segmental bronchial lumen in treated and untreated lung lobes: Correlation with changes in lung volume, clinical and pulmonary function tests.

OBJECTIVES: To assess the impact of endobronchial coiling on the segment bronchus cross-sectional area and volumes in patients with lung emphysema using quantitative chest-CT measurements. MATERIALS AND METHODS: Thirty patients (female = 15; median age = 65.36 years) received chest-CT before and after endobronchial coiling for lung volume reduction (LVR) between January 2010 and December 2014. Thin-slice (0.6 mm) non-enhanced image data sets were acquired both at end-inspiration and end-expiration using helical technique and 120 kV/100-150 mAs. Clinical response was defined as an increase in the walking distance (Six-minute walk test; 6MWT) after LVR-therapy. Additionally, pulmonary function test (PFT) measurements were used for clinical correlation. RESULTS: In the treated segmental bronchia, the cross-sectional lumen area showed significant reduction (p < 0.05) in inspiration and tendency towards enlargement in expiration (p > 0.05). In the ipsilateral lobes, the lumina showed no significant changes. In the contralateral lung, we found tendency towards increased cross-sectional area in inspiration (p = 0.06). Volumes of the treated segments correlated with the treated segmental bronchial lumina in expiration (r = 0.80, p < 0.001). Clinical correlation with changes in 6MWT/PFT showed a significant decrease of the inspiratory volume of the treated lobe in responders only. CONCLUSION: Endobronchial coiling causes significant decrease in the cross-sectional area of treated segment bronchi in inspiration and a slight increase in expiration accompanied by a volume reduction. KEY POINTS: • Endobronchial coiling has indirect impact on cross-sectional area of treated segment bronchi • Volume changes of treated lobes correlate with changes in bronchial cross-sectional area • Coil-induced effects reflect their stabilizing and stiffening impact on lung parenchyma • Endobronchial coiling reduces bronchial collapsing compensating the loss of elasticity.

The effect of intraparenchymal blood patching on the rate of pneumothorax in patients undergoing percutaneous CT-guided core biopsy of the lung.

PURPOSE: To assess the effect of intraparenchymal blood patching (IBP) as well as tumor- and operator-related risk factors on the rate of pneumothoraxes after percutaneous CT-guided core needle biopsy of the lung. MATERIALS AND METHODS: We performed a retrospective analysis of 868 CT-guided lung biopsies that were conducted at our institution between 2003 and 2018, of which 419 (48%) received an IBP. Outcome variable included the rates of pneumothorax and chest tube placement, as well as lesion size (<3 cm versus ≥3 cm long axis diameter), lesion depth (≤2 cm, >2-4 cm, >4-5 cm and >5 cm distance to the pleura), location within the lungs (upper lobe, lower lobe, middle lobe), needle caliber (13 G, 15 G, 17 G, 19 G), number of samples taken (1-3 versus ≥4 samples), and experience of the performing physician. RESULTS: The rate of pneumothorax was significantly (p < 0.05) lower in the group with IBP (10.7%) compared to the group without IBP (15.4%). The number of post-interventional chest tube placements was also lower in the IBP group (3.1% vs. 5.8%) but not statistically significant. The lesion size correlated negatively with the rate of pneumothoraxes, whereas in both groups (±IBP) lesions ≥ 3 cm showed a significantly lower rate of pneumothorax (p < 0.05). With increasing lesion depth, the pneumothorax rate increased with (p < 0.01) and without (p < 0.001) IBP. The rate of pneumothorax was significantly lower (p < 0.05) for 17 G needles with IBP, but not for other calibers. For biopsies in the lower lobe, the pneumothorax rate reduced significantly (p < 0.001) with IBP. In case of ≥4 tissue samples, the pneumothorax rate was significantly lower with IBP (p < 0.01). For experienced operators, the overall pneumothorax rate was significantly lower compared to less experienced operators (p < 0001). CONCLUSIONS: IBP significantly reduces the rate of pneumothorax following CT-guided lung biopsies in particular for lesions located deeper in the lungs, when ≥4 samples are taken, when samples are taken by less-experienced operators, and when sampling from the lower lobes.

Discriminatory CT-textural features in splenic infiltration of lymphoma versus splenomegaly in liver cirrhosis versus normal spleens in controls and evaluation of their role for longitudinal lymphoma monitoring.

PURPOSE: To find CT-texture analysis (CTTA) features for the discrimination of splenomegaly due to diffuse lymphoma involvement and liver cirrhosis versus normal-sized spleens in controls and to assess their potential role for longitudinal lymphoma monitoring. MATERIAL AND METHODS: We had retrospectively identified 74 subjects with diffuse splenic involvement due to lymphoma (n = 29) and liver cirrhosis (n = 30), and healthy controls (n = 15), who underwent contrast-enhanced abdominal CT between August 2013 and October 2017. CTTA evaluation included heterogeneity, intensity, average, deviation, skewness, entropy of co-occurrence, number non-uniformity (NGLDM) and entropy NGLDM. A greater than 50% reduction of spleen volume after chemotherapy was considered proof for splenic involvement. RESULTS: There were significant differences of splenic CTTA-values before and after treatment of patients with lymphoma, including mean of entropy(p < .001), uniformity of average(p < .001), uniformity of deviation(p = .002) and entropy of skewness(p < .001). Significant differences of splenic CTTA-values in subjects with lymphoma vs. healthy controls were found for mean intensity(p < .001), mean average(p < .001), and entropy of deviation(p < .001). No significant differences in splenic CTTA-values were found in subjects with lymphoma that reached complete remission vs. controls. Splenic CTTA values mean intensity(p = .002) and mean average(p = .004) were significantly different between subjects with untreated lymphoma and subjects with liver cirrhosis. At end-of-treatment all lymphomas reached complete remission. Entropy/uniformity of heterogeneity(p < .001), mean intensity(p = .007), mean average (p = .007), uniformity of average(p = .008) and mean/entropy/uniformity of skewness(p = .001) measured at this time differed significantly from baseline. CONCLUSIONS: CTTA features in subjects with splenomegaly due to lymphoma and liver cirrhosis differ significantly from those of healthy controls and can be also used for monitoring lymphoma treatment. Quantitative CTTA features may increase the accuracy of diagnosing causes of splenomegaly.

Chest CT texture analysis for response assessment in systemic sclerosis.

PURPOSE: To evaluate the role of CT-textural features for monitoring lung involvement in subjects with systemic sclerosis(SSc) undergoing autologous stem cell transplantation(SCT) by comparison with semi-quantitative chest-CT, pulmonary function tests(PFT) and clinical parameters (modified Rodnan skin score[mRSS]). METHODS: In a retrospective single centre analysis, we identified 23 consecutive subjects(11male) with SSc between 07/2005 and 11/2016 that underwent chest CTs before, 6 and 12 months post-SCT. Response to therapy was defined at 6 months after transplantation as stabilisation or improvement in FVC > 10% and DLCOSB > 10%. CT-texture analysis(CTTA) including mean, entropy and uniformity were calculated. RESULTS: PFT classified the subjects into responders(18/23;78%) and non-responders(5/23;22%). mRSS improved in responders from 28.46 ±â€¯9.53 to 15.70 ±â€¯10.07 6 months after auto-SCT(p = .001) whereas in non-responders no significant improvement was registered. Fibrosis score increased significantly(mean2.33 ±â€¯1.23 vs.1.41 ±â€¯0.78; p = .005) in non-responders after 6 and 12months. Significant lower mean intensity and entropy of skewness and higher uniformity of skewness was found in responders vs. non-responders at baseline. Significant changes in CTTA-parameters were found in both responders and non-responders at 6months and only in responders also at 12months post-SCT. CONCLUSIONS: Changes in CT-textural features after SCT are associated with visual CT evaluation of SSc-related lung abnormalities, but complementary provide information about therapy-induced, structural pulmonary changes.

Repeated surgeries in invasive lobular breast cancer with preoperative MRI: Role of additional carcinoma in situ and background parenchymal enhancement.

OBJECTIVES: Analysing the influence of additional carcinoma in situ (CIS) and background parenchymal enhancement (BPE) in preoperative MRI on repeated surgeries in patients with invasive lobular carcinoma (ILC) of the breast. METHODS: Retrospective analysis of 106 patients (mean age 58.6±9.9years) with 108 ILC. Preoperative tumour size as assessed by MRI, mammography and sonography was recorded and compared to histopathology. In contrast-enhanced MRI, the degree of BPE was categorised by two readers. The influence of additionally detected CIS and BPE on the rate of repeated surgeries was analysed. RESULTS: Additional CIS was present in 45.4% of the cases (49/108). The degree of BPE was minimal or mild in 80% of the cases and moderate or marked in 20% of the cases. In 17 cases (15.7%) at least one repeated surgery was performed. In n=15 of these cases, repeated surgery was performed after BCT (n=9 re-excisions, n=6 conversions to mastectomy), in n=2 cases after initial mastectomy. The initial surgical procedure (p=0.008) and additional CIS (p=0.046) significantly influenced the rate of repeated surgeries, while tumour size, patient age and BPE did not (p=ns). CONCLUSIONS: Additional CIS was associated with a higher rate of repeated surgeries, whereas BPE had no influence.

VEGFR-2 expression in HCC, dysplastic and regenerative liver nodules, and correlation with pre-biopsy Dynamic Contrast Enhanced CT.

PURPOSE: To evaluate whether VEGFR-2-expression in hepatocellular carcinoma (HCC), dysplastic (DLN) and regenerative liver nodules (RLN) correlates with pre-histology, in vivo Dynamic Contrast Enhanced-Computed Tomography (DCE-CT) data as VEGFR-2-expression affects prognosis and therapeutic options. MATERIALS AND METHODS: 34 patients (63.6±8.9years, 7 females) underwent liver biopsy or surgery due to suspected HCC or dysplastic nodules after DCE-CT between 2009 and 2015 with no previous chemo- or interventional therapy. Immunohistochemistry staining for VEGFR-2 was performed using Immunoreactive-Remmele-Stegner-Score (IRS) for quantification. A 128-row CT-scanner was used for DCE-CT with assessment of perfusion parameters blood flow (BF), blood volume (BV), arterial liver perfusion (ALP), portal venous perfusion (PVP), and hepatic perfusion index (HPI). RESULTS: Histology confirmed HCC (n=10), DLN (n=7) and RLN (n=34). Mean IRS for VEGFR-2 in HCCs was 9.1±3.0, 7.3±1.6 for DLN and 5.2±2.8 for RLN (p=0.0004 for HCC vs. RLN). Perfusion values varied significantly between all three groups for BF and HPI (p<0.001 and p<0.0001) and for BV in HCC vs. RLN (p<0.0001) and DLN vs. RLN (p=0.0019). Strong correlations between VEGFR-2-IRS and perfusion parameters were observed for BF in HCC (r=0.88, p<0.01) and HPI in HCC and DLN (r=0.85, p<0.04; r=0.9, p<0.01). CONCLUSION: Immunostaining revealed different VEGFR-2-expression levels in HCC, dysplastic and regenerative liver nodules. Perfusion markers blood flow, blood volume and hepatic perfusion index correlated well with VEGFR-2-immunostaining. This non-invasive discrimination between regenerative and dysplastic/HCC nodules might open new perspectives for diagnosis, therapy planning, and anti-VEGFR therapy monitoring.

Frequency Selective Non-Linear Blending to Improve Image Quality in Liver CT.

Purpose: To evaluate the effects of a new frequency selective non-linear blending (NLB) algorithm on the contrast resolution of liver CT with low intravascular concentration of iodine contrast. Materials and Methods: Our local ethics committee approved this retrospective study. The informed consent requirement was waived. CT exams of 25 patients (60 % female, mean age: 65 ±â€Š16 years of age) with late phase CT scans of the liver were included as a model for poor intrahepatic vascular contrast enhancement. Optimal post-processing settings to enhance the contrast of hepatic vessels were determined. Outcome variables included signal-to-noise (SNR) and contrast-to-noise ratios (CNR) of hepatic vessels and SNR of liver parenchyma of standard and post-processed images. Image quality was quantified by two independent readers using Likert scales. Results: The post-processing settings for the visualization of hepatic vasculature were optimal at a center of 115HU, delta of 25HU, and slope of 5. Image noise was statistically indifferent between standard and post-processed images. The CNR between the hepatic vasculature (HV) and liver parenchyma could be significantly increased for liver veins (CNRStandard 1.62 ±â€Š1.10, CNRNLB 3.6 ±â€Š2.94, p = 0.0002) and portal veins (CNRStandard 1.31 ±â€Š0.85, CNRNLB 2.42 ±â€Š3.03, p = 0.046). The SNR of liver parenchyma was significantly higher on post-processed images (SNRNLB 11.26 ±â€Š3.16, SNRStandard 8.85 ± 2.27, p = 0.008). The overall image quality and depiction of HV were significantly higher on post-processed images (NLBDHV: 4 [3 - 4.75], StandardDHV: 2 [1.3 - 2.5], p = < 0.0001; NLBIQ: 4 [4 - 4], StandardIQ: 2 [2 - 3], p = < 0.0001). Conclusion: The use of a frequency selective non-linear blending algorithm increases the contrast resolution of liver CT and can improve the visibility of the hepatic vasculature in the setting of a low contrast ratio between vessels and the parenchyma. Key Points: • Using the new frequency selective non-linear blending algorithm is feasible in contrast-enhanced liver CT.• Optimal post-processing settings make it possible to significantly increase the contrast resolution of liver CT without affecting image noise.• Especially in low contrast CT images, the novel algorithm is capable of significantly increasing image quality. Citation Format: • Bongers MN, Bier G, Kloth C et al. Frequency Selective Non-Linear Blending to Improve Image Quality in Liver CT. Fortschr Röntgenstr 2016; 188: 1163 - 1168.

Characterization of hepatocellular carcinoma (HCC) lesions using a novel CT-based volume perfusion (VPCT) technique.

OBJECTIVE: To characterize hepatocellular carcinoma (HCC) in terms of perfusion parameters using volume perfusion CT (VPCT) and two different calculation methods, compare their results, look for interobserver agreement of measurements and correlation between tumor arterialization and lesion size. MATERIAL AND METHODS: This study was part of a prospective monitoring study in patients with HCC undergoing TACE, which was approved by the local Institutional Review Board. 79 HCC-patients (mean age, 64.7) with liver cirrhosis were enrolled. VPCT was performed for 40s covering the involved liver (80 kV, 100/120 mAs) using 64 mm × 0.6 mm collimation, 26 consecutive volume measurements, 50 mL iodinated contrast IV and 5 mL/s flow rate. Mean/maximum blood flow (BF; ml/100mL/min), blood volume (BV) and k-trans were determined both with the maximum slope+Patlak vs. deconvolution method. Additionally, the portal venous liver perfusion (PVP), the arterial liver perfusion (ALP) and the hepatic perfusion index (HPI) were determined for each tumor including size measurements. Interobserver agreement for all perfusion parameters was calculated using intraclass correlation coefficients (ICC). RESULTS: The max. slope+Patlak method yielded: BFmean/max=37.8/57 mL/100g-tissue/', BVmean/max=9.8/11.1 mL/100g-tissue, k-trans-mean/max=34.4/44.5 mL/100g-tissue/'. For the deconvolution method BFmean/max, BVmean/max and, k-trans-mean/max were 68.3/106.1 mL/100g-tissue/', 12.6/15.5 mL/100g-tissue and 24/33.8 mL/100g-tissue/'. Mean ALP, PVP, HPI and size were 53.7 mL/100g-tissue/', 2.4 mL/100g-tissue/', 96.4 and 3.5 cm, respectively. Interobserver agreement measured with intraclass coefficient correlation (ICC) was very good for all perfusion parameters (≥ 0.99). Best correlation between calculation methods was achieved for measurements of BF, while BV and k-trans values were less correlated. There was no relationship between HPI and lesion size. CONCLUSION: VPCT can measure tumor volume perfusion non-invasively and enables quantification of the degree of HCC arterialization. Results are dependent on the technique used with best inter-method correlation for BF. Tumor HPI did not proved size-dependent.

Noninfectious Generalized Bronchiolitis in the Setting of Allogeneic Stem Cell Transplantation: A Potential Mimic of Lower Respiratory Tract Infection.

RATIONALE AND OBJECTIVES: To describe a little-known therapy-related small-airway phenomenon presumably caused by mucosal irritation in patients undergoing allogeneic stem cell transplantation (allo-SCT). MATERIALS AND METHODS: Retrospective database search at our institution identified 739 hematologic patients who underwent chemotherapy + allo-SCT between September 2004 and March 2014. After infectious pulmonary complications were excluded, 75 patients (female = 24; male = 51; median age = 47 years) with signs of generalized bronchiolitis (GB) on chest high-resolution computed tomography were identified. Computed tomography (CT) was performed proximate to chemotherapy onset; 92% had follow-up CT (mean, 1.9 weeks). The presence of centrilobular nodules, bronchial wall thickening (BWT), tree-in-bud (distributed diffuse vs. focal), ground-glass opacity, airspace opacification, luminal impactions, and air trapping was correlated with occurrence and duration of oral mucositis and therapy characteristics. Intensity of tree-in-bud and centrilobular nodules was graded absent (grade = 0), moderate (grade = 1), or marked (grade = 2). RESULTS: Overall incidence of GB among allo-SCT patients was 10.14%. GB was diagnosed at the time point of transplantation with a mean duration of CT findings of 4 weeks (±2.7). Tree-in-bud (17% [grade 2] and 83% [grade 1]) and BWT were present in 100% of the patients. Centrilobular nodules diffusely distributed were found in 45.5% of patients (20% [grade 2], 24% [grade 1], and 56% [none]). Air trapping and mosaic pattern were found in 13% and 16% of the patients, respectively. Resolution of GB was spontaneous. GB and its severity correlated with the temporal course and grade of oral mucositis; frequency and degree were not significantly influenced by the chemotherapy regimen. The incidence of GB in high-resolution computed tomography was statistically and significantly higher in patients with oral mucositis (P < 0.035). CONCLUSIONS: GB is frequent during chemotherapy for allo-SCT and is characterized by an even distribution of tree-in-bud, BWT, centrilobular nodules, mild clinical symptoms, and spontaneous resolution.

Comparison of chest-CT findings of Influenza virus-associated pneumonia in immunocompetent vs. immunocompromised patients.

PURPOSE: To retrospectively compare CT-patterns of pulmonary infiltration caused by different Influenza virus types and subtypes in immunocompetent and immunocompromised patients for possible discrimination. MATERIALS AND METHODS: Retrospective database search at our institution yielded 237 patients who were tested positive for Influenza virus type A or type B by bronchoalveolar lavage between January 2009 and April 2014. Fifty-six of these patients (female 26; male 30; median age 55.8 y, range 17-86 y; SD ± 14.4 y) underwent chest-HRCT due to a more severe clinical course of pulmonary infection. We registered all CT-findings compatible with pulmonary infection classifying them as airway predominant (tree-in-bud, centrilobular nodules, bronchial wall thickening ± peribronchial ground-glass opacity and consolidation) vs. interstitial-parenchymal predominant (bilateral, symmetrical GGO, consolidation, crazy paving and/or interlobular septal thickening). Twenty-six patients (46.4%) had follow-up CT-studies (0.78 mean, SD ± 5.8 scans). RESULTS: Thirty-six patients were immunocompromised (group I) whereas 20 patients were immunocompetent (group II). An airway-centric pattern of infection was found in 15 patients (group I) and 14 patients (group II) whereas an interstitial-parenchymal predominant pattern was found in 14 patients (group I) and 2 patients (group II). Eleven patients had a mixed pattern with no clear assignment to one group. At FU, 12 patients from group I and 3 from group II showed transitional infiltration patterns: in 10 patients from interstitial-parenchymal into airway predominant pattern and in five patients from airway predominant into interstitial-parenchymal. No significant differences in the pattern of pulmonary infection were found between different types and subtypes of Influenza viruses. CONCLUSION: Patterns of pulmonary infiltration caused by Influenza viruses do not significantly differ between immunocompetent and immunocompromised patients or between different types and subtypes of Influenza virus. One possible explanation for this could be the temporarily interchangeable character of pulmonary infiltration in this infection.