Free-breathing quantification of regional ventilation derived by phase-resolved functional lung (PREFUL) MRI.

PURPOSE: To test the feasibility of regional fully quantitative ventilation measurement in free breathing derived by phase-resolved functional lung (PREFUL) MRI in the supine and prone positions. In addition, the influence of T2 * relaxation time on ventilation quantification is assessed. METHODS: Twelve healthy volunteers underwent functional MRI at 1.5 T using a 2D triple-echo spoiled gradient echo sequence allowing for quantitative measurement of T2 * relaxation time. Minute ventilation (ΔV) was quantified by conventional fractional ventilation (FV) and the newly introduced regional ventilation (VR), which corrects volume errors due to image registration. ΔVFV versus ΔVVR and ΔVVR versus ΔVVR with T2 * correction were compared using Bland-Altman plots and correlation analysis. The repeatability and physiological plausibility of all measurements were tested in the supine and prone positions. RESULTS: On global and regional scales a strong correlation was observed between ΔVFV versus ΔVVR and ΔVVR versus ΔVVRT2* (r > 0.93); however, regional Bland-Altman analysis showed systematic differences (p < 0.0001). Unlike ΔVVRT2* , ΔVVR and ΔVFV showed expected physiologic anterior-posterior gradients, which decreased in the supine but not in the prone position at second measurement during 3 min in the same position. For all quantification methods a moderate repeatability (coefficient of variation <20%) of ventilation was found. CONCLUSION: A fully quantified regional ventilation measurement using ΔVVR in free breathing is feasible and shows physiologically plausible results. In contrast to conventional ΔVFV, volume errors due to image registration are eliminated with the ΔVVR approach. However, correction for the T2 * effect remains challenging.

Evaluation of a newly developed 2D parametric parenchymal blood flow technique with an automated vessel suppression algorithm in patients with chronic thromboembolic pulmonary hypertension undergoing balloon pulmonary angioplasty.

AIM: To evaluate the feasibility of two-dimensional parametric parenchymal blood flow (2D-PPBF) to quantify perfusion changes in the lung parenchyma following balloon pulmonary angioplasty (BPA) for treatment of chronic thromboembolic pulmonary hypertension. MATERIALS AND METHODS: Overall, 35 consecutive interventions in 18 patients with 98 treated pulmonary arteries were included. To quantify changes in pulmonary blood flow using 2D-PPBF, the acquired digital subtraction angiography (DSA) series were post-processed using dedicated software. A reference region of interest (ROI; arterial inflow) in the treated pulmonary artery and a distal target ROI, including the whole lung parenchyma distal to the targeted stenosis, were placed in corresponding areas on DSA pre- and post-BPA. Half-peak density (HPD), wash-in rate (WIR), arrival to peak (AP), area under the curve (AUC), and mean transit time (MTT) were assessed. The ratios of the reference ROI to the target ROI (HPDparenchyma/HPDinflow, WIRparenchyma/WIRinflow; APparenchyma/APinflow, AUCparenchyma/AUCinflow, MTTparenchyma/MTTinflow) were calculated. The relative differences of the 2D-PPBF parameters were correlated to changes in the pulmonary flow grade score. RESULTS: The pulmonary flow grade score improved significantly after BPA (1 versus 3; p<0.0001). Likewise, the mean HPDparenchyma/HPDinflow (-10.2%; p<0.0001), APparenchyma/APinflow (-24.4%; p=0.0007), and MTTparenchyma/MTTinflow (-3.5%; p=0.0449) decreased significantly, whereas WIRparenchyma/WIRinflow (+82.4%) and AUCparenchyma/AUCinflow (+58.6%) showed a significant increase (p<0.0001). Furthermore, a significant correlation between changes of the pulmonary flow grade score and changes of HPDparenchyma/HPDinflow (ρ=-0.21, p=0.04), WIRparenchyma/WIRinflow (ρ=0.43, p<0.0001), APparenchyma/APinflow (ρ=-0.22, p=0.03), AUCparenchyma/AUCinflow (ρ=0.48, p<0.0001), and MTTparenchyma/MTTinflow (ρ=-0.39, p<0.0001) could be observed. CONCLUSION: The 2D-PPBF technique is feasible for the quantification of perfusion changes following BPA and has the potential to improve monitoring of BPA.

Detection of chronic lung allograft dysfunction using ventilation-weighted Fourier decomposition MRI.

Chronic lung allograft dysfunction (CLAD) remains the leading cause of morbidity and mortality after lung transplantation. Diagnosis requires spirometric change, which becomes increasingly difficult with advancing CLAD. Fourier decomposition magnetic resonance imaging (FD-MRI) permits acquisition of ventilated-weighted images during free-breathing. This study evaluates FD-MRI in detecting CLAD in selected patients after bilateral lung transplantation (DLTx). DLTx recipients demonstrating CLAD at various stages participated. Radiologists remained blinded to clinical status until completion of image analysis. Image acquisition used a 1.5-T MR scanner using a spoiled gradient echo sequence. After FD processing and regional fractional ventilation (RFV) quantification, the volume defect percentage at 2 thresholds (VDP1,2 ), median lung RFV and quartile coefficient of dispersion (QCD) were calculated. Sixty-two patients participated. CLAD was present in 29/62 (47%) patients, of whom 17/62 (27%) had forced expiratory volume in 1 second ≤65% at image acquisition. VDP1 was higher among these participants compared to other groups (P < .001). Increased VDP1 was associated with subsequent graft loss, with values >2% showing reduced survival, independent of degree of graft dysfunction (P = .005). VDP2 discriminated between presence or absence of CLAD (area under the curve = 0.71; P = .03). QCD increased significantly with advancing disease (P < .001). In conclusion, FD-MRI-derived parameters demonstrate potential in quantitative CLAD diagnosis and assessment after DLTx.

[Quantification of Ventilation, Inflammation, Perfusion and Structure (VIPS)]. / Quantifizierung von Ventilation, Inflammation, Perfusion und Struktur (VIPS).

Technical innovation in pulmonary imaging during the recent years has led to a shift from morphological description of pulmonary pathologies to regional quantification of pulmonary function. This article summarizes current clinical standards in pulmonary imaging and introduces the reader to new innovative techniques of functional lung imaging. In the context of actual clinical studies for COPD, asthma, pulmonary hypertension and cystic fibrosis the application of quantitative imaging methods using computed tomography and magnetic resonance imaging is demonstrated and possible future applications are discussed.

Interleukin-1 from epithelial cells fosters T cell-dependent skin inflammation.

BACKGROUND: Chronic inflammatory skin diseases such as atopic dermatitis and psoriasis are characterized by the infiltration of lymphocytes into the epidermal compartment. Several studies point to an active role of skin epithelial cells in the pathophysiology of such diseases. OBJECTIVES: In this study we addressed the regulatory function of primary human keratinocytes in the interaction with autologous T cells and monocytes. METHODS: We used a human coculture model with keratinocytes grown from epidermal stem cells of the outer root sheath of human hair follicles and autologous T cells. RESULTS: In our coculture system we observed a high production of interferon (IFN)-γ, but not Th2 cytokines, in the presence of superantigen or antigen-pulsed autologous monocytes. Critical parameters for this effect were: (i) T-cell receptor activation, (ii) an intercellular adhesion molecule-1/lymphocyte function-associated antigen (LFA)-1-dependent interaction between keratinocytes and T cells, and (iii) secretion of interleukin (IL)-1ß. Remarkably, in the presence of activated T cells, epithelial cells seemed to be a more significant source of IL-1ß than monocytes. Application of the LFA-1 blocker efalizumab or IL-1 receptor antagonist anakinra enabled us to suppress completely the production of IFN-γ by T cells in the coculture. CONCLUSIONS: IL-1 secretion and the physical contact between keratinocytes and activated, infiltrating T cells may be central for the development of chronic inflammatory skin conditions.

Fat macroglobulemia caused by fractures or total hip replacement.

The numbers of fat macroglobules in peripheral venous blood were recorded for 136 prospectively studied patients with fractures of the pelvis, femur, or tibia. Groups of healthy volunteers and patients undergoing total hip replacement or abdominal surgery served as controls. The highest incidence of fat macroglobulemia occurred in patients with fractures of the femur who also had these clinical signs: petechiae, hypoxia, and depression of the central nervous system. The peak incidence occurred within the first eight hours after fracture. The over-all incidence of fat macroglobulemia in the other surgical patients was roughly equivalent to that in the fracture patients.

[The surgical treatment of distal humeral fractures]. / Die operative behandlung der distalen Humerusfrakturen

The treatment of this kind of fractures, especially involving the elbow-joint still is difficult and needs a thoroughly preoperative planning as well as an exact operative technique. Even in spite of optimal therapy failures are not avoidable in some cases, as our statistic shows.

Squamous-cell carcinoma of the nail bed.

Carcinoma of the nail bed is rare. Two patients with squamous-cell carcinoma are presented. We recommend biopsies for recalcitrant lesions of the nail bed and treatment by amputation or Mohs' surgery if carcinoma is found.

[Infected tibial shaft pseudarthroses, treatment and results (author's transl)]. / Infizierte Tibiaschaftpseudarthrosen, Behandlung und Ergebnisse

In a follow up study of 47 patients with infected pseudarthrosis of tibia therapy and results are declared. The most important matter in therapy is the osteosyntesis with compression of the pseudarthrosis. In the majority of cases externe stabilisation is used; seldom compression plate or medullary nailing is indicated. Such cases require much experience in the therapy of bone infection, although if the stabilisation with the fibula is tryed. Flush drainage, suction drainage, antibiotic therapy and cancellous bone grafting are necessary for localisation and decreasing of infection and for induction and acceleration of bone union. In some cases amutation can't be prevented. With correct judgement and consequent treatment in the majority of cases bone union will be obtained.