[Pulmonary manifestations in collagen vascular diseases]. / Pulmonale Manifestationen bei Kollagenosen.

CLINICAL/METHODICAL ISSUE: Pulmonary complications are frequent in patients with collagen vascular diseases (CVD). Frequent causes are a direct manifestation of the underlying disease, side effects of specific medications and lung infections. STANDARD RADIOLOGICAL METHODS: The standard radiological procedure for the work-up of pulmonary pathologies in patients with CVD is multidetector computed tomography (MDCT) with thin-slice high-resolution reconstruction. PERFORMANCE: The accuracy of thin-slice CT for the identification of particular disease patterns is very high. The pattern of usual interstitial pneumonia (UIP) representing the direct pulmonary manifestation of rheumatoid arthritis (RA) can be identified with a sensitivity of 45 % and a specificity of 96 %. ACHIEVEMENTS: Both direct pulmonary manifestations, drug-induced toxicity and certain infections can have a similar appearance in thin-slice MDCT in various forms of CVD. Knowledge of the patterns and causes contributes to the diagnostic certainty. PRACTICAL RECOMMENDATIONS: At first diagnosis of a CVD and associated pulmonary symptoms thin-slice MDCT is recommended. Clinical, lung function and imaging follow-up examinations should be performed every 6-12 months depending on the results of the MDCT. In every case the individual CT morphological patterns of pulmonary involvement must be identified. The combination of information on the anamnesis, clinical and imaging results is a prerequisite for an appropriate disease management.

Reduction in growth threshold for pulmonary metastases: an opportunity for volumetry and its impact on treatment decisions.

OBJECTIVES: This study compares tumour response assessment by automated CT volumetry and standard manual measurements regarding the impact on treatment decisions and patient outcome. METHODS: 58 consecutive patients with 203 pulmonary metastases undergoing baseline and follow-up multirow detector CT (MDCT) under chemotherapy were assessed for response to chemotherapy. Tumour burden of pulmonary target lesions was quantified in three ways: (1) following response evaluation criteria in solid tumours (RECIST); (2) following the volume equivalents of RECIST (i.e. with a threshold of -65/+73%); and (3) using calculated limits for stable disease (SD). For volumetry, calculated limits had been set at ±38% prior to the study by repeated quantification of nodules scanned twice. Results were compared using non-weighted κ-values and were evaluated for their impact on treatment decisions and patient outcome. RESULTS: In 15 (17%) of the 58 patients, the results of response assessment were inconsistent with 1 of the 3 methods, which would have had an impact on treatment decisions in 8 (13%). Patient outcome regarding therapy response could be verified in 5 (33%) of the 15 patients with inconsistent measurement results and was consistent with both RECIST and volumetry in 1, with calculated limits in 3 and with none in 1. Diagnosis as to the overall response was consistent with RECIST in six patients, with volumetry in six and with calculated limits in eight cases. There is an impact of different methods for therapy response assessment on treatment decisions. CONCLUSION: A reduction of threshold for SD to ±30-40% of volume change seems reasonable when using volumetry.

T2 and DWI in pilocytic and pilomyxoid astrocytoma with pathologic correlation.

OBJECTIVE: To quantify and compare T2 signal and apparent diffusion coefficient (ADC) in pilocytic and pilomyxoid astrocytoma (PA and PMA) and correlate results with myxoid content. METHODS: Echo-planar diffusion weighted images (DWI) and standard magnetic resonance imaging (MRI) findings were reviewed retrospectively in patients with PA (n=34) and PMA (n=8). Regions of interest (ROIs) were drawn on ADC maps within tumor parts with lowest ADC values. Apparent diffusion coefficient values in tumor were normalized to those in cerebrospinal fluid (ADC/CSF). The ratio of T2 signal intensity in solid tumor parts to CSF (T2/CSF) was registered. Myxoid matrix was histologically quantified retrospectively in 8 PMAs and 17 PAs and correlated with imaging findings. RESULTS: Mean ADC/CSF for PA and PMA was 0.53±0.10 and 0.69±0.10 (p<0.01). Mean T2/CSF for PA and PMA was 0.78±0.19 and 0.93±0.09 (p<0.01). Mean proportion of myxoid tumor matrix in PA was 50% (range, 10-100%) and 93% (range, 90-100%) in PMA (p=0.004). Eight patients (32%; all PA) had less than 50% myxoid content and 17 (68%; 8 PA; 9 PMA) had more. There was positive correlation of ADC/CSF, T2/CSF and ADC (r2=0.61, 0.65 and 0.60 respectively) and significant difference between the groups with more and less than 50% myxoid content (p=0.01 for ADC/CSF and T2/CSF and p=0.02 for ADC). CONCLUSIONS: General imaging features of PA and PMA are non-specific, ADC values and T2 signal intensity are generally higher in the latter, reflecting the proportion of myxoid matrix in these tumors.

HRCT-features of Pneumocystis jiroveci pneumonia and their evolution before and after treatment in non-HIV immunocompromised patients.

OBJECTIVE: This study retrospectively analyzes the characteristics and kinetics of pulmonary changes in Pneumocystis jiroveci pneumonia (PJP) before and after treatment as depicted by thin-section-CT in HIV-negative patients. MATERIALS AND METHODS: Serial CT scans of 84 consecutive HIV-negative PJP patients were reviewed retrospectively encompassing a median follow-up of 76 (range, 37-506) days. Along with underlying disease and time span between the onset of symptoms and specific antimicrobial therapy, early and late pulmonary CT-findings were evaluated. RESULTS: Imaging findings at initial diagnosis differed from those in the posttherapeutic setting. In the acute (initial) PJP-phase, most frequent finding was symmetric, apically distributed ground glass opacities (GGO) with peripheral sparing 43% (n = 36). These initial changes resolved up to 1st follow-up-examination in 57% (n = 48), and finally in all except for two patients after a median period of 13 (mean 26, range 1-58) days following application of specific therapy. In 42% (n = 35) architectural distortions occurred, but they resolved after a median period of 27 (mean 60, range 11-302) days. Only in 9 patients, complete resolution could not be documented. Significant correlations of the underlying disease or the time span between the onset of symptoms and specific antibiotic therapy and morphologic kinetic could not be found. CONCLUSION: Thin-section CT-findings of PJP usually resolve soon after onset of specific therapy. Postinfectious fibrosis rarely occurs following PJP in HIV-negative patients.

CT features of neutropenic enterocolitis in adult patients with hematological diseases undergoing chemotherapy.

PURPOSE: This study investigates the features of neutropenic enterocolitis (NE) in adults. MATERIALS AND METHODS: Chart and radiology report reviews were used to identify neutropenic patients with hematological diseases undergoing chemotherapy, who had CT scans for the clarification of abdominal symptoms between October 2003 and October 2009. Patients with any cause for enteritis other than NE were excluded. The scans were analyzed with respect to imaging features and location. Morphological findings were correlated with clinical data. RESULTS: Thirty-one patients with NE (median age 46 years; range 20 - 75) could be identified. Wall thickening and hyperemia could be found in all bowel segments from jejunum to rectum. The right hemicolon was the most frequent location in 19 patients (61%). Involvement was generalized in 6 patients (19%) and segmental in 25 cases (81%). The longer the duration of neutropenia, the more likely generalized involvement of the bowel was. In 8 patients who underwent CT follow-up, the appearance of bowel segments had completely (n = 5) or partially (n = 3) returned to normal at the latest 14 days after the initial diagnosis. Eight patients (26%) died 1 - 78 days after NE, 7 of who had previously recovered from NE. CONCLUSION: CT findings are useful for the diagnosis of NE and should be considered even in the presence of isolated small bowel involvement. The terms NE and typhlitis should thus no longer be used synonymously.

[Automated pulmonary nodule volumetry with an optimized algorithm. Accuracy at different slice thicknesses compared to unidimensional and bidimensional measurements]. / Lungenrundherdvolumetrie mit optimiertem Segmentierungsalgorithmus. Genauigkeit bei verschiedenen Schichtdicken verglichen mit ein- und zweidimensionalen Messungen.

PURPOSE: This in-vivo study quantifies the accuracy of automated pulmonary nodule volumetry in reconstructions with different slice thicknesses (ST) of clinical routine CT scans. The accuracy of volumetry is compared to that of unidimensional and bidimensional measurements. MATERIALS AND METHODS: 28 patients underwent contrast enhanced 64-row CT scans of the chest and abdomen obtained in the clinical routine. All scans were reconstructed with 1, 3, and 5 mm ST. Volume, maximum axial diameter, and areas following the guidelines of Response Evaluation Criteria in Solid Tumors (RECIST) and the World Health Organization (WHO) were measured in all 101 lesions located in the overlap region of both scans using the new software tool OncoTreat (MeVis, Deutschland). The accuracy of quantifications in both scans was evaluated using the Bland and Altmann method. The reproducibility of measurements in dependence on the ST was compared using the likelihood ratio Chi-squared test. RESULTS: A total of 101 nodules were identified in all patients. Segmentation was considered successful in 88.1% of the cases without local manual correction which was deliberately not employed in this study. For 80 nodules all 6 measurements were successful. These were statistically evaluated. The volumes were in the range 0.1 to 15.6 ml. Of all 80 lesions, 34 (42%) had direct contact to the pleura parietalis oder diaphragmalis and were termed parapleural, 32 (40%) were paravascular, 7 (9%) both parapleural and paravascular, the remaining 21 (27%) were free standing in the lung. The trueness differed significantly (Chi-square 7.22, p value 0.027) and was best with an ST of 3 mm and worst at 5 mm. Differences in precision were not significant (Chi-square 5.20, p value 0.074). The limits of agreement for an ST of 3 mm were +/- 17.5 % of the mean volume for volumetry, for maximum diameters +/- 1.3 mm, and +/- 31.8 % for the calculated areas. CONCLUSION: Automated volumetry of pulmonary nodules using OncoTREAT has a conformable accuracy for an ST of 3 mm and 1 mm and is even more accurate for an ST of 5 mm than unidimensional or bidimensional measurements. A difference of more than +/- 17.5% occurs with a probability of less than 5% at an ST of 3 mm.

Differences and similarities of cytomegalovirus and pneumocystis pneumonia in HIV-negative immunocompromised patients thin section CT morphology in the early phase of the disease.

The purpose of this study was to assess CT morphology of pneumocystis pneumonia (PcP) and cytomegalovirus (CMV) pneumonia for specific characteristic features, similarities as well as differences, which might contribute to an early diagnosis and, therefore, influence patient management 58 patients were included, 31 with CMV pneumonia and 27 with PcP. All patients with CMV pneumonia had underlying haematological malignancies (n = 31) mainly treated by haematopoietic cell transplantation (HCT) (n = 26). Patients with PcP had haematological malignancies (n = 17) treated by HCT in 6, solid tumours (n = 5) and corticosteroid therapy (n = 5). Thin section CTs were analysed retrospectively by two radiologists. 18 CT morphological criteria were evaluated for presence or absence. Significance was calculated by chi2 test. Interobserver correlation was tested by kappa-statistic (K) Only 5 of the 18 features were found to have significantly different frequencies in the two entities. Apical distribution (p<0.01), mosaic pattern (p<0.01) and homogeneous structure of ground-glass opacities (GGO) (p<0.05) were found more frequently in PcP (each K: 0.7-0.9), whereas small nodules or unsharp demarcation of GGO and consolidation were typical of CMV pneumonia (p<0.05). Peripheral sparing, consolidation and septal thickening inter alia were found equally in both groups In conclusion analysis of craniocaudal distribution, demarcation and structure of infiltrates may be helpful in prioritizing differential diagnosis of CMV pneumonia or PcP. However, some features thought typical for one or the other entities appear with similar frequency in both groups in HIV-negative patients.

[Evaluation of different breathing and contrast-protocols concerning quality and alignment in 18F-FDG PET/CT]. / Vergleich verschiedener Atem- und Kontrastmittelprotokolle bezüglich Bild- und Koregistrierungsqualität bei 18F-FDG-PET/CT-Untersuchungen.

PURPOSE: The purpose of this study was to establish a reliable and simple parameter for alignment evaluation and the evaluation and optimization of state-of-the-art contrast-enhanced examination protocols for (18)F FDG-PET/CT. MATERIALS AND METHODS: 44 consecutive patients were referred to 4 examination protocols. Group A and B underwent single-phase, contrast-enhanced CT (90 s delay) performed either during free shallow breathing (FA; group A) or normal expiration (NormExp; group B). Groups C and D underwent arterial and portal venous multiphase examinations performed during FA (group C) or during NormExp (group D) followed by a low-dose CT scan for attenuation correction. Organ displacement in the cranio-caudal direction was correlated with a 3D-vectorial shift. For alignment evaluation discrepancies with respect to size and liver location, the spleen and kidneys were calculated. Additionally, the groups were compared with regard to the presence of CT artifacts. RESULTS: Cranio-caudal organ shift and 3D-vectorial shift showed a high correlation (r > 0.8). Single-phase CT scans performed during NormExp yielded better image quality (p < 0.001) and alignment (p < 0.01 for liver, spleen and right kidney) than those performed during FA. Differences in organ size did not differ during FA and NormExp. Depending on the evaluated organ, breathing and contrast protocol misalignment was in the cranio-caudal direction 0-27 mm (mean: 6.8; standard deviation: +/- 4.9) in multiphase CT compared to 0 - 11 mm (mean: 4.5 +/- 2.3) in single-phase examinations. CONCLUSION: 1. Organ shift in the cranio-caudal direction is a good and simple parameter for alignment evaluation. 2. Alignment and CT quality are best in expiration protocols. 3. Despite comparatively low alignment quality, integrated multiphase CT examinations show acceptable quality and alignment.

Unusual distribution of red marrow mimicking chloroma in a patient with acute myelogenous leukemia.

We present a case of unusual distribution of red marrow in a patient with extramedullary acute myelogenous leukemia (AML). In adults, hematopoietic marrow is usually located in the axial skeleton and the proximal aspects of the limbs, except for the epiphyses. Nodular islets of red marrow located in the epiphyseal and distal parts of the limbs may mimic tumoral infiltration and be mistaken for chloroma in a patient with AML.

The vascular component of proliferative vitreoretinopathy membranes: an immunohistochemical and ultrastructural study.

BACKGROUND: The basic cellular components of proliferative vitreoretinopathy (PVR) membranes are well studied. Endothelial cells have also been documented. The importance of the vascular element in PVR has received little attention, as vascular components are clinically inapparent. The aim of this study was to obtain a better characterization and quantification of occurrence of the vascular component. METHODS: Serial sections of surgically excised PVR membranes were examined with Lectin histochemistry (25 membranes with ulex europaeus agglutinin I [UEA I] and rhicinus communis agglutinin I [RCA I]), immunohistochemistry for von Willebrand factor (31 membranes), and electron microscopy. RESULTS: Vascular endothelial cells were identified by visualization of UEA I and RCA I binding sites or by marking for von Willebrand factor. A total of 28.6% of the PVR membranes showed a vascular component. Vascular components consisted mostly of capillary-sized vessels; larger vessels were rarely found. Ultrastructurally, most vascular elements were found to be capillaries of the nonfenestrated type. Membranes from eyes that underwent PVR surgery with silicone oil tamponade showed vascular components less frequently (18.5%) than did membranes from eyes without silicone oil (43.8%).

[Imaging of laser thermokeratoplasty lesions by optical low coherence tomography and polarization microscopy after Sirius Red staining]. / Darstellung von LTK-Läsionen durch optische Kurzkohärenztomographie (OCT) und Polarisationsmikroskopie nach Sirius-Rot-Färbung.

BACKGROUND: Information on the extent and degree of the thermal effect produced is of great importance for control of the laser dosage in laser thermokeratoplasty (LTK) and for postoperative follow-up. We investigated on acute LTK effects which information images obtained by optical low coherence tomography (OCT) offer compared to those obtained by polarization microscopy. METHODS: Porcine eyes were irradiated through a 400 microns quartz fiber using light from a laser diode emitting up to 300 mW at a wavelength of 1.86 microns. Thermal lesions of varying strength were scanned using an experimental OCT device with about 25 microns lateral and 20 microns axial resolution. Histologic evaluation of the scanned areas was done by polarization microscopy after Sirlus-Red staining, and similar lesions were also analyzed by TEM. RESULTS: Both methods differentiated three damage zones a transition zone, a zone of moderate coagulation, and a central zone of strong coagulation. In the transition zone, increased birefringence was seen in polarization microscopy, which correlated with increased light scattering seen in the OCT images. In the moderately coagulated zone, a decrease in birefringence was associated with an even stronger increase of the OCT signal. In the central zone, a loss of the fibrillar tissue structure was observed, which led to a complete loss of birefringence and a strong reduction of the OCT signal. CONCLUSIONS: Although OCT does not provide the detailed information on thermal changes of tissue seen by the histologic method, it offers information on the extent and degree of tissue changes without preparation artifacts and provides a non-invasive method of immediate and follow-up control of LTK lesions. A quantitative analysis of changes in corneal thickness and curvature is much simpler than by a slit lamp. Time-resolved measurements of corneal light scattering may be used for on-line control of the laser-light dosage during LTK.

Histologic analysis of thermal effects of laser thermokeratoplasty and corneal ablation using Sirius-red polarization microscopy.

PURPOSE: To evaluate how well several histologic techniques differentiate degrees of thermally induced changes in corneal tissue after laser thermokeratoplasty (LTK) or corneal ablation. SETTING: Medical Laser Center Lübeck, Germany. METHODS: Corneas of freshly enucleated porcine eyes were treated with a continuous wave laser diode (1.86 microns) and a pulsed chromium-thulium-holmium: YAG laser (2.1 microns) to produce LTK lesions or ablated with a Q-switched and a free-running chromium-erbium: YSGG laser (2.70 microns), a free-running erbium: YAG laser (2.94 microns), and an argon-fluoride excimer laser (193 nm). The lesions were evaluated by light microscopy (LM) (hematoxylin and eosin, Azan, van Gieson's, and Masson-Goldner's trichrome stains), transmission electron microscopy (TEM), and polarization microscopy after Sirius-red staining. Sirius-red, a strongly elongated, birefringent molecule binding parallel to collagen molecules, was used to enhance corneal birefringence. RESULTS: With routine LM, it was difficult to discriminate the degrees of thermal alterations in LTK lesions. Combined Sirius-red staining and polarization microscopy distinguished between a strongly coagulated central zone and the transition zone to normal tissue. Sirius-red uptake was increased in both zones, reflecting the availability of new binding sites. The central zone appeared darker under polarization than normal collagen because of a loss of birefringence. Intrinsic birefringence was greatly reduced; however, form birefringence partly remained as long as some collagen fibrils were intact. In the center of very strong lesions, where the collagen was hyalinized, birefringence was completely lost because of the complete disintegration of the fibrillar structure, which was visible under TEM. The transition zone toward normal cornea showed increased birefringence because the natural birefringence was largely preserved and enhanced by the increased Sirius-red uptake. Mechanical stretching between neighboring LTK lesions was manifested by increased birefringence. CONCLUSION: Sirius red offered an improved and simple histologic method for analyzing thermal collagen changes. It may contribute to a better understanding of the working mechanisms of LTK and improve analysis of thermal effects in corneal ablation.

Ultrastructural features of a solitary vitreous cyst.

BACKGROUND: Vitreous cysts are rare, and their origin and morphologic features unclear. The authors present ultrastructural observations made in a case of a 47-year-old woman who, after undergoing retinal detachment surgery on several occasions, developed disturbing vitreous opacities and a solitary cystic structure in the anterior vitreous cavity. METHODS: Clinical and intraoperative biomicroscopy and histologic examination by light microscopy and transmission electron microscopy were performed. RESULTS: The cystic structure was attached at its posterior aspect to a vitreous membrane and enclosed within a vitreous body lacuna. It had an oval form with a smooth surface and was translucent. Histology showed the cyst wall to consist of retinal tissue with gliotic changes that had placed itself within the vitreous. CONCLUSION: The morphologic studies do not rule out the possibility of a congenital cyst. However, the authors presume that in association with the retinal detachment or the operations, a displacement of retinal tissue into the vitreous body occurred from which the cyst developed.

[Case study of a solitary vitreous body cyst]. / Fallstudie einer solitären Glaskörperzyste.

Vitreous cysts are rare and their origin unclear. We present a case of a 47-year-old woman who, after undergoing retinal detachment surgery on several occasions, developed disturbing vitreous opacities with which she presented for possible vitrectomy. Besides the typical postoperative vitreous condensations and opacifications, a solitary spherical cystic structure was present in the anterior vitreous cavity. The cystic structure was attached at its posterior aspect onto a vitreous membrane and was otherwise floating within a vitreous body lacuna. The vitreous opacities and the cyst were removed by performing a pars plana vitrectomy. The patient's visual acuity improved from 0.5 to 0.7. We presume that the cyst was acquired in association with the retinal detachment or the operations.

Intraocular photodisruption with picosecond and nanosecond laser pulses: tissue effects in cornea, lens, and retina.

PURPOSE: Nd:YAG laser photodisruption with nanosecond (ns) pulses in the millijoule range is an established tool for intraocular surgery. This study investigates tissue effects in cornea, lens, and retina to assess whether picosecond (ps) pulses with energies in the microjoule range can increase the surgical precision, reduce collateral damage, and allow applications requiring more localized tissue effects than can be achieved with ns pulses. METHODS: Both ps and ns Nd:YAG laser effects on Descemet's membrane, in the corneal stroma, in the lens, and at the retina were investigated in vitro in bovine and sheep eyes and in cataractous human lens nuclei. For each tissue, the optical breakdown threshold was determined. The morphology of the tissue effects and the damage range of the laser pulses were examined by light and scanning electron microscopy. The cavitation bubble dynamics during the formation of corneal intrastromal laser effects were documented by time-resolved photography. RESULTS: The optical breakdown threshold for ps pulses in clear cornea, lens, and vitreous is, on average, 12 times lower than that for ns pulses. In cataractous lens nuclei, it is lower by a factor of 7. Using ps pulses, Descemet's membrane could be dissected with fewer disruptive side effects than with ns pulses, whereby the damage range decreased by a factor of 3. The range for retinal damage was only 0.5 mm when 200 microJ ps pulses were focused into the vitreous. Picosecond pulses could be used for corneal intrastromal tissue evaporation without damaging the corneal epithelium or endothelium, when the pulses were applied in the anterior part of the stroma. The range for endothelial damage was 150 microns at 80 microJ pulse energy. Intrastromal corneal refractive surgery is compromised by the laser-induced cavitation effects. Tissue displacement during bubble expansion is more pronounced than tissue evaporation, and irregular bubble formation creates difficulties in producing predictable refractive changes. CONCLUSIONS: The use of ps pulses improves the precision of intraocular Nd:YAG laser surgery and diminishes unwanted disruptive side effects, thereby widening the field of potential applications. Promising fields for further studies are intrastromal corneal refractive surgery, cataract fragmentation, membrane cutting, and vitreolysis close to the retina.

Lens refilling and endocapsular polymerization of an injectable intraocular lens: in vitro and in vivo study of potential risks and benefits.

Endocapsular cataract removal and injection of a liquid artificial lens has several advantages, including restitution of accommodation, small corneoscleral incision, a more physiological position of the intraocular lens, and a reduced rate of secondary opacification. Our technique consists of bimanual phacofragmentation followed by injection of a fluid monomeric material that can be polymerized inside the capsular bag by short light exposure. Our study assessed the potential risks of the technique (e.g., heat damage to ocular tissue, light damage to the retina) and investigated the technique in vivo. We performed in vitro experiments on porcine cadaver eyes and an in vivo study on 15 rabbits. After a clinical follow-up of at least 12 weeks, the eyes were investigated histopathologically. During the polymerization process, the highest temperature measured at the posterior lens capsule was 45.1 degrees Celsius for a few seconds. The measured irradiance (0.065 watts per cm2) and the risk of photochemical damage to the retina during 20 seconds of polymerization were comparable to that caused by 1.5 minutes of standard coaxial illumination with the operating microscope. In vivo there were no serious inflammatory reactions except in four cases in which there had been intraoperative problems. The rate of secondary opacification appeared less than in conventional intraocular lens implantation in rabbits, especially when the capsule refilled completely. Retinal damage could not be detected histopathologically. In conclusion, refilling techniques may be successful once appropriate refilling materials become available.