Overall and disease-specific survival of sinonasal adenoid cystic carcinoma: a systematic review and meta-analysis.

This meta-analysis aims to investigate the outcome of sinonasal adenoid cystic carcinoma (snAdCC). We followed PRISMA guidelines and included studies reporting 5-year overall survival (OS) rates for snAdCC. Eligible studies were identified through a literature search and assessed using JBI critical appraisal checklist. A total of 17 studies were included comprising 2259 patients (mean age: 58.1 years, 52.7% female, 47.3% male). The meta-analysis demonstrated that the 5-year OS, 10-year OS, and 5-year disease-free survival (DFS) were 68%, 40%, and 47.2%, respectively. Descriptive statistics on study level showed high rates of locally advanced tumor stages at diagnosis: 23% cT3, 53% cT4, 3.4% N+, and 4.2% M+. 29.7% of the tumors were in the nasal cavity, 67.6% in the paranasal sinuses. The maxillary, ethmoid, sphenoid, and frontal sinus were affected in 50.9%, 7.2%, 4%, and 0.5%, of cases. A combination of surgery and radiotherapy was used in 45.4% of the patients and 19.3% of patients received surgery only. In conclusion, these findings emphasize the significance of thorough surveillance for individuals with snAdCC to identify any potential recurrence or progression of the disease.

Potential role of hybrid positron emission tomography in pre-operative assessment of primary salivary gland carcinomas.

OBJECTIVE: The added value of hybrid positron emission tomography is increasingly recognised in head and neck cancer. However, its potential role in salivary gland carcinomas has been scarcely investigated. METHODS: A consecutive cohort of 45 salivary gland carcinoma patients who underwent pre-therapeutic hybrid positron emission tomography and surgical resection was reviewed. This study investigated whether maximum standardised uptake value correlated with tumour phenotype. RESULTS: Tumours of high-grade disease on histology (salivary duct carcinoma, carcinoma ex pleomorphic adenoma) had higher maximum standardised uptake value (Kruskal-Wallis test, p = 0.011) than low-grade tumours (adenoid cystic carcinoma and acinic cell carcinoma). Patients with pathologically confirmed node-positive disease had significantly higher maximum standardised uptake value of the primary tumour than patients with pathologically confirmed node-negative disease (Kruskal-Wallis test, p = 0.012). CONCLUSION: Maximum standardised uptake value of the primary tumour may guide clinical decision-making in patients with salivary gland carcinomas, as a high maximum standardised uptake value is associated with high-grade tumour histology and the presence of lymph node metastases. Clinicians may consider more aggressive surgery for these patients.

[FH-deficient renal cell carcinoma expands the spectrum of renal papillary tumors]. / Das FH-defiziente Nierenzellkarzinom erweitert das Spektrum der papillären Tumoren in der Niere.

Fumarate hydratase (FH)-deficient renal cell carcinoma (RCC) is a distinct entity, which shows a biallelic inactivation of the FH gene that consequently leads to FH protein expression and function loss, respectively. This alteration leads to an accumulation of the oncometabolite fumarate in the citrate cycle and various disorders of the cell balance and DNA processing. FH-deficient RCC often shows a morphologically overlapping spectrum with papillary renal cell carcinoma (type 2), whereby a typical mixture of growth patterns including tubulo-cystic, cribriform, and/or solid differentiation can be observed. A characteristic but non-specific morphological feature is prominent eosinophilic, virus-inclusion body-like nucleoli with perinucleolar halos. Tumoral immunohistochemical loss of FH expression supports the diagnosis but may be preserved in rare cases. Most FH-deficient RCCs show very aggressive biological behavior and are often metastasized at the time of diagnosis. The initial description encompassed RCC in association with the hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome, which also includes cutaneous and uterine leiomyomas. However, current data also show an increasing proportion of sporadic cases, so that a distinction (hereditary vs. sporadic) seems appropriate. So far, few but promising data on effective systemic therapeutic options have been reported. In summary, precise diagnosis is of great importance due to the frequent aggressive biological behavior, potential need to deviate from the therapeutic standard, and the possible indicator of a hereditary disease.

Salvage Robotic-assisted Laparoscopic Radical Prostatectomy Following Focal High-Intensity Focused Ultrasound for ISUP 2/3 Cancer.

OBJECTIVE: To report feasibility and outcome of salvage robotic-assisted laparoscopic radical prostatectomy (S-RALP) after focal therapy using high-intensity focused ultrasound (HIFU) treatment compared to primary robotic-assisted laparoscopic radical prostatectomy (pRALP). METHODS: In this bicentric trial patients undergoing S-RALP for detection of WHO2016/ISUP Grade Group 2 or 3 prostate cancer were previously treated in prospective focal HIFU trials. Perioperative data, complications, oncological and functional outcome were analysed. Patients who underwent pRALP were matched in a ratio 2(pRALP):1(S-RALP) according to preoperatively functional, oncological and clinical parameters. RESULTS: A total of 39 patients were included in the study (13S-RALP, 26pRALP). Median operative time in the S-RALP group was 260minutes (pRALP: 257minutes), blood loss was 230ml (pRALP: 300ml). Complications occurred in 46.2% (6/13) of S-RALP patients (pRALP: 26.9%), including four Clavien-Dindo III complications (pRALP: 2/26). In S-RALP adverse histological outcome (≥pT3a, pN+ or R1) was detected in 23.1% (3/13) (pRALP: 26.9%). There was one patient with PSA-persistence (pRALP: 2/26). Regarding functional outcomes there was no difference between the two groups observed (incontinence P=.71, erectile function P=.21). CONCLUSION: S-RALP should be offered to patients with an early relapse after focal HIFU. The early oncological outcome is satisfactory and functional outcome one year postoperatively is similar to pRALP. However, S-RALP is associated with a higher rate of Clavien-Dindo III complications (mainly, placement of a drainage), of which patients should be informed beforehand.

[Characterization of different renal cell carcinoma entities]. / Charakterisierung der unterschiedlichen Entitäten beim Nierenzellkarzinom.

BACKGROUND: In recent years, the characterization of different renal cell carcinoma entities has significantly improved, in particular due to molecular typing. OBJECTIVES: Classical, accepted and emerging renal cell carcinoma entities are described. MATERIALS AND METHODS: A literature search was performed, followed by evaluation and description of the literature focusing on different renal cell carcinoma entities. RESULTS: Classical renal cell carcinoma entities such as clear cell carcinoma, papillary renal cell carcinoma and chromophobe renal cell carcinoma have been expanded in particular by molecular techniques to include, for example, translocation carcinoma or carcinoma with mutations in genes of the mitochondrial energy metabolism. Some rare entities have been accepted by the World Health Organization (WHO) classification, while some are considered as emerging entities. CONCLUSIONS: A range of newly accepted and emerging renal cell carcinoma entities have been introduced in the 2016 WHO classification. A precise and correct diagnosis is of major importance regarding the prognostic assessment, potential new therapeutic strategies and possible hereditary associations.

Cervical artery dissection: improved diagnosis by B-Flow ultrasound.

OBJECTIVE: The objective of this study was to evaluate the efficiency of B-Flow ultrasound in diagnosing supraaortic vessel dissections compared with other ultrasound techniques including B scan, Color-Coded Doppler (CCDS) and Power Doppler (PD). MATERIALS AND METHODS: Eighty-eight patients with suspected arterial dissection of the neck vessels were included in this prospective trial. All patients were examined using B scan, Color-Coded Doppler sonography and Power Doppler. After documentation of the diagnoses, the patients were additionally examined by B-Flow ultrasound. Contrast-enhanced magnetic resonance angiography (MRA) was used as reference standard in all cases. RESULTS: Dissections of the carotid artery (n=19) and of the vertebral artery (n=35) were found in 44 patients. B-Flow imaging identified 52 of 54 arterial dissections that were confirmed by MRA. There were no false-positive diagnoses in ultrasound examination. The sensitivity of ultrasound examination using B scan, CCDS and PD in detecting all dissections was 95.9% and 99.1% with additional B-Flow examination. Sensitivity using B-Flow increased from 98.3% to 100% for carotid dissections and from 93.3% to 94.3% for vertebral artery dissections. Due to the lack of overwriting artifacts, B-Flow imaging detected residual flow within the false lumen more precisely. The reduced effect of the ultrasound probe angle facilitated imaging of fissures, membranes and low flow phenomena and improved the identification of low-reflection wall structures. The cine mode of the B-Flow showed undulating membrane movement most clearly. Contrast-enhanced MRA in conjunction with axial T1 and T2 weighted sequences enabled the best visualization of intramural hematomas. CONCLUSION: B-Flow imaging can significantly increase the sensitivity of ultrasound examination for dissections of the neck vessels. It also improves the visualization of flow within the true and false lumen, of hypoechoic thrombi and of intramural hematoma.

B-flow and B-flow with 3D and SRI postprocessing before intervention and monitoring after stenting of the internal carotid artery.

OBJECTIVE: To investigate the extent to which B-flow and B-flow with 3D postprocessing and speckle reduction imaging (SRI) have advantages in appraising the morphology of a high-grade stenosis of the internal carotid artery (ICA) for preinterventional planning and for postinterventional ultrasonographic follow-up. MATERIALS/METHODS: A comparative appraisal of flow with CCDS, power Doppler, B-flow and 3D B-Flow with SRI were carried out prospectively in 50 patients with >70% stenosis according to NASCET criteria in contrast medium-enhanced MRA before and after the intervention. After stenting of the internal carotid artery (ICA), i.a. digital substraction angiography (DSA) served as an additional reference method. RESULTS: In >70% ICA stenosis, simultaneous imaging of the pre-stenotic, intra-stenotic and post-stenotic flow was attained with B-flow in 45/90 cases (90%), with power Doppler in 39/50 cases (78%) and with CCDS in only 31/50 cases (62%). After intervention, a complete detection of flow without overwriting or blooming artifacts was achieved in all 50 patients only by B-flow. The intrastenotic flow (p<0.05) could be better demarcated against the lumen and the vessel wall before the intervention, whereas the flow within the stent could be very much better appraised after the intervention (p<0.01) using 3D postprocessing of B-flow with additional SRI. Re-stenoses with hypoechoic vascular wall changes (3/50 patients) were detected at an early stage using B-flow. CONCLUSIONS: B-flow technique with SRI and 3D postprocessing can facilitate the intrastenotic detection of flow in >70% ICA stenosis with fewer flow artifacts. After stenting, the perfused vascular lumen shows less flow artifacts compared with CCDS and power Doppler. In order to elucidate hemodynamic changes, additional Doppler examinations are still necessary.

Diagnostics and characterisation of preocclusive stenoses and occlusions of the internal carotid artery with B-flow.

The purpose was to evaluate whether B-flow can improve the ultrasonographic diagnosis of preocclusive stenosis and occlusion of the internal carotid artery (ICA) compared with colour-coded Doppler and power Doppler. Ninety patients with occlusions or preocclusive stenoses of the ICA suspected by Doppler sonography were examined with B-flow in comparison with colour-coded Doppler sonography (CCDS), power Doppler (PD) and intra-arterial digital subtraction angiography (DSA). Intrastenotic flow detection and lengths of stenoses were the main criteria. Ulcerated plaques found by surgery in 42/90 patients were compared by ultrasonography (US). Diagnosis of ICA occlusion with CCDS, PD and B-flow was correct in all 42 cases. A preocclusive ICA stenosis in DSA was detected correctly in all 48/48 cases (100%) for B-flow, in 44/48 (92%) for PD and in 39/48 (81%) for CCDS. Surgical findings showed in 17/42 cases ulcerated plaques; 15/17 (89%) of these cases were detected with B-flow, 12/17 (71%) with PD, 10/17 (59%) with CCDS, and 8/17 (47%) with DSA. With B-flow the extent of stenosis was appraised more precisely than with PD and CCDS (P<0.0001). In conclusion, B-flow is a reliable method for preocclusive stenosis of the ICA with less intrastenotic flow artefacts. B-flow facilitates the characterization of plaque morphologies.

Cost analysis in interventional radiology--A tool to optimize management costs.

OBJECTIVE: The objective of the study was to analyze the methods to reduce cost in interventional radiology departments by reorganizing procurement. MATERIALS AND METHODS: All products used in the Department of Interventional Radiology were inventoried. An ABC-analysis was completed and A-products (high-value and high turnover products) underwent a XYZ-analysis which predicted demand on the basis of ordering frequency. Then criteria for a procurement strategy for the different material categories were fixed. The net working capital (NWC) was calculated using an interest rate of 8%/year. RESULTS: Total annual material turnover was 353,000 euro. The value of all A-products determined by the inventory was 260,000 euro. Changes in the A-product procurement strategy tapped a cost reduction potential of 14,500/year euro. The resulting total saving was 17,200 euro. Improved stores management added another 37,500 euro. The total cost cut of 52,000 euro is equivalent to 14.7% of annual expenses. CONCLUSION: A flexible procurement strategy helps to reduce the storage and capital tie-up costs of A-products in interventional radiology without affecting the quality of service provided to patients.

Improved diagnosis of vascular dissection by ultrasound B-flow: a comparison with color-coded Doppler and power Doppler sonography.

The purpose was to evaluate the diagnostic results of different ultrasound techniques: color-coded Doppler (CCD), power Doppler (PD) and B-flow in the diagnosis of vascular dissection. Findings from 68 patients with arterial dissection proven either by vascular ultrasound (US) or by magnetic resonance angiography (MRA), computed tomographic angiography (CTA) or intra-arterial digital subtraction angiography (DSA) were reviewed in retrospect. The study compared results from three different modes of ultrasound, i.e., CCD, PD and B-flow, in dissections of the carotid artery (n=11), of the vertebral artery (n=9), of the abdominal aorta (n=13), of the iliac artery (n=12) and of the femoral artery (n=23). MRA, CTA and DSA were considered as reference standard. The sensitivity of CCD for detecting all dissections was 78%, 84% for the PD and 98% for B-flow. For carotid artery dissection, the sensitivity of CCD, PD and B-flow was 82, 91 and 98%, for the vertebral artery 67, 78 and 98%, for the abdominal aorta 85, 85 and 98%, for the iliac artery 67, 75 and 98%, for the femoral artery 83, 87 and 98%, respectively. Intima flaps, fissures of membranes and residual flow within the true and false lumen were better detected by B-flow than by CCD and PD. The lack of angle dependence of the US probe in B-flow made the examination procedure easier. In the cine mode of B-flow, the pulse synchronic movement of the membrane was more apparent than in any other imaging method. With B-flow, accuracy for the diagnosis of arterial dissection is improved compared to CCD and PD. Flow within the true and false lumen, low-echo thrombi, intramural hematoma and even movements of the dissection membrane are clearly distinguished.

[Tissue harmonic imaging (THI) and contrast harmonic imaging (CHI) for sonographically guided vacuum-assisted biopsy of mammographically occult breast tumors]. / Tissue Harmonic Imaging (THI) und Contrast Harmonic Imaging (CHI) zur sonographisch gezielten Vakuumstanzbiopsie mammographisch okkulter Brusttumoren.

PURPOSE: To assess the guidance of tissue harmonic imaging (THI) and contrast harmonic imaging (CHI) for vacuum assisted biopsies of suspicious breast lesions compared to fundamental B-mode ultrasound-guided biopsies. MATERIAL AND METHODS: In 550 patients, ultrasound examinations of the breast were performed prospectively using fundamental B-scan, THI, and CHI. Focal lesions were documented in comparable projections for all three ultrasound modes. As contrast agent, a dose of 0.5 milliliters of Perflutren Protein-Type A microspheres ( Optison) was injected. An ultrasound-guided biopsy was performed in 38 focal lesions. Three radiologists experienced in breast imaging retrospectively assessed the lesions on the ultrasound images. RESULTS: Thirty-eight suspicious focal lesions [size 4 - 15 mm; median 8 mm] were detected by ultrasound. Of these, 29 were detected by fundamental B-scan images, 34 by THI, and 38 by CHI. Ultrasound-guided biopsy was performed on all of these lesions. No complications related to the biopsy were observed. In 25/38 cases, invasive carcinomas were found; in 6/38 ductal carcinomas in situ; in 3 cases metastases of already known invasive ductal carcinomas; and in 4 cases fibroadenomas. The size of the lesion was best identified using THI, smaller lesions (< 10 mm) using CHI. CONCLUSION: THI and CHI can help to detect focal lesions in dense breasts. Both modes can make it easier to perform ultrasound-guided biopsies of focal breast lesions.

[Materials management system in interventional radiology -- initial experience with a computer-supported program]. / Materialverwaltung in der interventionellen Radiologie -- erste Erfahrungen mit einem computergestützten Programm.

PURPOSE: To perform a cost analysis for assessing options of reorganizing material supplies and reducing costs of the radiology division through the introduction of a materials management system. MATERIALS AND METHODS: A materials management system (Piranha, Boston Scientific) was installed on an existing computer system. All consumables were inventoried and entered into the system. An ABC analysis determined further action. On the basis of order frequencies and availability requirements for emergencies, safety levels were agreed with physicians and other medical staff. Inventory costs were computed using these data. The interest rate for the capital tied up in the inventory was 8 % per year. RESULTS: The inventory showed that the capital tied up in stocks was euro 260,000 in 2001 and euro 190,000 in 2002. A change in supply strategy reduced inventory cost in 2001 and 2002. Annual interest expense was lowered by euro 18,420. Another saving of euro 2,700 was achieved by a reduction in storage cost. Annual inventory turnover totaled euro 298,000. The total cost cut through improved inventory management was euro 21,120 per year, which is equivalent to 7 % of the annual expenses. Adding the decline in the cost of shelf time overruns equal to 5 % of the annual expenses, the saving was approximately 12 % of total interventional radiology cost in 2001 and some 11 % in 2002. CONCLUSION: Flexible supply strategies and the introduction of a materials management program can help to reduce inventory costs in interventional radiology divisions without any impact on service levels.

[Contrast-enhanced ultrasound with Optison in percutaneous thermoablation of liver tumors]. / Erste Erfahrungen mit der kontrastmittelverstärkten Sonographie mit Optison bei der perkutanen Thermoablation von Lebertumoren.

PURPOSE: To detect vascularization of liver tumors by ultrasound enhanced with Optison and to determine whether increasing necrosis during a percutaneous thermal ablation can be visualized by this method. MATERIALS AND METHODS: Twenty-two patients with non-resectable malignant liver tumors (9 patients with HCC, 13 patients with metastases) and a total number of 34 lesions underwent percutaneous radiofrequency thermoablation using a needle applicator perfused with a 0.9 % NaCl solution (Electrotome HiTT 106, Berchtold). The tumor size ranged from 2 to 8 cm with an average size of 3.6 cm. While intermittent energy was supplied during thermoablation, multi-slice CT (Volume-Zoom, Siemens) and ultrasound were obtained. Ultrasound was performed with a multi-frequency transducer (3 - 7 MHz, LOGIQ 700, GE) and 0.5 to 1 ml of Optison as contrast agent. If necessary, the injection of the contrast agent was repeated after about 30 min. The mechanical index (MI) was set low (0.2 - 0.3) to prevent bubble destruction. Ultrasound power Doppler (PD), contrast harmonic imaging (CHI) and coded harmonic angiography (CHA) as subtraction mode of harmonic imaging were applied intermittently. RESULTS: Only 21 of the 34 lesions showed increased intratumoral perfusion when the conventional B-Mode with PD was used. Similar to spiral CT, the tumor vascularization in the early arterial phase was only reliably visible with CHA after application of contrast agent. CHI with PD was best to detect increasing hypoperfusion of the tumors. When the energy supply was continued, hyperechoic border zones became visible around the central hypoechoic defects. The contrast between remaining tumor and surrounding liver tissue improved in CHI for up to 30 min after the bolus injection of contrast medium, considerably facilitating the evaluation of perfusion. Metal artifacts and the limited amount of contrast agent that can be safely administered interfered with monitoring the thermal ablation with spiral-CT. After an administered energy of maximal 100.000 watts, no more tumor vascularization was seen in 28 of 34 cases. Follow-up spiral-CT showed a complete necrosis in these cases. CONCLUSION: Evaluating perfusion with contrast-enhanced ultrasound may be helpful in monitoring the evolving necrosis during thermoablation of liver tumors. The more reliable assessment of the tumor necrosis enables a more targeted therapy.

[B-flow and color-coded B-flow in sonographic diagnosis of filiform stenosis of the internal carotid artery]. / B-Flow und Color-Coded-B-Flow zur sonographischen Diagnostik der filiformen Stenose der A. carotis interna.

PURPOSE: To evaluate B-flow ultrasound in filiform (> 90 %) stenosis or occlusion of the internal carotid artery (ICA) and to compare it with other imaging modalities. METHODS AND MATERIALS: Fifty patients with suspected occlusion or filiform stenosis of the internal carotid artery (ICA) on Doppler ultrasound were examined using B-flow ultrasound in either color-coded or brightness mode. The pre-, intra- and poststenotic flow phenomena were compared with color-coded duplex (CCD) and power Doppler (PD) ultrasound. A contrast agent (Optison) was injected in 15 cases. The results were compared with those of selective intraarterial DSA and in 15 cases also with those of MR-angiography (MRA). Twenty-two patients came to surgical intervention. RESULTS: Diagnosis of ICA occlusion was correct in all 22 cases using CCD, PD and B-flow ultrasound. A filiform ICA-stenosis was correctly seen in all 28 cases when using brightness-modulated or color-coded B-flow or contrast-enhanced power Doppler, but only in 15 cases when using CCD. All 9 ulcerated plaques with appositional thrombi were detected with B-flow, but only 4 cases with CCD. Pre-, intra- and poststenotic flow phenomena in the longitudinal scan were demonstrated simultaneously using color-coded B-flow in 27 out of 28 cases, but only in 17 cases using CCD and in 22 cases using PD. In the 15 cases given contrast agent, B-flow showed no superimposed vessel walls (reverberation artefacts) in the intra- and poststenotic area. In the longitudinal scan, true extend and degree of the distal stenosis of ICA carotid artery stenosis were more precisely measured with B-flow than with PD and CCD. CONCLUSIONS: The ultrasound diagnosis of filiform stenosis of the ICA is more reliable with B-flow ultrasound than with other ultrasound modalities. B-flow ultrasound has flow phenomena that are less angle-dependent and that are better demarcated against the vessel walls. It is free of superimposed vessel walls and offers better simultaneous intra- and poststenotic flow detection. The improved delineation of the plaque morphology by B-flow ultrasound enables a better evaluation of ulcerations and possible thrombi.

[Improved evaluation of stenoses of hemodialysis fistulas by B-flow ultrasound]. / B-Flow zur verbesserten sonographischen Beurteilung von Dialyse-Shunt-Stenosen.

PURPOSE: To evaluate the new technique of B-flow ultrasound in assessing stenoses of hemodialysis fistulas. MATERIALS AND METHODS: 50 patients (mean age 58 years) with Brescia-Cimino-Shunts (27 shunts of the radial and 23 of the cubital artery) were prospectively assessed with intraarterial DSA and vascular ultrasound by independent examiners. Eligibility for the study was a shunt-volume of less than 400 ml/min and an angiographically suspected hemodynamically significant stenosis of the anastomosis or of shunt veins. Sonography was performed with a multifrequency ultrasound probe (5 to 10 MHz, Logic 700, GE) using B-mode, color coded Doppler sonography (CCDS) and B-flow technique. RESULTS: Anastomotic stenosis and stenosis of the shunt veins were equally distributed, found in 25 patients each. The measurements of the residual lumen of the 25 anastomotic stenoses were 1.47 to 3.43 mm (average: 2.3 mm) for intraarterial DSA, 1.57 to 3.73 mm (average: 2.6 mm) for B-mode ultrasound, 1.97 to 4.17 mm (average: 2.9 mm) for CCDS, 1.43 to 3.47 mm (average: 2.3 mm) for B-flow technique in the brightness mode and 1.6 to 3.47 mm (average: 2.4 mm) for B-flow technique in the B-mode. The brightness mode of the B-flow correlated best with intraarterial DSA (r=0.994), with a significantly lower correlation between CCDS and intraarterial DSA. B-flow displays less vascular distortion within the stenosis and fewer flow artifacts. Even in angulated stenoses, the detected intra- and poststenotic flow was markedly less angle-dependent in comparison with CCDS. B-flow clearly facilitates the visualization of hypoechoic plaques and intima proliferation. Furthermore, eccentric cicatricial stenoses, intima flaps or hypoechoic thrombi, which were not seen with DSA or B-mode, showed improved visualization in comparison with CCDS. CONCLUSION: Ultrasound B-flow makes it easier to assess the morphology and the local degree of stenotic hemodialysis fistulas. Flow detection is achieved with fewer artifacts and reduced angle dependence. This opens the way for better planning of interventional therapy.

[Examination of the constancy of the medium optical density of conventional chest radiographs]. / Untersuchungen über die Konstanz der mittleren optischen Dichte bei konventionellen Röntgen-Thorax-Aufnahmen.

PURPOSE: To determine whether the medium optical density of conventional chest radiographs is constant. MATERIALS AND METHODS: 47 PA chest radiographs were digitized to measure the optical density and its dynamic range of normal and pathologically altered lungs. RESULTS: For constant exposure factors and a correctly positioned region of interest, the medium optical density deviates only minimal despite differences in AP chest diameter, entry dose and dynamic range, and is largely independent of the pathologic pulmonary findings. CONCLUSION: Digitization of the radiograph enables the determination of the physical parameters used to operate the imaging system, such as medium optical density, image contrast, image latitude and density distribution, in accordance to the guidelines of the German Medical Association. If the region of interest encompasses the clinically relevant region of the lung, the measured value of the optical density corresponds with only minor variation to the average value of the entire lung region.