Can contrast-enhanced ultrasound and acoustic radiation force impulse imaging characterize CT-indeterminate renal masses? A prospective evaluation with histological confirmation.

PURPOSE: To prospectively characterize computed tomography (CT)-indeterminate renal masses (CTIRM) using acoustic radiation force impulse (ARFI) elastography and contrast-enhanced ultrasound (CEUS) and to correlate quantitative imaging findings with histopathology or interim follow-up (FU). METHODS: 123 patients with CTIRM (longest diameter < 4 cm) underwent ARFI and CEUS with CT image fusion (IF). Exclusion criteria included all contraindications for CEUS and IF. Shear wave velocity (SWV), shear wave ratio (SWR), peak intensity (PE), time to peak (TTP) and wash-in rate (Wi) were quantified. In case of a cystic lesion classified as ≤ Bosniak 2F, follow-up imaging was performed. RESULTS: 77 out of 123 patients underwent surgical resection of a lesion due to suspect imaging findings, whereas 46 patients underwent FU, which did not show upgrading in Bosniak category. Histopathology revealed 58 renal cell carcinomas [five chromophobe (chRCC), 18 papillary (pRCC) and 35 clear cell (ccRCC)], ten oncocytomas and nine non-malignant renal lesions (one minimal fat AML, three focal nephritis and five infected cysts). SWV and SWR differed significantly between ccRCC, pRCC, chRCC (p = 0.0024, F = 13.94) and in SWR also for oncocytoma (p < 0.0001, F = 14.35). In CEUS, oncocytoma and ccRCC showed significant higher PE values (p < 0.0001, F = 77.31) as well as higher Wi and lower TTP compared to all other solid lesions. CONCLUSIONS: Quantitative CEUS and ARFI imaging can provide relevant information to further characterize CT-indeterminate renal masses to guide urological decision making and offer the possibility of differentiation between ccRCC from less malignant RCC subtypes and from oncocytoma.

Case report of dependent venous contrast pooling and layering in a patient without acute cardiogenic shock.

RATIONALE: We present a case of incidental venous contrast pooling and layering in a patient without sudden cardiac arrest or cardiogenic shock. PATIENT CONCERNS: The patient presented with only discrete symptoms and did not suffer fatal cessation of the cardiac pump function during or shortly after the scan. DIAGNOSIS: The patient showed stigmata of venous gravity-dependent pooling and layering of contrast medium, which has frequently been described as a sign of imminent cardiogenic shock and cardiac arrest. INTERVENTIONS: A cardiologic consultation including echocardiography was initiated. OUTCOMES: Echocardiography confirmed valvular heart disease and biventricular heart failure. A subsequent follow-up CT acquired 8 months after the incidental finding showed no signs of dependent contrast pooling. LESSONS: Pooling and layering of contrast medium can occur in patients not suffering acute fatal cessation of the cardiac pump function. Nonetheless, any signs of venous pooling observed in CT examinations, especially gravity-dependent layering of contrast medium, are indicative of severe heart dysfunction and should prompt immediate cardio-pulmonary monitoring and increased level of medical care.

Osteitis pubis in professional football players: MRI findings and correlation with clinical outcome.

BACKGROUND AND PURPOSE: Osteitis pubis (OP), a common pathology in elite athletes, is an aseptic inflammatory process of the pubic symphysis bone, and may involve surrounding soft tissues, tendons and muscles. OP is typically characterized by (often recurring) groin pain and is an important cause of time-off from sports activity in athletes. Aim of this retrospective study was to analyze magnetic resonance imaging (MRI) findings in professional football players with clinical diagnosis of OP and to correlate MRI findings with clinical outcome. MATERIAL AND METHODS: All professional football players (23 males, 1 female; mean age: 21±3.7years; range: 16-30 years) with groin pain and clinical diagnosis of OP, who underwent pelvic MRI in our institution were retrospectively analyzed. The MR images were analyzed regarding the presence of bone marrow edema and its extension, whether fluid in the symphysis pubis or periarticular soft tissue edema with a rim-like periosteal distribution or edema in the muscles located around the symphyseal joint were present, whether degenerative changes of the symphysis pubis and of signs of symphyseal instability were encountered. A quantitative measurement of the signal intensity in bone marrow edema on 3T STIR sequences was performed, normalizing these values to the mean signal intensity values in the ipsilateral iliopsoas muscle. All patients were classified according to a 3-point grading scale. For each patient, both the symptoms 18 months after the initial MRI examination, the duration of time off from playing football and the kind of treatment applied were evaluated. RESULTS: Among all professional athletes, in 20/24 (83.3%) MRI showed signs of OP with bone marrow edema at the pubic bone. 12 of these patients showed complete clinical recovery without any symptoms after 18 months, while in 8 patients partial recovery with persistence of groin pain during higher sports activity was observed. Patients with edema in periarticular soft tissues or in the muscles around the symphyseal joint on MRI at the beginning of symptoms presented significantly more often with a partial recovery after returning to high sports activity (p=0.042 and p=0.036, respectively). A partial recovery was also significantly associated with higher normalized mean signal intensity values in bone marrow edema on STIR sequences at the beginning of symptoms (mean=4.77±1.63 in the group with partial recovery vs. mean=2.86±0.45 in the group with complete recovery; p=0.0019). No significant association was noticed between MRI findings and time of abstinence from high sports activity, as well as between the 3-point grading scale and the time off from high sport activity and recovery at 18 months. CONCLUSIONS: Edema in periarticular soft tissues, edema with extension to the muscles located around the symphyseal joint, as well as higher normalized signal intensity values in bone marrow edema on STIR sequences in the pubic bones at the beginning of groin pain are the most reliable MRI findings of a poor clinical long-term outcome of OP in professional football players and should be regarded as negative prognostic factors.

3D-modeling of the spine using EOS imaging system: Inter-reader reproducibility and reliability.

OBJECTIVES: To retrospectively assess the interreader reproducibility and reliability of EOS 3D full spine reconstructions in patients with adolescent idiopathic scoliosis (AIS). METHODS: 73 patients with mean age of 17 years and a moderate AIS (median Cobb Angle 18.2°) obtained low-dose standing biplanar radiographs with EOS. Two independent readers performed "full spine" 3D reconstructions of the spine with the "full-spine" method adjusting the bone contour of every thoracic and lumbar vertebra (Th1-L5). Interreader reproducibility was assessed regarding rotation of every single vertebra in the coronal (i.e. frontal), sagittal (i.e. lateral), and axial plane, T1/T12 kyphosis, T4/T12 kyphosis, L1/L5 lordosis, L1/S1 lordosis and pelvic parameters. Radiation exposure, scan-time and 3D reconstruction time were recorded. RESULTS: Interclass correlation (ICC) ranged between 0.83 and 0.98 for frontal vertebral rotation, between 0.94 and 0.99 for lateral vertebral rotation and between 0.51 and 0.88 for axial vertebral rotation. ICC was 0.92 for T1/T12 kyphosis, 0.95 for T4/T12 kyphosis, 0.90 for L1/L5 lordosis, 0.85 for L1/S1 lordosis, 0.97 for pelvic incidence, 0.96 for sacral slope, 0.98 for sagittal pelvic tilt and 0.94 for lateral pelvic tilt. The mean time for reconstruction was 14.9 minutes (reader 1: 14.6 minutes, reader 2: 15.2 minutes, p<0.0001). The mean total absorbed dose was 593.4µGy ±212.3 per patient. CONCLUSION: EOS "full spine" 3D angle measurement of vertebral rotation proved to be reliable and was performed in an acceptable reconstruction time. Interreader reproducibility of axial rotation was limited to some degree in the upper and middle thoracic spine due the obtuse angulation of the pedicles and the processi spinosi in the frontal view somewhat complicating their delineation.

Impact of transjugular intrahepatic portosystemic shunt implantation on liver perfusion measured by volume perfusion CT.

Background Implantation of a transjugular intrahepatic portosystemic shunt (TIPS) induces changes of liver perfusion. Purpose To determine the changes in arterial, portal venous, and total perfusion of the liver parenchyma induced by TIPS using the technique of volume perfusion computed tomography (VPCT) and compare results with invasively measured hepatic intravascular pressure values. Material and Methods VPCT quantification of liver perfusion was performed in 23 patients (mean age, 62.5 ± 8.8 years) with portal hypertension in the pre-TIPS and post-TIPS setting, respectively. A commercially available software package was used for post-processing, enabling separate calculation of the dual (arterial [ALP] and portal venous [PVP]) blood supply and additionally of the hepatic perfusion index (HPI) (HPI = ALP/(ALP + PVP)*100%). Invasive pressure measurements were performed during the intervention, before and after TIPS placement. Liver function tests performed before and after the procedure were compared. Results Mean decrease of pressure gradient through TIPS was 13.3 mmHg. Mean normal values for ALP, PVP, and total perfusion (ALP + PVP) before TIPS were 15.9, 37.7, and 53.5 mL/100 mL/min, respectively, mean HPI was 35.4%. After TIPS, ALP increased to a mean value of 37.7 mL/100 mL/min, PVP decreased (15.7 mL/100 mL/min, P < 0.05), whereas total perfusion remained unchanged (53.4 mL/100 mL/min, P = 0.97). HPI increased (71.9%; P < 0.05). No correlation between invasive pressure measurement and VPCT parameters was observed. After TIPS, liver function tests were found to worsen with a significant increase of bilirubin ( P < 0.05). Conclusion Following TIPS placement, ALP and HPI increased in all patients, whereas PVP markedly decreased. Interestingly, the magnitude of decrease in portosystemic pressure gradients was not found to correlate with VPCT parameters.

Implantability, Complications, and Follow-Up After Transjugular Intrahepatic Portosystemic Stent-Shunt Creation With the 6F Self-Expanding Sinus-SuperFlex-Visual Stent.

BACKGROUND: The transjugular intrahepatic portosystemic stent-shunt (TIPSS) builds a shortcut between the portal vein and a liver vein, and represents a sophisticated alternative to open surgery in the management of portal hypertension or its complications. OBJECTIVES: To describe clinical experiences with a low-profile nitinol stent system in TIPSS creation, and to assess primary and long-term success. PATIENTS AND METHODS: Twenty-six patients (5 females, 21 males; mean age 54.6 years) were treated using a low-profile 6F self-expanding sinus-SuperFlex-Visual stent system. The indication for TIPSS creation was refractory bleeding in 9 of the 26 patients, refractory ascites in 18 patients, and acute thrombosis of the portal vein confluence in one patient. Portosystemic pressure gradients before and after TIPSS, periprocedural and long-term complications, and the time to orthotopic liver transplantation (OLT) or death were recorded. RESULTS: The portosystemic pressure gradient was significantly reduced, from 20.9 ± 6.3 mmHg before to 8.2 ± 2.3 mmHg after TIPSS creation (P < 0.001). Procedure-related complications included acute tract occlusion (n = 2), liver hematoma (n = 1), hepatic encephalopathy (n = 1), and cardiac failure (n = 1). Three of the 26 patients had late-onset TIPSS occlusion (at 12, 12, and 39 months after TIPSS creation). Three patients died within one week after the procedure due to their poor general condition (multiorgan failure, acute respiratory distress syndrome, necrotizing pancreatitis, and aspiration pneumonia). Another four patients succumbed to their underlying advanced liver disease within one year after TIPSS insertion. Seven patients underwent OLT at a mean time of 9.4 months after TIPSS creation. CONCLUSION: The sinus-SuperFlex-Visual stent system can be safely deployed as a TIPSS device. The pressure gradient reduction was clinically sufficient to treat the patients' symptoms, and periprocedural complications were due to the TIPSS procedure per se rather than to the particular stent system employed in this study.

Labeling Human Melanoma Cells With SPIO: In Vitro Observations.

OBJECTIVES: To use the superparamagnetic iron oxide (SPIO) contrast agent Resovist (±transfection agent) to label human melanoma cells and determine its effects on cellular viability, microstructure, iron quantity, and magnetic resonance imaging (MRI) detectability. MATERIALS AND METHODS: Human SK-Mel28 melanoma cells were incubated with Resovist (±liposomal transfection agent DOSPER). The cellular iron content was measured, and labeled cells were examined at 1.5 T and 3.0 T. The intracellular and extracellular distributions of the contrast agent were assessed by light and electron microscopy. RESULTS: The incubation of melanoma cells with SPIO does not interfere with cell viability or proliferation. The iron is located both intracellularly and extracellularly as iron clusters associated with the exterior of the cell membrane. Despite thorough washing, the extracellular SPIO remained associated with the cell membrane. The liposomal transfection agent does not change the maximum achievable cellular iron content but promotes a faster iron uptake. The MRI detectability persists for at least 7 days. CONCLUSION: The transfection agent DOSPER facilitates the efficient labeling of human metastatic melanoma cells with Resovist. Our findings raise the possibility that other Resovist-labeled cells may collect associated extracellular nanoparticles. The SPIO may be available to other iron-handling cells and not completely compartmentalized during the labeling procedure.

CT-Guided Biopsy in Suspected Spondylodiscitis--The Association of Paravertebral Inflammation with Microbial Pathogen Detection.

OBJECTIVES: To search for imaging characteristics distinguishing patients with successful from those with futile microbiological pathogen detection by CT-guided biopsy in suspected spondylodiscitis. METHODS: 34 consecutive patients with suspected spondylodiscitis underwent CT-guided biopsy for pathogen detection. MR-images were assessed for inflammatory infiltration of disks, adjacent vertebrae, epidural and paravertebral space. CT-images were reviewed for arrosion of adjacent end plates and reduced disk height. Biopsy samples were sent for microbiological examination in 34/34 patients, and for additional histological analysis in 28/34 patients. RESULTS: Paravertebral infiltration was present in all 10/10 patients with positive microbiology and occurred in only 12/24 patients with negative microbiology, resulting in a sensitivity of 100% and a specificity of 50% for pathogen detection. Despite its limited sensitivities, epidural infiltration and paravertebral abscesses showed considerably higher specificities of 83.3% and 90.9%, respectively. Paravertebral infiltration was more extensive in patients with positive as compared to negative microbiology (p = 0.002). Even though sensitivities for pathogen detection were also high in case of vertebral and disk infiltration, or end plate arrosion, specificities remained below 10%. CONCLUSIONS: Inflammatory infiltration of the paravertebral space indicated successful pathogen detection by CT-guided biopsy. Specificity was increased by the additional occurrence of epidural infiltration or paravertebral abscesses.

Therapeutic angiographic procedures: differences in dose area product between analog image intensifier and digital flat panel detector.

BACKGROUND: Radiation exposure remains an unceasing concern in angiographic procedures. Modern angiography machines such as analog image intensifiers (AII) or the new flat panel detectors (FPD) aim at a further dose reduction. PURPOSE: To present dose area products (DAP) in a broad spectrum of therapeutic angiographic procedures, comparing an AII to an FPD angiography system. MATERIAL AND METHODS: A total of 999 peripheral therapeutic angiography procedures performed with an FPD (n = 562) and an AII system (n = 437) were evaluated. DAP, fluoroscopy time, and patients' body mass index (BMI) were recorded. Interventions were classified into five main groups: percutaneous transluminal angioplasty (PTA); PTA and stent placement; intra-arterial thrombolysis; embolization procedures; and specialized interventions. RESULTS: DAP values in therapeutic angiographic procedures were significantly higher when performed with the FPD compared to the AII system. The increase of the FPD versus AII system was 100.1% for PTA, 39.9% for PTA and stent placement, 187% for intra-arterial thrombolysis, 31.3% for embolization procedures, and 361% for specialized interventions. These differences persisted after standardizing DAP values to the geometric mean fluoroscopy duration of each procedure. Fluoroscopy times were shorter in all interventions performed at the FPD as compared to the AII system. DAPs increased with higher BMI, but the DAP increase of both systems with elevated BMI was variable, depending on the individual intervention. CONCLUSION: In therapeutic angiographic procedures, the FPD system required higher DAPs despite shorter fluoroscopy times as compared to an AII system. Better ergonomics and speediness of the FPD system may be advantageous in the emergency setting.

Comparison of volume perfusion computed tomography and contrast-enhanced ultrasound for assessment of therapeutic effect of transarterial chemoembolization in patients with hepatocellular carcinoma: a preliminary report.

BACKGROUND: Evaluation of transarterial chemoembolization (TACE) by using contrast-enhanced ultrasound (CEUS) and volume perfusion computed tomography (VPCT) as methods that display tumor vascularization. PURPOSE: To assess early results of TACE in patients with hepatocellular carcinoma (HCC) using CEUS and VPCT. MATERIAL AND METHODS: Twenty patients with HCC underwent CEUS and VPCT in the pre- and post-TACE setting (1 day). Hepatic perfusion index (HPI), arterial liver perfusion (ALP), blood flow (BF), and blood volume (BV) were measured with VPCT. Peak intensity (PI), time-to-peak (TTP), and regional blood flow (RBF) were measured with CEUS. Sensitivity, specificity, negative and positive predictive values, and cutoff values for these parameters were calculated. Immediate tumor response after TACE was classified as responder or non-responder. Results were compared with those at follow-up after 2 and 4 months (FU2mo/FU4mo) following modified RECIST. RESULTS: CEUS and VPCT showed comparable immediate post-TACE results in 20/20 cases. Complete response was confirmed in 10/20 patients at FU2mo and in 9/20 at FU4mo. For responders, reduction in HPI, ALP, BV, and BF at day 1 post TACE proved significant (P < 0.001). For non-responders, the course of all VPCT parameters proved non-significant. A cutoff of 40% reduction in HPI and a reduction in ALP of >29.6%, in BV of >41.4%, or in BF of >53.1% was indicative of response according to FU2mo. For responders only, changes in PI (P < 0.001), TTP (P < 0.01), and BF (P < 0.01) proved significant whereas for non-responders, all CEUS parameters proved non-significant. CONCLUSION: CEUS performs equally to VPCT for assessment of early response to TACE in HCC by a lesion-by-lesion assessment and showed prognostic value at mid-term.

MRI parametric monitoring of biological therapies in primary large vessel vasculitides: a pilot study.

OBJECTIVE: To evaluate the development of characteristic MRI changes in patients with primary large-vessel vasculitis (LVV) when treated with biological therapies. METHODS: 12 patients with primary LVV (8 patients with Takayasu arteritis and 4 patients with giant-cell arteritis) received biological therapy with tumour necrosis factor-α blockers (n = 9) or an interleukin-6 inhibitor (n = 3). MRI investigations were performed at baseline (pre-treatment) and follow-up. All patients underwent the same MRI/MR angiography (MRA) protocol. Laboratory parameters (C-reactive protein and erythrocyte sedimentation rate) and clinical response (Birmingham Vasculitis Activity Score) were assessed. RESULTS: Wall thickness was 4.2 ± 0.3 mm pre-treatment and significantly decreased to 3.2 ± 0.3 mm post treatment in 9/12 patients. Mural enhancement was increased in all 12/12 patients with LVV, and subsided with therapy in 5/12 patients. Mural oedema or ill-defined contour were less prevalent but also improved with biological treatment. C-reactive protein and erythrocyte sedimentation rate levels decreased, and clinical assessment revealed a significant improvement from pre-treatment to post-treatment. However, the course of imaging characteristics often did not parallel that of laboratory or clinical parameters. In all three patients receiving interleukin-6 blockade, laboratory markers and clinical scores normalized despite persistent vascular inflammation in one patient which was disclosed by MRI. CONCLUSION: Contrast-enhanced MRI/MRA may be useful when evaluating the development of disease activity in primary LVV under biological therapies. A high degree of suspicion and regular imaging follow-up is needed to detect persistent inflammation. ADVANCES IN KNOWLEDGE: This is the first study investigating the applicability of different MRI/MRA parameters for monitoring biological therapy in patients with primary LVV.

Iodine concentration as a perfusion surrogate marker in oncology: Further elucidation of the underlying mechanisms using Volume Perfusion CT with 80 kVp.

OBJECTIVES: To assess the value of iodine concentration (IC) in computed tomography data acquired with 80 kVp, as a surrogate for perfusion imaging in hepatocellular carcinoma (HCC) and lymphoma by comparing iodine related attenuation (IRA) with quantitative Volume Perfusion CT (VPCT)-parameters. METHODS: VPCT-parameters were compared with intra-tumoral IC at 5 time points after the aortic peak enhancement (APE) with a temporal resolution of 3.5 sec in untreated 30 HCC and 30 lymphoma patients. RESULTS: Intra-tumoral perfusion parameters for HCC showed a blood flow (BF) of 52.7 ± 17.0 mL/100 mL/min, blood volume (BV) 12.6 ± 4.3 mL/100 mL, arterial liver perfusion (ALP) 44.4 ± 12.8 mL/100 mL/min. Lesion IC 7 sec after APE was 133.4 ± 57.3 mg/100 mL. Lymphoma showed a BF of 36.8 ± 13.4 mL/100 mL/min, BV of 8.8 ± 2.8 mL/100 mL and IC of 118.2 ± 64.5 mg/100 mL 3.5 sec after APE. Strongest correlations exist for VPCT-derived BF and ALP with IC in HCC 7 sec after APE (r = 0.71 and r = 0.84) and 3.5 sec after APE in lymphoma lesions (r = 0.77). Significant correlations are also present for BV (r = 0.60 and r = 0.65 for HCC and lymphoma, respectively). CONCLUSIONS: We identified a good, time-dependent agreement between VPCT-derived flow values and IC in HCC and lymphoma. Thus, CT-derived ICs 7 sec after APE in HCC and 3.5 sec in lymphoma may be used as surrogate imaging biomarkers for tumor perfusion with 80 kVp. KEY POINTS: • Iodine concentration derived from low kVp CT is regarded as perfusion surrogate • Correlation with Perfusion CT was performed to elucidate timing and histology dependencies • Highest correlation was present 7 sec after aortic peak enhancement in hepatocellular carcinoma • In lymphoma, highest correlation was calculated 3.5 sec after aortic peak enhancement • With these results, further optimization of Dual energy CT protocols is possible.

Cell Cycle Regulation of Smooth Muscle Cells--Searching for Inhibitors of Neointima Formation: Is Combretastatin A4 an Alternative to Sirolimus and Paclitaxel?

PURPOSE: To compare the effects of sirolimus, paclitaxel, and combretastatin A4 (CA4) on regulatory proteins of the cell cycle in proliferating smooth muscle cells (SMCs). MATERIALS AND METHODS: Human aortic SMCs were treated with sirolimus, paclitaxel, and CA4 at 5 × 10(-9) mol/L. After 1 day, half of the cells were harvested (DAY1 group). The treatment medium of the other half was replaced with culture medium on day 4, and those cells were harvested on day 5 (DAY5 group). Cyclins D1, D2, E, and A and cyclin-dependent kinase (CDK) inhibitors p16, p21, and p27 were detected by Western blot technique. Quantification was performed by scanning densitometry of the specific bands. RESULTS: In the DAY1 group, treatment with sirolimus resulted in decreased intracellular levels of cyclins D2 and A (P < .05). Increased D cyclins and reduced levels of cyclins E and A (P < .05) in the DAY5 group indicated a permanent G1/S block by sirolimus. Paclitaxel led to only slight alterations of cyclin and CDK inhibitor expression (P > .05). In the DAY1 group, CA4 decreased intracellular levels of cyclins D2, E, and A (P < .05). Despite recovery effects in the DAY5 group (increase of cyclins D1, D2, and A compared with DAY1 group; P < .05), the upregulation of the CDK inhibitor p21, increased D cyclins, and decreased cyclins E and A (P < .05) are compatible with a G1 arrest. CONCLUSIONS: CA4 is a stronger inhibitor of the SMC cycle than sirolimus or paclitaxel and may represent an alternative for drug-eluting stents in atherosclerotic luminal stenosis. The effect of CA4 on neointima formation should be evaluated further.

Modern multimodality diagnosis of portal vein infiltration in hepatocellular carcinoma and expected changes during current therapies.

Diagnosis of malignant portal vein infiltration and especially differentiation from bland thrombosis is challenging for most imaging techniques. The use of contrast-enhanced real-time modern imaging modalities like contrast-enhanced ultrasound (CEUS), volume perfusion CT (VPCT), or dynamic contrast-enhanced MRI (DCE-MRI) with dedicated postprocessing tools provides additional support in difficult cases and is therefore recommended.The purpose of this review is to present a practical overview of strengths and limitations of modern imaging techniques in the diagnosis of malignant infiltration of the portal vein by hepatocellular carcinoma and to describe subsequent changes during therapy.

Added value of integrated circuit detector in head CT: objective and subjective image quality in comparison to conventional detector design.

RATIONALE AND OBJECTIVES: A new computed tomography (CT) detector with integrated electric components and shorter conducting pathways has recently been introduced to decrease system inherent electronic noise. The purpose of this study was to assess the potential benefit of such integrated circuit detector (ICD) in head CT by comparing objective and subjective image quality in low-dose examinations with a conventional detector design. MATERIALS AND METHODS: Using a conventional detector, reduced-dose noncontrast head CT (255 mAs; effective dose, 1.7 mSv) was performed in 25 consecutive patients. Following transition to ICD, 25 consecutive patients were scanned using identical imaging parameters. Images in both groups were reconstructed with iterative reconstruction (IR) and filtered back projection (FBP) and assessed in terms of quantitative and qualitative image quality. RESULTS: Acquisition of head CT using ICD increased signal-to-noise ratio of gray and white matter by 14% (10.0 ± 1.6 vs. 11.4 ± 2.5; P = .02) and 17% (8.2 ± 0.8 vs. 9.6 ± 1.5; P = .000). The associated improvement in contrast-to-noise ratio was 12% (2.0 ± 0.5 vs. 2.2 ± 0.6; P = .121). In addition, there was a 51% increase in objective image sharpness (582 ± 85 vs. 884.5 ± 191; change in HU/Pixel; P < .000). Compared to standard acquisitions, subjective grading of noise and overall image quality scores were significantly improved with ICD (2.1 ± 0.3 vs. 1.6 ± 0.3; P < .000; 2.0 ± 0.5 vs. 1.6 ± 0.3; P = .001). Moreover, streak artifacts in the posterior fossa were substantially reduced (2.3 ± 0.7 vs. 1.7 ± 0.5; P = .004). CONCLUSIONS: At the same radiation level, acquisition of head CT with ICD achieves superior objective and subjective image quality and provides potential for significant dose reduction.

Midtreatment evaluation of lymphoma response to chemotherapy by volume perfusion computed tomography.

OBJECTIVE: The aim of this study was to search for chemotherapy-induced perfusion changes of diffuse large B-cell lymphoma, follicular lymphoma, and Hodgkin lymphoma at midtreatment versus baseline volume perfusion computed tomography (VPCT). METHODS: Forty-five consecutive patients with untreated diffuse large B-cell lymphoma, follicular lymphoma, and Hodgkin lymphoma received VPCT examinations of the tumor bulk at baseline and during chemotherapy (midtreatment). Blood flow (BF), blood volume (BV), and transit constant (K-trans) were determined. Treatment response was categorized according to the Cheson criteria into complete or partial remission and stable or relapsed/progressive disease. RESULTS: Midtreatment follow-up showed a reduction in BF, BV, and K-trans in all lymphoma subtypes compared with baseline. The reduction in BV was less pronounced in larger tumors. Notably, BF, BV, and K-trans decreased in the responders (complete remission/partial remission) when compared with the nonresponders (stable or relapsed/progressive disease). Less than 10% reduction in BF was shown to be the best VPCT criterion for the identification of nonresponse. CONCLUSIONS: Chemotherapy-induced perfusion changes in responders are recognizable at midtreatment VPCT.

Increasing bone sclerosis during bortezomib therapy in multiple myeloma patients: results of a reduced-dose whole-body MDCT study.

OBJECTIVE: The objective of our study was to assess the frequency, location, extent, and patterns of bone sclerosis occurring in patients with multiple myeloma (MM) during bortezomib-based therapy. MATERIALS AND METHODS: From June 2003 through December 2011, 593 whole-body reduced-dose MDCT studies were performed of 79 consecutive patients receiving bortezomib. The median surveillance time was 21 months (range, 3-67 months). Baseline studies were compared with follow-up studies during therapy (follow-up 1), at the end of therapy (follow-up 2), and 12 months after cessation of bortezomib therapy (follow-up 3). We recorded any sclerotic change occurring inside or along the margins of the osteolytic lesions, in the cancellous bone, or inside preexistent medullary or extramedullary lesions. The time point of occurrence of bone sclerosis was correlated with the best hematologic response category. RESULTS: Fourteen (17.7%) patients developed focal (n = 11) or diffuse (n = 3) bone sclerosis. The time window from bortezomib initiation to radiographic detection of bone sclerosis was 8 months (SD, 7 months). Sclerosis occurred at multiple sites (n = 7) or at an isolated site (n = 7). On subsequent whole-body reduced-dose MDCT studies, sclerosis further increased in seven (50%) patients. Hematologic best response during bortezomib treatment was complete response (n = 1), very good partial response (n = 2), partial response (n = 8), and stable disease (n = 3). Radiologic response at the time of sclerosis detection was partial response (n = 8), stable disease (n = 2), and progressive disease (n = 4). CONCLUSION: Bone remineralization may occur during bortezomib-based therapy for MM in a substantial proportion of patients. The extent, location, and patterns of sclerosis differ among patients and are unpredictable. Sclerosis was documented even in patients showing suboptimal hematologic response.

High prevalence of psoriatic arthritis in dermatological patients with psoriasis: a cross-sectional study.

The exact prevalence of psoriatic arthritis (PsA) among patients with psoriasis is still not conclusive. Data in the literature vary between 5.8 and 30 %. Objective of this study was to gain more information on the prevalence of PsA among patients with psoriasis in Germany. Between 09/2010 and 05/2011, consecutive patients from dermatological private practices and a university hospital with psoriasis were asked to fill out the validated German Psoriatic Arthritis Diagnostic (GEPARD) Questionnaire. Patients who answered ≥4 questions with "yes" were invited to come for a rheumatological check up. Those patients who refused a rheumatological examination were counted as "absence of PsA". Laboratory tests for inflammatory markers as well as the severity of skin manifestations were assessed. The diagnosis of PsA was made according to the CASPAR criteria, and imaging was performed in addition. A total of 404 questionnaires were evaluated; 50.5 % answered ≥4 questions positively; 19.3 % had a history of PsA confirmed by a rheumatologist; and in 10.9 %, PsA or spondyloarthritis was newly diagnosed during the present study. This leads to an overall prevalence of PsA in patients with psoriasis of 30.2 %. The frequency of psoriatic arthritis in the present study is higher than expected from previous studies in Germany. The prevalence is consistent with findings of a large observational survey from Scandinavia. Using the CASPAR criteria and imaging in all patients, certainty of the diagnosis is very high. The GEPARD Questionnaire is a helpful tool to identify people at risk for psoriatic arthritis.

Explanations for the heterogeneity of splenic enhancement derived from blood flow kinetic measurements using dynamic contrast-enhanced CT (DCE-CT).

BACKGROUND: The heterogeneity of splenic computed tomography (CT) attenuation is still not fully understood. A differentiation of these enhancement patterns and other conditions such as diffuse spleen infiltration can be challenging. PURPOSE: To understand the underlying physiological mechanisms of flow heterogeneity in normal and cirrhosis patients by quantifying perfusion parameters such as blood flow (BF), blood volume (BV), time to peak (TTP), flow extraction product (K(trans)), and mean transit time (MTT) using dynamic contrast-enhanced CT (DCE-CT). MATERIAL AND METHODS: Sixteen patients without splenic or hepatic disease and 16 patients with liver cirrhosis were retrospectively analyzed. Perfusion assessment included rapidly and slowly enhancing areas of the spleen, the entire splenic volume, as well as intra- and inter-observer reliability analysis. RESULTS: Significant differences between rapidly and slowly enhancing areas were found in controls for BF (109.8 mL/100 mL/min vs. 63.5 mL/100 mL/min), BV (37.1 mL/100 mL vs. 18.9 mL/100 mL), MTT (10.1 s vs. 13.0 s), but not for TTP (17.6 s vs. 18.6 s) and K(trans) (40.3 mL/100 mL/min vs. 44.7 mL/100 mL/min). In cirrhotic patients, differences proved significant for BF (90.5 mL/100 mL/min vs. 58.7 mL/100 mL/min), BV (17.5 mL/100 mL vs. 8.8 mL/100 mL), but not for K(trans) (60.9 mL/100 mL/min vs. 50.5 mL/100 mL/min), TTP (18.8 s vs. 20.0 s), and MTT (11.4 s vs. 14.2 s). Differences between rapidly enhancing areas in controls and cirrhotic patients reached a significant level for BV and K(trans). CONCLUSION: Preliminary results suggest that DCE-CT-based splenic perfusion measurements enable detection of different blood flow kinetics presumed to represent the complex and characteristic architecture of splenic vascular channels. It is the separate analysis of flow kinetics through the rapidly enhancing channels that allow for additional differentiation between controls and patients with portal hypertension.

Does volume perfusion computed tomography enable differentiation of metastatic and non-metastatic mediastinal lymph nodes in lung cancer patients? A feasibility study.

OBJECTIVES: To compare the perfusion characteristics of mediastinal lymph node metastases with those of non-metastatic nodes in patients with newly diagnosed lung cancer using volume perfusion computed tomography (VPCT). MATERIALS AND METHODS: Between January 2010 and October 2011, 101 patients with histologically confirmed, untreated lung cancer received a 40-s VPCT of the tumor bulk; 32/101 patients had evident hilar/mediastinal metastatic disease and 17/101 patients had proven non-metastasized lymph nodes within the VPCT scan range. Validation or exclusion of metastatic node involvement was proven by mediastinoscopy, biopsy, positron emission tomography imaging and/or unequivocal volume dynamics on follow-up computed tomography. A total of 45 metastases and 23 non-metastatic lymph nodes were found within the scan range and subsequently evaluated. Blood flow (BF), blood volume (BV) and K(trans) were determined. Tumor volume was recorded as whole tumor volume. RESULTS: In a comparison between metastatic and non-metastatic lymph nodes, we controlled for age, lymph node volume, lung tumor volume, lung tumor location, and histologic type effects and found no significant differences with respect to BF, BV, K(trans) or heterogeneity in nodal perfusion (P > 0.05, respectively), even after adjusting lymph node perfusion values to the perfusion parameters of the primary tumor (P > 0.05, respectively). Metastatic lymph node volume had a significant increasing effect on perfusion heterogeneity (P < 0.05, respectively) and BV in the primary was a highly significant factor for BV in metastatic disease (P < 0.001). CONCLUSION: Perfusion characteristics of mediastinal metastatic and non-metastatic lymph nodes in untreated lung cancer show considerable overlap, so that a reliable differentiation via VPCT is not possible.