Diffuse and localized pigmented villonodular synovitis: evaluation of treatment of 38 patients

We performed a retrospective study of 38 patients with pigmented villonodular synovitis (PVNS) to evaluate the treatment and functional results. The mean age of the patients was 32 (range 12-72) years at the time of treatment. Three types of PVNS have been identified: localized nodules in 9 patients, diffuse PVNS of the entire synovial membrane in 26, a combination of a diffuse involvement of the synovial membrane and an extra-articular presentation in 1, and extra-articular lesions in 2. The location of the lesions was knee (n = 31), hip (n = 3), ankle (n = 2), femoral triangle (n = 1), and gluteal region (n = 1). The procedures performed were surgery alone, surgery combined with radiosynovectomy and radiosynovectomy only. A follow-up was done after a mean of 4 (range 1-19) years in 34 patients. A functional evaluation according to the Musculoskeletal Tumor Society was performed in 31 patients. The mean functional evaluation score of 34 patients was 24 (range 15-30). Most of the ratings were excellent or good, in 6 cases fair, and in 2 cases poor. This study demonstrates that the functional results are good despite residual or recurrent disease; in addition, we showed that functional evaluation after treatment gives an optimal view of the impact and results of the operation.     

High dose propofol enhances red cell antioxidant capacity during CPB in humans

PURPOSE: To compare low vs. high dose propofol and isoflurane on red cell RBC antioxidant capacity in patients during aortocoronary bypass surgery (ACBP). METHODS: Twenty-one patients, for ACBP, were anesthetized with sufentanil 0.5-10 microg x kg(-1) and isoflurane 0-2%; ISO = control; n = 7), or sufentanil 0.3 microg x kg(-1), propofol 1-2.5 mg x kg(-1) bolus then 100 microg x kg(-1) min(-1) before, and 50 microg x kg(-1) x min(-1) during CPB (LO; n = 7), or sufentanil 0.3 microg x kg(-1), propofol 2-2.5 mg x kg(-1) bolus then 200 microg x kg(-1) x min(-1) (HI; n = 7). Venous blood was drawn pre- and post-induction, after 30 min CPB, 5, 10, and 30 min of reperfusion, and 120 min post-CPB to measure red cell antioxidant capacity (malondialdehyde (MDA) production in response to oxidative challenge with t-butyl hydrogen peroxide) and plasma propofol concentration. Pre- induction blood samples were analyzed for antioxidant effects of nitrates on red cells. The tBHP concentration response curves for RBC MDA in ISO, LO and HI were determined. RESULTS: Preoperative nitrate therapy did not effect RBC MDA production. Perioperative RBC MDA production was similar in ISO and LO groups. Sustained intraoperative decrease in RBC MDA was seen with propofol 8.0+/-2.4 - 11.8+/-4.5 microg x ml(-1) in HI (P<0.05-0.0001). MDA production vs. log plasma propofol concentration was linear in HI dose. CONCLUSIONS: During CPB, RBC antioxidant capacity is enhanced and maintained with HI dose propofol. Propofol, at this dose, may prove useful in protecting against cardiopulmonary ischemia-reperfusion injury associated with ACBP.     

Cell type-specific acquired protection from crystal adherence by renal tubule cells in culture

BACKGROUND: Adherence of crystals to the surface of renal tubule epithelial cells is considered an important step in the development of nephrolithiasis. Previously, we demonstrated that functional monolayers formed by the renal tubule cell line, Madin-Darby canine kidney (MDCK), acquire protection against the adherence of calcium oxalate monohydrate crystals. We now examined whether this property is cell type specific. The susceptibility of the cells to crystal binding was further studied under different culture conditions. METHODS: Cell-type specificity and the influence of the growth substrate was tested by comparing calcium oxalate monohydrate crystal binding to LLC-PK1 cells and to two MDCK strains cultured on either permeable or impermeable supports. These cell lines are representative for the renal proximal tubule (LLC-PK1) and distal tubule/collecting duct (MDCK) segments of the nephron, in which crystals are expected to be absent and present, respectively. RESULTS: Whereas relatively large amounts of crystals adhered to subconfluent MDCK cultures, the level of crystal binding to confluent monolayers was reduced for both MDCK strains. On permeable supports, MDCK cells not only obtained a higher level of morphological differentiation, but also acquired a higher degree of protection than on impermeable surfaces. Crystals avidly adhered to LLC-PK1 cells, irrespective of their developmental stage or growth substrate used. CONCLUSIONS: These results show that the prevention of crystal binding is cell type specific and expressed only by differentiated MDCK cells. The anti-adherence properties acquired by MDCK cells may mirror a specific functional characteristic of its in situ equivalent, the renal distal tubule/collecting ducts.     

Feasibility, safety and image quality of cardiac FDG studies during hyperinsulinaemic-euglycaemic clamping

Fluorine-18 fluorodeoxyglucose (FDG) imaging for the assessment of myocardial viability has become an integral part of the diagnostic and prognostic work-up of patients with ischaemic cardiomyopathy. To ensure good image quality, in particular in patients with diabetes mellitus, hyperinsulinaemic-euglycaemic clamping has been proposed. In this study we evaluated the safety and the image quality of cardiac FDG imaging during clamping in a large group of patients, including a subgroup with diabetes mellitus. The incidence of viability (on both a segment and a patient basis) was also determined for patients with and without diabetes mellitus. The safety and image quality of cardiac FDG studies during clamping were evaluated in 131 patients, including 19 with diabetes mellitus. Image quality was assessed visually and quantitatively using heart-to-lung (H/L), heart-to-liver (H/Li) and myocardium-to-background (M/B) ratios. Blood samples were drawn at baseline and at the time of FDG injection to determine levels of glucose, free fatty acids and insulin. The metabolic circumstances were optimal for FDG imaging: high insulin levels, low free fatty acid levels and glucose levels in the normal range (levels of substrates were comparable between patients with and patients without diabetes mellitus). No serious side-effects occurred in any patient. Image quality (assessed visually) was good in all patients. The quantitative parameters of image quality (H/L, H/Li and M/B) were comparable between patients with and patients without diabetes mellitus. The incidence of viability was high: 38% of patients without and 58% of patients with diabetes mellitus had substantial viability despite contractile dysfunction. It is concluded that cardiac FDG imaging during clamping is safe and provides excellent image quality, including in patients with diabetes mellitus. The incidence of viability is high, in particular in patients with diabetes mellitus.     

Pancreatic Neuroendocrine Tumors: Radiographic Calcifications Correlate with Grade and Metastasis

Background

Studies to identify preoperative prognostic variables for pancreatic neuroendocrine tumor (PNET) have been inconclusive. Specifically, the prevalence and prognostic significance of radiographic calcifications in these tumors remains unclear.

Methods

From 1998 to 2009, a total of 110 patients with well-differentiated PNET underwent surgical resection at our institution. Synchronous liver metastases present in 31 patients (28%) were addressed surgically with curative intent. Patients with high-grade PNET were excluded. The presence of calcifications in the primary tumor on preoperative computed tomography was recorded and correlated with clinicopathologic variables and overall survival.

Results

Calcifications were present in 16% of patients and were more common in gastrinomas and glucagonomas (50%), but never encountered in insulinomas. Calcified tumors were larger (median size 4.5 vs. 2.3?cm, P?=?0.04) and more commonly associated with lymph node metastasis (75 vs. 35%, P?=?0.01), synchronous liver metastasis (62 vs. 21%, P?P?P?=?0.01) and size (P?P?=?0.04), but not in the presence of radiographic calcifications.

Conclusions

Calcifications on preoperative computed tomography correlate with intermediate grade and lymph node metastasis in well-differentiated PNET. This information is available preoperatively and supports the routine dissection of regional lymph nodes through formal pancreatectomy rather than enucleation in calcified PNET.     

Changing management of gallstone disease during pregnancy

Background: Symptomatic gallstones may be problematic during pregnancy. The advisability of laparoscopic cholecystectomy (LC) is uncertain. The objective of this study is to define the natural history of gallstone disease during pregnancy and evaluate the safety of LC during pregnancy. Methods: Review of medical records of all pregnant patients with gallstone disease at the University of California, San Francisco, from 1980 to 1996. Results: Of approximately 29,750 deliveries, 47 (0.16%) patients were treated for gallstone disease, including biliary colic in 33, acute cholecystitis in 12, and pancreatitis in two. Conservative treatment was attempted in all patients but failed in 17 (36%) cases. Two patients required combined preterm Cesarean-section cholecystectomy and 10 required surgery in the early postpartum period for persistent symptoms. Seventeen patients required cholecystectomy during pregnancy for biliary colic (10), acute cholecystitis (six), and pancreatitis (one). Three patients were treated with open cholecystectomy. Fourteen patients underwent LC at a mean gestational age of 18.6 weeks, mean OR time of 74 min, and mean length of stay of 1.2 days. Hasson cannulation was utilized in 11 patients. Reduced-pressure pneumoperitoneum (6–10 mmHg) was used in seven patients. Prophylactic tocolytics were used in seven patients, with transient postoperative preterm labor observed in one. There were no open conversions, preterm deliveries, fetal loss, teratogenicity, or maternal morbidity. Conclusions: In past years, symptomatic gallstones during pregnancy were managed conservatively or with open cholecystectomy. LC is a feasible and safe method for treating severely symptomatic patients. Received: 3 April 1997/Accepted: 5 July 1997     

Local recurrence after cystectomy and survival of patients with bladder cancer: a population based study in greater amsterdam

PURPOSE: We determined retrospectively in a population based study the survival of patients with bladder cancer and the local recurrence rate (LRR) after cystectomy. MATERIALS AND METHODS: All patients with bladder cancer diagnosed between 1988 and 2001 (vital status updated until September 2003) were selected from the Amsterdam Cancer Registry, which covers a population of 2.84 million individuals. For all patients who underwent cystectomy between 1988 and 1997 at 18 participating hospitals information on local recurrence and vital status was collected from the medical records. RESULTS: Five-year relative survival in all 8,321 bladder cancer cases combined was 75%. For clinical stage 0-a this was 99%, decreasing to 85% for stage 0-is and 82% for stage I, and to 44%, 28% and 9% for stages II to IV, respectively. Five-year relative survival after cystectomy was 81%, 44% and 23% for stages II to IV, respectively. The LRR after cystectomy was 19% in all 566 cases and all institutions combined. The LRR increased with higher pT stage and it achieved 11%, 23% and 31% for stages II to IV, respectively. It was slightly lower at oncological centers than at community hospitals (18% vs 20%, not significant). CONCLUSIONS: Survival is higher than the European average but below the value in the United States. Only 1 of 3 stages II-III cases was treated with cystectomy. Relatively high stage specific survival is experienced after cystectomy despite local recurrence in 1 of 5 patients.     

Imaging the Intracranial Atherosclerotic Vessel Wall Using 7T MRI: Initial Comparison with Histopathology

BACKGROUND AND PURPOSE:Several studies have attempted to characterize intracranial atherosclerotic plaques by using MR imaging sequences. However, dedicated validation of these sequences with histology has not yet been performed. The current study assessed the ability of ultra-high-resolution 7T MR imaging sequences with different image contrast weightings to image plaque components, by using histology as criterion standard.MATERIALS AND METHODS:Five specimens of the circle of Wills were imaged at 7T with 0.11 × 0.11 mm in-plane-resolution proton attenuation–, T1-, T2-, and T2*-weighted sequences (through-plane resolution, 0.11–1 mm). Tissue samples from 13 fiducial-marked locations (per specimen) on MR imaging underwent histologic processing and atherosclerotic plaque classification. Reconstructed MR images were matched with histologic sections at corresponding locations.RESULTS:Forty-four samples were available for subsequent evaluation of agreement or disagreement between plaque components and image contrast differences. Of samples, 52.3% (n = 23) showed no image contrast heterogeneity; this group comprised solely no lesions or early lesions. Of samples, 25.0% (n = 11, mostly advanced lesions) showed good correlation between the spatial organization of MR imaging heterogeneities and plaque components. Areas of foamy macrophages were generally seen as proton attenuation–, T2-, and T2*- hypointense areas, while areas of increased collagen content showed more ambiguous signal intensities. Five samples showed image-contrast heterogeneity without corresponding plaque components on histology; 5 other samples showed contrast heterogeneity based on intima-media artifacts.CONCLUSIONS:MR imaging at 7T has the image contrast capable of identifying both focal intracranial vessel wall thickening and distinguishing areas of different signal intensities spatially corresponding to plaque components within more advanced atherosclerotic plaques.

Intracranial atherosclerosis is emerging as one of the main causes of cerebral ischemic stroke and transient ischemic attack, with a high risk of recurrent ischemic events.¹ In recent years, several MR imaging sequences have been developed on 3T and 7T field strengths that specifically visualize the intracranial arterial vessel wall, enabling direct assessment of intracranial atherosclerotic plaques.^2–8 Similar to studies of carotid artery atherosclerosis almost a decade ago, several studies have recently attempted to characterize intracranial plaque components, such as intraplaque hemorrhage,^9,10 fibrous cap,¹¹ and lipid components, by using MR imaging.^12,13For the carotid arteries, much research has already been done validating image signal heterogeneity within the vessel wall with histology, the criterion standard.^14–20 Imaging carotid artery atherosclerosis has the advantage of easy access to ex vivo atherosclerotic plaque material for validation, using carotid endarterectomy specimens. It is now possible to image calcification, fibrous cap, intraplaque hemorrhage, and lipid-rich necrotic core in the carotid artery with moderate-to-good sensitivity and specificity by using multicontrast MR imaging.²⁰ Although 1 recent study showed promising preliminary results of plaque characterization by using a combined T1- and T2-weighted sequence²¹ compared with histology, dedicated validation with histology of intracranial vessel wall sequences with multiple image contrast weightings has not yet been performed. Therefore, whether MR imaging with multiple image contrast weightings has enough image contrast to also visualize various intracranial atherosclerotic plaque components remains a question.Validation of MR images with histology for intracranial atherosclerosis in vivo is much more cumbersome compared with carotid plaques, because no therapies (comparable with carotid endarterectomy) exist in which intracranial atherosclerotic plaques are removed. Furthermore, intracranial arteries are smaller than carotid (or other major peripheral) arteries,²² necessitating a high spatial resolution, and therefore high SNR, for plaque visualization. Because the SNR increases approximately linearly with field strength, 7T MR imaging might provide the spatial resolution necessary to image small atherosclerotic plaques.²² Furthermore, several dedicated intracranial vessel wall sequences at 7T have already shown promising results in the visualization of vessel wall lesions in vivo.In this feasibility study, ultra-high-resolution 7T MR imaging sequences with different image contrast weightings were developed and used in an ex vivo setting, to assess the ability (image contrast) of 7T MR imaging to image different intracranial atherosclerotic plaque components. For validation of our findings, results were compared with histology.     

The Netherlands protocol for standardisation and quantification of FDG whole body PET studies in multi-centre trials

Introduction  Several studies have shown the usefulness of positron emission tomography (PET) quantification using standardised uptake values (SUV) for diagnosis and staging, prognosis and response monitoring. Many factors affect SUV, such as patient preparation procedures, scan acquisition, image reconstruction and data analysis settings, and the variability in methodology across centres prohibits exchange of SUV data. Therefore, standardisation of 2-[¹⁸F] fluoro-2-deoxy-D-glucose (FDG) PET whole body procedures is required in multi-centre trials. Methods  A protocol for standardisation of quantitative FDG whole body PET studies in the Netherlands (NL) was defined. This protocol is based on standardisation of: (1) patient preparation; (2) matching of scan statistics by prescribing dosage as function of patient weight, scan time per bed position, percentage of bed overlap and image acquisition mode (2D or 3D); (3) matching of image resolution by prescribing reconstruction settings for each type of scanner; (4) matching of data analysis procedure by defining volume of interest methods and SUV calculations and; (5) finally, a multi-centre QC procedure is defined using a 20-cm diameter phantom for verification of scanner calibration and the NEMA NU 2 2001 Image Quality phantom for verification of activity concentration recoveries (i.e., verification of image resolution and reconstruction convergence). Discussion  This paper describes a protocol for standardization of quantitative FDG whole body multi-centre PET studies. Conclusion  The protocol was successfully implemented in the Netherlands and has been approved by the Netherlands Society of Nuclear Medicine. An erratum to this article can be found at     

Stroke volume measurements with first-pass dynamic positron emission tomography: Comparison with cardiovascular magnetic resonance

Background  The assessment of forward stroke volume (SV) using dynamic, first-pass cardiac positron emission tomography (PET) was shown to be feasible in a limited number of studies with small numbers of subjects. The aim of this study was to compare first-pass derived SV with cardiovascular magnetic resonance imaging (CMR)-obtained values in a larger population of subjects. Methods and Results  Fifty-nine subjects with varying degrees of cardiac function were studied. Stroke volume was assessed using oxygen-15-labeled water (H₂ ¹⁵O) dynamic first-pass PET for both the right ventricle (RV) and left ventricle (LV), and compared with the findings of aorta velocity-encoded phase-contrast CMR. The PET-estimated SV was higher for the RV than for the LV (133±34 vs 116±31 mL, P<.01, ±SD), and both were higher compared with values obtained by CMR (81±20 mL, both P<.01,±SD). Although significant, the correlations between PET and CMR were moderate for both the RV (r=0.37, P<.01) and the LV (r=0.40, P<.01,±SD). Bland-Altman analysis revealed a progressive overestimation with increasing SV measured in either ventricle. Conclusions  First-pass dynamic H₂ ¹⁵O PET for the assessment of forward SV is feasible, although values are progressively overestimated with increasing SV, particularly when the RV is used, and correlations with aorta velocity-encoded phase-contrast CMR are moderate. These findings are probably protocol-dependent and warrant further study before the use of first-pass dynamic H₂ ¹⁵O PET in clinical or research settings can be advocated.