Correction to: National survey on dose data analysis in computed tomography.

The original version of this article, published on 28 May 2018, unfortunately contained a mistake.

National survey on dose data analysis in computed tomography.

OBJECTIVES: A nationwide survey was performed assessing current practice of dose data analysis in computed tomography (CT). MATERIAL AND METHODS: All radiological departments in Switzerland were asked to participate in the on-line survey composed of 19 questions (16 multiple choice, 3 free text). It consisted of four sections: (1) general information on the department, (2) dose data analysis, (3) use of a dose management software (DMS) and (4) radiation protection activities. RESULTS: In total, 152 out of 241 Swiss radiological departments filled in the whole questionnaire (return rate, 63%). Seventy-nine per cent of the departments (n = 120/152) analyse dose data on a regular basis with considerable heterogeneity in the frequency (1-2 times per year, 45%, n = 54/120; every month, 35%, n = 42/120) and method of analysis. Manual analysis is carried out by 58% (n = 70/120) compared with 42% (n = 50/120) of departments using a DMS. Purchase of a DMS is planned by 43% (n = 30/70) of the departments with manual analysis. Real-time analysis of dose data is performed by 42% (n = 21/50) of the departments with a DMS; however, residents can access the DMS in clinical routine only in 20% (n = 10/50) of the departments. An interdisciplinary dose team, which among other things communicates dose data internally (63%, n = 76/120) and externally, is already implemented in 57% (n = 68/120) departments. CONCLUSION: Swiss radiological departments are committed to radiation safety. However, there is high heterogeneity among them regarding the frequency and method of dose data analysis as well as the use of DMS and radiation protection activities. KEY POINTS: • Swiss radiological departments are committed to and interest in radiation safety as proven by a 63% return rate of the survey. • Seventy-nine per cent of departments analyse dose data on a regular basis with differences in the frequency and method of analysis: 42% use a dose management software, while 58% currently perform manual dose data analysis. Of the latter, 43% plan to buy a dose management software. • Currently, only 25% of the departments add radiation exposure data to the final CT report.

Implementation of a patient dose monitoring system in conventional digital X-ray imaging: initial experiences.

OBJECTIVES: The purpose was to report on the initial experience after implementation of a patient dose-monitoring system in conventional X-ray imaging. METHODS: A dose-monitoring system collected dose data relating to different radiographs (one projection) and studies (two or more projections). Images were acquired on digital X-ray systems equipped with flat-panel detectors. During period 1, examinations were performed in a routine fashion in 12,614 patients. After period 1, technical modifications were performed and radiographers underwent training in radiation protection. During period 2, examinations were performed in 14,514 patients, and the radiographers were advised to read dose data after each radiograph/study. Dose data were compared by means of kerma area product (KAP, gray × centimetre squared) and entrance surface air kerma (ESAK, milligray). RESULTS: During period 1, 13,955 radiographs and 8,466 studies were performed, and in period 2 16,090 radiographs and 10,389 studies. In period 2, KAP values for radiographs were an average of 25 % lower and for studies 7 % lower, and ESAK values for radiographs were 24 % lower and for studies 5 % lower. The reduction in KAP was significant in 8/13 radiographs and in 6/14 studies, and the reduction in ESAK was significant in 6/13 radiographs and 5/14 studies. CONCLUSIONS: Implementation of a patient dose-monitoring system in conventional X-ray imaging allows easy data collection, supports dose reduction efforts, and may increase radiographers' dose awareness. KEY POINTS: • A dose-monitoring system enables easy dose data collection in X-ray imaging. • The system facilitates dose reduction efforts and may increase radiographers' radiation awareness. • Mean kerma-area-product significantly declined in period 2 in 8/13 radiographs and 6/14 studies. • In ESAK a significant decline was evident in 6/13 radiographs and 5/14 studies.

Magnetic resonance imaging of pelvic floor dysfunction - joint recommendations of the ESUR and ESGAR Pelvic Floor Working Group.

OBJECTIVE: To develop recommendations that can be used as guidance for standardized approach regarding indications, patient preparation, sequences acquisition, interpretation and reporting of magnetic resonance imaging (MRI) for diagnosis and grading of pelvic floor dysfunction (PFD). METHODS: The technique included critical literature between 1993 and 2013 and expert consensus about MRI protocols by the pelvic floor-imaging working group of the European Society of Urogenital Radiology (ESUR) and the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) from one Egyptian and seven European institutions. Data collection and analysis were achieved in 5 consecutive steps. Eighty-two items were scored to be eligible for further analysis and scaling. Agreement of at least 80 % was defined as consensus finding. RESULTS: Consensus was reached for 88 % of 82 items. Recommended reporting template should include two main sections for measurements and grading. The pubococcygeal line (PCL) is recommended as the reference line to measure pelvic organ prolapse. The recommended grading scheme is the "Rule of three" for Pelvic Organ Prolapse (POP), while a rectocele and ARJ descent each has its specific grading system. CONCLUSION: This literature review and expert consensus recommendations can be used as guidance for MR imaging and reporting of PFD. KEY POINTS: • These recommendations highlight the most important prerequisites to obtain a diagnostic PFD-MRI. • Static, dynamic and evacuation sequences should be generally performed for PFD evaluation. • The recommendations were constructed through consensus among 13 radiologists from 8 institutions.

Establishing Local Diagnostic Reference Levels in IR Procedures with Dose Management Software.

PURPOSE: To obtain local diagnostic reference levels (DRLs) in diagnostic and therapeutic IR procedures with dose management software to improve radiation protection. MATERIALS AND METHODS: Dose data of various vascular and nonvascular IR procedures performed within 18 months were collected and analyzed with dose management software. To account for different levels of complexity, procedures were subdivided into simple, standard, and difficult procedures as graded by interventional radiologists. Based on these analyses, local DRLs (given as kerma-area product [KAP]) were proposed. Comparison with dose data of others was conducted, and Spearman correlation coefficients were calculated to evaluate relationships between dose metrics. RESULTS: Analysis included 1,403 IR procedures (simple/standard/difficult, n = 346/702/355). Within the same procedure, KAP tended to increase with level of complexity. Overall, very strong correlation between KAP (Gy ∙ cm2) and cumulative air kerma (KA,R; Gy) was observed, and moderate to strong correlation between KAP and time and KA,R and time was observed. For simple procedures, strong correlation was seen between KAP and time and KA,R and time; for standard and difficult procedures, only moderate correlation was seen. Correlation between KAP and time and KA,R and time was strong in nonvascular procedures but only moderate in vascular procedures. CONCLUSIONS: Dose management software can be used to derive local DRLs for various IR procedures, taking into consideration different levels of complexity. Proposed local DRLs can contribute to obtaining detailed national DRLs as part of efforts to improve patients' radiation protection further.

Combined Use of a Patient Dose Monitoring System and a Real-Time Occupational Dose Monitoring System for Fluoroscopically Guided Interventions.

PURPOSE: To determine the effect on patient radiation exposure of the combined use of a patient dose monitoring system and real-time occupational dose monitoring during fluoroscopically guided interventions (FGIs). MATERIALS AND METHODS: Patient radiation exposure, in terms of the kerma area product (KAP; Gy ∙ cm(2)), was measured in period 1 with a patient dose monitoring system, and a real-time occupational dose monitoring system was additionally applied in period 2. Mean/median KAP in 19 different types of FGIs was analyzed in both periods for two experienced interventional radiologists combined as well as individually. Patient dose and occupational dose were correlated, applying Pearson and Spearman correlation coefficients. RESULTS: Although FGIs were similar in numbers and types over both periods, a substantial decrease was found for period 2 in total mean ± SD/median KAP for both operators together (period 1, 47 Gy ∙ cm(2) ± 67/41 Gy ∙ cm(2); period 2, 37 Gy ∙ cm(2) ± 69/34 Gy ∙ cm(2)) as well as for each individual operator (for all, P < .05). Overall, KAP declined considerably in 15 of 19 types of FGIs in period 2. Mean accumulated dose per intervention was 4.6 µSv, and mean dose rate was 0.24 mSv/h. There was a strong positive correlation between patient and occupational dose (r = 0.88). CONCLUSIONS: Combined use of a patient dose monitoring system and a real-time occupational dose monitoring system in FGIs significantly lessens patient and operator doses.

Does Real-Time Monitoring of Patient Dose With Dose Management Software Increase CT Technologists' Radiation Awareness?

OBJECTIVE: Dose management software can be used to increase patient safety. The purpose of the current study was to evaluate whether real-time monitoring of patient dose in CT examinations increases CT technologists' dose awareness. MATERIALS AND METHODS: Dose data of two scanners (clinical routine CT scanner, mainly outpatients; emergency CT scanner, predominantly emergency department and ICU patients) were analyzed before (period 1) and after (period 2) dose management software was implemented in clinical routine and technologists were advised to check for dose notifications (dose values above reference levels) after each examination (i.e., real-time monitoring). To assess statistically significant differences between both the scanners and the study periods, we used chi-square tests. RESULTS: A total of 6413 examinations were performed (period 1 = 3214 examinations, period 2 = 3199 examinations). Dose notifications were mainly because of patient miscentering (period 1 = 45% of examinations, period 2 = 23%), overweight patients (period 1 = 35%, period 2 = 49%), and scanning repetition (period 1 = 10%, period 2 = 15%). Overall, the number of dose notifications significantly declined in period 2 (period 1, n = 210; period 2, n = 120; p < 0.001). Miscentering was more often seen on the clinical routine CT examinations (period 1 = 46%, period 2 = 23%) than on the emergency CT examinations (period 1 = 44%, period 2 = 22%) and occurred significantly less frequently on both scanners in period 2 (period 1: n = 94; period 2: n = 27; p < 0.001). The relative values of dose notifications due to overweight patients or scanning repetition were higher in period 2, but these differences did not reach statistical significance (p > 0.05). CONCLUSION: Real-time monitoring of patient dose with dose management software increases CT technologists' dose awareness and leads to a reduced number of dose notifications due to human error.

Assessment of Obstructive Defecation by High-Resolution Anorectal Manometry Compared With Magnetic Resonance Defecography.

BACKGROUND & AIMS: Patients with obstructive defecation have abnormalities of anorectal function and/or structure. Conventional anorectal manometry (ARM) can identify abnormal function and behavior (dyssynergia); however, agreement between manometry and defecography is only fair. High-resolution (HR)-ARM may improve diagnostic agreement by differentiating pressure effects caused by dyssynergia and obstruction. We compared HR-ARM findings with magnetic resonance (MR) defecography in the clinical assessment of patients with symptoms of obstructive defecation defined by Rome III criteria. METHODS: HR-ARM (Manoscan AR 360; Given Imaging, Yoqeam, Israel) assessed anal sphincter function and pressure during simulated defecation. Abnormal manometric findings were classified according to the Rao system and compared with MR defecography as the reference standard. RESULTS: A total of 188 consecutive patients (155 women; age, 19-93 y) with obstructive defecation underwent a full investigation. Compared with patients with dyssynergia on MR imaging (n = 66), patients with structural pathology (n = 87) had lower resting (P < .003) and squeeze pressures (P < .011), but a higher rectoanal pressure gradient (P < .0001) on HR-ARM. High intrarectal pressure with a steep, positive pressure gradient consistent with outlet obstruction on HR-ARM was present in 24 patients with intra-anal intussusception on MR imaging. This pattern was not observed in other patients. Interobserver agreement was substantial for HR-ARM diagnoses (κ = 0.67; 95% confidence interval, 0.559-0.779). Diagnostic accuracy for dyssynergia was 82% compared with MR imaging (sensitivity, 77% [51 of 66]; specificity, 85% [104 of 122]). CONCLUSIONS: The diagnostic agreement between anorectal HR-ARM and MR defecography is high and pressure measurements accurately identify recto-anal dyssynergia and intra-anal outlet obstruction by structural pathology as causes of obstructive defecation.

Improving Patient Safety: Implementing Dose Monitoring Software in Fluoroscopically Guided Interventions.

PURPOSE: To assess whether dose monitoring software can be successfully implemented in fluoroscopically guided interventions and to provide dose data based on levels of complexity. MATERIALS AND METHODS: After launching the software (DoseWatch; GE Healthcare Systems, Buc, France), data were collected for 6 months and analyzed by means of kerma-area product (KAP; Gy/cm(2)), cumulative air kerma (KA,R; Gy), and fluoroscopic time (minutes). Data analysis was executed by level of complexity as graded by the operators. Complexity grading was based on factors such as tortuosity and calcification of vessel, variant anatomy, and patient cooperation. RESULTS: The software successfully transferred dose data of 357 fluoroscopically guided procedures. KAP was 0.238-400 Gy/cm(2) with mean, median, and 75th percentile values of 46.0 Gy/cm(2), 163.2 Gy/cm(2), and 541.1 Gy/cm(2) (KA,R, 0.013-4.1 Gy; mean, median, 75th percentile, 0.48 Gy, 0.97 Gy, 3.98 Gy). Highest dose values were seen in transarterial chemoembolization (KAP mean, median, 75th percentile, 229.5 Gy/cm(2), 216.4 Gy/cm(2), 299.9 Gy/cm(2); KA,R mean, median, 75th percentile, 1.9 Gy, 1.2 Gy, 1.7 Gy). Analysis revealed that the level of complexity strongly correlated with KAP (r = 0.88; P < .001) whereas there was no direct correlation of KAP and fluoroscopy time. During the same intervention, KA,R and fluoroscopy time increased with level of complexity, but the correlation was not statistically significant. CONCLUSIONS: Implementation of dose monitoring software in fluoroscopically guided interventions can be successfully accomplished, and it facilitates data comparison.

Abdominal aortic calcification and its distribution in normal-sized and aneurysmatic abdominal aortas.

BACKGROUND: Multi-detector computed tomography (MDCT) is more and more used for evaluation and quantification of coronary artery calcification, but correlation between the degree of calcification and occurrence of clinical events is also known for other vascular beds such as the aorta. PURPOSE: To assess possible differences in amount and pattern of calcification in aneurysmatic and non-aneurysmatic abdominal aortas. PATIENTS AND METHODS: Thirty-four subjects displayed infrarenal abdominal aneurysm (AAA) and were compared to 33 patients with normal-sized aortas using MDCT. Quantitative and qualitative analysis was performed by two radiologists. Calcium scores were assessed for the whole abdominal aorta as well as separately for the supra- and infrarenal segments. Moreover, plaque patterns were evaluated and classified according to their thickness and size. Furthermore, calcium scores were correlated with a number of cardiovascular risk factors. RESULTS: Total calcium scores were comparable in patients with and without AAA (1,213 ± 1,351 and 1,211 ± 1,535, respectively), but significant differences were found regarding plaque density that was considerably higher both in the supra- and infrarenal segments in the non-aneurysmatic group (AAA: suprarenal, 0.01, infrarenal, 0.07; non-AAA: suprarenal, 0.06, infrarenal, 0.16). Plaque pattern were considerably different in the infrarenal segments in aneurysmatic aortas: they were thinner (1 and 2 mm) and smaller (< 100 mm2) than in normal-sized aortas (mainly > 3mm and > 100 mm2). Distribution of risk factors was similar in both groups with the highest mean calcium score being present in patients with 4 risk factors. Pearson's correlation coefficient indicating correlation between total calcium score and number of risk factors was almost the same in both groups: AAA, r = 0.67; non-AAA, r = 0.65. CONCLUSIONS: Compared to normal-sized aortas thinner and smaller plaques are present in AAA, which may be due to degenerative processes.

Sirolimus and kidney growth in autosomal dominant polycystic kidney disease.

BACKGROUND: In autosomal dominant polycystic kidney disease (ADPKD), aberrant activation of the mammalian target of rapamycin (mTOR) pathway is associated with progressive kidney enlargement. The drug sirolimus suppresses mTOR signaling. METHODS: In this 18-month, open-label, randomized, controlled trial, we sought to determine whether sirolimus halts the growth in kidney volume among patients with ADPKD. We randomly assigned 100 patients between the ages of 18 and 40 years to receive either sirolimus (target dose, 2 mg daily) or standard care. All patients had an estimated creatinine clearance of at least 70 ml per minute. Serial magnetic resonance imaging was performed to measure the volume of polycystic kidneys. The primary outcome was total kidney volume at 18 months on blinded assessment. Secondary outcomes were the glomerular filtration rate and urinary albumin excretion rate at 18 months. RESULTS: At randomization, the median total kidney volume was 907 cm3 (interquartile range, 577 to 1330) in the sirolimus group and 1003 cm3 (interquartile range, 574 to 1422) in the control group. The median increase over the 18-month period was 99 cm3 (interquartile range, 43 to 173) in the sirolimus group and 97 cm3 (interquartile range, 37 to 181) in the control group. At 18 months, the median total kidney volume in the sirolimus group was 102% of that in the control group (95% confidence interval, 99 to 105; P=0.26). The glomerular filtration rate did not differ significantly between the two groups; however, the urinary albumin excretion rate was higher in the sirolimus group. CONCLUSIONS: In adults with ADPKD and early chronic kidney disease, 18 months of treatment with sirolimus did not halt polycystic kidney growth. (Funded by Wyeth and others; ClinicalTrials.gov number, NCT00346918.)

Accuracy of multidetector-row CT for restaging after neoadjuvant treatment in patients with oesophageal cancer.

OBJECTIVES: To assess the diagnostic accuracy of 64-multidetector CT (MDCT) for restaging of patients with oesophageal cancer undergoing neoadjuvant therapy. METHODS: Results of pathological staging were correlated with those from 64-MDCT before and after neoadjuvant treatment in 35 patients using the American Joint Committee on Cancer/TNM classification (7th edition). CT response was determined using the Response Evaluation Criteria in Solid Tumours (RECIST) method, modified for one-dimensional tumour diameter measurement. RESULTS: 64-MDCT predicted T stage correctly in 34 % (12/35), overstaged in 49 % (17/35) and understaged in 17 % (6/35). Sensitivity/specificity values were as follows: T0, 20 %/92 %; T1-T2, 31 %/59 %; T3, 60 %/64 %; T4, 100 %/4 %. Negative predictive values for T3/T4 were 80 %/100 %. MDCT accurately predicted complete histopathological response in 20 % (accuracy 74 %) and overstaged in 80 %. Tumour regression grade was predicted correctly in only 8 % (2/25) and underestimated in 68 % (17/25). Accurate N stage was noted in 69 % (24/35). CONCLUSION: Although MDCT tends to be able to exclude advanced tumour stages (T3, T4) with a higher likelihood, the diagnostic accuracy of high resolution MDCT for restaging oesophageal cancer and assessing the response to neoadjuvant therapy has not improved in comparison to older-generation CT. Therefore, the future assessment of oesophageal tumour response should focus on combined morphologic and metabolic imaging. KEY POINTS: • Multidetector CT (MDCT) has been beneficial for the evaluation of many tumours. • However diagnostic accuracy for restaging oesophageal cancer has not improved with MDCT. • MDCT tends to be able to exclude advanced tumour stages (T3/T4). • MDCT has a low accuracy for determining lymph node metastasis. • Oesophageal tumour response should be assessed by combined morphological and metabolic imaging.

Dynamic pelvic floor imaging: MRI techniques and imaging parameters.

Magnetic resonance imaging (MRI) is an excellent tool to understand the complex anatomy of the pelvic floor and to assess pelvic floor disorders. MRI enables static and dynamic imaging of the pelvic floor. Using static T2-weighted sequences the morphology of the pelvic floor can be visualized in great detail. A rapid half-Fourier T2-weighted, balanced steady state free precession, or gradient-recalled echo sequence are used to obtain sagittal images while the patient is at rest, during pelvic squeeze, during pelvic strain and to document the evacuation process. On these images the radiologist identifies the pubococcygeal line (PCL) (which represents the level of the pelvic floor). In normal findings, the base of the anterior and the middle compartment are above the PCL at rest, and the pelvic floor elevates during contraction. During straining the pelvic floor muscles should relax and the pelvic floor descends normally less than 3 cm below the PCL. Pelvic floor MRI based on the static and dynamic MRI sequences allows for the detection and characterization of a vast array of morphologic and functional pelvic floor disorders. In this review, we focus on technical aspects of static and dynamic pelvic floor MRI.

Diagnostic accuracy of whole-body MRI/DWI image fusion for detection of malignant tumours: a comparison with PET/CT.

OBJECTIVE: To prospectively evaluate the diagnostic accuracy of whole-body T2-weighted (wbT2), whole-body diffusion-weighted imaging (wbDWI) and wbT2/wbDWI image fusion for malignant tumour detection compared with PET/CT. METHODS: Sixty-eight patients (44 men; 60 ± 14 years) underwent PET/CT for staging of malignancy and were consecutively examined by 1.5-Tesla MRI including wbT2 and wbDWI. Two radiologists independently assessed wbDWI, wbT2, wbT2 + wbDWI (side-by-side) and wbT2 + wbDWI + wbT2/wbDWI image fusion for the presence of malignancy. PET/CT served as a reference standard. RESULTS: PET/CT revealed 374 malignant lesions in 48/64 (75%) patients. Detection rates and positive predictive value (PPV) of wbT2 and wbDWI alone were 64% and 84%, and 57% and 93%, respectively. Detection rates and PPV of wbT2 and wbDWI for side-by-side analysis without and with fused images were 72% and 89%, and 74% and 91%, respectively. The detection rate was significantly higher with side-by-side analysis and fused image analysis compared with wbT2 and wbDWI alone (p = .0159; p < .0001). There was no significant difference between fused image interpretation and side-by-side analysis. CONCLUSIONS: WbDWI allows detection of malignant lesions with a similar detection rate to wbT2. Side-by-side analysis of wbT2 and wbDWI significantly improves the overall detection rate and fused image data provides no added value.

Effects of pentoxifylline on liver regeneration: a double-blinded, randomized, controlled trial in 101 patients undergoing major liver resection.

OBJECTIVES: To evaluate the effects of pentoxifylline (PTX) on liver regeneration in patients undergoing major liver resection. BACKGROUND: Recent experimental data suggest that PTX, a tumor necrosis factor (TNF) α inhibitor, enhances liver regeneration and reduces ischemic injury through activation of the interleukin-6 (IL-6) signaling pathway. However, the clinical impact of PTX in patients undergoing major liver surgery is unknown. METHODS: One hundred one consecutive noncirrhotic patients undergoing major liver surgery with inflow occlusion were included in a double-blinded, randomized, controlled trial (RCT) at a single tertiary care center (2006-2009). Fifty-one patients received intravenous administration of PTX starting 12 hours before and ending 72 hours after surgery, whereas 50 control patients received a placebo infusion. Primary endpoint was liver regeneration as assessed by three-dimensional volumetry based on magnetic resonance (MR) tomography at postoperative day 8 compared with preoperative images. Secondary endpoints were transaminases, cytokines, and postoperative complications. RESULTS: Both groups were comparable regarding demographics, risk score, preoperative laboratory tests, and type and extent of liver resection. Treatment with PTX resulted in significantly better volume regeneration for small remnant livers [remnant liver to body weight (RLBW) ratio ≤ 1.2%], whereas no beneficial effect was observed for RLBW ratio of more than 1.2%. There was a 3.6-fold stronger induction of IL-6 mRNA for the PTX group (P < 0.001). Postoperative alanine aminotransferase (AST) levels were significantly decreased for the PTX group on the second postoperative day (442 vs 585 U/L, P = 0.025). No significant benefit could be identified regarding the number and severity of postoperative complications and median ICU (1 vs 1 day) and hospital stay (10 vs 10 days). However, the PTX group had significantly more drug-related adverse events (23 vs 8, P = 0.007). CONCLUSIONS: This is the first RCT evaluating the effects of PTX on liver regeneration after major liver resection. The study demonstrates beneficial effects of PTX on regeneration of small remnant livers (RLBW ratio ≤ 1.2%) that seems to be mediated by IL-6.

Increases in kidney volume in autosomal dominant polycystic kidney disease can be detected within 6 months.

Kidney volume growth is considered the best surrogate marker predicting the decline of renal function in autosomal dominant polycystic kidney disease. To assess the therapeutic benefit of new drugs more rapidly, changes in kidney volume need to be determined over a short time interval. Here we measured renal volume changes by manual segmentation volumetry applied to magnetic resonance imaging scans obtained with an optimized T1-weighted acquisition protocol without gadolinium-based contrast agents. One hundred young patients with autosomal dominant polycystic kidney disease and preserved renal function had a significant increase in total kidney volume by 2.71+/-4.82% in 6 months. Volume measurements were highly reproducible and accurate, as indicated by correlation coefficients of 1.000 for intra-observer and 0.996 for inter-observer agreement, with acceptable within-subject standard deviations. The change in renal volume correlated with baseline total kidney volume in all age subgroups. Total kidney volume positively correlated with male gender, hypertension, albuminuria and a history of macrohematuria but negatively with creatinine clearance. Albuminuria was associated with accelerated volume progression. Our study shows that increases in kidney volume can be reliably measured over a 6 month period in early autosomal dominant polycystic kidney disease using unenhanced magnetic resonance imaging sequences.

Focal liver lesions: detection and characterization at double-contrast liver MR Imaging with ferucarbotran and gadobutrol versus single-contrast liver MR imaging.

PURPOSE: To retrospectively compare, in a multiobserver study, double-contrast-material (sequential administration of ferucarbotran and gadobutrol) magnetic resonance (MR) imaging with single-contrast-material ferucarbotran-enhanced and dynamic postferucarbotran gadobutrol-enhanced MR imaging for the detection and characterization of benign and malignant focal liver lesions. MATERIALS AND METHODS: This study was institutional review board approved, and the requirement for informed patient consent was waived. Eighty-nine patients with a total of 128 focal liver lesions underwent double-contrast liver MR imaging (nonenhanced, ferucarbotran-enhanced, and dynamic postferucarbotran gadobutrol-enhanced MR imaging performed during one session). Four readers independently reviewed the data sets during three reading sessions focused on focal liver lesion detection and characterization: In session 1, the nonenhanced and dynamic postferucarbotran gadobutrol-enhanced images obtained at double-contrast MR imaging were analyzed. In session 2, the nonenhanced and ferucarbotran-enhanced images were analyzed. In session 3, all MR images were analyzed together. The diagnostic performance of each MR technique and each reader was evaluated by using receiver operating characteristic (ROC) analysis; differences between postferucarbotran gadobutrol-enhanced, ferucarbotran-enhanced, and double-contrast MR imaging were assessed at Wilcoxon signed rank testing; and interreader agreement was assessed at Cohen kappa analysis. Histopathologic confirmation or an unchanged clinical course or MR finding was the reference standard. RESULTS: The four readers' detection of the benign and malignant lesions was not significantly different (P > or = .11) between the three MR techniques. The benign and malignant focal liver lesions were differentiated with significantly higher confidence (P < or = .01) on the double-contrast (area under ROC curve [A(z)] = 0.988) and ferucarbotran-enhanced (A(z) = 0.985) MR images than on the dynamic gadobutrol-enhanced images (A(z) = 0.963). Accuracy in the diagnosis of hepatocellular carcinoma (HCC) was highest (P = .02) and confidence in the final diagnosis of HCC (P = .001) or metastasis (P = .049) was significantly higher with double-contrast imaging. CONCLUSION: In select cases, double-contrast MR imaging can improve diagnostic accuracy and increase confidence in characterizing focal liver lesions as HCC or metastasis.

Kidney function and volume progression in unilateral autosomal dominant polycystic kidney disease with contralateral renal agenesis or hypoplasia: a case series.

BACKGROUND: The occurrence of unilateral autosomal dominant polycystic kidney disease (ADPKD) with absence of the contralateral kidney has been described only rarely in the literature. Whether unilateral ADPKD is associated with faster disease progression is not known. STUDY DESIGN: Case series. SETTING & PARTICIPANTS: In a prospective cohort of 182 patients with ADPKD, we identified 3 patients with ADPKD and unilateral renal agenesis (2 patients) or severe hypoplasia (1 patient). MEASUREMENTS & OUTCOMES: Genetic analysis of the PKD1 and PKD2 genes was performed for all 3 patients. Serum creatinine levels and kidney volumes based on magnetic resonance imaging were determined twice, with a 6-month interval between measurements. Characteristics of the 3 patients were compared with age- and sex-matched controls from the full cohort. RESULTS: Genotyping of the 3 patients indicated that each had a different [corrected] mutation in the PKD1 gene that is predicted to cause frameshift and/or truncation of the protein product. [corrected] All 3 patients with unilateral ADPKD had renal volumes and progression rates greater than the mean values of their matched control groups. However, their glomerular filtration rates were well preserved, with estimated single-kidney creatinine clearances much greater than their controls. LIMITATIONS: The number of cases in this study is small and time of follow-up was limited. CONCLUSIONS: Unilateral renal agenesis or hypoplasia in patients with ADPKD might not be as rare as previously thought. Glomerular filtration rate was preserved despite unilateral renal absence, suggesting that renal compensatory mechanisms are well conserved in patients with ADPKD.

Safety and tolerability of sirolimus treatment in patients with autosomal dominant polycystic kidney disease.

BACKGROUND: We initiated a randomized controlled clinical trial to assess the effect of sirolimus on disease progression in patients affected by autosomal dominant polycystic kidney disease (ADPKD). Here we report the preliminary safety results of the first 6 months of treatment. METHOD: A total of 25 patients were randomized to sirolimus 2 mg/day and 25 patients to no treatment except standard care. Treatment adherence was monitored electronically. At baseline and at Month 6, laboratory parameters were analysed and the urinary protein profile in 24-h urine collections was determined. RESULTS: Both treatment groups were well balanced for age, sex and renal function. In 94.1 +/- 11.4% of the study days, patients in the sirolimus group were exposed to the drug when assuming a therapeutic efficacy duration of 30 h. At Month 6, the mean sirolimus dose and trough level were 1.28 +/- 0.71 mg/day and 3.8 +/- 1.9 microg/l, respectively. Glomerular (albumin, transferrin, IgG) and tubular (retinol-binding protein, alpha(1)-microglobulin) protein excretion remained unchanged. Glomerular filtration rate also did not change significantly. Haematological parameters were similar in both groups, except for a mild reduction of the mean corpuscular volume of erythrocytes in patients receiving sirolimus. Lipid levels were similar in both groups. Adverse events were transient and mild, and no grade 3 or 4 events occurred. The incidence of infections was similar in the sirolimus group (80%) and the standard group (88%). The most common gastrointestinal adverse events were mucositis (72% in the sirolimus group versus 16% in the standard group, P = 0.0001) and diarrhoea (36% in the sirolimus versus 20% in the standard group, P = 0.345). CONCLUSION: Treatment of ADPKD patients with sirolimus with a dose of 1-2 mg/day is safe and does not cause proteinuria or impairment of GFR. Treatment adherence was excellent. (ClinicalTrials.gov number, NCT00346918.).

MR angiography with parallel acquisition for assessment of the visceral arteries: comparison with conventional MR angiography and 64-detector-row computed tomography.

The purpose of the study was to retrospectively compare three-dimensional gadolinium-enhanced magnetic resonance angiography (conventional MRA) with MRA accelerated by a parallel acquisition technique (fast MRA) for the assessment of visceral arteries, using 64-detector-row computed tomography angiography (MDCTA) as the reference standard. Eighteen patients underwent fast MRA (imaging time 17 s), conventional MRA (29 s) and MDCTA of the abdomen and pelvis. Two independent readers assessed subjective image quality and the presence of arterial stenosis. Data were analysed on per-patient and per-segment bases. Fast MRA yielded better subjective image quality in all segments compared with conventional MRA (P = 0.012 for reader 1, P = 0.055 for reader 2) because of fewer motion-induced artefacts. Sensitivity and specificity of fast MRA for the detection of arterial stenosis were 100% for both readers. Sensitivity of conventional MRA was 89% for both readers, and specificity was 100% (reader 1) and 99% (reader 2). Differences in sensitivity between the two types of MRA were not significant for either reader. Interobserver agreement for the detection of arterial stenosis was excellent for fast (kappa = 1.00) and good for conventional MRA (kappa = 0.76). Thus, subjective image quality of visceral arteries remains good on fast MRA compared with conventional MRA, and the two techniques do not differ substantially in the grading of arterial stenosis, despite the markedly reduced acquisition time of fast MRA.