Wael Shabana

Prevention of Contrast-Induced Acute Kidney Injury: Is Simple Oral Hydration Similar To Intravenous? A Systematic Review of the Evidence

Background Pre-procedural intravenous fluid administration is an effective prophylaxis measure for contrast-induced acute kidney injury. For logistical ease, the oral route is an alternative to the intravenous. The objective of this study was to compare the efficacy of the oral to the intravenous route in prevention of contrast-induced acute kidney injury. Study Design A systematic review and meta-analysis of randomised trials with a stratified analysis and metaregression. Databases included MEDLINE (1950 to November 23 2011), EMBASE (1947 to week 47 2011), Cochrane CENTRAL (3rd quarter 2011). Two reviewers identified relevant trials and abstracted data. Settings and Population Trials including patients undergoing a contrast enhanced procedure. Selection Criteria Randomised controlled trial; adult (>18 years) population; comparison of oral versus intravenous volume expansion. Intervention Oral route of volume expansion compared to the intravenous route. Outcomes Any measure of acute kidney injury, need for renal replacement therapy, hospitalization and death. Results Six trials including 513 patients met inclusion criteria. The summary odds ratio was 1.19 (95% CI 0.46, 3.10, pu200a=u200a0.73) suggesting no difference between the two routes of volume expansion. There was significant heterogeneity (Cochran’s Qu200a=u200a11.65, pu200a=u200a0.04; I2u200a=u200a57). In the stratified analysis, inclusion of the five studies with a prespecified oral volume expansion protocol resulted in a shift towards oral volume expansion (OR 0.75, 95% CI 0.37, 1.50, pu200a=u200a0.42) and also resolved the heterogeneity (Qu200a=u200a3.19, Pu200a=u200a0.53; I2u200a=u200a0). Limitations Small number of studies identified; lack of hard clinical outcomes. Conclusion The oral route may be as effective as the intravenous route for volume expansion for contrast-induced acute kidney injury prevention. Adequately powered trials with hard endpoints should be done given the potential advantages of oral (e.g. reduced patient burden and cost) over intravenous volume expansion.

Triphasic CT in the diagnosis of acute mesenteric ischaemia

ObjectiveTo evaluate the yield of each phase in a triphasic CT protocol used to diagnose acute mesenteric ischaemia (AMI).MethodsRetrospective analysis of patients who underwent CT to exclude AMI was conducted. From 218 patients, 80 were randomly selected for analysis: 39 with proven AMI; 41 controls. Three readers evaluated the studies; two readers were provided with only portions of the examination to determine the yield of unenhanced CT (NECT) and CT angiography (CTA). The diagnostic accuracy of CT findings was calculated and compared between readers.ResultsThe sensitivity and specificity of submucosal haemorrhage were 10xa0% and 98xa0%. Interobserver variability was poor (κu2009=u20090.17). All true-positive cases had other CT findings of AMI (nu2009=u20094). There was no difference in the assessment of bowel enhancement between readers (Pu2009<u20090.05). There was no difference between readers (Pu2009<u20090.05) and interobserver variability was moderate to good when diagnosing arterial abnormalities without CTA. Sample size was small and errors occurred when using only the portal venous phase for this purpose.ConclusionNECT is not required for diagnosis of AMI. Splanchnic arterial abnormalities can be diagnosed without CTA although errors occur when using only the portal venous phase for this purpose.Key points• Triphasic CT is the current gold standard for diagnosing acute mesenteric ischaemia.• Multiphase CT multiplies the radiation dose when compared to single phase CT.• Each phase in a multiphase CT examination should be independently validated.• Unenhanced CT is not required for diagnosis of acute mesenteric ischaemia.• CT angiography should be performed for diagnosis of acute mesenteric ischaemia.

Diagnosis of Sarcomatoid Renal Cell Carcinoma With CT: Evaluation by Qualitative Imaging Features and Texture Analysis.

OBJECTIVEnThe objective of our study was to determine whether CT findings, including texture analysis, can differentiate sarcomatoid renal cell carcinoma (RCC) from clear cell RCC.nnnMATERIALS AND METHODSnA retrospective case-control study was performed of consecutive patients with a histologic diagnosis of sarcomatoid RCC (n = 20) and clear cell RCC (n = 25) who underwent preoperative CT over a 3-year period. The CT images were independently reviewed by two blinded abdominal radiologists; they evaluated the following: tumor heterogeneity, tumor margin, calcification, intratumoral neovascularity, peritumoral neovascularity, renal sinus invasion, renal vein invasion, and adjacent organ invasion. Interobserver agreement was assessed using the Cohen kappa coefficient, and results were compared between groups using an independent Student t test and the chi-square test with a Bonferroni correction. For texture analysis, gray-level co-occurrence and run-length matrix features were extracted and compared using Mann-Whitney U tests. ROC curves for each tumor were constructed, and AUCs were calculated.nnnRESULTSnOverall, sarcomatoid RCCs were larger than clear cell RCCs, measuring 77 ± 27 mm (mean ± SD) compared with 50 ± 29 mm (p = 0.003), respectively; however, there was no difference in tumor size between the tumors that were compared using texture analysis or subjective analysis (p = 0.06 and 0.03, respectively). From the subjective analysis, only peritumoral neovascularity (readers 1 and 2: 70% and 70% sarcomatoid RCCs vs 0% and 41.6% clear cell RCCs, respectively; p = 0.001) and the size of the peritumoral vessels (p < 0.001) differed between sarcomatoid RCCs and clear cell RCCs, and interobserver agreement was fair (κ = 0.38). Other subjective imaging features did not differ between the tumors (p > 0.005). There was greater run-length nonuniformity and greater gray-level nonuniformity in sarcomatoid RCCs than in clear cell RCCs (p = 0.03 and p = 0.04, respectively). The combined textural features identified sarcomatoid RCC with an AUC of 0.81 ± 0.08 (standard error) (p < 0.0001).nnnCONCLUSIONnLarge tumor size, the presence of peritumoral neovascularity, and larger peritumoral vessels are features that are more commonly associated with sarcomatoid RCCs than with clear cell RCCs. Sarcomatoid RCCs are also more heterogeneous by texture analysis than clear cell RCCs.

Evaluation of the European Society of Urogenital Radiology (ESUR) PI-RADS scoring system for assessment of extra-prostatic extension in prostatic carcinoma

INTRODUCTIONnTo evaluate extra-prostatic extension (EPE) comparing PI-RADS to non-standardized reporting.nnnMATERIALS AND METHODSnWith IRB approval, 145 consecutive patients underwent radical prostatectomy (RP) and multi-parametric (T2W+DWI+DCE) MRI between 2012 and 2013. Eighty patients (66.3% with EPE) were staged without PI-RADS and 65 patients (64.6% with EPE) were staged using a 5-point PI-RADS scoring system. Studies were reported by fellowship-trained radiologists in routine clinical practice. Individual PIRADS scores were assessed using ROC to determine the score which optimized sensitivity/specificity. Diagnostic accuracy for EPE was compared with/without PI-RADS using the McNemar test. Subgroup analysis by radiologist experience was performed using Spearman correlation and chi-square.nnnRESULTSnArea under ROC curve for EPE using PI-RADS was 0.62 and optimal sensitivity/specificity was achieved with PI-RADS score ≥ 3. Compared to non-standardized reporting, sensitivity for EPE improved with PI-RADS (59.5% [49.1-68.2] vs. 24.5% [16.7-31.2]), p=0.01; with no difference in specificity (68.0% [50.5-82.6]) vs. (75.0% [60.1-87.6]), p=0.06. Overall accuracy improved with PI-RADS (62.7% [49.6-73.6] vs. 42.0% [31.7-50.7%]), p=0.006. Diagnostic accuracy was better among experienced radiologists without PI-RADS (p=0.005); however, there was no difference in accuracy by reader experience using PI-RADS (p=0.24).nnnCONCLUSIONnThe PI-RADS criteria for EPE improves sensitivity without reducing specificity. PI-RADS may reduce differences in accuracy by reader experience.

Patterns of recurrence following selective intraoperative radiofrequency ablation as an adjunct to hepatic resection for colorectal liver metastases

The purpose of this study was to analyze the patterns of recurrence following intraoperative radiofrequency ablation (RFA) combined with hepatic resection for patients with colorectal liver metastases (CLM).

Does a cleansing enema improve image quality of 3T surface coil multiparametric prostate MRI

To assesses the utility of a preparatory enema in the interpretation of prostate multiparametric (MP) magnetic resonance imaging (MRI).

Multi-echo gradient recalled echo imaging of the pelvis for improved depiction of brachytherapy seeds and fiducial markers facilitating radiotherapy planning and treatment of prostatic carcinoma

MR localization of implanted devices for radiotherapy (RT) in prostatic carcinoma is critical for treatment planning. This clinical note studies the application of a multi‐echo gradient recalled echo (GRE) pulse sequence with sum of squares echo combination (ME GRE) to enhance detection of seeds and fiducials.

Solid Renal Cell Carcinoma Measuring Water Attenuation (−10 to 20 HU) on Unenhanced CT

OBJECTIVEnThe objectives of this study were to evaluate the incidence of solid renal cell carcinoma (RCC) with attenuation similar to that of water (-10 to 20 HU) on unenhanced CT and to examine imaging features that can allow RCC to be differentiated from simple cysts.nnnMATERIALS AND METHODSnWe performed an enriched quantitative and qualitative retrospective analysis of consecutive patients who underwent unenhanced CT before resection of solid (noncystic and nonnecrotic) renal masses measuring < 5 cm from 2008 to 2013. In all, 93 patients with 96 tumors (55 clear cell, 27 papillary, and 14 chromophobe) were evaluated with unenhanced CT. Attenuation was measured at three standardized levels and compared using the Kruskal-Wallis test. Two radiologists independently assessed calcification, margin (smooth or irregular), and heterogeneity (homogeneous or heterogeneous). Results were compared using the chi-square test with Bonferroni correction.nnnRESULTSnMean ± SD attenuation values were 31.8 ± 9.6 HU (range, 11-63 HU) overall, 29.9 ± 8.8 HU (range, 11.0-49.0 HU) for clear cell tumors, 34.6 ± 10.3 HU (range, 20.3-63.0 HU) for papillary tumors, and 35.5 ± 9.2 HU (range, 20.7-47 HU) for chromophobe tumors (p = 0.06). Eight clear cell RCCs had attenuation similar to that of water (15.7 ± 2.4 HU; range, 11-18.7 HU). There was no significant difference in calcification or margin among different types of tumors (p = 0.91 and p = 0.55, respectively). Chromophobe tumors were more likely to be homogeneous (p < 0.001). Interobserver agreement was moderate to very good (κ = 0.91 for calcification, κ = 0.55 for margin, and κ = 0.44 for heterogeneity). All eight clear cell RCCs with attenuation similar to that of water were considered heterogeneous by both readers. Irregular margins were identified in three of these eight tumors by reader 1 and four of eight tumors by reader 2.nnnCONCLUSIONnA minority of solid RCCs have attenuation similar to that of water on unenhanced CT. In this study, all such tumors were of the clear cell subtype and qualitatively heterogeneous, suggesting they can be distinguished from simple cysts on unenhanced CT.

Evaluation of apparent diffusion coefficient and MR volumetry as independent associative factors for extra-prostatic extension (EPE) in prostatic carcinoma.

To assess mean apparent diffusion coefficient (ADC) and MR‐derived tumor volume (Vt) as associative factors for extra‐prostatic extension (EPE) in prostate cancer (PCa).

Prostatic ductal adenocarcinoma: an aggressive tumour variant unrecognized on T2 weighted magnetic resonance imaging (MRI)

AbstractIntroductionProstatic ductal adenocarcinoma (DCa) is an aggressive variant. The purpose of this study was to determine if T2 signal intensity (SI) differs from conventional adenocarcinoma (CCa).Materials and methodsA retrospective study of patients who underwent preoperative MRI and prostatectomy between 2009 and 2012 was performed. T2 SI ratios (SIR) for tumour (T) to obturator internus muscle (M) and normal peripheral zone (PZ) were compared. Two radiologists evaluated the central gland/PZ to detect tumours and compared diagnostic accuracy.ResultsT2 SIR for DCa were 3.60 (T/M), 0.66 (T/PZ); 2.68 (T/M), 0.47 (T/PZ) for Gleason 9; 2.50 (T/M), 0.47 (T/PZ) for Gleason 7/8 and 3.95 (T/M), 0.73 (T/PZ) for Gleason 6 tumours. There was a difference in T2 T/M and T/PZ SIR between DCa and Gleason 9 (pu2009=u20090.003, pu2009=u20090.004) and Gleason 7/8 (pu2009=u20090.006, pu2009=u20090.002), but no difference in SIR between DCa and Gleason 6 tumours. The sensitivity for tumour detection was 0–27xa0% for DCa, 64–82xa0% for Gleason 9, 44–88xa0% for Gleason 7–8 and 0–20xa0% for Gleason 6. There was a difference in the sensitivity of detecting Gleason 9 and 7/8 tumours when compared to DCa (pu2009=u20090.004, pu2009=u20090.001).ConclusionsDCa resembles Gleason score 6 tumour at T2-weighted MRI, which underestimates tumour grade and renders the tumour occult.Key Points• Prostatic ductal adenocarcinoma is aggressive, resembling endometrial carcinoma at histopathology.n • Prostatic ductal adenocarcinoma resembles Gleason score 6 tumour at T2-weighted MRI.n • MRI grading may underestimate ductal adenocarcinoma based on increased T2 signal.