Diffusion weighted MRI in evaluation of transplanted kidney: Preliminary clinical experience

Purpose: To evaluate the diagnostic performance ofDiffusion Weighted (DW) magnetic resonance(MR) imaging in evaluation of transplantedkidneys.Patients and methods: One hundred twelve patientswith transplanted kidney from live kidney donorswere evaluated with coronal T2w and DW MRI ofthe kidney. There was 86 males and 26 females andthe mean age was 26.911.5ys (range 10-55).Apparent diffusion coefficient (ADC) wascalculated and the kidneys studied for any areasdiffusion restriction. Our patients classified into 2groups: Group 1 included 81 patients with stablekidney function and normal serum creatinine andthe second group included 31 patients with alteredkidney function, it includes 18 patients with chronicnephropathies and 13 patients with acute cellularrejection.Results: The mean ADC values for group 1 was2.70.26 x 10-3 mm2 /sec (range 1.93-3.6). In casesof chronic nephropathies, the mean ADC valueswas 2.30.22mm2/sec (range 2.05-2.77) while incases of acute cellular rejection it was1.80.2mm2/sec (range 1.7-2.2). When we use the2.4mm2/sec as a low cutoff ADC value fordiagnosis of normal kidney function, the sensitivity,specificity and overall accuracy for DWI MRI was80%, 96% and 93.5% respectively.When we used the ADC value of 2mm2/sec as acutoff value between acute cellular rejection andchronic nephropathies, the sensitivity, specificityand overall accuracy of DWI MRI was 90%, 98%and 90% respectively.Conclusion: In this relatively large study includingstable and abnormal function in transplantedkidneys, we can conclude that DW MRI isrelatively a new technique that allows diagnosis oftransplanted kidney with normal and alteredfunction

Adrenal Hemangioma: Findings at Multidetector CT with Short Review of the Literature

We present the computed tomography (CT) imaging findings of a 44-year-old male with incidentally discovered right adrenal hemangioma displaying imaging pattern of nonadenomatous pattern, associated with multiple hepatic hemangiomata using 64-slice multidetector scanner with reviewing published CT imaging findings with short review of the literature

Static T2w MRU in Noncalcular Urinary Obstruction: Comparison of Its Two Techniques

The purpose of this study was to compare the diagnostic accuracy of T2-weighted (T2w) MR urography (MRU) techniques — the standard MRU using fast spin echo (FSE) and postprocessing maximum intensity projection (MIP) and the single-shot MRU — in the diagnosis of ureteric obstruction in patients with noncalcular urinary obstruction. The study included 150 patients admitted to our center between January 2005 and December 2006. There were 203 renal units with noncalcular obstruction; 53 patients had bilateral obstruction. Patients with calcular obstruction were excluded. There were 85 males and 65 females with a mean age of 50 (range: 5–83) years. All patients were examined with static MRU using both single-shot (thick slab) and multisection MRU. Using single-shot MRU, we obtained images at the direct coronal and oblique coronal, as well as sagittal, planes for each renal unit. Postprocessing MIP for the standard coronal heavy T2 source images to obtain coronal and oblique images was done. Among the obstructed 203 units, the intrinsic causes were present in 157 units (151 were stricture and six were ureteric tumors), while the extrinsic causes were present in 46 units (35 bladder tumor, four ureterocele, five retroperitoneal fibrosis, one prostatic tumor, and one local pelvic recurrence after radical cystectomy for bladder cancer). The overall accuracy of single-shot MRU was 89% and was 93% for the multisection MRU in cases of intrinsic ureteric obstruction, while in cases of extrinsic obstruction, it was 20% for single-shot MRU and 96% for multisection MRU. T2w static MRU is a very useful technique in diagnosing noncalcular ureteric obstruction. Multisection MRU has a high diagnostic accuracy and reliability over that of the single-shot technique. The single-section technique is very rapid and useful in diagnosing ureteric stricture so it could be used as a localizer, while multisection images with postprocessing MIP is mandatory, especially in cases of suspected ureteric tumors or extraureteric causes

Efficacy of ketamine in prevention of agitation in children undergoing magnetic resonance imaging under face mask sevoflurane: A randomized trial

Background: Emergence agitation (EA) is a common distressing problem in children after sevoflurane general anesthesia. The aim of the present study was to test the efficacy of ketamine in prevention of EA after sevoflurane general anesthesia in children undergoing magnetic resonance imaging (MRI) scan. Also, we evaluated the safety and efficacy of the face mask for administration of sevoflurane anesthesia in children. Methods: In this randomized study, 120 children aged 2–7 years (ASA I or II) of either sex scheduled for elective MRI scan under sevoflurane anesthesia were enrolled in the study protocol. Patients were randomly allocated to one of 3 groups: saline group receiving normal saline (n = 40), ketamine 0.25 group receiving 0.25 mg/kg of ketamine intravenously 10 min prior the end of the procedure (n = 40), and ketamine 1.0 group receiving 1.0 mg/kg of ketamine intravenously before sevoflurane induction, (n = 40). Anesthesia was provided with sevoflurane in 100% oxygen. EA score, pausing of the scan, scan time, discharge time and any reported adverse events were recorded. Results: No significant differences as regards age, weight, sex, or ASA score were found among the studied groups. Children in ketamine 1.0 group reported significant lower EA score in comparison with ketamine 0.25 and saline groups (P < 0.05). Ketamine 0.25 group reported significant lower EA score in comparison with saline group (P < 0.05). Children in ketamine 1.0 group reported significant lower incidence of pausing in comparison with ketamine 0.25 and saline groups (P < 0.05). No significant differences as regards nausea, vomiting, desaturation, scan and discharge times among the studied groups (P < 0.05) were found. Conclusion: Ketamine premedication was effective in reducing EA without delay in recovery and significantly reduced the incidence of pausing of MRI scan

Evaluation of CT perfusion parameters for assessment of split renal function in healthy donors

Objectives: To assess feasibility of automatically calculated CT perfusion parameters using two different methods of drawing regions of interest (ROIs) to reflect split renal function in comparison with MAG3 renography. Methods and materials: 51 potential kidney donors (24 males, 27 females) were prospectively evaluated by preoperative CT perfusion. Post processing was done twice; one with ROI around renal cortex only and the other around cortex and medulla. Perfusion parameters (perfusion, peak enhancement intensity PEI and blood volume BV) were compared between the two methods. Split values for each of these parameters were calculated and compared to split renal function measured by MAG3 renography using paired samples t test. Results: Perfusion was significantly lower in method 2 than in method 1 while PEI and BV showed no significant difference between the two methods. Split values of CT parameters showed no significant difference from corresponding renography split function (p value > 0.1) except BV by method 1 and perfusion by method 2 which showed significant difference (p value < 0.05). Conclusion: Certain CT perfusion parameters can reflect split renal function. Perfusion was more accurate in reflecting split renal function with ROI around the cortex while BV was more accurate with ROI around the whole parenchyma

Diagnostic value of combined static-excretory MR Urography in children with hydroneph

The aim of this study was to determine the feasibility, accuracy and diagnostic potential of combined static-excretory MR Urography in children with sonographically detected hydronephrosis. We prospectively evaluated 28 children (11 girls and 17 boys), mean age 8.3 years (range 2 months–16 years). Static-excretory MR Urography was performed in all cases. The results of MR Urography were compared with the results of other imaging modalities, cystoscopy and surgery. In 28 children, 61 renal units were evaluated by MR Urography (the renal unit is the kidney and its draining ureter). The final diagnoses included: normal renal units (n = 23); uretropelvic junction obstruction (n = 14); megaureter (n = 8); midureteric stricture (n = 1), complicated duplicated systems (n = 5), post ESWL non-obstructive dilation (n = 2), extrarenal pelvis (n = 4), dysplastic kidney (n = 4). Complex pathology and more than one disease entity in were found in 7 children. The MRI diagnosis correlated with the final diagnosis in 57 units, with diagnostic accuracy 93.4%. In conclusions static and excretory MRU give both morphological and functional information in a single examination without exposure to ionizing radiation and iodinated contrast agent. It is a valuable imaging technique for children with upper urinary tract dilatation; especially in cases of complex congenital pathologies and severely hydronephrotic kidney

Towards non-invasive diagnostic techniques for early detection of acute renal transplant rejection: A review

The kidney is a very important complicated filtering organ of the body. When the kidney reaches stage 5 chronic kidney disease, end stage renal failure, the preeminent therapy is renal transplantation. Although it is the best form of treatment, lack of kidney donors is still challenging. Therefore, all efforts should be employed to prolong the survival rate of the transplanted kidney. However, graft dysfunction (e.g., acute rejection) is one of the serious barriers to long term kidney transplant survival. Currently, graft dysfunction’s gold standard of diagnosis is renal biopsy. Although renal biopsy is helpful, it is not preferred due to its invasive nature, high morbidity rates, and expensiveness. Therefore, noninvasive imaging techniques have become the subject of extensive research and interest, giving a strong promise to replace, or at least to decrease, biopsy usage in diagnosing graft dysfunction. This survey will discuss not only the current diagnosis and treatment of graft dysfunction but also the state-of-the-art imaging techniques in detecting acute renal transplant rejection

Diagnostic accuracy of computed tomography angiography in detection of post traumatic renal vascular injury

Objectives: To evaluate accuracy of computed tomography angiography (CTA) in evaluation of post traumatic renal vascular injury. Patients and methods: 38 patients were presented with post traumatic intermittent or persistent hematuria. Renal CTA and digital subtraction angiography (DSA) were done for all patients. Results: CTA demonstrated pseudoaneurysm (PA) in 30 patients (78.9%) and no vascular lesions in 8 patient (21.1%). CTA had 86.11% sensitivity and 50% specificity in detection of post traumatic renal pseudoaneurysms, CTA missed diagnosis of renal arteriovenous fistula (RAVF) in 10 patients which discovered later by DSA. Conclusion: CTA with MIP as non invasive technique widely replaced renal DSA in detection of posttraumatic renal pseudoaneurysm. Renal DSA is still best modality in detection of RAVF and also has the upper hand in planning of selective renal artery embolization for the management of persistent or delayed hemorrhage from renal vessels. Keywords: Renal CTA, Renal vascular injur

Radiation dose associated with common computed tomography examination

Objective: To survey computed tomography (CT) radiation dose associated with non-contrast spiral Multislice CT examination in our institute. Methods: Detailed parameters for 362 consecutive examinations, including the patient weight, height, volume CT dose index (CTDIvol), scan length, and dose length product (DLP) were recorded from the dose report. Effective dose (E) was estimated for each patient. The differences between E doses were statistically analyzed using SSPS. Results: Patients body mass index (BMI) was 13.4 to 51.42 (average BMI 29.5 kg/m). Patients dose data (1 scan phase for each patient) from dose information: the median value of DLP was 586.45 mGy cm (83.30â1179.70 mGy cm), median value of CTDIvol was 12.07 (2.20â23.9 mGy), median value of mAs used was 186.50 (34â334 mAs). Effective dose range was (1.1â16.5 mSv) according to international commission of radiological protection (ICRP) 103 and according to ICRP60 the range was (1.3â18.93 mSv). Median value of frequent CT examinations for the same patient was 2 (min 1 scan/year & max 11 scan/year). CT dose variation was highly significant (p value <0.01) depending on high variation on mAs with (r = 0.98). CT dose was moderate depending on BMI (r = 0.55). Conclusion: There was statistically highly significant variation in effective radiation doses associated with non-contrast CT scan of abdomen and pelvis. The reason for this variation must be avoided. Keywords: Computed tomography (CT), CT dose, volume CT dose index, dose length product (DLP), Effective dose (E), International commission of radiological protection (ICRP) 10