Apparent diffusion coefficient values obtained by unenhanced MRI predicts disease-specific survival in bladder cancer.

AIM: To assess the ability of apparent diffusion coefficient (ADC) measurements obtained by MRI to predict disease-specific survival (DSS) in patients with bladder cancer and compare it with established clinico-pathological prognostic factors. MATERIAL AND METHODS: The ethical review board approved this cross-sectional study. Patients with suspected bladder cancer receiving diagnostic 3 T diffusion-weighted imaging (DWI) of the bladder before transurethral resection of the bladder (TUR-B) or radical cystectomy were evaluated prospectively. Two independent radiologists measured ADC values in bladder cancer lesions in regions of interest. Associations between ADC values and pathological features with DSS were tested statistically. A combined model was established using artificial neuronal network (ANN) methodology. RESULTS: A total of 51 patients (median age 69 years, range 41-89 years) were included. Three patients were lost to follow-up, leaving 48 patients for survival analysis. Seven patients died during the 795 months studied. ADC showed significant potential to predict DSS (p<0.05). Except for grading, all pathological features as assessed by TUR-B could predict DSS (p<0.05, respectively). The combined ANN classifier showed the highest accuracy to predict DSS (0.889, 95% confidence interval: 0.732-1, p=0.001) compared to all single parameters. ADC was the second important predictor of the ANN. CONCLUSIONS: ADC measurements obtained by unenhanced MRI predicts DSS in bladder cancer patients. A combined classifier including ADC and clinico-pathological information showed high accuracy to identify patients at high risk for disease-related death.

Imaging of renal leiomyomas.

BACKGROUND: Renal leiomyomas are rare benign tumors of the kidney which can be found at autopsy as small capsular nodules in about 5% of cases. The clinical incidence of such lesions is much smaller, and only case reports or small series have been reported in the imaging literature. PURPOSE: To describe the imaging characteristics observed in a series of eight patients with pathology-proven asymptomatic leiomyomas of the kidney. MATERIAL AND METHODS: We reviewed the imaging findings observed in eight patients with pathologically proven asymptomatic renal leiomyomas discovered during studies performed for reasons unrelated to the kidney. All patients had undergone computed tomography (CT), two ultrasonography, and one magnetic resonance imaging (MRI). RESULTS: Lesions ranged in size from 1.2 to 13 cm. Six were at the periphery of the kidney, compressed its outer surface, but did not cause disruption of the cortex; two involved the renal cortex. All had regular outer margins. A cleavage plane between the tumor and the kidney was revealed at CT and/or ultrasonography in three of the cases located at the periphery. At ultrasonography, leiomyomas appeared hypoechogenic. At CT, they were slightly hyperdense before contrast medium injection; all were hypodense to the renal cortex after contrast medium. Four were homogeneous, two were slightly heterogeneous, and the remaining two were frankly heterogeneous. The lesion studied by MRI, which was homogeneous at the postcontrast CT study, had a heterogeneous structure on both T1- and T2-weighted images, with internal areas of hypointensity on T1. CONCLUSION: There are some imaging findings that can help to suggest the diagnosis of renal leiomyomas. First, their density: all tumors examined before contrast were hyperdense to the kidney, with density similar to that of muscles, and all had lower enhancement than the adjacent renal parenchyma. Second, the location and margins of the tumors: most were peripheral, without involvement of the renal cortex and with well-defined margins. Although not pathognomonic for a renal leiomyoma, the combination of these findings should include leiomyoma in the list of differential diagnoses.

Anemia and carnitine supplementation in hemodialyzed patients.

Carnitine supplementation in hemodialyzed patients was studied in a double-blinded, randomized, controlled trial in order to elucidate the effect of intravenous carnitine on renal anemia in patients treated with recombinant human erythropoietin (rHuEPO). Twenty stable hemodialysis (HD) patients received intravenous L-carnitine after each dialysis session in a dosage of 5 (N = 15) and 25 (N = 5) mg/kg, respectively, together with intravenous iron saccharate (20 mg/HD session) for four months and without iron for a further four months. Twenty patients received placebo instead of carnitine with an identical iron regimen. After a run-in phase of six months with a stable rHuEPO requirement, the rHuEPO dose was adjusted monthly when necessary to maintain target hemoglobin levels. At study entry (T0), plasma and red blood cell carnitine levels did not correlate significantly with the rHuEPO requirement. However, plasma free and total carnitine levels showed a significant negative correlation with erythrocyte survival time at T0. After four months of coadministration of intravenous iron and L-carnitine (T4), the rHuEPO requirement decreased in 8 of 19 evaluable HD patients. In these responders, the weekly rHuEPO dose was decreased significantly by 36.9+/-23.3% (183.7+/-131.7 at T0 vs. 126.6+/-127.9 U/kg/week at T4, P < 0.001). The rHuEPO requirement, however, was unchanged when all carnitine-treated patients were compared between T0 and T4 (T0: 172.0+/-118.0 vs. T4: 152.3+/-118.8 U/kg/week, P = 0.07, NS), but the erythropoietin resistance index decreased significantly in this group (T0: 16.0+/-11.0 vs. T4: 13.6+/-10.5 U/kg/week/g of hemoglobin, P < 0.02). The erythrocyte survival time was measured in five HD patients treated with iron and carnitine at T0 and T4. Two out of these patients were carnitine responders and showed an increase of erythrocyte survival time of 15 and 20%, respectively. After the withdrawal of iron supplementation, the rHuEPO requirement increased comparably in both L-carnitine- and placebo-treated patients during four more months. According to our data, L-carnitine, in addition to iron supplementation, may have an effect on erythropoietin resistance and erythrocyte survival time in HD patients. More than half of our patients, however, showed no benefit. Further studies to identify those HD patients who might have a benefit of carnitine supplementation, as well as studies concerning the optimal dosage, duration, and way of administration of carnitine supplementation and its mechanism of action, are required.

Spontaneous nontraumatic rupture of a contracted kidney with subcapsular and perirenal hematoma in a patient receiving chronic hemodialysis.

Spontaneous renal bleeding with diversion of blood into the subcapsular and/or perinephric spaces in a patient on chronic hemodialysis is a very rare clinical entity. We describe a patient on chronic hemodialysis in whom a spontaneous renal subcapsular hematoma and perirenal hemorrhage developed in a contracted kidney.

Paclitaxel and carboplatin in patients with metastatic transitional cell cancer of the urinary tract.

OBJECTIVES: The combination of methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC) is currently considered the most effective chemotherapy for metastatic transitional cell cancer (TCC) of the urinary tract, but because of its considerable toxicity, alternative regimens appear very interesting. We evaluated the efficacy and toxicity of a combination of paclitaxel and carboplatin as first-line therapy for metastatic TCC. METHODS: Thirty-two patients (8 women, 24 men; mean age 67.03 years, range 50 to 79) with metastatic TCC of the bladder or upper urinary tract were included in the study. Paclitaxel (175 mg/m2) was given as a 3-hour intravenous infusion, carboplatin was dosed to an area under the plasma concentration curve of 5 mg/m/min calculated according to the Calvert formula [(creatinine clearance + 25) x 5] as a 30-minute intravenous infusion immediately after paclitaxel. Response evaluation was performed after every 2 cycles and additional therapy depended on response. The maximum number of cycles was 6. RESULTS: With a mean follow-up of 13.1 months (range 2 to 28), 23 of 32 patients responded to treatment (response rate 71.9%), with 31.3% complete remission (CR) (10 of 32) and 40.6% partial remission (PR) (13 of 32). Four patients (12.5%) had stable disease, and 5 patients (15.6%) showed progression. These results compare well with the outcome after MVAC. Toxicity was mainly characterized by neurotoxicity grade 3 and 4 in 9.4%, grade 3 and 4 leukopenia in 37.5%, and grade 3 thrombocytopenia in 3.1% of the patients. No nephrotoxicity was observed, but all patients developed alopecia. Time to progression after CR was a mean of 7.0 months (range 4 to 13) and after PR a mean of 5.9 months (range 2 to 9). CONCLUSIONS: Paclitaxel/carboplatin is an effective therapy for metastatic TCC, with low toxicity.

Role of magnetic resonance imaging in renal transplant recipients with acquired cystic kidney disease.

OBJECTIVES: To evaluate the impact of magnetic resonance imaging (MRI) in renal transplant recipients whose ultrasound (US) examinations of the native kidneys have met the criteria of acquired cystic kidney disease (ACKD). METHODS: The US scans of 840 renal allograft recipients were prospectively studied. In addition, 46 of 169 patients diagnosed with ACKD by US scans underwent MR examination. MRI protocols included (a) T1 and T2-weighted fast spin echo imaging, (b) T2-weighted gradient echo imaging, and (c) gadolinium-enhanced T1-weighted imaging in 7 patients with evidence of complex cysts. In the case of complex lesions, both US and MRI follow-up examinations were performed between 6 and 12 months after the prior examination. RESULTS: US examination showed ACKD in 169 of 840 patients. In addition, US revealed 8 patients with renal cell carcinomas (RCC). Of these 8 patients, 7 had evidence of ACKD. The median number of cysts depicted on US examination in native kidneys of renal transplant recipients was 3 (range 0 to 10) on both sides. MRI revealed significantly more and smaller cysts compared to US. The median number of cysts was seven on the left and nine on the right native kidneys, respectively. MRI revealed 18 complex lesions in 7 patients. Thirteen of 18 complex lesions were undetected by US. CONCLUSIONS: MRI is superior to US in depiction of simple and complex lesions of native kidneys in renal allograft recipients. MRI exhibits no overestimation of the prevalence of ACKD on the basis of the US criteria already mentioned. Advantages of MRI do not justify routine screening tests by this imaging modality. However, MRI should be used for further evaluation of complex lesions detected by US.

Magnetic resonance imaging in hemophilic children: value of gradient echo and contrast-enhanced imaging.

The purpose of this study was to determine the value of Gradient Echo imaging for the evaluation of cartilage (3D fatsat) and blood products (2D Hemoflash), and the use of contrast enhanced SE imaging for the evaluation of synovial changes, in comparison to the clinical evaluation of children with hemophilia A. We investigated 21 joints in 16 patients with evidence of hemophilia A (mean age 11.3+/-2.1 years). In all patients, clinical examination, plain film radiographs, and MR evaluation were performed magnetic resonance imaging (MRI) was performed by using sagittal T1 SE and T2 SE images, as well as 3D fatsat GE and 2D GE images. Axial and sagittal T1 weighted SE images were obtained before and after contrast application. Findings from the clinical examination and MR imaging, regarding the evaluation of blood, synovia, and cartilage were compared. Clinical examination revealed evidence of a bleeding episode in 12 joints (57.1%), whereas MRI revealed evidence of blood or blood products in 15 joints (71.4%). Clinical investigations, including bleeding scores, pain scores, and physical examination scores did not correlate with MR findings. Due to the MR findings in 6 of 16 patients, therapeutic management was changed from on demand to prophylactic therapy. MR imaging with gradient echo and contrast-enhanced sequences is more sensitive than clinical examination for the detection of blood products in children with hemophilia. Its ability to demonstrate potentially early stages of cartilage or synovial alterations might assist in therapy planning. Clinical scores might underestimate effects of hemophilia.

[Malignant neoplasms after kidney transplantation: value of an annual radiological screening program]. / Malignome nach Nierentransplantation: Stellenwert eines jährlichen radiologischen Screeningprogramms.

PURPOSE: To evaluate the prevalence of malignant neoplasms after renal transplantation by means of a radiological screening programme and to determine the role of some clinical and demographic parameters concerning pathogenesis of these malignancies. MATERIAL AND METHODS: Between November 1992 and June 1994 in a prospective study 504 consecutive renal allograft recipients (331 m, 173 f) aged 51 +/- 13 years underwent routine abdominal ultrasound examinations including the renal transplant and p.a. and lateral chest x-rays once a year. RESULTS: This screening programme revealed 11 malignant neoplasms in 11 patients (2.2%). We detected 6 renal cell carcinomas (RCC) in the patient's native kidneys, two RCCs in two renal allografts, two non-Hodgkin-lymphomas in the liver and the renal allograft, respectively, and one ovarial carcinoma. Patients with renal cell carcinomas in the native kidneys were significantly older than allograft recipients without tumors. The presence of acquired cystic kidney disease (ACKD) seems to be an additional risk for the development of RCC. There were no significant differences in the time on dialysis, the time with functional renal allograft, and the immunosuppressive therapy. CONCLUSION: Yearly abdominal ultrasound screening including the renal allograft is a valuable tool for the early detection of neoplasms in asymptomatic renal allograft recipients. However, routine yearly chest x-rays should not be performed in renal allograft recipients without preexisting tumours.

[Differential diagnosis of space-occupying adrenal masses]. / Differentialdiagnose raumfordernder Prozesse der Nebennieren.

Computed tomography (CT) and magnetic resonance (MR) imaging are first line modalities in the evaluation of patients with adrenal gland masses, and have the potential to be very accurate for the localization of adrenal gland masses in patients with diseases associated with hyperfunctioning conditions of the adrenal gland. Both CT and MR imaging allow a specific diagnosis of acute adrenal hemorrhage, adrenal myelolipoma, and adrenal cysts. CT is also helpful in the assessment of patients with Addison's disease, particularly the subacute form secondary to granulomatous diseases. Quantitative evaluation of adrenal masses on unenhanced CT scans and/or qualitative analysis on chemical-shift MR imaging have been shown to be accurate in distinguishing adrenal adenomas from non-adenomas. Attenuation of 11 HE or less on unenhanced CT scans and/or signal loss on opposed phase MR images indicate adenoma with a high specificity and acceptable sensitivity. More recently, delayed-enhanced CT has yielded higher sensitivity and specificity values in distinguishing between adrenal adenomas and non-adenomas than both unenhanced CT and chemical-shift MR imaging do. On delayed-enhanced CT scans, adrenal adenomas exhibit a greater washout of contrast material than do adrenal non-adenomas. Therefore, adrenal non-adenomas have significantly higher attenuation than adenomas on delayed-enhanced CT scans obtained at several arbitrarily chosen time points (3-60 min) after the initiation of contrast material administration.

[The experiences of a hospital radiology department with outside referrals for the preoperative marking of suspicious breast lesions]. / Erfahrungen einer radiologischen Spitalsabteilung mit auswärtigen Zuweisungen zur präoperativen Markierung suspekter Mammaläsionen.

PURPOSE: To outline the experience of a referral radiology department with preoperative localisation procedures on the basic of mammograms obtained by other facilities. MATERIAL AND METHODS: 342 consecutive female patients aged 56.5 +/- 11.9 years underwent preoperative breast localisation procedures prior to surgery. Of these patients 241 had their mammograms obtained in various private practices and 101 in the radiology department. Retrospectively all mammograms were classified by lesions morphology, lesion size and presence or absence of calcifications. RESULTS: The overall benign-to-malignant ratio (B/M-ratio) was 1.7:1. In the referred patient group the B/M-ratio was 1.9:1, compared to a B/M-ratio of 1.3:1 obtained by the radiology department. Referred patients presented significantly (p < 0.001) more often with calcifications that patients from the radiology department. CONCLUSION: Possible factors for the higher B/M-ratio in referred patients are prompt referral to surgical biopsy, misinterpretation of mammograms, failure in the written report, lack of a second opinion and lack of feedback and communication between surgeon, pathologist and radiologist.

[Injuries to the lateral ligaments of the ankle joint: study technic and demonstration by means of MRI]. / Verletzungen des Aussenbandapparates am oberen Sprunggelenk: Untersuchungstechnik und Nachweis mittels MRT.

PURPOSE: To evaluate the visualisation and extent of injury of lateral ankle ligaments using MRI. METHODS: 56 patients with the clinical diagnosis of sprained ankles were investigated. Evaluation of the anterior (AFTL) and posterior fibulotalar ligament (PFTL) was performed with the foot in dorsiflexion (20 degrees) and of the fibulo calcanear ligament (FCL) in plantarflexion (45 degrees). Axial T1w-SE and T2w-TSE images were obtained. Full-length visualisation of ligaments in one slice and the extent of injury were evaluated. 12 ankle injuries were confirmed by operation. RESULTS: With MRI full-length visualisation of lateral ankle ligaments was possible in 86%. A partial/complete rupture of the AFTL was noticed in 33/64% and of the FCI in 29/39%, and of the PFTL in 27/5%. Sensitivity/specificity of MRI when compared to surgery was 100/100% for injuries of the AFTL, 64/100% for the FCL, and 33/78% for the PFTL. CONCLUSION: Full-length visualisation of ligaments, achieved by appropriate combination of foot position and imaging plane is essential for evaluation of injured ankle ligaments on MRI. High assessment for ligamentous injuries on MRI in relation to surgery was found.

Function of reinserted abductor muscles after femoral replacement.

We compared two methods of reconstruction of the abductor mechanism in 15 patients after prosthetic replacement of the upper femur, to assess abductor strength and function. Six patients in group I had direct fixation of the gluteus medius tendon and a segment of the original bone to the prosthesis. Nine patients in group 2 had the abductor tendon fixed to the iliotibial band. We assessed clinical function, isometric muscle strength and muscle cross-sectional area for each patient. The patients in group 1 had better clinical and functional results (p = 0.059), with average peak torques for hip abduction of 92% of that in the non-operated leg in group 1, and of 57% in group 2. Group 1 had a mean muscle cross-sectional area of 69% and a mean value of strength per cross-sectional area of 134% when compared with the control side. The respective values for group 2 were 52% and 91%. Direct fixation of the abductor muscles to the prostheses gave improved function and higher isometric abductor muscle force.

Utility and limitations of 3-Tesla diffusion-weighted magnetic resonance imaging for differentiation of renal tumors.

OBJECTIVE: To investigate utility and limitations of 3-Tesla diffusion-weighted (DW) magnetic resonance imaging (MRI) for differentiation of benign versus malignant renal lesions and renal cell carcinoma (RCC) subtypes. MATERIALS AND METHODS: Sixty patients with 71 renal lesions underwent 3 Tesla DW-MRI of the kidney before diagnostic tissue confirmation. The images were retrospectively evaluated blinded to histology. Single-shot echo-planar imaging was used as the DW imaging technique. Apparent diffusion coefficient (ADC) values were measured and compared with histopathological characteristics. RESULTS: There were 54 malignant and 17 benign lesions, 46 lesions being small renal masses ≤ 4 cm. Papillary RCC lesions had lower ADC values (p=0.029) than other RCC subtypes (clear cell or chromophobe). Diagnostic accuracy of DW-MRI for differentiation of papillary from non-papillary RCC was 70.3% resulting in a sensitivity and specificity of 64.3% (95% CI, 35.1-87.2) and 77.1 (95% CI, 59.9-89.6%). Accuracy increased to 83.7% in small renal masses (≤ 4 cm diameter) and sensitivity and specificity were 75.0% and 88.5%, respectively. The ADC values did not differ significantly between benign and malignant renal lesions (p=0.45). CONCLUSIONS: DW-MRI seems to distinguish between papillary and other subtypes of RCCs especially in small renal masses but could not differentiate between benign and malignant renal lesions. Therefore, the use of DW-MRI for preoperative differentiation of renal lesions is limited.

[MR urography: principles, examination techniques, indications]. / MR-Urographie: Prinzipien, Untersuchungstechniken, Indikationen.

MR urography is an evolving and promising technique in the evaluation of the urinary tract. MR urography is currently considered the method of choice for imaging of the renal parenchyma and the collecting systems in patients who cannot undergo routine radiographic studies such as pregnant women, pediatric patients, patients allergic to iodinated contrast agents, or patients with impaired renal function. The future development of MR urography in terms of functional, cellular, and molecular imaging is presently the subject of research. The ability of MR imaging to provide quantitative functional information (e.g., on blood flow, perfusion, glomerular filtration rate, and excretion as well as urine drainage) in addition to morphologic assessment of the parenchyma and the collecting system could lead to a single, "all-in-one approach" examination technique.

[Virtual multislice computed tomography cystoscopy for evaluation of urinary bladder lesions]. / Virtuelle MDCT-Zystoskopie bei der Detektion von Blasenläsionen.

The introduction of multislice computed tomography (MDCT) with the possibility of acquiring isotropic datasets has been an ideal prerequisite for development of virtual MDCT cystoscopy. Remarkable technical progress regarding post-processing of high-resolution 3D datasets as well as a considerable reduction of the time required for post-processing made it possible to introduce virtual MDCT cystoscopy into the clinical routine. 3D post-processing that often required 7-8 h when virtual endoscopy techniques were first developed can now be performed in less than 5 min after transfer of data to the 3D workstation. With the limitations and contraindications of conventional cystoscopy in mind, virtual MDCT cystoscopy may be seen as a valuable alternative to conventional cystoscopy for evaluation of hematuria.

[Imaging techniques and their impact in treatment management of patients with acute flank pain]. / Die bildgebenden Verfahren und ihre Rolle beim Behandlungsmanagement von Patienten mit akutem Flankenschmerz.

The purpose of this overview is to provide a general summary of the imaging techniques applied at the Vienna Hospital for the investigation of acute flank pain and the diagnosis of stone disease and the evaluation of their efficacy and impact on therapy management. The number of publications on the issue of "intravenous urography (IVU) vs computed tomography (CT)" is abundant; in recent years, advocates of CT make up the majority. In the Department of Urology at the Vienna Hospital, conventional techniques such as ultrasound and IVU besides UHCT still play an important role. This overview presents the advantages and disadvantages of the various imaging techniques for diagnosis of stone disease and evaluates their significance regarding therapy management of patients with acute flank pain.

[Urological and nephrological emergency--value of diagnostic imaging]. / Der urologische und nephrologische Notfall--Stellenwert der Radiodiagnostik.

Many diseases of the kidneys and the urinary tract may develop to urinary emergencies. A prompt evaluation of these critical situations is of utmost importance concerning therapeutic consequences, and implicates a considerable challenge for the radiologist. The use of the appropriate imaging method allows rapid diagnosis, and thus enables optimal therapeutic management. In this article we describe the most important urinary emergencies: urolithiasis, hydronephrosis, acute renal infection, acute obstruction, testicular torsion, complications after renal transplantation, and urinary trauma. Aetiology and pathogenesis of the specific entities are described as well as the use of the adequate imaging method. In addition, especially for CT examinations precise imaging techniques are reported. Complications and differential diagnosis of the specific emergencies are mentioned.