Sonography of the kidneys and urinary tract in infancy

Sonography is the imaging method of choice in all diseases of the kidneys and urinary tract in infancy. The most important indications are all malformation syndromes, especially malformations of the urinary tract, urinary tract infections, space occupying lesions of the kidney, renal insufficiency, hematuria, arterial hypertension, abdominal pain and inherited kidney diseases.     

Magnetic resonance imaging of renal lymphoma with computed tomography correlation

The magnetic resonance (MR) imaging and computed tomography (CT) findings in four patients (five kidneys) with non-Hodgkin's lymphoma involving the kidneys and perirenal spaces are presented. The patterns of disease in each case were as follows: bilateral renal nodules, infiltration in the perirenal space, infiltration in the perirenal space with renal involvement, and direct invasion from contiguous retroperitoneum. On plain CT, the lesions showed slight hyperdensity (three kidneys) and isodensity (two kidneys) as compared with normal renal parenchyma. But all lesions appeared as hypodense masses with more definite margins after contrast enhancement. MR imaging findings showed iso- or slight hypointense masses on T1-weighted images and definite hypointense masses on T2-weighted images as compared with the signal intensity of the renal cortex. Dynamic imaging and conventional delayed T1-weighted imaging following Gd-DTPA injection showed no significant enhancement of the lesions. In comparison with contrast enhanced CT, despite its poorer resolution, T2-weighted MR imaging showed nearly the same accuracy in the evaluation of number and extent of the lesions without contrast medium administration. MR imaging was also useful to evaluate the patency of vessel lumen surrounded by tumor mass and to determine the location and extent of huge lesions by its multiplanar imaging capabilities.     

Splenunculus mimicking late local recurrence of renal cell carcinoma

We report on a case of a splenunculus found in the renal fossa 14 years after left transperitoneal radical nephrectomy and splenectomy for renal cell carcinoma. The significance of splenunculi in differential diagnosis of space occupying lesions in the left renal bed is discussed.     

In vitro studies on the potential for biological control of Aspergillus flavus and Fusarium moniliforme by Trichoderma species. 1. Macroscopical and microscopical observations of fungal interactions

Since the advent of CT, secondary neoplastic lesions of the kidneys have been detected with increasing frequency. After reviewing a large series of cases of renal metastases, we have been able to classify the CT findings into seven major categories that are discussed and illustrated in this article. The differential diagnoses between metastatic disease of the kidneys and other lesions such as renal infarctions, renal lymphoma, and primary malignancies are also considered.     

Computer tomographic diagnosis of cardiac, pericardial and paracardial space occupying lesions

By means of the pathological findings of 63 patients diagnosed by CT of the heart the radiodiagnostic signs of myocardial, pericardial and paracardial space occupying processes are demonstrated with emphasis on CT of the heart. In addition the electrocardiographic findings of 46 patients are compared with the CT-findings. Whereas there are no essential differences between the results of the two methods diagnosing intramural and greater intracavitary tumors, CT is to prefer at the differential diagnosis of pericardial and paracardial tumors. CT is superior to echocardiography diagnosing small intracavitary thrombi.     

Late diagnosis of the avulsion of the pyelo-ureteral junction treated by ureterocalicostomy

The authors report an exceptional case of delayed diagnosis of avulsion of the ureteropelvic junction in a 27-year-old man. Organization of the urohaematoma prevented ureteropelvic anastomosis and the kidney could only be preserved by performing ureterocalicostomy. This technique, generally used for tuberculous retracted renal pelvis, or failure of pyelotomy or ureteropelvic junction repair in horseshoe kidneys or kidneys with retracted renal pelvis, allowed renal preservation in this case.     

Role of sodium in contrast medium-induced polymorphic ventricular tachycardia: results in a rabbit model of lengthened QT interval

OBJECTIVES: To describe the imaging features of nephroblastomatosis with US, CT and MR, to point out characteristics of differentiation between nephrogenic rests (NR) and Wilms' tumour (WT) and to determine the most appropriate imaging modality. MATERIALS AND METHODS: We reviewed the US, CT and MR images of 29 cases of histopathologically confirmed nephroblastomatosis sent to our department for reference evaluation (German nephroblastoma study). The series included 17 kidneys with NR, 6 kidneys with WT and 32 kidneys with both NR and WT. RESULTS: NR presented as multinodular, peripheral, cortical lesions, the diffuse form of distribution being less common. Foci were homogeneous and of low echogenicity, density or signal intensity. The lesions were most clearly depicted with contrast-enhanced CT and T1-weighted (T1-W) MR images. Lesions smaller than 1 cm were rarely identified by US. The most reliable criterion to differentiate NR from WT was their homogeneity. CONCLUSIONS: Contrast-enhanced CT and T1-W MR images are of similar potential and superior to US in the diagnosis of nephroblastomatosis. Due to the significant radiation dose of serial CT, MR imaging should be the method of choice wherever it is available. The cost-effectiveness and availability of US makes it ideal for serial follow-up of known lesions.     

Characterization of hepatic neoplasms: contribution of magnetic resonance

The reliability of MR imaging in the diagnosis and characterization of space occupying lesions affecting the liver are discussed in this study. We discuss the role of MR imaging in the diagnosis of these tumours and its advantages compared with other available techniques such as ultrasonography and CT. We also discuss the results of MR in the characterization of focal neoplastic masses.     

Ultrasonic diagnosis in diseases of kidneys (author's transl)

The diagnostic value of echoscopy and echography in kidney disease is presented and illustrated. Ultrasound examination is primarily used for the differentiation of cystic and solid lesions of the kidney. Our personal experience and the recent literature on this problem is reviewed. Based on the overall diagnostic accuracy of more than 90%, a procedure to investigate space occupying lesions of the kidney is suggested. The indication for ultrasound scans in obstructive kidney disease and the unilateral nonexcreting kidney is briefly discussed.     

Blunt renal traumas: contribution of spiral CT with three dimensional reconstruction to the surgical decision process?

Spiral CT has proved to be a valuable tool by providing various kinds of three-dimensional (3D) images of the studied structures. Such 3D images, which offer a more realistic depiction of the lesions, could be of interest for surgeons who are attempting to treat conservatively blunt abdominal traumas and lead to less inappropriate triage between conservative and operative management particularly for renal trauma. A good working relationship between surgeons and radiologists allowed us to perform an early follow-up 3D spiral CT on a commercially available spiral CT scanner. In the first adult patient, the 3D CT demonstrated minor spleen injury associated with severe lacerations of the left kidney with complete separation of the kidney lower pole. A delayed partial lower nephrectomy was performed. For the second 12-year-old patient presenting with severe spleen trauma and macroscopic hematuria, the 3D CT accurately documented the spleen and renal lesions that were safely amenable to nonoperative treatment. For hemodynamically stable patients, 3D CT is a potentially helpful addition to conventional axial CT for quantifying blunt renal traumas and for making the strategic choice between nonoperative, emergency or delayed surgical treatment.     

Value of CT-angiography in diagnosis of cerebral sinus and venous thromboses

Dural sinus thrombosis is not uncommon. Due to the nonspecific symptomatology, as well as the manifold etiology, clinical diagnosis may be difficult. In these cases imaging procedures are frequently crucial in deciding how to proceed and how to treat. The aim of our study was to evaluate the diagnostic utility of helical CT in the detection of dural sinus thrombosis. In 20 patients with clinically suspected thrombosis CT angiography was performed. In 6 patients dural sinus thrombosis was diagnosed. In order to acquire also arterial vessels, a short delay of about 22 s after the onset of the application of contrast medium was selected. By this method we found an occlusion of the MCA in two patients with clinically suspected sinus thrombosis. In all patients the transverse slices and the multiplanar reconstructions showed filling defects or an "empty delta" sign. With irregular outlines the thrombus could be depicted over the complete course of the sinus. The MIP reconstructions were particularly helpful in the evaluation of the vessel anatomy and the pathological collateral venous drainage. In three patients MR angiograms were available for comparison. The smaller veins, such as the v. vermis inferior, were less clearly depicted than in CT angiography. CT angiography is a fast and reliable method to exclude or verify a sinus thrombosis. It can be performed immediately after non-enhanced CT. According to our present experience CT angiography is sufficient for the diagnosis of a sinus thrombosis.     

Helical CT angiography for examination of living renal donors

OBJECTIVE: This prospective study was intended to determine if helical CT arteriography plus conventional radiography is sufficiently accurate to replace and less costly than excretory urography and conventional renal arteriography, the techniques currently used to examine living renal donors. SUBJECTS AND METHODS: Patients underwent CT arteriography with a helical CT scanner. Conventional radiographs were obtained during the pyelographic phase to evaluate the urothelium. Findings on CT arteriograms were compared with findings on conventional arteriograms and at surgery. RESULTS: Of 57 patients who underwent CT arteriography, 46 also underwent conventional arteriography and 40 underwent surgery. For those 46 patients, we found agreement between results of CT arteriography and conventional arteriography in 89% of kidneys. For those 40 patients, we found agreement between results of CT arteriography and findings at surgery in 90% of kidneys and agreement between results of conventional arteriography and findings at surgery in 87% of kidneys. Of the 57 patients, six (11%) had findings on CT angiograms that precluded further consideration for donation. CONCLUSION: Eight to ten percent of renal arteries are not seen on renal arteriograms when compared with findings at surgery. Our results indicate that CT arteriography is as accurate as conventional arteriography at revealing the number of vessels that perfuse and drain the kidneys and can replace conventional arteriography. Use of CT angiography plus conventional radiography instead of excretory urography and conventional arteriography can result in a 35-50% reduction in cost of the imaging studies in potential renal donors.     

Small solid renal lesions: usefulness of power Doppler US

PURPOSE: To evaluate whether the vascular pattern at power Doppler ultrasonography (US) improves diagnostic accuracy in small solid renal lesions over that at gray-scale US. MATERIALS AND METHODS: Gray-scale and power Doppler US were performed prospectively in 64 small (1.5-3.0-cm-diameter) solid renal lesions (26 renal cell carcinomas [RCCs], 34 angiomyolipomas, two oncocytomas, two pseudotumors). At gray-scale US, echogenicity and homogeneity of the lesion, an anechoic rim, intratumoral cysts, shadowing, or a central scar were sought. At power Doppler US, the vascular distribution was divided into four patterns. RESULTS: Findings at gray-scale US included an anechoic rim or intratumoral cysts in 20 of 26 RCCs (77%) and the two oncocytomas. Shadowing was seen in seven of 34 angiomyolipomas (21%). Echogenicity, homogeneity, and a central scar were not pathognomonic. At power Doppler US, pattern 3 (peripheral) or 4 (mixed penetrating and peripheral) was seen in all RCCs, seven of 34 angiomyolipomas, and the two oncocytomas. Pattern 1 (intratumoral focal) or 2 (penetrating) was seen in 27 angiomyolipomas. Pattern 1 or 2 was characteristic of angiomyolipoma. The rate of correct diagnosis was significantly increased with combined US (78%) as compared to that with gray-scale (42%) or power Doppler (45%) US alone. CONCLUSION: The vascular distribution at power Doppler US could add important information to gray-scale US findings for differential diagnosis of small solid renal lesions.     

Ultrasonic diagnosis of space-occupying lesions of the kidney (author's transl)

In 140 patients who were suspected of having space-occupying lesions of the kidney the ultrasound findings were analysed. There were no false negative results. Out of 4 false positives two could be explained by nontumourous focal renal disease. In a further 10 cases a space-occupying lesion could not be excluded with certainty on the grounds of the ultrasound investigation alone. Out of a total of 96 space-occupying lesions (48 solid tumours, 48 cystic processes) 83 were correctly diagnosed sonographically.     

MR diagnosis of cerebrospinal fluid fistulas using a 3D-CISS sequence

PURPOSE: We compared a new MR method for diagnosis of CSF fistulas with CT cisternography. MATERIAL AND METHODS: In a prospective case study we examined 35 patients with posttraumatic CSF fistulas and compared the results with the intraoperative findings. The MR investigation was performed using a 1.0T whole body MR-system. We used a strongly T2*-weighted 3D-CISS sequence. The examinations were performed in prone position, in patients with severe CSF rhinorrhoea additionally in supine position. RESULTS: The sensitivity and specificity of the MR method (88.9% and 95.1%) is higher compared with CT cisternography (77.8% and 87.8%). The reason for the lower sensitivity of CT compared with MRI are complex fracture systems, involving several paranasal cavities in patients with false positive results in CT cisternography. Reasons for the lower specificity of CT cisternography are false negative results in patients with small dural lesions below 2 mm2. CONCLUSION: Using a new method MRI can detect CSF-fistulas. The MR method is superior to CT cisternography, is noninvasive, the administration of contrast and agent is no longer necessary.     

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.     

Factors influencing long-term survival after lung metastasectomy

PURPOSE: To explore the mode of spread of disease between the perirenal space and the perivascular central retroperitoneum and to determine the anatomy along the medial border of the perirenal space. MATERIALS AND METHODS: Anatomic dissection, injection of latex, and observation of cross sections of the abdomen were performed in nine cadavers. Attention was paid to the juncture of the central prevertebral, perivascular, and extraperitoneal regions, and the perirenal space. Anatomic findings were correlated with observations made at computed tomography (CT) in 82 patients with retroperitoneal hemorrhage (n = 24), inflammation (n = 37), and neoplasia (n = 21) involving the perirenal spaces or the central retroperitoneum. RESULTS: Along most of the length of each kidney, no apparent fascia separates the perirenal space from the central retroperitoneum. At this location, septa between fat lobules form a fenestrated multitier barrier. These septa were imperceptible on CT scans obtained in healthy individuals. After injection of latex in cadavers, this potential barrier was seen. In the clinical study, spread of disease was allowed in only 38 (30%) of 128 instances of potential spread. Spread was facilitated along the renal vessels and the interlobular septa. CONCLUSION: Beyond the kidneys, the renal fascia is closed, forming a cone superiorly and an inverted cone inferiorly. A network of interlobular septa acted as a barrier or pathway to the free spread of disease from the perirenal space to the central retroperitoneum or from the central retroperitoneum to the perirenal space.     

CT of the extraperitoneal space: normal anatomy and fluid collections

Knowledge of the appearance and location of the normal fascial structures surrounding the kidneys and the bladder is the key to proper CT analysis of extraperitoneal fluid collections. Recent studies have shown that the renal fascia and the perirenal space are more complex than previously recognized. An extracapsular renal hematoma, confined against the kidney by the posterior renorenal septum within the perirenal space, can entirely simulate a subcapsular hematoma. Pancreatitis fluid can dissect between the discrete layers that constitute the posterior renal fascia, allowing fluid in the anterior pararenal space to extend posterior to the kidney without directly involving the posterior pararenal space. The umbilicovesical fascia separates the small perivesical space from the potential large reservoir of the prevesical space in the extraperitoneal portion of the pelvis. Fluid in the prevesical space can communicate directly with the retroperitoneal spaces surrounding the kidney. In addition to compartmental localization, CT features of the fluid itself or the presence of ancillary findings such as aortic aneurysm, enlarged pancreas, renal mass, or hydronephrosis will frequently indicate the cause and the extent of most extraperitoneal fluid collections.     

Advances in the imaging of renal infection. Helical CT and modern coordinated imaging

Traditionally, imaging of renal infections was largely through a multimodality approach. Excretory urography, ultrasonography, nuclear scintigraphy, and CT all played major roles; however, in recent years, CT has increased in prominence in the imaging and evaluation of renal infection. Part of the reason for this trend includes improvements in the availability of CT scanners and more timely access to them. Helical scanning technology has also greatly increased the quality and usefulness of the information CT provides. Most uncomplicated cases of acute renal infection in adults do not require imaging for diagnosis and treatment. When imaging is indicated, however, contrast-enhanced CT almost always is the study of choice. For cases in which renal calculi may be present, the study should also include noncontrast images through the kidneys.     

Identification of Asp95 as the site of succinimide formation in recombinant human glial cell line-derived neurotrophic factor

PURPOSE: To compare gadolinium-enhanced inversion-recovery magnetic resonance (MR) imaging with renal cortical scintigraphy in the diagnosis of childhood pyelonephritis. MATERIALS AND METHODS: Thirty-seven patients with fever-producing urinary tract infection underwent gadolinium-enhanced inversion-recovery MR imaging and technetium-99m renal cortical scintigraphy. Each study was read in double-blind fashion by two radiologists. The kidney was divided into three zones, and each was graded as positive, equivocal, or negative for pyelonephritis. RESULTS: Seventy kidneys (210 zones) were imaged. Twenty-six kidneys (54 zones) had evidence of pyelonephritis at both MR imaging and scintigraphy. Twenty-four kidneys (100 zones) were negative on both studies. Twelve kidneys (42 zones) were positive at MR imaging but negative at scintigraphy, and four kidneys (seven zones) were negative at MR imaging but positive at scintigraphy. The results of MR imaging for pyelonephritis were not equivalent to the results of scintigraphy (P = .001 for renal zones). The proportion of positive agreement between readers for the presence of pyelonephritis was 0.85 and 0.57 for MR imaging and scintigraphy, respectively. The proportion of negative agreement was 0.88 and 0.80 for MR imaging and scintigraphy, respectively. CONCLUSION: Gadolinium-enhanced inversion-recovery MR imaging enabled detection of more pyelonephritic lesions than did renal cortical scintigraphy and had superior interobserver agreement.