Renal imaging in long-term dialysis patients: a comparison of CT and sonography

Patients undergoing long-term dialysis are subject to cyst formation, hemorrhage, and neoplasia in their native kidneys. Detection of these complications with incremental dynamic CT and detection with sonography were compared prospectively in 41 patients (79 kidneys) who had been undergoing dialysis intermittently for 3 or more years. Acquired cystic kidney disease (five or more cysts per kidney) was identified in 59% of kidneys by use of CT and in 18% by use of sonography. CT showed a complete renal contour definition in all cases, sonography did so in only 57%. Three solid renal tumors (2- to 4-cm diameter) were identified with both techniques with no false-negative evaluations. Four benign hemorrhagic cysts were identified with combined CT (hyperdense mass) and sonography (benign cysts). CT provided the best anatomic image quality and was more accurate for detection of acquired cystic kidney disease. CT and sonography were equivalent for detection of solid tumors. Our results suggest that dynamic contrast-enhanced CT scanning with the supplemental use of sonography is the best imaging regimen for the evaluation of suspected acquired cystic kidney disease and its potential complications.     

Spontaneous subcapsular and perinephric hemorrhage in end-stage kidney disease: clinical and CT findings

Clinical, CT, and pathologic findings were analyzed in six patients with spontaneous subcapsular or perinephric hematomas complicating end-stage kidney disease. Renal failure had been managed by hemodialysis in four patients, by renal transplantation in one, and by conservative methods in one. All patients had nonspecific abdominal pain. CT clearly showed in all cases that the pain resulted from hemorrhage and also revealed the extent and location of hematomas. In addition, in four patients, CT showed underlying acquired cystic kidney disease that was the probable cause of hemorrhage. In one of these patients, CT also showed a renal cell carcinoma in the opposite kidney. Other causes for renal hemorrhage encountered in the series included renal infarction due to small vessel disease, heparinization during hemodialysis, and thrombocytopenia. Abdominal CT is a useful technique for evaluating patients with end-stage renal disease who have abdominal pain or who exhibit clinical evidence of blood loss.     

Sonographic evaluation of kidneys undergoing dialysis

Sonograms in 205 patients undergoing dialysis were obtained to evaluate renal features according to duration of treatment. Both length and parenchymal thickness had gradually decreased in kidneys treated for less than 3 years. After the 3rd year of treatment, an apparent increase in the incidence of cysts was seen. Forty-three cases of acquired cystic disease, including 1 case with renal cell carcinoma, were detected. All kidneys had increased cortical echogenicity, with prominence first occurring after 7 years of dialysis. In patients undergoing dialysis for less than 3 years, those with diabetic nephropathy showed fewer changes from normal appearances than patients undergoing dialysis for treatment of glomerulonephritis.     

Sonographic evaluation of kidneys undergoing dialysis

Sonograms in 205 patients undergoing dialysis were obtained to evaluate renal features according to duration of treatment. Both length and parenchymal thickness had gradually decreased in kidneys treated for less than 3 years. After the 3rd year of treatment, an apparent increase in the incidence of cysts was seen. Forty-three cases of acquired cystic disease, including 1 case with renal cell carcinoma, were detected. All kidneys had increased cortical echogenicity, with prominence first occurring after 7 years of dialysis. In patients undergoing dialysis for less than 3 years, those with diabetic nephropathy showed fewer changes from normal appearances than patients undergoing dialysis for treatment of glomerulonephritis.     

Natural history of acquired renal cystic disease in dialysis patients: a prospective longitudinal CT study

Patients with end-stage kidney disease, particularly those treated with dialysis, develop proliferative processes in their native kidneys that result in the formation of multiple acquired renal cysts, renal adenomas, and carcinomas. Data about these abnormalities have been acquired mainly from retrospective studies. We undertook a longitudinal prospective study in which the native kidneys of 30 dialysis patients were surveyed by serial CT during a 7-year period to study the natural history of acquired renal cystic disease and the frequency of associated complications. Acquired cysts were seen in 87% of patients at the end of the study compared with 57% at the study's onset, and a significant increase was seen in mean renal volume with time. Five patients (17%) developed large hemorrhagic renal cysts and four (13%) developed large perinephric hematomas. Renal cell carcinomas developed in two patients (7%) without renal symptoms. One carcinoma invaded the renal capsule, but did not cause metastases. The other carcinoma was widely metastatic. Our findings are consistent with those of earlier studies documenting an increased prevalence of renal cell carcinoma in dialysis patients as compared with the general population. However, our conclusions are limited because the study sample is small and no control population was studied. We conclude that acquired renal cystic disease in dialysis patients is a progressive disorder often associated with cyst hemorrhage. Dialysis patients may also have an increased prevalence of renal cell carcinoma.     

肾集合管癌的CT表现及诊断价值

目的探讨肾集合管癌的CT表现及其诊断价值,提高对本病的认识。方法结合文献回顾性总结并分析6例肾集合管癌的临床表现及影像学、病理学特征。5例行CT平扫及增强扫描,1例患者仅行CT平扫。结果6例中男3例,女3例,肿瘤位于左肾3例,右肾3例;肿瘤直径3～10 cm,平均5.8 cm;累及肾皮质和髓质者2例,同时累及肾皮质、髓质及肾盂者4例;平扫肿块呈实性成分者2例,囊实性混杂成分者4例;增强扫描肿块多呈轻中度强化;4例肾脏轮廓改变;4例肿瘤内可见钙化;肾门周围淋巴结转移者5例,肺转移1例,左侧胸壁转移者1例,腰骶椎椎体转移1例;术前诊断为肾癌者5例,肾淋巴瘤1例。结论肾集合管癌的CT表现具有一定的特征,起源于髓质、增强扫描轻中度强化并且呈浸润性生长的肿瘤应考虑到该病可能。     

Renal cystic diseases

Renal cystic disease comprises a mixed group of heritable, developmental, and acquired disorders. Because of their diverse etiology, histology, and clinical presentation, no single scheme of classification has gained acceptance. Conditions include autosomal dominant polycystic kidney disease, acquired renal cystic disease, medullary sponge kidney, autosomal recessive polycystic kidney disease, multicystic dysplastic kidney, medullary cystic disease, tuberous sclerosis, cysts of the renal sinus, and von Hippel-Lindau's disease. An awareness of the pathology of each cystic disease is helpful in the understanding of the corresponding radiological images. Imaging techniques used in evaluating renal cystic disease include intravenous urography, sonography, CT, MRI, nuclear medicine, and renal angiography. Many types of cystic disease show similar imaging features. Meticulous attention to subtle radiological findings is therefore essential for reaching a correct diagnosis. Imaging features requiring analysis include whether the cysts are unilateral or bilateral, renal size and functional status, cyst distribution in the kidneys, and the presence of hemorrhagic and calcified renal cysts, solid renal masses, renal sinus cysts, and cysts in adjacent organs. Radiological findings should be carefully correlated with clinical features such as patient age, family history, symptoms, physical findings, and renal functional status before a diagnosis is attempted. Received 10 October 1996; Revision received 30 January 1997; Accepted 4 February 1997     

Differentialdiagnose fokaler Nierenläsionen in CT und MRT

The great majority of renal masses are found incidentally as a result of the use of ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI). If ultrasonography is not diagnostic CT or MRI should be initiated to differentiate lesions of the kidney that need surgical intervention from those that do not and from those that need follow-up examinations.Cystic renal masses are characterized by using the Bosniak classification, including category IIF. In solid lesions of the kidney first non-surgical lesions as well as lymphoma, renal infarction and nephritis should be excluded. Identifying fatty components in renal lesions is very important because in angiomyolipoma they are almost always present.CT and MRI are exellent for tumor detection. Careful evaluation of imaging finding combined with the patient′s history should assist the radiologist in making the proper diagnosis or recommending the appropriate treatment in most cases.This article provides a review about renal masses, the imaging methods for their evaluation and their characteristic features at CT and MR imaging. Different lesions are demonstrated like xantogranulomatous pyelonephritis, acute pyelonephritis, renal infarction, lymphoma, angiomyolipoma, renal oncocytoma, cystic lesion and polycystic disease the kidney, echinococcosis, renal cystadenoma, metastases, renal cell carcinoma (RCC), and multiple bilateral RCC in patients with Hippel-Lindau-Syndrome.This article should help to differentiate complex cystic lesions of the kidney by using the Bosniak-classification, especially Bosniak Category IIF. Solid masses should be characterized and the major question to be answered is whether the mass represents a surgical or nonsurgical lesion or if follow-up studies are necessary.     

CT of acquired cystic kidney disease and renal tumors in long-term dialysis patients

The kidneys of long-term dialysis patients frequently demonstrate multiple small acquired cysts and renal cell tumors on pathologic examination. The original kidneys of 30 long-term dialysis patients and six renal transplant patients were evaluated by computed tomography to determine the incidence of these abnormalities. Among dialysis patients, 43.3% had diffuse bilateral cysts, while 16.7% had occasional cysts (fewer than five per kidney), and 40% showed no renal cysts. Seven solid renal tumors were detected in four dialysis patients with renal cysts. Acquired cystic kidney disease tends to result in renal enlargement, is more common in patients who have been maintained on dialysis for prolonged periods, and may lead to spontaneous renal hemorrhage. The six transplant patients showed no evidence of renal cysts, and all had markedly shrunken kidneys. Acquired cystic disease and renal cell tumors in the original kidneys of dialysis patients may be due to biologically active substances that are not cleared effectively by dialysis but that are removed by normally functioning transplant kidneys.     

Acinic cell carcinoma of the head and neck: radiologic-pathologic correlation

OBJECTIVE: To describe and correlate the imaging and pathologic findings of acinic cell carcinoma (ACC) in the head and neck. METHODS: We reviewed the radiologic findings of 12 patients with pathologically proven ACC in the head and neck. They were 6 males and 6 females (ages: 5-75 years, mean 36 years) who undergoing computed tomography (CT, n=9) and CT with magnetic resonance (MR) imaging (n=3). RESULTS: The lesions in the superficial lobe of the parotid gland were solid (n=7), cystic (n=1), and cystic mass with mural nodule (n=1) on CT. A parapharyngeal lesion was cystic mass with mural nodule, and a submandibular and a palate tumor were cystic lesions on CT. All solid masses in the parotid gland (n=7) included focal low-attenuating portions on CT, which were microcyst, hemorrhage, or necrosis on pathologic examination. We could not find intratumoral calcifications or metastatic lymphadenopathy on imaging and histologic studies in all 12 cases. Internal hemorrhage on the MR images was seen in a parapharyngeal and a parotid lesion. CONCLUSION: Although ACC appears to have nonspecific imaging findings, familiarity with some imaging features can be helpful for differential diagnosis of head and neck tumors.     

儿童肾母细胞瘤的CT诊断和鉴别诊断

目的探讨CT在小儿肾母细胞瘤的诊断及鉴别诊断中的作用。方法回顾性分析经临床及病理证实的小儿肾母细胞瘤45例,肾透明细胞癌2例,肾横纹肌肉瘤1例。结合手术病理,了解其在CT上的表现特点。结果肾母细胞瘤表现为实性肿块34例（76%）、囊实性9例（20%）、囊性2例（4%）。肿瘤实质及囊壁有明显强化。7例（15.6%）肾或腔静脉内有癌栓形成。肾细胞癌表现与肾母细胞瘤相似。肾横纹肌肉瘤表现为肾中心囊实性肿块,内有线状钙化,有肾包膜下积液。结论肾母细胞瘤在恶性肾脏肿瘤中最常见,好发于肾实质,易侵犯肾盂肾盏,肿瘤常伴有出血、坏死、囊变,影像学上与肾细胞瘤很难鉴别。肾横纹肌肉瘤常好发于肾中心,包绕于瘤叶的线状钙化及包膜下积液为其特点。     

多房囊性肾细胞癌的CT分析

目的:探讨多房性囊性肾细胞癌的CT表现特点及诊断价值。方法:回顾性分析13例经手术病理证实的多房性囊性肾细胞癌患者的CT图像及相关临床资料。结果:病变位于右肾8例,左肾5例。病灶直径4~25cm,平均13cm。病灶由多个囊腔和分隔构成,5例伴附壁结节,2例见囊壁钙化,增强后囊壁、分隔和壁结节可有强化。结论:多房囊性肾细胞癌的CT表现有一定特征性。CT在多房性囊性肾细胞癌的诊断中具有重要作用,但在鉴别时仍有一定难度。     

囊性肾癌的CT、超声影像分析(附13例报告)

目的 探讨囊性肾癌的CT、超声特点及诊断价值。资料与方法 回顾性分析13例经手术病理证实的囊性肾癌的CT和超声表现。结果 CT及超声对囊性。肾癌的诊断准确性高，其主要特点为囊壁及分隔的不规则增厚、囊壁结节、钙化，囊液混浊，实性部分增强后强化，实性部分或分隔上出现彩色血流。结论 CT及超声检查对囊性肾癌有较高的诊断价值，但对不典型者可误诊为良性囊肿，应行超声引导下穿刺活检。     

Acquired cystic disease of the kidneys. Computed tomography and ultrasonography appraisal in patients on peritoneal and hemodialysis

Screening chronic hemodialysis patients (CHD) for acquired cystic disease of the kidneys (ACDK) and its complications (hemorrhage and neoplasm) has become accepted management. We evaluated patients on CHD as well as patients on chronic peritoneal dialysis (CPD) for ACDK. The kidneys of 80 chronic dialysis patients were examined by CT and real time sonography. Forty-four were hemodialysis and 36 were peritoneal dialysis patients. ACDK was found in more than 90% of both CHD and CPD patients who had been dialyzed longer than three years. Bilateral renal carcinoma was detected in one hemodialysis patient. Our results show that chronic peritoneal dialysis patients are also at risk for ACDK and its associated complications. A similar natural history for the development of ACDK in both forms of dialysis suggests that the same screening precautions should be instituted for chronic peritoneal dialysis patients.     

肾脏少见病变CT诊断(附4例误诊肾细胞癌的病例报道)

目的:分析4例误诊肾细胞癌的肾脏少见病变CT影像学表现,以期提高对这类病变的认识能力。方法:描述4例误诊肾细胞癌的肾脏少见病变临床与CT影像学表现。4例肾脏病变分别为肾血管畸形伴囊肿出血1例,肾神经内分泌癌(不典型类癌)1例,肾平滑肌瘤1例,肾结核1例。CT行平扫及3期增强扫描,其中2例作多平面重建(MPR)观察。结果:肾平扫等高混杂密度肿块及增强后对比剂圆弧形压迹可支持肾血管畸形伴囊肿出血的诊断。肾神经内分泌癌所示肾内肿块强化幅度不同于常见肾细胞癌。左肾平滑肌瘤表现为肾内球形肿块,境界光整,强化均匀,符合肾平滑肌瘤特征。左肾结核患肾病变内低密度灶境界锐利,肾皮髓质纹理模糊,符合肾结核乳头炎及结核脓腔的病理特点。结论:肾脏少见病变常难与肾癌鉴别。CT三期增强扫描和多平面重组常有必要。仔细观察病灶的形态、范围和强化情况,有助于作出正确判断。     

Benign multilocal cystic nephroma.

Three cases of multilocular cystic nephroma are described. This entity differs from congenital multicystic kidney and adult polycystic disease in that it involves only a segment of one kidney. While the excretory urogram, nephrotomogram, and arteriogram show the lesion to be primarily avascular, the two cases studied by ultrasound were predominantly solid. This finding is felt to relate to the small size of the cysts as well as the presence of some solid primitive components. Because it is difficult to differentiate this lesion from an avascular renal carcinoma, surgical biopsy should be considered to help avoid a needless nephrectomy.     

螺旋CT在小肾癌诊断中的价值

目的评价螺旋CT多期扫描在小肾癌诊断中的价值。方法收集经手术病理证实的小肾癌14例,分析其螺旋CT平扫、皮质期、实质期及肾盂期的表现。结果CT平扫病灶呈等密度7例,稍低密度5例,稍高密度1例,1例为囊实性肿块,其中2例伴斑点状钙化。增强扫描皮质期12例呈明显强化,2例呈轻中度强化。肾实质期肿瘤密度迅速减退,肾盂期肿瘤密度进一步减退。结论小肾癌螺旋CT增强多期扫描征象有一定特征性,对小肾癌的诊断有重要价值。     

Primary renal carcinoid tumor: A rare cystic renal neoplasm

We present the case of a 21-year-old man with an incidentally detected cystic renal mass.A well-defined,solid mass measuring approximately 8 cm x 6 cm with a cystic component was identified in the left kidney by abdominal multidetector computed tomography(CT) and ultrasonography.The mass was well-enhanced on the corticomedullary CT phase and washout of enhancement occurred on the nephrographic phase.The mass contained peripheral wall and septal calcifications in the cystic component.The lesion was resected and diagnosed as a primary renal carcinoid tumor.Primary carcinoid tumors of the kidney are extremely rare.This case is notable because of the rarity of this neoplasm and its unique radiologic and pathologic findings.A review of previously reported cases in the literature is also presented.     

巨大肾癌类肿瘤的CT诊断

目的:探讨巨大肾癌类肿瘤的CT表现特点。材料和方法:回顾性分析经手术病理证实的13例巨大肾癌类肿瘤(肾癌6例、肉瘤样癌5例和癌肉瘤2例)的CT表现。结果:13例巨大肾癌类肿瘤的CT表现为肿瘤以实性破坏为主,伴有出血坏死及钙化6例,肿瘤以囊性破坏为主4例和整个肾呈多囊及单囊样破坏伴有壁结节3例。结论:巨大肾癌类肿瘤因肿瘤巨大,多数侵犯邻近脏器,瘤内多发大的坏死、囊变区,是巨大肾癌类肿瘤的诊断特点。     

螺旋CT扫描在小肾癌诊断中的应用价值(附14例报告)

目的探讨螺旋CT多期扫描在小肾癌诊断中的价值。方法收集经手术病理证实的小肾癌14例,行螺旋CT平扫和皮质期、实质期及肾盂期增强扫描,分析其表现。结果CT平扫病灶呈等密度9例,稍低密度4例,稍高密度1例,2例为囊实性肿块,其中1例伴斑点状钙化。增强扫描皮质期11例呈明显强化,3例呈轻中度强化。肾实质期肿瘤密度迅速减退,肾盂期肿瘤密度进一步减退。结论小肾癌螺旋CT增强多期扫描征象有一定的特征性,对小肾癌的诊断有重要价值。