BACKGROUNDThere are relatively few reports focusing on clinical and multi-slice CT (MSCT) imaging findings of mucinous tubular and spindle cell carcinoma (MTSCC). Our study aimed to characterize the clinical and MSCT imaging features of MTSCC.

METHODSThe imaging findings in 17 patients with MTSCC by MSCT were retrospectively studied. MSCT was undertaken to investigate tumor location, size, density, cystic or solid appearance, calcification, capsule sign, enhancement pattern, and retroperitoneal lymph node metastasis.

RESULTSTumors (mean diameter, (3.9 ± 1.7) cm) were solitary (17/17), solid (16/17) with cystic components (5/17), had no calcifications (14/17), had a poorly defined margin (14/17), were centered in the medulla (15/17), compressed the renal pelvis (7/17), and neither lymph node nor distant metastasis was found. The attenuation of MTSCC tumors was equal to that of the renal cortex or medulla on unenhanced CT (32.3 ± 2.6, 36.3 ± 4.6, 33.2 ± 3.9, respectively, P > 0.05), while tumor enhancement after administration of a contrast agent was lower than that of normal renal cortex and medulla during all phases (P < 0.05).

CONCLUSIONMTSCC tends to be a solitary, isodense mass with poorly defined margin arising from the renal medulla with enhancement less than the cortex and medulla during all phases.

Adenocarcinoma, Mucinous ; diagnosis ; diagnostic imaging ; Adult ; Carcinoma ; diagnosis ; diagnostic imaging ; Carcinoma, Renal Cell ; diagnosis ; diagnostic imaging ; Female ; Humans ; Kidney Neoplasms ; diagnosis ; diagnostic imaging ; Male ; Middle Aged ; Radiography

OBJECTIVETo explore the possibility of predicting the histopathological types of small renal cell carcinoma (RCC) by analyzing the different ways of enhancement with multiphasic multidetector computed tomography (MDCT) of small renal cell carcinomas (diameter≤4 cm).

METHODSCT images of 93 cases, diagnosed as RCC by pathology, were analyzed retrospectively, including 70 clear cell renal cell carcinoma (CCRCC), 13 papillary renal cell carcinoma (PRCC) and 10 chromophobe renal cell carcinoma (CRCC). All of the cases were examined by multiphasic multidetector CT scanning.

RESULTSIn plain scans, 46 CCRCCs were homogeneous, 21 CCRCCs were heterogeneous with low-density area and 3 of them had calcification. CCRCCs were enhanced in contrast scan with a presence of "wash in and wash out" enhancement in general. 11 PRCCs were homogeneous and 2 PRCCs had calcification. Slight-homogeneous enhancement and "delayed enhancement" were present in the PRCCs. Six CRCCs were homogeneous and 2 were calcified, 2 CRCCs were heterogeneous with low-density area. The CRCCs presented as slight or moderate enhancement and 5 CRCCs as homogeneous enhancement, while one CRCC was "spoke-wheel-like enhancement", with a trend of "delayed enhancement". Statistically significant differences were revealed among the actual enhanced CT values, the ratio of enhanced CT value to aorta CT value in the corticomedullary phase, nephrographic phase and excretory phase between the CCRCCs and non-CCRCCs (P<0.001). The analysis of receiver operating characteristic curves (ROC) revealed that when the actual enhanced CT value of tumors in CMP larger than 84.2 HU, the ratio of actual enhanced CT value to aorta CT value at the same phase in CMP larger than 0.315 were used as criteria to diagnose CCRCCs and excluded non-CCRCCs, the diagnostic value was best.

CONCLUSIONSMDCT is of an important significance in the diagnosis and differential diagnosis of small CCRCCs and non-CCRCCs.

Calcinosis ; diagnostic imaging ; Carcinoma, Papillary ; diagnostic imaging ; Carcinoma, Renal Cell ; diagnostic imaging ; Carcinoma, Small Cell ; diagnostic imaging ; Contrast Media ; Diagnosis, Differential ; Humans ; Kidney Neoplasms ; diagnostic imaging ; Multidetector Computed Tomography ; ROC Curve ; Retrospective Studies

OBJECTIVETo investigate the value of real-time contrast-enhanced ultrasound (CEUS) in the diagnosis and differential diagnosis of renal solid renal lesions (RSLs).

METHODSWe retrospectively analyzed 140 cases of 152 RSLs with a mean diameter 3.1∓1.9 cm. CEUS was performed and the perfusion characteristics were analyzed using contrast pulse sequences (CPS) technique. CEUS findings were compared with biopsy histopathologic findings.

RESULTSA total of 137 malignant lesions (including 127 renal clear cell carcinomas, 8 renal papillary carcinomas and 2 chromophobe cell carcinomas) and 15 benign lesions (13 angiomyolipomas and 2 renal oncocytomas) were detected. Of the 137 malignant lesions, 98 (71.5%) showed contrast agent fast perfusion and hyper-enhancement or iso-enhancement in cortical phase, 104 (75.9%) showed hypo-enhancement in later corticalmedullary and late phase, and 125 (91.2%) showed rim-like enhancement. Tumors with a diameter ≤2 cm presented with homogeneous enhancement, and those ranging from 2 to 4 cm showed heterogeneous enhancement with a honeycomb feature; tumors greater than 4 cm featured heterogeneous enhancement with large no-enhancement necrotic areas. Of the benign lesions, 13 angiomyolipomas and 2 renal oncocytomas showed slow wash-in and slow wash-out mode. The diagnostic specificity, accuracy and positive predictive value of CEUS for RSLs were 94.9%, 96.1%, and 73.7%, as compared to 72.3%, 71.1%, and 19.1% with conventional US, respectively (P<0.001). The sensitivity and negative predictive value of CEUS were 93.3% and 99.2%, respectively, significantly higher than those of conventional US (60% and 94.3%, P=0.084, and 0.062, respectively).

CONCLUSIONReal-time CEUS can provide valuable information for improving the diagnosis and differential diagnosis of RSLs.

Adenoma, Oxyphilic ; diagnostic imaging ; Carcinoma, Renal Cell ; diagnostic imaging ; Contrast Media ; Diagnosis, Differential ; Humans ; Kidney Diseases ; diagnostic imaging ; Kidney Neoplasms ; diagnostic imaging ; Retrospective Studies ; Sensitivity and Specificity ; Ultrasonography

BACKGROUNDRenal clear cell carcinoma (RCCC) is the most common malignant renal tumor. It is highly malignant, does not cause clinical symptoms in its early stages, and cannot be diagnosed using conventional ultrasound. This study was aimed to investigate the contrast-enhanced ultrasound (CEUS) mode and characteristics of the time-intensity curve for RCCC and its pathological basis.

METHODSForty-two patients with pathologically diagnosed RCCC underwent CEUS examination before surgery. The patients' kidneys were visualized after injection of contrast agents using the Technos MPX DU8. We analyzed the CEUS mode, time-intensity curve, and pathological findings.

RESULTSThe detection rate of RCCC with conventional ultrasound was about 71%, while the rate using CEUS was 100%. Larger tumors (33 cases) showed non-uniform enhancement with defective filling. CEUS modes were divided into 4 types: type I, "quick in and out" (26.19%, 11/42); type II, "quick in and slow out" (40.48%, 17/42); type III, "Simultaneous in and out" (16.67%, 7/42); and type IV "slow in and out" (16.67%, 7/42). All types had a close correlation to the pathological basis. Time-intensity curve of CEUS consisted of 3 phases, the perfusion phase, regression phase, and lag phase. Cases of types I and III only had a perfusion and regression phase, those of type II and IV had a perfusion phase, regression phase, and lag phase. Quantitative analysis of the time-intensity curve showed that the time-to-peak (TTP) of the lesions was shorter than that of normal renal parenchyma (P < 0.0001), the mean value of the up slope rate of the absolute value of lesions was higher than that of the ipsilateral normal renal parenchyma (P < 0.0001), and that the mean value of descent slope rate of the absolute value of lesions was lower than that of the ipsilateral normal renal parenchyma (P < 0.0001).

CONCLUSIONSCEUS is useful in detecting small vessels in tumors. Although there are several different CEUS modes, type I "quick in and out" and type II "quick in and slow out" accounted for the most cases that had a close correlation to pathologic angiogenesis. Time-intensity curves also showed some special characteristics. These data could provide valuable information for the clinical diagnosis of RCCC.

Adult ; Aged ; Carcinoma, Renal Cell ; diagnostic imaging ; Contrast Media ; Female ; Humans ; Kidney Neoplasms ; diagnostic imaging ; Male ; Middle Aged ; Ultrasonography

Adult ; Aged ; Angiomyolipoma ; diagnosis ; diagnostic imaging ; Carcinoma, Renal Cell ; diagnosis ; diagnostic imaging ; Diagnosis, Differential ; Female ; Fibroma ; diagnosis ; diagnostic imaging ; Humans ; Kidney Neoplasms ; diagnosis ; diagnostic imaging ; Leiomyosarcoma ; diagnosis ; diagnostic imaging ; Male ; Mesenchymoma ; diagnosis ; diagnostic imaging ; Middle Aged ; Tomography, Spiral Computed ; methods

OBJECTIVETo study the CT findings of cystic nephroma (CN) and multilocular cystic renal cell carcinoma (MCRCC) and to improve the accuracy of preoperative diagnosis of these two diseases.

METHODSThe CT findings of nine CN cases and 19 MCRCC cases confirmed by pathology were blindly reviewed and compared with their pathological results. Fisher's exact test and independent-samples T test were applied to statistically analyze some of the CT features of the CN and MCRCC lesions.

RESULTSThe thickness of cystic walls and partitions in the nine CN cases ranged from 0.5 to 5 mm. Cystic walls and partitions were slightly thicker in some parts without visible mural nodules. Varying amounts of solid tissue could be found in all the 19 MCRCC tumors, and the cystic walls and partitions were found partially thickened ranging from 3 mm to 13 mm. Eight cases were with mural nodules (nodule diameter: 4.5-16 mm). Nine cases of CN tumors were lobulated and 7 protruded into the renal sinus. Three out of the 19 MCRCC presented shallow lobulation, and 7 tumors protruded into the renal sinus. The CT contrast-enhancement scanning displayed moderate delayed enhancement in the cystic walls and partitions in 8 cases. The enhanced scanning revealed that all the nine cases showed enhancement of the cystic walls and partitions, while 8 cases of them had mild to moderate delayed enhancement. The cystic walls, partitions and nodules were enhanced in 19 MRCC cases, among them 17 cases displayed obvious enhancement in the cortical phase. Among the differences of CT findings between MC and MRCC, the shallow lobulation, protruding into the renal sinus, mural nodules, cystic wall and partition thickness, and net growth in the cortical and nephrographic phase were statistically significantly different (P<0.05 for all).

CONCLUSIONSCT scan can provide significant evidence for CN and MCRCC diagnosis. CN cases usually present relatively thin and even cystic walls and partitions without mural nodules and with shallow lobulation and protruding into the renal sinus. The enhancement is mild to moderate, dynamic and delayed, while the opposite CT findings may indicate a higher possibility of MCRCC.

Adenocarcinoma, Clear Cell ; diagnostic imaging ; Carcinoma, Renal Cell ; diagnostic imaging ; Diagnosis, Differential ; Humans ; Kidney ; diagnostic imaging ; Kidney Diseases, Cystic ; diagnostic imaging ; Kidney Neoplasms ; diagnostic imaging ; Tomography, X-Ray Computed

BACKGROUNDThe difference between renal oncocytomas (RO) and renal clear cell carcinomas (RCCs) presents the greatest diagnostic challenge. The aim of this study was to retrospectively determine if RO and RCCs could be differentiated on computed tomography (CT) images on the basis of their enhancement patterns with a new enhancement correcting method.

METHODSForty-six patients with a solitary renal mass who underwent total or partial nephrectomy were included in this study. Fourteen of those were RO and 32 were RCCs. All patients were examined with contrast-enhanced CT. The pattern and degree of enhancement were evaluated. We selected the area that demonstrated the greatest degree of enhancement of the renal lesion in the corticomedullary nephrographic and excretory phase images. Regions of interest (ROI) were also placed in adjacent normal renal cortex for normalization. We used the values of the normal renal cortex that were measured at the same time as divisors. The ratios of lesion-to-renal cortex enhancement were calculated for all three phases. The Student's t-test and Pearson's Chi-square test were used for statistical analyses.

RESULTSAll RCCs masses showed contrast that appeared to be better enhanced than RO on all contrast-enhanced phases of CT imaging, but there was no significant difference in absolute attenuation values between these two diseases (P > 0.05). The ratio of lesion-to-cortex attenuation in the corticomedullary phase showed significantly different values between RO and RCCs. The degree of contrast enhancement in RCCs was equal to or greater than that of the normal renal cortex, but it was less than that of the normal cortex in RO in the corticomedullary phase. The ratio of lesion-to-cortex attenuation in the corticomedullary phase was higher than the cut off value of 1.0 in most RCCs (84%, 27/32) and lower than 1.0 in most RO (93%, 13/14) (P < 0.05). In the nephrographic phase, the ratio of lesion-to-cortex attenuation was higher than that in the corticomedullary phase in most RO (71%, 10/14), showing a prolonged enhancement pattern; and was lower than that in most RCCs (97%, 31/32), showing an early washout pattern (P < 0.05). In the differentiation of RO from RCCs, the sensitivity was 93%, specificity 84%, positive predictive value 72%, negative predictive value 84%, and accuracy for RO was 87, if the ratio of lesion-to-cortex attenuation in a cortex phase was lower than the cutoff value of 1.0. The sensitivity was 71%, specificity was 97%, positive predictive value was 91%, negative predictive value was 91%, and accuracy for RO was 89%, if the ratio of lesion-to-cortex attenuation in nephrographic phase was higher than that in the corticomedullary phase.

CONCLUSIONSThe ratios of renal lesion-to-cortex attenuation ratios may be helpful in differentiating RO from RCCs.

Adenoma, Oxyphilic ; diagnosis ; diagnostic imaging ; Adult ; Aged ; Carcinoma, Renal Cell ; diagnosis ; diagnostic imaging ; Female ; Humans ; Kidney Neoplasms ; diagnosis ; diagnostic imaging ; Male ; Middle Aged ; Tomography, X-Ray Computed

OBJECTIVETo study the sonographic features and patterns of cystic renal carcinomas.

METHODSThirteen cases of cystic renal carcinoma confirmed by operation and pathology were examined by ultrasonography, and the cystic walls, septa and solid mural nodules were studied.

RESULTSSolid mural nodules of some cases and irregular thickening of the cystic walls and septa were characteristic findings for the ultrasonic diagnosis of cystic renal carcinomas. According to their pathologic mechanisms and sonographic features, cystic renal carcinomas were classified into 3 patterns: unilocular cystic mass, multiloculated cystic mass and cystic-solid mass.

CONCLUSIONSTypical cystic renal carcinomas can be well diagnosed, while atypical cases may be misdiagnosed as benign renal cysts by ultrasonography. Color Doppler ultrasonography and needle aspiration guided by ultrasonography are helpful in the diagnosis of these atypical cases.

Adult ; Aged ; Biopsy, Needle ; Carcinoma, Renal Cell ; diagnostic imaging ; Diagnosis, Differential ; Female ; Humans ; Kidney Diseases, Cystic ; diagnostic imaging ; Kidney Neoplasms ; diagnostic imaging ; Male ; Middle Aged ; Ultrasonography, Doppler, Color

Aged ; Carcinoma, Renal Cell ; diagnosis ; diagnostic imaging ; Female ; Humans ; Kidney Neoplasms ; diagnosis ; diagnostic imaging ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Tomography, Emission-Computed ; Ultrasonography

OBJECTIVETo investigate the FDG uptake characteristics, the factors affecting 18F-FDG uptake and the extra CT diagnostic value of 18F-FDG PET/CT scan in the malignant tumor with false negative 18F-FDG PET image.

METHODSThe data of PET/CT image in 17 patients with various kinds of cancers were reviewed and analyzed by visual observation and semi-quantity analysis ( SUV). The results were compared with the CT and histopathological diagnosis, respectively.

RESULTSOf 6 well-differentiated HCC patients confirmed by histopathological diagnosis, one had two lesions in the right lobe of the liver. One of these two lesions showed low FDG uptake on 18F-FDG PET scan and low density on CT scan. The other one was not shown on either 18F-FDG PET or plain CT scan. But on enhanced CT scan, these two lesions were found to be inhomogeneous with high density at arterial phase. The false negative 18F-FDG PET images of one gastric signet ring cell carcinoma in the gastric fundus with right adnexa metastasis, 3 renal cell carcinoma, one greater omentum and peritoneal metastatic adenocarcinoma and one well-differentiated prostate cancer were caused by normal physical uptake in the digestive tract or FDG retention in the urinary system due to normal excretion. The size of three metastases was smaller than or equal to 1 cm in diameter, however, two primary lesions of these metastases showed high FDG uptake and only one was negative on either 18F-FDG PET or CT scan. In this series, 68.8% of the primary tumors and 66.7% of metastases were found to show abnormal density on CT scan, and 31. 2% of the primary tumors and 33. 3% of metastases were not detectable on either PET or CT images.

CONCLUSIONFalse negative 18F-FDG PET in malignant tumor may be correlated with the pathologic type, differentiation degree and the lesion size. Combining CT information with PET or paying attention to the scan methods during 8 F-FDG PET examination may reduce the rate of false negative 18F-FDG PET diagnosis in various kinds of malignant tumors.

Adenocarcinoma ; diagnostic imaging ; secondary ; Adult ; Aged ; Carcinoma, Hepatocellular ; diagnostic imaging ; pathology ; Carcinoma, Renal Cell ; diagnostic imaging ; pathology ; Carcinoma, Signet Ring Cell ; diagnostic imaging ; pathology ; False Negative Reactions ; Female ; Fluorodeoxyglucose F18 ; Humans ; Kidney Neoplasms ; diagnostic imaging ; pathology ; Liver Neoplasms ; diagnostic imaging ; pathology ; Male ; Middle Aged ; Omentum ; diagnostic imaging ; Peritoneal Neoplasms ; diagnostic imaging ; secondary ; Positron-Emission Tomography ; methods ; Radiographic Image Enhancement ; Stomach Neoplasms ; diagnostic imaging ; pathology ; Tomography, X-Ray Computed