Quantitative Evaluation of Intravoxel Incoherent Motion and Diffusion Kurtosis Imaging in Assessment of Pathological Grade of Clear Cell Renal Cell Carcinoma.

RATIONALE AND OBJECTIVES: To evaluate the diagnostic value of intravoxel incoherent motion and diffusion kurtosis imaging parameters for clear cell renal cell carcinoma (ccRCC) grading. MATERIALS AND METHODS: A total of 60 patients with pathologically proven ccRCC who underwent intravoxel incoherent motion and diffusion kurtosis imaging were retrospectively evaluated. The standard apparent diffusion coefficient (ADC), true diffusivity (D), pseudo-diffusion coefficient (D*), perfusion fraction (f), mean kurtosis (MK), and mean diffusivity (MD) maps were calculated and compared between high-grade and low-grade ccRCC using Mann-Whitney U test. Receiver-operating characteristic analysis was performed for all parameters. RESULTS: ADC, D and MD values were significantly lower for high-grade ccRCC compared to low-grade ccRCC (p < 0.05). MK values were significantly higher in high-grade ccRCC compared to low-grade ccRCC (p < 0.05). However, D* and f were not significantly difference between the two groups (p > 0.05). MD had the largest area under the curve (AUC = 0.888), followed by ADC (AUC = 0.796), D (AUC = 0.780), MK (AUC = 0.736), f (AUC = 0.582), and D*(AUC = 0.533). CONCLUSION: Diffusion-related parameters (D, ADC, MD, and MK) were able to significantly distinguish between low- and high-grade ccRCC. However, perfusion-related parameters (D* and f) were unable to separate high- and low-grade ccRCC. MD may be the most promising parameter for grading ccRCC in the clinic.

[Assessment of the diagnostic value of CT and X-ray enterography for small intestinal Crohn disease].

OBJECTIVE: To investigate the value of CT and X-ray enterography in the diagnosis of small intestinal Crohn disease(CD). METHODS: Data of 39 CD cases confirmed by surgery and pathology who underwent CT and X-ray enterography were analyzed retrospectively. All the patients had complete CT data, 28 cases had X-ray intestinal barium meal data, and 18 had sinus tract enterography. RESULTS: CT enterography showed mural thickening(>4 mm) in 34(87.2%) patients, mural gas in 7(17.9%), mural edema in 7(17.9%), mural fat in 4(10.3%), increased enhancement of bowel wall(>10 HU) in 37(94.9%), multiple segmental lesions in 33(84.6%), single segmental lesions in 6(15.4%), mesenteric lymphadenopathy(>5 mm) in 13(33.3%), vascular bundle thickening in 9(23.1%), cellulitis in 12(30.8%), peritoneal abscess in 10(25.6%), phlegmon in 8(20.5%), incomplete intestinal obstruction in 14(35.9%), seroperitoneum in 22(56.4%), and fistulization in 4(10.3%). CT enterography did not demonstrate the change of mucosa such as strip ulcer or cobblestone. Among the 28 cases of small bowel X-ray enterography, 23 cases(82.1%) presented with multiple segmental lesions, 5(17.9%) with single segmental lesions, 18(64.3%) with strip ulcer, 16(57.1%) with cobblestones, 4(14.3%) with intestinal fistula, while no bowel wall and extraintestinal complication of CD disease was observed. Among the 18 cases of sinus tract enterography, 13 cases (72.2%) presented with intestinal fistula, 12(66.7%) with peritoneal abscess, 8(44.4%) with sinus tract. CONCLUSIONS: CT enterography can demonstrate exactly the diseased bowel wall and extraintestinal complication of CD disease, which is important to evaluate the extent of CD and guide the treatment, however strip ulcer and cobblestone sign cannot be demonstrated. The X-ray enterography is available to demonstrate the characteristic changes of CD such as trip ulcers and cobblestones, but is difficult to show the bowel wall and extraintestinal inflammatory mass and abscesses. The sinus tract enterography is easy to demonstrate the intestinal fistula and intra-abdominal abscess. Combination of these methods is more beneficial to guild the diagnosis and treatment.