Dual energy CT in patients with polycystic kidney disease

• Published in: European radiology 2012-10, Vol.22 (10), p.2125-2129
• Main Authors: Arndt, Nikolaus, Staehler, Michael, Siegert, Sabine, Reiser, Maximilian F., Graser, Anno
• Format: Article
• Language: English
• Subjects: Abdomen; Adenoma - complications; Adenoma - diagnostic imaging; Adult; Aged; Aged, 80 and over; Carcinoma, Renal Cell - complications; Carcinoma, Renal Cell - diagnostic imaging; Computed Tomography; Cysts; Diagnostic Radiology; Energy; Female; Humans; Imaging; Internal Medicine; Interventional Radiology; Iodine; Kidney cancer; Kidney diseases; Kidney Neoplasms - complications; Kidney Neoplasms - diagnostic imaging; Magnetic resonance imaging; Male; Medicine; Medicine & Public Health; Middle Aged; Neuroradiology; Patients; Polycystic Kidney Diseases - complications; Polycystic Kidney Diseases - diagnostic imaging; Radiation; Radiology; Tomography; Tomography, X-Ray Computed - methods; Tumors; Ultrasound
• ISSN: 0938-7994; 1432-1084
• DOI: 10.1007/s00330-012-2481-7

Objectives To evaluate the diagnostic efficacy of dual source–dual energy CT (DECT) in the detection of neoplasia in patients with polycystic kidney disease (PKD). Methods A total of 21 patients with PKD underwent DECT on a dual source system, using kVp settings of Sn140/100 or 140/80. Colour-coded iodine maps and virtual unenhanced images were used to determine enhancement within cysts and to differentiate haemorrhagic from simple cysts. A cut-off of 15 HU was used as a threshold for malignancy. In patients with malignancy, histopathology was the gold standard; otherwise, patients underwent follow-up imaging for 150–908 days. Results On the basis of measured enhancement, 13 enhancing masses were seen in 4 patients (12 renal cell cancers and 1 adenoma); follow-up imaging showed no malignancy in 18 patients. Cysts did not enhance by more than 15 HU, whereas masses showed a mean enhancement of 45 (25–123) HU. Average radiation exposure was 9.6 mSv for the biphasic protocol and 5.8 mSv for DECT only. Conclusion DECT greatly facilitates the detection of malignancy in patients with polycystic kidney disease, at the same time reducing radiation exposure by omission of a true unenhanced phase. Key Points • Identification of tumours within polycystic kidneys can be difficult. • Dual energy computed tomography (DECT) provides two separate sets of images . • Iodine maps and virtual non-enhanced (VNE) images can then be calculated. • DECT facilitates screening for potential renal tumours in polycystic kidneys.