Helical CT for detection and characterization of renal masses

Comparison of post contrast CT urography phases in bladder cancer detection

OBJECTIVES

The aim of this study was to investigate which post-contrast phase(s) in a four-phase CT urography protocol is (are) most suitable for bladder cancer detection.

METHODS

The medical records of 106 patients with visible haematuria who underwent a CT urography examination, including unenhanced, enhancement-triggered corticomedullary (CMP), nephrographic (NP) and excretory (EP) phases, were reviewed. The post-contrast phases (n = 318 different phases) were randomized into an evaluation order and blindly reviewed by two uroradiologists.

RESULTS

Twenty-one patients were diagnosed with bladder cancer. Sensitivity for bladder cancer detection was 0.95 in CMP, 0.83 in NP and 0.81 in EP. Negative predictive value (NPV) was 0.99 in CMP, 0.96 in NP and 0.95 in EP. The sensitivity was higher in CMP than in both NP (p-value 0.016) and EP (p-value 0.0003). NPV was higher in CMP than in NP (p-value 0.024) and EP (p-value 0.002).

CONCLUSIONS

In the CT urography protocol with enhancement-triggered scan, sensitivity and NPV were highest in the corticomedullary phase, and this phase should be used for bladder assessment.

KEY POINTS

• More bladder tumours are detected during the corticomedullary phase than during other phases. • Sensitivity and NPV for bladder cancer detection were highest in corticomedullary phase. • The corticomedullary phase in CT urography should be used for bladder assessment.

Bladder cancer detection in patients with gross haematuria: Computed tomography urography with enhancement-triggered scan versus flexible cystoscopy

OBJECTIVE

Computed tomography urography (CTU) can be used to direct further investigation of patients if the bladder tumour detection rate is high. The aim of this study was to compare a CTU protocol including an enhancement-triggered scan and flexible cystoscopy for detecting bladder tumours.

MATERIALS AND METHODS

Patients with gross haematuria undergoing CTU during 2005-2008 were included. For patients younger than 50 years the CTU protocol included unenhanced, enhancement-triggered corticomedullary, and excretory phases. Patients older than 50 years followed the same protocol plus a nephrographic phase. The entire urinary tract was examined in all phases.

RESULTS

Of 435 patients, 55 patients were diagnosed with bladder tumour. CTU detected bladder tumour in 48 patients (87%). Five CTU examination reports were false positive. With CTU, sensitivity for finding bladder tumour was 0.87, specificity 0.99, positive predictive value (PPV) 0.91 and negative predictive value (NPV) 0.98. Cystoscopy detected bladder tumour in 48 patients (87%) and had one false-positive finding, resulting in sensitivity of 0.87, specificity 1.0, PPV 0.98 and NPV 0.98.

CONCLUSIONS

The detection rate of bladder tumours for the CTU protocol including an enhancement-triggered scan was high and comparable to flexible cystoscopy. Hence, this protocol could be used to assess the bladder as the primary investigation and direct further investigation of the patient.

Imaging of kidney cancer

Advances in molecular genetics have expanded the understanding of renal cell tumors. Now it is understood that renal cortical tumors are a family of neoplasms with distinct cytogenetics and molecular defects, unique histopathologic features, and different malignant potentials. Imaging contributes to clinical management of patients with renal tumors in providing diagnostic information for tumor detection, characterization, staging, treatment planning, and follow-up.

Multidetektorcomputertomographie (MDCT) der Nieren

Multidetector computed tomography (MDCT) possesses distinct advantages for examination of the kidneys. It carries the potential of becoming the gold standard of diagnostic work-up and surgical planning for most renal diseases and replacing conventional methods such as i.v. urography and angiography. The most outstanding improvements, in comparison to single slice spiral CT, are the speedier image acquisition and enhanced z-axis resolution, which aids particularly in visualization of the urinary tract as it aligns along the axis of the body. Respiratory artifacts are few or nonexistent even in patients who cannot hold their breath. This overview presents a strategy for prudent management of MDCT examinations and describes examination of the most important and frequent renal diseases using MDCT.

Incidental detection of preclinical renal tumors with electron beam computed tomography: report of 26 consecutive operated patients

PURPOSE

The purpose of this work was to describe the positive predictive value of electron beam CT (EBCT) for diagnosis of solid renal tumors.

METHOD

Among 11,932 consecutive patients undergoing screening EBCT, 27 cases met EBCT criteria for solid renal tumors. Twenty-six of 27 patients underwent surgery.

RESULTS

Surgical pathology identified 25 solid renal tumors and 1 adrenal hemorrhage with thrombus. Twenty tumors were classified as T1N0M0, one was T2N0M0, and one was T3aN0M0. All tumor patients are clinically well at 1-41 months (mean 17 months) postoperatively. None of the patients had clinical signs or symptoms characteristic of renal malignancy.

CONCLUSION

EBCT is an effective tool for detection of solid renal tumors in a healthy outpatient population (positive predictive value 0.96). The detection rate is low [0.2% (26/11,932) at our facility] in patients undergoing EBCT for other indications. The cost-effectiveness and sensitivity of this technique for solid renal tumor detection among various populations remain to be determined.

Helical computed tomography of renal lesions

Helical computed tomography is a new technique that acquires a volumetric data set of both kidneys within a single breath-hold. It has proved to be superior to conventional computed tomography. Multiphasic helical computed tomography after the administration of contrast material shows advantages concerning the detection and characterization of renal lesions and the preoperative staging of renal cell carcinomas. The proper scan protocol for a sufficient examination of the kidneys is described as well as its diagnostic value. The characteristic computed tomography morphology of benign and malignant renal lesions is reviewed and the advantages of helical computed tomography are illustrated.