MR renography using a dynamic gradient-echo sequence and low-dose gadopentetate dimeglumine as an alternative to radionuclide renography

OBJECTIVE

Our aim was to evaluate the feasibility of acquiring an MR signal intensity-time renographic curve and dynamic serial images in a way similar to that of acquiring radionuclide renograms, with a dynamic gradient-echo sequence and a low-dose gadopentetate dimeglumine technique, using a commonly available 1.5-T MR scanner. SUBJECTS AND METHODS. Patients who underwent both radionuclide and MR renographic studies within a 3-month period were included in the analysis. This yielded 21 studies from 19 patients. Nineteen of the 21 studies were available for analysis. Two studies were excluded because of technical errors during MR renographic acquisition. Serial MR renograms were obtained using a dynamic two-dimensional spoiled gradient-echo fast low-angle shot T1-weighted sequence. Low-dose IV furosemide and gadopentetate dimeglumine (0.025 mmol/kg of body weight) were administered. Intensity-time curves were obtained from the manually selected regions of interest over the renal parenchyma and whole kidney for calculation of split renal function and assessment of urinary excretion, respectively. Results were compared with those obtained with radionuclide renography.

RESULTS

Good correlation (Pearson's correlation coefficient, r = 0.97, p < 0.001) was observed when the volume-corrected split renal function acquired with MR renography was compared with that obtained with radionuclide renography. There was also good agreement in the excretory curve patterns (weighted kappa(observer 1) = 0.77 and kappa(observer 2) = 0.81) between the two techniques.

CONCLUSION

Dynamic MR gradient-echo imaging with a low-dose gadopentetate dimeglumine technique can produce an intensity-time curve and serial dynamic images of the urinary system, in a way similar to that of radionuclide renography. This technique allows assessment of split renal function and urinary excretory status and is a feasible alternative to radionuclide renography.

Penile colour duplex ultrasonography as a screening tool for venogenic erectile dysfunction

INTRODUCTION

Vasculogenic impotence is one of the major causes of erectile dysfunction. Cavernosometry and cavernosography is traditionally the gold standard for evaluation of venogenic impotence. However, it is invasive and there are potentially significant complications. Penile colour flow Doppler imaging (PCDI) is non-invasive and can be used to assess venous incompetence.

MATERIALS AND METHODS

One hundred and sixty-eight patients were referred for PCDI assessment from March 1998 to February 2001. Forty-three of these also had cavernosogram and cavernosometry done and were included in the study.

RESULTS

The sensitivity was 93.9%, the specificity was 90.0%, the accuracy was 93.0% with a negative predictive value of 81.8% and a positive predictive value of 96.9%. Kappa value of 0.81 was obtained, indicating excellent agreement between PCDI and cavernosogram and cavernometry.

CONCLUSIONS

Penile colour flow Doppler imaging is accurate in the assessment of venogenic erectile dysfunction. It can replace cavernometry and cavernosogram as a screening tool. Cavernometry and cavernosogram should only be done in cases when PCDI suggests venogenic impotence, and when surgery is contemplated.

Adrenal myelolipoma presenting with spontaneous retroperitoneal haemorrhage demonstrated on computed tomography and angiogram--a case report

INTRODUCTION

A rare case of adrenal myelolipoma presenting with spontaneous rupture and retroperitoneal haemorrhage is described.

CLINICAL PICTURE

A 51-year-old Caucasian male presented with acute onset of right loin pain. Preliminary diagnosis of haemorrhagic adrenal tumour was made on computed tomography (CT) and angiography.

TREATMENT

Vascular embolisation was performed to stabilise the patient prior to definitive surgery. Tumour resection was subsequently performed. Histology confirmed ruptured adrenal myelolipoma.

OUTCOME

The patient made an uneventful recovery.

CONCLUSION

Ruptured adrenal myelolipoma should be considered in cases of spontaneous retroperitoneal haemorrhage. Vascular embolisation may be useful in stabilising the patient prior to definitive surgery.