Imaging of horseshoe kidneys and their complications

Horseshoe kidney is the most common renal fusion anomaly and the patients are prone to a variety of complications, such as stone disease, pelviureteric junction (PUJ) obstruction, trauma, infections and tumours. As result of the abnormal anatomy of a horseshoe kidney, imaging and treatment pathways vary substantially from the normal kidney. In this review, we describe the role of modern imaging in depicting horseshoe kidneys and their complications, in tandem with the role the interventional radiologist plays in treating these patients.

Urolithiasis: how accurate are plain radiographs?

OBJECTIVE

To determine the value of the kidneys, ureters, and bladder radiograph (KUB) in the diagnosis of urolithiasis using unenhanced helical computerized tomography (UHCT) as the gold standard.

METHODS

A retrospective study was performed on 100 consecutive patients being investigated for suspected urolithiasis. All patients presented with acute renal colic and had a KUB and UHCT within a 3-hour period. UHCT and KUB pairs were assessed separately by 2 radiologists in consensus who were blinded to the clinical details of the patients and the results of the other tests and examinations. The presence, location, number, and size of stones were recorded. Each UHCT and KUB pair was then compared for concordance on a stone-by-stone basis.

RESULTS

KUB was concordant with the gold standard UHCT in only 50% of patients (11 positive, 39 negative), giving a sensitivity of 18.6%, a specificity of 95.1%, a positive predictive value of 84.6%, and a negative predictive value of 44.8%.

CONCLUSION

KUB has a very low sensitivity for the detection of urolithiasis, although specificity is acceptable.

Ultrasound-guided removal of Implanon devices

Our study has shown that ultrasound-guided localisation and removal of Implanon rods is safe, practical and highly successful. Over a 4-year period, 119 patients had successful, uncomplicated removal of their subdermal devices.The technique is particularly useful for removal of the device when it is not palpable or when an attempt at removal of a palpable device has not been successful.

Calvarial tuberculosis: an unusual presentation (2007: 8b)

We describe a case of calvarial tuberculosis with an associated extra-dural collection. This presentation has rarely been reported in the literature and the magnetic resonance imaging features are not well documented.

Intramuscular injections into the buttocks: Are they truly intramuscular?

AIM

To radiologically determine if intramuscular (IM) injections into the buttocks are truly intramuscular.

MATERIALS AND METHODS

This was a prospective study conducted during a 6 month period beginning in October 2004. Fifty inpatients were recruited from a single tertiary referral hospital. Approval was obtained from the hospital research ethics committee and informed written consent was acquired from all participants. Prior to computerised tomography (CT), each patient received an IM injection of their prescribed medication along with 1 mL of air into the upper outer quadrant of the buttocks. CT images were subsequently analyzed by two radiologists to determine the position of the injected air bubble and to assess whether it was intramuscular or subcutaneous in position. Body mass index (BMI), distance to injection site, subcutaneous fat and muscle thickness were also measured.

RESULTS

Overall, only 32% (n=16/50) of patients had intramuscular injections, with the majority of injections (68%, n=34/50) being subcutaneous. When analysed by gender, 56% (n=14/25) of males had intramuscular injections while in females, the efficacy rate was significantly lower at 8% (n=2/25).

CONCLUSION

The majority of assumed intramuscular injections are actually subcutaneous.