US as Good as CT in the Diagnosis of Nephrolithiasis

Smith-Bindman et al report in the NEJM the results of a three-year trial on 2,759 adults who presented in 15 emergency departments with symptoms of nephrolithiasis. The patients were randomly assigned to undergo initial diagnostic ultrasonography performed by an emergency physician (point-of-care ultrasonography), ultrasonography performed by a radiologist (radiology ultrasonography), or abdominal CT.

Physicians in the ED performed ultrasonography in 908 patients, while radiologists performed ultrasonography in 893 patients, and 958 patients had CT. The incidence of high-risk diagnoses with complications in the first 30 days was low (0.4%) and did not vary according to imaging method. The mean 6-month cumulative radiation exposure was significantly lower in the ultrasonography groups than in the CT group (P<0.001). Serious adverse events occurred in 12.4% of the patients assigned to point-of-care ultrasonography, 10.8% of those assigned to radiology ultrasonography, and 11.2% of those assigned to CT (P=0.50). Related adverse events were infrequent (incidence, 0.4%) and similar across groups. By 7 days, the average pain score was 2.0 in each group (P=0.84). Return visits to emergency department, hospitalizations, and diagnostic accuracy did not differ significantly among the groups.

The authors concluded that no significant differences were found in diagnostic accuracy, serious adverse events, pain scores, return visits to the emergency department, or hospitalizations when ultrasound was used instead of CT.   Ultrasonography was associated with lower cumulative radiation exposure than CT, and is less expensive therefore it may become the study of choice in the diagnosis of nephrolithiasis in the ED department.

3-minute MRI of the Breast for Cancer Screening

Kuhl et al in their JCO article report on the suitability of a fast MRI of breast cancer for screening.  Their protocol consisted of one pre-contrast and one post-contrast sequences their derived images [FAST] and maximum-intensity projection [MIP] images.

They conducted a prospective observational study in 443 women who were at mildly to moderately increased risk for breast cancer who underwent 606 screening MRIs. Eligible women had normal or benign digital mammograms and, for those with heterogeneously dense or extremely dense breasts (n = 427), normal or benign ultrasounds. Breast radiologists with expertise in MRI reviewed the MIP image first to search for significant enhancement and then reviewed the complete study that consisted of MIP and FAST images and optionally their non-subtracted source images and characterized the enhancement in order to establish a diagnosis. Only thereafter was the regular full diagnostic protocol study was analyzed.

MRI acquisition time for complete diagnostic protocol was 17 minutes, versus 3 minutes for the abbreviated protocol (AP). Average time to read the single MIP and complete AP was 2.8 and 28 seconds, respectively. Eleven breast cancers (four ductal carcinomas in situ and seven invasive cancers; all T1N0 intermediate or high grade) were diagnosed, for an additional cancer yield of 18.2 per 1,000. MIP readings were positive in 10 (90.9%) of 11 cancers and allowed establishment of the absence of breast cancer, with a negative predictive value (NPV) of 99.8% (418 of 419). Interpretation of the study using the abbreviated protocol, as with the full diagnostic protocol(FDP), allowed diagnosis of all cancers (11 [100%] of 11). Specificity and positive predictive value (PPV) of AP versus FDP were equivalent (94.3% v 93.9% and 24.4% v 23.4%, respectively).

The authors conclude that the 3 minutes abbreviated protocol and a MIP image are sufficient for an expert radiologist to establish in 3 seconds the absence of breast cancer, with an NPV of 99.8%. With a reading time < 30 seconds for the complete AP, diagnostic accuracy was equivalent to that of the FDP and resulted in an additional cancer yield of 18.2 per 1,000.

MR–guided Focused Ultrasound a Palliative Treatment for Painful Bone Metastases

In a study published by the Journal of National Cancer Institute Hurwitz et al report on findings of a multicenter phase III trial regarding the efficacy and safety of magnetic resonance-guided focused ultrasound (MRgFUS), for palliation of pain due to bone metastases.

One hundred forty-seven patients were enrolled, with 112 and 35 randomly assigned to MRgFUS and placebo treatments, respectively. The 147 patients were treated in 17 centers in the U.S., Canada, Israel, Italy and Russia. Response rate for the primary endpoint, improvement in self-reported pain score without increase of pain medication 3 months after treatment, was 64.3% in the MRgFUS arm and 20.0% in the placebo arm (P < .001). MRgFUS was also superior to placebo at 3 months on the secondary endpoints assessing worst score Numerical Rating Scale for pain (NRS) and morphine equivalent daily dose intake (P < .001) and Brief Pain Inventory (BPI-QoL), a measure of functional interference of pain on quality of life (P < .001). The most common treatment-related adverse event was sonication pain, which occurred in 32.1% of patients. Two patients had pathological fractures, one patient had third-degree skin burn, and one patient suffered from neuropathy. Overall 60.3% of all treatment-related adverse events resolved on same day the sonication treatment was delivered.

The authors concluded that MRgFUS, a non-invasive technique, can relieve pain and improve function in most patients with skeletal metastases who have failed standard treatment such as radiation therapy.

iPad is Accurate in the Diagnosis of Pediatric Pneumonias

In the 51^st annual meeting of the European Society of Pediatric Radiology in Amsterdam, Papaioannou et al from Mitera Hospital in Athens, and Ohio State University in Columbus , Ohio presented their findings regarding the accuracy and usefulness of the iPad in the diagnosis of pneumonias in neonates and infants.

The chest x-rays of 99 consecutive cases were retrospectively evaluated. Findings included consolidation (19), patchy densities/air-space shadowing (7), diffuse air-space shadowing (4), bilateral peribronchial thickening (18), peribronchial thickening and consolidation (4), RLL Hyperinflation (1), patchy hyperlucencies (2) and coarse pattern (2). The images were anonymized and distributed after randomization to two experienced pediatric attending radiologists and two fellows. Diagnostic monitors and a non-retina display iPad2 device were used for viewing the studies.

On the diagnostic monitors, the correct/incorrect ratio was 139/59 for the attendings and 137/61 for fellows. On the iPad, it was 141/57 and 150/48 respectively. In the detection of lung disease, the iPad sensitivity was 79.8%, specificity 64.9%, PPV 5.5% and NPV 70.3%. As a group the attendings and fellows correct/incorrect ratio was 276/120 on the monitors and 291/105 on the iPad. There was no difference in the accuracy of interpretation or the performance depending on the device used among attendings and fellows.

The authors concluded that although diagnostic monitors will continue to be the device of choice in Radiology departments, mobile tablets will play an increasingly important role in the radiographic detection of lung disease in neonates and infants in the intensive care units, emergency department and/or for teleradiology purposes.

John Spigos, BS