Adhesive Small-Bowel Obstruction: Value of CT in Identifying Findings Associated with the Effectiveness of Nonsurgical Treatment

This retrospective study of imaging findings in patients with SBO due to adhesions is mostly valuable because the author's have tried to actually correlate the findings to actual impact on management. It is a moderate sized review of 221 patients with SBO on CT, and review of findings on those studies. The specific features they identify as predictive of successful non-operative management is the presence of fewer than two beak signs and the presence of an anterior parietal adhesion are predictive of successful non-operative management. U shaped or C shaped loops were predictive of non-operative management failure.

PICO Analysis:
Population: patients with SBO on CT
Intervention: non-operative management
Comparison: none
Outcome: successful non-operative management

Reference: Pubmed Full Text

Repeatability of Diagnostic Features and Scoring Systems for Hepatocellular Carcinoma by Using MR Imaging

This article evaluated the inter-rater reliability of assessing characteristics of liver lesions and overall staging of hepatocellular carcinomas using various staging systems (OTPN, AASLD, and LI-RADS).

10 blinded readers reviewed 100 liver MRI cases assessing lesions for HCC criteria (arterial hyper-enhancement, washout, and pseudocapsule). Readers were also asked to assign an OTPN, AASLD and LI-RADS score (ver. 2013.1) based on their findings.

5 abdominal imaging staff at an OPTN approved liver transplant center (6-11 years of experience) and 5 “novice” radiology residents were selected to be a part of the study. 10 cases were used for training but not included as part of the study results.

High Kappa scores were achieved for the finding of arterial hyper-enhancement (0.67). Moderate scores for wash-out and the presence of a pseudocapsule (0.48 and 0.52 respectively).

As for staging moderate agreement was noted for OPTN staging (0.53) and fair agreement for LI-RADS and AASLD (0.35 and 0.39).

Overall agreement amongst experts was significantly higher in comparison to that of novice residents (P<.001). Interestingly (yet not surprising) agreement between experts for LI-RADS and AASLD was fair to moderate (0.43 and 0.46) in comparison to OPTN (0.64).


PICO Analysis:

Population: Radiologists
Intervention: The effect of experience for interpretation and accurate staging of hepatocellular carcinomas.
Comparison: “experts” versus “novice” residents
Outcome: There is higher consistency and accuracy amongst experts reading liver MRI. There is moderate agreement amongst “experts” for relatively complex classification systems (LI-RADS and AASLD) in comparison to high agreement for OPTN




Advancement in Knowledge:

1. Experience plays a role in the interpretation of Liver MRI
2. There is only moderate agreement amongst “experts” in staging hepatocellular carcinoma using LI-RADS and AASLD.



Reference:
Pubmed Full Text

Diagnostic accuracy and patient acceptance of MRI in children with suspected appendicitis

This prospective study compares 3 strategies for imaging suspected appendicitis. Ultrasound alone, US+conditional MRI and MRI alone. The sensitivity of MRI alone and US + conditional MRI was 100%, ultrasound alone was found to be significantly lower at 76%.
The specificity was found to be comparable among the three investigated strategies; MRI alone 89%, US + conditional MRI 80% and US alone 89%.

The study on a technical basis is quite good, with patients enrolled consecutively and prospectively. Surgical diagnosis or 3mo followup including contact of all patients primary physician was used for clinical followup. While no flowchart is provided in the text documenting the different arms it appears none were lost to followup and all 'positive' cases did proceed to surgery. The study population had a relatively high prevalence of appendicitis at 56%.

Limitations are that the US was performed by radiology residents, and the surgical management is not clear for all cases which makes assessment of the applicability of these results to different practices (such as in Canada or US) somewhat challenging, and may explain the relatively low sensitivity of US alone despite relatively high subjective quality evaluation of the US studies.

PICO Analysis:
Population: pediatric patients 4-18yo (mean 12yo)
Intervention: US alone, MRI alone or US + conditional MRI
Comparison: Surgical dx or 3mo clinical followup
Outcome: Sensitivity and Specificity

Reference: Pubmed Full Text

Comparison of Two-dimensional Synthesized Mammograms versus Original Digital Mammograms Alone and in Combination with Tomosynthesis Images

This study is a case control series of patients assessing the performance of digital breast tomosynthesis + simulated mammogram with tomosynthesis + FFDM. The series of 123 patients included both normals (defined as 1yr followup normal mammo) as well as biopsy/surgery proven benign and malignant lesions. Lesions included both asymmetries and microcalcifications.

Overall the study demonstrates similar performance of the simulated mammogram and FFDM when both are combined with tomosynthesis. The study did not report the dose of the two techniques in the study used. This study is further limited in that it is a population of convenience as opposed to a true screening population, and future work with true prospective screening is required for this technology. Another limitation of this study (and most assessments of the simulated 2D mammogram) is the lack of comparison between FFDM alone and Tomo+simulated mammo in a non-inferiority analysis for sensitivity and assessment of specificity, and a true comparison of the total dose from the two techniques.

PICO Analysis:
Population: Case-Control series of 123 patients
Intervention: Tomosynthesis + Simulated 2D Mammogram
Comparison: Tomosynthesis + FFDM
Outcome: ROC

Reference: Pubmed Full Text

Prostate Cancer: Can Multiparametric MR Imaging Help Identify Patients Who Are Candidates for Active Surveillance?

Retrospective study of 133 patients who underwent multiparametric MRI before radical prostatectomy.  The MRI results were compared to clinical scoring systems, with pathology (tumour<0.5cc) as the reference standard for assessing eligibility for Active Surveillance. 14/133 would have been eligible for AS based on pathologic results, and the MRI was highly accurate for predicting eligibility for AS.

D'Amico system:  sensitivity 93%, PPV 25%, and accuracy 70%.

Epstein criteria: sensitivity 64%, PPV 45%, and accuracy 88%. 

CAPRA system: sensitivity 93%, PPV 20%, and accuracy 59%.
Multiparametric MR: sensitivity 93%, PPV 57%, and accuracy of 92% (P < .005). 

This is limited by its retrospective nature, but provides further evidence of the utility of multiparametric MRI in the evaluation of prostate cancer.

PICO Analysis:
Population:

• 133 patients (mean age, 59.3 years) 
• Mean PSA 6.73 ng/mL (median, 4.39 ng/mL) 

Intervention: Multiparametric MR imaging at 3.0 T before radical prostatectomy.
Comparison: Conventional clinical assessment scores (the D'Amico, Epstein, and CAPRA scoring systems)
Outcome: Radical prostatectomy pathology specimen (gross tumour <0.5cc) as Active Surveillance eligible.

Reference: Turkbey et al., Radiology, July 2013, 268(1): 144-152.
Links: Pubmed Full Text

Comparison of Imaging Strategies with Conditional Contrast-enhanced CT and Unenhanced MR Imaging in Patients Suspected of Having Appendicitis: A Multicenter Diagnostic Performance Study.

Prospective study of 230 patients with suspected appendicitis. All underwent MRI, and remainder followed clinical pathway with US +/- CT. the results of immediate MRI, conditional MRI after US and conditional CT after US were analyzed. 

Conditonal CT missed appendicitis in 3%, with 8% (10 of 125; 95% CI: 4%, 14%) false-positives.
Conditional MR missed appendicitis in 2% with 10% (13 of 129; 95% CI: 6%, 16%) false-positives.
Immediate MR missed appendicitis in 3% with 6% (seven of 120; 95% CI: 3%, 12%) false-positives.

While no consistent gold standard was applied in this study, the similar results of conditional or staged MRI and CT after inconclusive or negative US are impressive, and support the possibility of using MRI in suspected appendicitis when ionizing radiation from CT is a concern. No information on bmi or detailed demographics were provided to assess for applicability or correlate with results from the paediatric radiology literature.

PICO Analysis:
Population: adult patients with suspected appendicitis
Intervention: unenhanced MRI
Comparison: unenhanced MRI after ultrasound and CT after ultrasound
Outcome: expert consensus (surgeons and radiologists)

Reference: Leeuwenburgh MM et al., Radiology, July 2013, 268(1):135-143.
Links:  Pubmed Full Text

Association of Study Quality with Completeness of Reporting: Have Completeness of Reporting and Quality of Systematic Reviews and Meta-Analyses in Major Radiology Journals Changed Since Publication of the PRISMA Statement?

This study provides an assessment of the reporting and quality of systematic reviews and meta analyses in the radiology literature. The study reviewed 130 studies from 11 journals, and assessed them for compliance with the PRISMA (reporting) and AMSTAR (methodology/quality) guidelines.

The results are comparable to similar studies in other fields of medicine, with higher scores post publication of PRISMA in 2009. There was strong positive correlation between the PRISMA and AMSTAR results.  There was high variability between journals, 'Radiology' had the highest PRISMA reported items and AJNR had the lowest at 19.6/27.  Specific items that are consistently weak (and should be paid attention to by authors of SR/MA) are registration of study protocol and assessment for bias. 

Reference: Tunis et al., Radiology, 2013 Jul 3. (epub).

Links: Pubmed Full Text

Acute lower intestinal bleeding: Feasibility and diagnostic performance of CT angiography

Prospective study to assess the diagnostic performance of CT Angiography (CTA) as the initial exam for all patients in ER with acute LGIB.  

Prospective, single center, N= 47 (mean age 68)

All patients underwent CTA first before continuing reference standard (c-scope, angio or laparotomy). 

Triphasic 64 slice MDCT scan of the abdomen and pelvis with IV contrast, no oral contrast. 

2 Radiologists scored for: Active extravasation (spot or jet) on art or pvp. High attenuation (>60hu) on c-. Possible cause of bleed. 

Results: 

Of the 47 pts, 19 had bleed by reference standard, 28 no bleed. Results for identifying bleed SENS 100% SPEC  96% (PPV 95%, NPV 100%).  Accuracy 93% for the cause of bleed in 44/47. 

Limitations: 

No description of severity of bleed or patient’s clinical status before inclusion

No control group

Standard of reference was a not a single gold standard test

Unclear if surgeons and IR were blinded to CTA results

No follow up of patient outcome

No discussion of time to CTA or intervention

PICO Analysis:
Population:

• Inclusion criteria: Acute LGIB defined by hematochezia, or melena. Indication for emergent colonoscopy, angiography, or laparotomy as determined by ER MD.
• Exclusion criteria: Concomitant upper GI bleed. Contraindication to IV contrast. Creatinine greater than 200 mg/L. Pregnancy.

Intervention: Triphasic CT angiogram
Comparison: Catheter angiography, Colonoscopy or Laparotomy.
Outcome: Sensitivity 100%, Specificity 96%.

Reference: Martí M et al. Radiology. 2012 Jan; 262(1):109-16. 
Links: Pubmed, Full Text

Use of high technology imaging for surveillance of early stage breast cancer

This was a retrospective analysis to assess the rates of imaging use in breast cancer patients. The study makes use of SEER/Medicare data to analyse the rate of use in comparison to a control cohort. 

Use of high tech imaging was 60% higher among breast ca pts than controls. The utilisation is primarily in the 1st year after dx suggesting the imaging is mostly linked to the breast ca. The study also documents an increase into the use of CT, US, MR & Nuc Med studies in both the breast ca pts as well as the controls over the time period. 

Limitations of this study are that the 'appropriateness' of indications and the outcome/findings of the studies were not assessed. The exclusion of pts who died or had documented recurrence is also interesting, this likely reduced the utilisation rate in the population, and skews the population towards asymptomatc pts, with studies done for 'follow up malignancy'. 

As far as clinical practice, this article doesn't provide any clear guidance as to what we should be doing, but does reinforce that we should be following the ACR/ASCO top 5 lists when ordering/protocolling studies. 

PICO Analysis:

Population: 

-Medicare recipients (>65yo) 1998-2003

-Stage I-II Primary breast ca (~25000pts)

-EXCLUDED pts with documented recurrence or death.

Intervention: High technology imaging (CT, US, MR, NM) during months 13-48 post-diagnosis.

Comparison: Age-matched random sample of women.

Outcome: Utilization of high tech imaging (HTRI)

Use of high technology imaging for surveillance of early stage breast cancer

Reference: K. S. Panageas et al., Breast Cancer Res Treat (2012) 131:663–67

Links: Pubmed, Full text

Clear Cell Renal Cell Carcinoma: Discrimination from Other Renal Cell Carcinoma Subtypes and Oncocytoma at Multiphasic Multidetector CT

The use of multiphasic CT scan may assist in characterizing renal lesions, especially discriminating some subtypes of renal cell carcinoma (RCC) from oncocytoma.  Young et al demonstrated that oncocytomas have peak enhancement in the corticomedullary phase with an average density of 106 Hu.  Clear cell RCC enhancement also peaks in the corticomedullary phase, however their enhancement is higher than oncocytomas with an average of 125 Hu (p=0.045).  The accuracy for discriminating these lesions was 77%.  Chromophobe and papillary RCCs have peak enhancement in the nephrographic phase.  Their average corticomedullary enhancement is 74 Hu and 54 Hu respectively.  

PICO analysis

P- 298 lesions in 274 patients with an average age of 62 (23-87)

I- Retrospective analysis of enhancement characteristics of renal lesions on multiphasic CT

C- Biopsy, partial nephrectomy, and full nephrectomy results

O-Differentiating renal lesions: Subtypes of RCC versus oncocytomas

Radiology, Volume 267: Number 2, May 2013
Links: Pubmed, Full text