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

QUADAS-2 tool for review of diagnostic accuracy studies

A good resource for those doing reviews of diagnostic accuracy studies is the QUADAS-2 tool.  This is an update of the QUADAS tool that allows flexibility and modification based on relevant parameters from the included studies in your review.  More information and user's guide can be found here:

http://www.bris.ac.uk/quadas/quadas-2/

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

Yield of CT Angiography and Contrast-Enhanced MR Imaging in Patients with Dizziness

This is a retrospective analysis of all CTAs, CE MRAs, and CE IAC studies acquired in patients with  "dizziness" or "vertigo" performed between January 2011 and June 2012. Patients that had focal neurologic findings specified on the requestion or in the history on the EMR were excluded (clinical findings such as vomiting, focal weakness, aphasia, and vision loss). Also patients with prior history of a posterior mass, an underlying inflammatory condition or vascular abnormalities were excluded from the study.  

A total of 798 studies were included (228 CTAs, 304 CE MR, and 266 CE IAC MR).  The age range was 6-93 years.  32% of the studies were performed in the ER setting.  Only 1.6 % of cases had a diagnostic efficacy* and 1.0% had a therapeutic efficacy**.  There was no statistical significance difference between the modalities or the ordering specialty (ie. ER, ENT or primary care).  

*Diagnostic Efficacy: defined by the ACR as the number of studies with a new or progressive major finding divided by the total number of studies.

**Therapeutic Efficacy: defined by the ACR as the number of studies resulting in a change in clinical management divided by the total number of studies

Population: All patients presenting to the ER, primary care physician, or otolaryngologist (including the pediatric population) with isolated dizziness or "vertigo".  Patients with a known posterior fossa mass, underlying inflammatory conditions (such as MS), or vascular abnormalities were excluded.   The age range in the study was 6-93.

Intervention: Utility of CTA, CE MR and/or CE IAC MR in the above stated patient population

Comparison: N/A

Outcome: The diagnostic and therapeutic efficacy of CTA, CE MR, and CE IAC MR for patients presenting with isolated dizziness is reported to be 1.6% and 1.0% respectively. 

Links: Pubmed, Original article 

Fakhran S et al (2013).  American Journal of Neuroradiology. 34:1077-81

Is Early Colonoscopy Beneficial in Patients With CT-Diagnosed Diverticulitis?

Elmi et al evaluated 402 patients with acute diverticulitis diagnosed on a contrast enhanced CT with subsequent colonoscopy.  Retrospectively, they looked at the complications of diverticulitis as markers for underlying carcinoma.   The presence of mesenteric or retroperitoneal lymph nodes and bowel obstruction were the highest risk factors for underlying colonic carcinoma (odds ratio of 23 and 24 respectively).  The presence of an abscess is also slightly associated with underlying carcinoma (odds ratio of 4).  Prior studies demonstrated that the presence of fisutulous tracts and perforation were also markers for underlying carcinoma (see link below).  This was not demonstrated on this study.

The incidence of carcinoma in this study was low at 9 cancers in the 402 patients included. 8 of the 9 cancers were diagnosed within 6 months of the initial presentation.
19% of the 402 patients had underlying colonic polyps.  The presence of "obvious" subjective enhancement was highly associated with underlying polyps or carcinoma.

Population: mean age of 63.3 (range 50-94)
Intervention: Colonoscopy post diagnosis of acute diverticulitis (retrospective analysis)
Comparison: the presence of complications associated with acute diverticulitis (obstruction, lymph nodes,  and associated lymph nodes)
Outcome: The presence of bowel obstruction and enlarged lymph nodes is highly associated with underlying carcinoma in patients with diverticulitis.

Links: Pubmed, Original article

Related literature: Is colonoscopy still mandatory after a CT diagnosis of left-sided diverticulitis: can colorectal cancer be confidently excluded?

Elmi et al (2013). American Journal of Radiology. 200: 1269-1274

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