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

Management of Nodules with Initially Nondiagnostic Results of Thyroid Fine-Needle Aspiration: Can We Avoid Repeat Biopsy?

This retrospective review of followup results from patients with non-diagnostic ultrasound guided thyroid biopsy. Of the 393 nodules with non-diagnostic initial result, only 9 were subsequently diagnosed with malignancy with either repeat FNA or surgical excision, and a very low percentage (2/336) had a malignancy diagnosed on repeat sampling. As such the authors propose ultrasound followup in lieu of repeat biopsy.

They further identify higher risk features including size, male gender and increased age.

While the study is limited as it is a retrospective sampling, it does provide some evidence to guide management of a frequent clinical conundrum in the setting of a non-diagnostic FNA.

PICO Analysis:
Population: Patients with initial negative US guided FNA
Intervention: Repeat FNA
Comparison: Followup US
Outcome: Prevalence of missed malignancy

 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

Advanced-stage Hodgkin Lymphoma: US/Chest Radiography for Detection of Relapse in Patients in First Complete Remission—A Randomized Trial of Routine Surveillance Imaging Procedures

This intriguing study looks at alternatives to PET/CT and CT for followup of Hodgkin lymphoma. The study prospectively enrolled 300 patients into either F18 PET/CT or US + CXR at specified intervals. The US/CXR arm had higher specificity than PET/CT (96% vs 86%), and both arms had similar sensitivity (97.5% vs 100%).
This is an intriguing approach to reduce radiation dose (14.5 mSv per PET/CT vs 0.1 mSv per CXR) in this population who have a high baseline risk of second malignancy (as documented in this study, ~5% 5yr risk of secondary malignancy with no difference between the two arms). Further benefit is the reduced cost of the US/CXR approach, which in Italy was estimated at €1071 per PET/CT vs €103 per US/CXR. There were also lower secondary costs and fewer invasive procedures (eg mediastinoscopy) in the US/CXR arm.
The main limitation is the technical feasibility of performing US screening, in the study this was all done by one 'expert' radiologist, and its extension to other practices may be challenging but is worth considering.

PICO Analysis:
Population: advanced stage Hodgkin Lymphoma
Intervention: US + CXR f/u post initial tx
Comparison: PET/CT f/u post initial tx
Outcome: Sensitivity & specificity for relapse, time to recurrence and cost

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

Thyroid Cancers Incidentally Detected at Imaging in a 10-year Period: How Many Cancers Would Be Missed with Use of the Recommendations from the Society of Radiologists in Ultrasound?

A large retrospective review of 2090 patients with thyroidectomy and comparison with the ultrasound findings. This confirms a low proportion of false negative results when the SRU guidelines are applied to thyroid ultrasounds. Furthermore the 'missed' cancers tended to be of lower grade than those that met the SRU guidelines.

PICO Analysis:
Population: 2090 patients with full or hemi-thyroidectomy
Intervention: thyroid ultrasound by SRU guidelines
Comparison: pathology
Outcome: False negative rate

Reference: Pubmed Full Text
Link: SRU Conference Statement (Radiology, 2005)

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

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

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