Is Carotid Plaque Contrast Enhancement on MRI Predictive for Cerebral or Cardiovascular Events? A Prospective Cohort Study.

OBJECTIVE: The aim of this study was to correlate carotid plaque contrast enhancement (CPCE) to onset of cerebral/cardiovascular events (CCVE) in patients with atherosclerotic carotid disease. METHODS: The ethics committee approved this prospective study. Patients with carotid artery stenosis underwent magnetic resonance angiography before/after injection of 0.1 mmol/kg of gadobenate dimeglumine. Carotid plaque contrast enhancement was graded as follows: 0, no CPCE; 1, 1 single enhancement focus; 2, 2 or more foci. RESULTS: Seventy-seven patients (71 ± 9 years) had a stenosis degree: 34 mild, 16 moderate, 27 severe at the right side, and 36, 15, and 25 at the left side. Carotid plaque contrast enhancement was 0 in 30 patients, 1 in 26, 2 in 11 at the right, and 37, 19, and 13 at the left. Forty-seven CCVE occurred after magnetic resonance imaging, correlated to both stenosis degree (P = 0.006) and CPCE (P = 0.032). Excluding surgery/stenting, the correlation held only for CPCE (P = 0.017). Of 49 patients showing CPCE, 5 (10%) reported CCVE; of 21 patients without CPCE, none reported CCVE (P = 0.129). CONCLUSIONS: The absence of CPCE seems to be a negative predictor for CCVE.

Adult Dual-Energy X-ray Absorptiometry in Clinical Practice: How I Report it.

Several imaging methods for the diagnosis and management of osteoporosis exist. Dual-energy X-ray absorptiometry (DXA) is the most widely available and commonly used for measuring bone mineral density (BMD). Central DXA has several advantages: It has very good reproducibility, administers a negligible radiation dose to the patient, and BMD values obtained by DXA relate to fracture risk. Nevertheless, DXA has some technical limitations that should be recognized by those physicians who interpret and report this examination. We provide recommendations for optimal DXA scan reporting in adults, including indications, skeletal sites to be measured, serial BMD measurements, and fracture risk assessment. In conclusion, DXA is the standard of reference in evaluating BMD and is effective in following up patients over time. Adequate reporting and analysis of previous DXA examinations is crucial to manage patients correctly.

Ultrasound-guided percutaneous irrigation in rotator cuff calcific tendinopathy: what is the evidence? A systematic review with proposals for future reporting.

OBJECTIVES: We performed a systematic review of current evidence regarding ultrasound-guided percutaneous irrigation of calcific tendinopathy (US-PICT) in the shoulder aimed to: assess different published techniques; evaluate clinical outcome in a large combined cohort; and propose suggestions for homogeneous future reporting. METHODS: Cochrane Collaboration for Systematic Reviews of Interventions Guidelines were followed. We searched MEDLINE/MEDLINE In-Process/EMBASE/Cochrane databases from 1992-2013 using the keywords 'ultrasound, shoulder, needling, calcification, lavage, rotator cuff' combined in appropriate algorithms. References of resulting papers were also screened. Risk of bias was assessed with a modified Newcastle-Ottawa Scale. RESULTS: Of 284 papers found, 15 were included, treating 1,450 shoulders in 1,403 patients (females, n = 838; mean age interval 40-63 years). There was no exclusion due to risk of bias. CONCLUSIONS: US-PICT of rotator cuff is a safe and effective procedure, with an estimated average 55% pain improvement at an average of 11 months, with a 10% minor complication rate. No evidence exists in favour of using a specific size/number of needles. Imaging follow-up should not be used routinely. Future studies should aim at structural uniformity, including the use of the Constant Score to assess outcomes and 1-year minimum follow-up. Alternatives to steroid injections should also be explored. KEY POINTS: • US-PICT of rotator cuff is a safe and effective procedure. • On average 55% pain improvement with 10% minor complication rate. • No evidence exists in favour of using a specific size/number of needles. • Future need to assess outcome using Constant Score with 1-year minimum follow-up.

Prevalence and type of errors in dual-energy x-ray absorptiometry.

OBJECTIVES: Pitfalls in dual-energy x-ray absorptiometry (DXA) are common. Our aim was to assess rate and type of errors in DXA examinations/reports, evaluating a consecutive series of DXA images of patients examined elsewhere and later presenting to our institution for a follow-up DXA. METHODS: After ethics committee approval, a radiologist retrospectively reviewed all DXA images provided by patients presenting at our institution for a new DXA. Errors were categorized as patient positioning (PP), data analysis (DA), artefacts and/or demographics. RESULTS: Of 2,476 patients, 1,198 had no previous DXA, while 793 had a previous DXA performed in our institution. The remaining 485 (20 %) patients entered the study (38 men and 447 women; mean age ± standard deviation, 68 ± 9 years). Previous DXA examinations were performed at a total of 37 centres. Of 485 reports, 451 (93 %) had at least one error out of a total of 558 errors distributed as follows: 441 (79 %) were DA, 66 (12 %) PP, 39 (7 %) artefacts and 12 (2 %) demographics. CONCLUSIONS: About 20 % of patients did not undergo DXA at the same institution as previously. More than 90 % of DXA presented at least one error, mainly of DA. International Society for Clinical Densitometry guidelines are very poorly adopted. KEY POINTS: • More than 90 % of DXA examinations/reports presented one or more errors. • About 80 % of errors are related to image data analysis. • Errors in DXA examinations may have potential implications for patients' management.

A new diagnostic score to detect osteoporosis in patients undergoing lumbar spine MRI.

OBJECTIVES: Signal intensity of lumbar-spine at magnetic resonance imaging (MRI) correlates to bone mineral density (BMD). Our aim was to define a quantitative MRI-based score to detect osteoporosis on lumbar-spine MRI. METHODS: After Ethics Committee approval, we selected female patients who underwent both lumbar-spine MRI and dual-energy X-ray absorptiometry (DXA) and a reference group of 131 healthy females (20-29 years) who underwent lumbar-spine MRI. We measured the intra-vertebral signal-to-noise ratio in L1-L4. We introduced an MRI-based score (M-score), on the model of T-score. M-score diagnostic performance in diagnosing osteoporosis was estimated against DXA using receiver operator characteristic (ROC) analysis. RESULTS: We included 226 patients (median age 65 years), 70 (31%) being osteoporotic at DXA. MRI signal-to-noise ratio correlated to BMD (r = -0.677, P < 0.001). M-score negatively correlated to T-score (r = -0.682, P < 0.001). Setting a 90%-specificity, an M-score threshold of 5.5 was found, distinguishing osteoporosis from non-osteoporosis (sensitivity 54%; ROC AUC 0.844). Thirty-one (14%) patients had a fragility fracture, with osteoporosis detected in 15 (48%) according to M-score and eight (26%) according to T-score (P = 0.016). CONCLUSIONS: M-score obtained on lumbar spine MRI is a quantitative method correlating with osteoporosis. Its diagnostic value remains to be demonstrated on a large prospective cohort of patients. KEY POINTS: • M-score is a quantitative score potentially screening osteoporosis on lumbar-spine MRI; • This method showed good intra- and inter-reader reproducibility; • M-score may be used for identifying patients who should undergo DXA.

Short-term precision assessment of trabecular bone score and bone mineral density using dual-energy X-ray absorptiometry with different scan modes: an in vivo study.

OBJECTIVES: We estimated the in vivo reproducibility of trabecular bone score (TBS) from dual-energy X-ray absorptiometry (DXA) using different imaging modes to be compared to that of bone mineral density (BMD). METHODS: We enrolled 30 patients for each imaging mode: fast-array, array, high definition. Each patient underwent two DXA examinations with in-between repositioning. BMD and TBS were obtained according to the International Society for Clinical Densitometry guidelines. The coefficient of variation (CoV) was calculated as the ratio between root mean square standard deviation and mean, percent least significant change (LSC) as 2.77 × CoV, reproducibility as the complement to 100% LSC. RESULTS: Fast-array imaging mode resulted in 0.8% CoV and 2.1% LSC for BMD, 1.9% and 5.3% for TBS, respectively; array imaging mode resulted in 0.7% and 2.0% for BMD, 1.9% and 5.2%, for TBS; high-definition imaging mode resulted in 0.7% and 2.0%, for BMD; 2.0% and 5.4% for TBS, respectively. Reproducibility of TBS (95%) was significantly lower than that of BMD (98%) (p < 0.012). Difference in reproducibility among the imaging modes was not significant for either BMD or TBS (p = 0.942). CONCLUSION: While TBS reproducibility was significantly lower than that of BMD, differences among imaging modes were not significant for both TBS and BMD. KEY POINTS: • TBS is an emerging tool for assessing BMD. • TBS reproducibility is lower than that of BMD. • Differences between imaging modes are not significant for either TBS or BMD.

Reproducibility of trabecular bone score with different scan modes using dual-energy X-ray absorptiometry: a phantom study.

OBJECTIVE: The trabecular bone score (TBS) accounts for the bone microarchitecture and is calculated on dual-energy X-ray absorptiometry (DXA). We estimated the reproducibility of the TBS using different scan modes compared to the reproducibility bone mineral density (BMD). MATERIALS AND METHODS: A spine phantom was used with a Hologic QDR-Discovery A densitometer. For each scan mode [fast array, array, high definition (HD)], 25 scans were automatically performed without phantom repositioning; a further 25 scans were performed with phantom repositioning. For each scan, the TBS was obtained. The coefficient of variation (CoV) was calculated as the ratio between standard deviation and mean; percent least significant change (LSC%) as 2.8 × CoV; reproducibility as the complement to 100 % of LSC%. Differences among scan modes were assessed using ANOVA. RESULTS: Without phantom repositioning, the mean TBS (mm(-1)) was: 1.352 (fast array), 1.321 (array), and 1.360 (HD); with phantom repositioning, it was 1.345, 1.332, and 1.362, respectively. Reproducibility of the TBS without phantom repositioning was 97.7 % (fast array), 98.3 % (array), and 98.2 % (HD); with phantom repositioning, it was 97.9 %, 98.7 %, and 98.4 %, respectively. LSC% was ≤ 2.26 %. Differences among scan modes were all statistically significant (p ≤ 0.019). Reproducibility of BMD was 99.1 % with all scan modes, while LSC% was from 0.86 % to 0.91 %. CONCLUSION: Reproducibility error of the TBS was 2-3-fold higher than that of BMD. Although statistically significant, differences in TBS among scan modes were within the highest LSC%. Thus, the three scan modes can be considered interchangeable.

In vivo differences among scan modes in bone mineral density measurement at dual-energy X-ray absorptiometry.

PURPOSE: Our aim was to estimate the in vivo reproducibility of bone mineral density (BMD) at dual-energy X-ray absorptiometry (DXA) and to compare fast array, array, and high-definition scan modes. MATERIALS AND METHODS: A total of 378 patients (38 males and 340 females; mean age 63 ± 9 years) underwent DXA using a QDR-Discovery A densitometer (Hologic). Considering the three scan modes on lumbar spine and right femur, six independent groups of 30 patients were examined twice (for a total of 180 patients). Least significant change (LSC) and smallest detectable difference (SDD) were calculated. The remaining 198 patients underwent three scans of the lumbar spine (n = 92) or of the right femur (n = 106), one for each scan mode. The student t test and Bland-Altman analysis used were. Scan times were recorded and radiation dose was estimated using the ICRP60 method. RESULTS: Intra-scan mode reproducibility was 98-99%, corresponding to an LSC of 1.49-2.08%. The SDD was 0.018-0.023 g/cm(2) (lumbar spine) and 0.017-0.019 g/cm(2) (right femur). All comparisons among scan modes were statistically significant (p < 0.001) but lower than SDDs, i.e. not clinically relevant. Considering lumbar spine and the right femur, scan times were 50 and 38 s for fast array, 98 and 74 s for array, and 195 and 148 s for high definition, respectively; radiation doses were 6.7 and 4.7 µSv for fast array, and 13.3 and 9.3 µSv for both array and high definition, respectively. CONCLUSION: Since all BMD differences were lower than the SSDs, the three scan modes can be considered interchangeable. As a consequence, although the absolute reduction in time and radiation dose is relatively low, when BMD measurement is the aim of DXA, fast array can be generally preferred.

Dose absorption in lumbar and femoral dual energy X-ray absorptiometry examinations using three different scan modalities: an anthropomorphic phantom study.

The aim of this study was to measure the effective dose on an anthropomorphic phantom undergoing lumbar and femoral dual energy X-ray absorption (DXA) examinations, using 3 different scan modalities (fast-array [FA], array [A], high-definition [HD]), and assess the differences in the lifetime attributable risk (LAR) of cancer due to radiation. An anthropomorphic phantom was used. Thermoluminescent dosimeters were placed over 12 anatomic phantom regions and outside the room (to measure background radiation). Fifty scans on the femur and spine were performed for each mode. The dose relative to a single DXA scan for each dosimeter was measured (mean over the 50 scans) and the background radiation was then subtracted. The equivalent dose per organ was obtained. The total body effective dose was calculated by adding the equivalent doses. We estimated the lifetime dose absorption and LAR for cancer for a male and a female patient undergoing 36 DXA studies (18 lumbar, 18 femoral) every 21 months for 32 years. The effective dose for lumbar scans was FA = 17.79 µSv, A = 32.88 µSv, HD = 31.08 µSv; for femoral scans, FA = 5.29 µSv, A = 9.55 µSv, HD = 7.54 µSv. LAR estimation showed a minimal increase in cancer risk (range 4.55 × 10⁻4% [FA, femoral, male] to 4.02 × 10⁻³% [A, lumbar, female]). The lifetime dose absorption and LAR for cancer for a male and a female patient undergoing 36 DXA studies (18 lumbar, 18 femoral) every 21 months for 32 years were 0.756 mSv, 3.82 × 10(-3)% and 0.756 mSv, 5.11 × 10⁻³%, respectively. DXA examinations cause radiation levels that are comparable to the background radiation. Regardless of the scan modality or the anatomic site, a patient undergoing DXA scans for a lifetime has a negligible increased risk of developing cancer.

Rotator cuff calcific tendinitis: does warm saline solution improve the short-term outcome of double-needle US-guided treatment?

PURPOSE: To determine whether saline temperature influences procedure performance and outcome in patients undergoing ultrasonography (US)-guided lavage for the treatment of rotator cuff calcific tendinitis (RCCT). MATERIALS AND METHODS: This study was approved by the institutional review board, and informed consent was obtained from all patients. From December 2009 to May 2011, 462 patients (191 men and 271 women; mean age, 39.7 years) with painful RCCT diagnosed at US were prospectively enrolled and randomized into two groups. Operators subjectively classified calcifications as hard, soft, or fluid according to their appearance at US. US-guided percutaneous treatment of RCCT (local anesthesia, double-needle lavage, intrabursal steroid injection) was performed with warm saline (42°C, 107°F) in 229 patients and with room-temperature saline in 233. Operators and patients were not blinded to saline temperature. The ease of calcium dissolution was subjectively scored (easy=1, intermediate=2, difficult=3). Procedure duration was recorded. Patient discomfort was assessed by using a visual analog scale (VAS). The occurrence of postprocedure bursitis was recorded. Statistical analyses were performed with Mann-Whitney U, χ2, and analysis of variance tests. RESULTS: Procedure duration was significantly shorter (P<.001) in patients treated with warm saline (mean, 576 seconds±121) than in those treated with room-temperature saline (mean, 777 seconds±151). Calcium dissolution was significantly easier in patients treated with warm saline (median score, 1) than in those treated with room-temperature saline (median score, 2). Subgroup analysis according to calcification appearance at US showed a significant difference between groups for both soft (P=.003) and hard (P<.001) calcifications. No overall significant differences were found for VAS score (warm saline group: baseline=8.9±0.6, 1 month=4.7±0.6, 2 months=4.0±0.7, 3 months=3.4±0.4, 1 year=3.0±0.7; room-temperature saline group: baseline=9.2±0.4, 1 month=4.5±0.7, 2 months=4.1±0.9, 3 months=3.1±0.7, 1 year=3.2±0.8; P=.491). Postprocedural bursitis was observed in eight patients in the warm saline group and 20 in the room-temperature saline group (P<.022). CONCLUSION: In the treatment of RCCT, warm saline appears to reduce procedure duration and improve calcification dissolution while reducing the frequency of postprocedural bursitis.

Reporting rotator cuff tears on magnetic resonance arthrography using the Snyder's arthroscopic classification.

AIM: To determine diagnostic performance of magnetic resonance arthrography (MRA) in evaluating rotator cuff tears (RCTs) using Snyder's classification for reporting. METHODS: One hundred and twenty-six patients (64 males, 62 females; median age 55 years) underwent shoulder MRA and arthroscopy, which represented our reference standard. Surgical arthroscopic reports were reviewed and the reported Snyder's classification was recorded. MRA examinations were evaluated by two independent radiologists (14 and 5 years' experience) using Snyder's classification system, blinded to arthroscopy. Agreement between arthroscopy and MRA on partial- and full-thickness tears was calculated, first regardless of their extent. Then, analysis took into account also the extent of the tear. Interobserver agreement was also calculated the quadratically-weighted Cohen kappa statistics. RESULTS: On arthroscopy, 71/126 patients (56%) had a full-thickness RCT. The remaining 55/126 patients (44%) had a partial-thickness RCT. Regardless of tear extent, out of 71 patients with arthroscopically-confirmed full-thickness RCTs, 66 (93%) were correctly scored by both readers. All 55 patients with arthroscopic diagnosis of partial-thickness RCT were correctly assigned as having a partial-thickness RCT at MRA by both readers. Interobserver reproducibility analysis showed total agreement between the two readers in distinguishing partial-thickness from full-thickness RCTs, regardless of tear extent (k = 1.000). With regard to tear extent, in patients in whom a complete tear was correctly diagnosed, correct tear extent was detected in 61/66 cases (92%); in the remaining 5/66 cases (8%), tear extent was underestimated. Agreement was k = 0.955. Interobserver agreement was total (k = 1.000). CONCLUSION: MRA shows high diagnostic accuracy and reproducibility in evaluating RCTs using the Snyder's classification for reporting. Snyder's classification may be adopted for routine reporting of MRA.

Relevant incidental findings at abdominal multi-detector contrast-enhanced computed tomography: A collateral screening?

AIM: To investigate the prevalence of relevant incidental findings (RIFs) detected during routine abdominal contrast-enhanced computed tomography (CeCT). METHODS: We retrospectively evaluated the reports of a consecutive series of abdominal CeCT studies performed between January and May 2013. For each report, patients' age and sex, admission as inpatient or outpatient, clinical suspicion as indicated by the requesting physician, availability of a previous abdominal examination, and name of the reporting radiologist were recorded. Based on the clinical suspicion, the presence and features of any RIFs (if needing additional workup) was noted. RESULTS: One thousand forty abdominal CeCT were performed in 949 patients (528 males, mean age 66 ± 14 years). No significant difference was found between inpatients and outpatients age and sex distribution (P > 0.472). RIFs were found in 195/1040 (18.8%) CeCT [inpatients = 108/470 (23.0%); outpatients = 87/570 (15.2%); P = 0.002]. RIFs were found in 30/440 (6.8%) CeCT with a previous exam and in 165/600 (27.5%) without a previous exam (P < 0.001). Radiologists' distribution between inpatients or outpatients was significantly different (P < 0.001). RIFs prevalence increased with aging, except for a peak in 40-49 year group. Most involved organs were kidneys, gallbladder, and lungs. CONCLUSION: A RIF is detected in 1/5 patients undergoing abdominal CeCT. Risk of overdiagnosis should be taken into account.

Less is better? Intraindividual and interindividual comparison between 0.075 mmol/kg of gadobenate dimeglumine and 0.1 mmol/kg of gadoterate meglumine for cranial MRI.

PURPOSE: To retrospectively compare a reduced dose (RD) (0.075 mmol/kg) of gadobenate dimeglumine (RD-gadobenate) with standard single dose (SSD) (0.1 mmol/kg) of gadoterate meglumine (SSD-gadoterate) for cranial MRI. MATERIALS AND METHODS: Thirty-one patients (12 males; aged 52 ± 16 years) underwent cranial MRI with SSD-gadoterate and repeated the examination with RD-gadobenate after a median interval of 10 months. Signal-to-noise ratio (SNR) was obtained on contrast-enhanced images for enhancing lesions (n=10) as well as for right and left transverse venous sinuses, internal carotid arteries, and parotid glands. Moreover, a consecutive series of 100 cranial MRI with SSD-gadoterate (49 males; aged 51 ± 19 years) was compared with a consecutive series of 100 cranial MRI with RD-gadobenate (45 males; aged 54 ± 18 years). Two blinded neuroradiologists (R1, R2) judged contrast enhancement as sufficient, good, or optimal. Wilcoxon, Mann-Whitney, χ(2), and Cohen κ statistics were used. RESULTS: At intraindividual analysis, median SNR ranged 57-88 for SSD-gadoterate and 79-99 for RD-gadobenate, the latter being systematically higher, the difference being significant for both transverse venous sinuses (p ≤ 0.011), not significant for both internal carotid arteries and both parotid glands, and enhancing lesions (p ≤ 0.101). The two series of interindividual analysis were not significantly different for gender/age (p>0.415). Contrast enhancement was optimal in 59% (R1) and 76% (R2) of patients using RD-gadobenate, in 39% (R1) and 49% (R2) of patients using SSD-gadoterate (p ≤ 0.016), with substantial reproducibility (κ ≥ 0.606). CONCLUSION: Both analyses showed an equal or better contrast enhancement when using RD-gadobenate compared to SSD-gadoterate for routine cranial MRI. The high relaxivity of gadobenate allowed for a 25% dose reduction.

Magnetic resonance imaging of the knee after medial unicompartmental arthroplasty.

OBJECTIVE: We evaluated safety and potential diagnostic value of magnetic resonance (MR) imaging of the knee treated with medial unicompartmental arthroplasty (MUA). METHODS: The treated knee of 8 patients who underwent MUA was studied with four different 1.5-T MR sequences. Two radiologists independently evaluated eleven anatomical items using a score from 0 (not assessable) to 3 (completely assessable). The sum of the scores for each sequence was divided by the potential maximal sum, obtaining a percentage visibility index (PVI) for each item. RESULTS: No adverse effect was reported during or within 30 min after the exam. Posterior cruciate ligament was unseen in all patients by both observers. The following PVIs were reported for the remaining ten items: femoral-patellar relationship 83-100%; femoral-patellar cartilage 92-100%; Hoffa's fat pad 75-92%; patellar ligament 79-100%; lateral meniscus 100%; femoral-tibial lateral joint 100%; lateral collateral ligament 96-100%; anterior cruciate ligament 54-83%; femoral-tibial lateral cartilages 92-100%; posterolateral corner 100%. Agreement between readers was found in 331/352 (94%) evaluations (k=0.74-0.78). CONCLUSIONS: MR imaging after MUA offers a safe and reproducible evaluation of residual knee anatomy except for cruciate ligament, and can be used to follow-up these patients.