Quantitative magnetic resonance imaging of meniscal pathology ex vivo

OBJECTIVE To determine the ability of conventional spin echo (SE) T2 and ultrashort echo time (UTE) T2* relaxation times to characterize pathology in cadaveric meniscus samples. MATERIALS AND METHODS From 10 human donors, 54 triangular (radially cut) meniscus samples were harvested. Meniscal pathology was classified as normal (n = 17), intrasubstance degenerated (n = 33), or torn (n = 4) using a modified arthroscopic grading system. Using a 3-T MR system, SE T2 and UTE T2* values of the menisci were determined, followed by histopathology. Effect of meniscal pathology on relaxation times and histology scores were determined, along with correlation between relaxation times and histology scores. RESULTS Mean ± standard deviation UTE T2* values for normal, degenerated, and torn menisci were 3.6 ± 1.3 ms, 7.4 ± 2.5 ms, and 9.8 ± 5.7 ms, respectively, being significantly higher in degenerated (p  0.14). In terms of histology, we found significant group-wise differences (each p < 0.05) in fiber organization and inner-tip surface integrity sub-scores, as well as the total score. Finally, we found a significant weak correlation between UTE T2* and histology total score (p = 0.007, R$_{s}$$^{2}$ = 0.19), unlike the correlation between SE T2 and histology (p = 0.09, R$_{s}$$^{2}$ = 0.05). CONCLUSION UTE T2* values were found to distinguish normal from both degenerated and torn menisci and correlated significantly with histopathology

The impact of immediate breast reconstruction on the time to delivery of adjuvant therapy: the iBRA-2 study

Background: Immediate breast reconstruction (IBR) is routinely offered to improve quality-of-life for women requiring mastectomy, but there are concerns that more complex surgery may delay adjuvant oncological treatments and compromise long-term outcomes. High-quality evidence is lacking. The iBRA-2 study aimed to investigate the impact of IBR on time to adjuvant therapy. Methods: Consecutive women undergoing mastectomy ± IBR for breast cancer July–December, 2016 were included. Patient demographics, operative, oncological and complication data were collected. Time from last definitive cancer surgery to first adjuvant treatment for patients undergoing mastectomy ± IBR were compared and risk factors associated with delays explored. Results: A total of 2540 patients were recruited from 76 centres; 1008 (39.7%) underwent IBR (implant-only [n = 675, 26.6%]; pedicled flaps [n = 105,4.1%] and free-flaps [n = 228, 8.9%]). Complications requiring re-admission or re-operation were significantly more common in patients undergoing IBR than those receiving mastectomy. Adjuvant chemotherapy or radiotherapy was required by 1235 (48.6%) patients. No clinically significant differences were seen in time to adjuvant therapy between patient groups but major complications irrespective of surgery received were significantly associated with treatment delays. Conclusions: IBR does not result in clinically significant delays to adjuvant therapy, but post-operative complications are associated with treatment delays. Strategies to minimise complications, including careful patient selection, are required to improve outcomes for patients

Muscle-Tendon-Enthesis Unit.

Injuries to the muscle-tendon-enthesis unit are common and a significant source of pain and loss of function. This article focuses on the important anatomical and biomechanical considerations for each component of the muscle-tendon-enthesis unit. We review normal and pathologic conditions affecting this unit, illustrating the imaging appearance of common disorders on magnetic resonance imaging and ultrasound. Knowledge of the anatomy and biomechanics of these structures is crucial for the radiologist to make accurate diagnoses and provide clinically relevant assessments

Three-dimensional ultrashort echo time cones T1ρ (3D UTE-cones-T1ρ ) imaging.

We report a novel three-dimensional (3D) ultrashort echo time (UTE) sequence employing Cones trajectory and T1ρ preparation (UTE-Cones-T1ρ ) for quantitative T1ρ assessment of short T2 tissues in the musculoskeletal system. A basic 3D UTE-Cones sequence was combined with a spin-locking preparation pulse for T1ρ contrast. A relatively short TR was used to decrease the scan time, which required T1 measurement and compensation using 3D UTE-Cones data acquisitions with variable TRs. Another strategy to reduce the total scan time was to acquire multiple Cones spokes (Nsp ) after each T1ρ preparation and fat saturation. Four spin-locking times (TSL = 0-20 ms) were acquired over 12 min, plus another 7 min for T1 measurement. The 3D UTE-Cones-T1ρ sequence was compared with a two-dimensional (2D) spiral-T1ρ sequence for the imaging of a spherical CuSO4 phantom and ex vivo meniscus and tendon specimens, as well as the knee and ankle joints of healthy volunteers, using a clinical 3-T scanner. The CuSO4 phantom showed a T1ρ value of 76.5 ± 1.6 ms with the 2D spiral-T1ρ sequence, as well as 85.7 ± 3.6 and 89.2 ± 1.4 ms for the 3D UTE-Cones-T1ρ sequences with Nsp of 1 and 5, respectively. The 3D UTE-Cones-T1ρ sequence provided shorter T1ρ values for the bovine meniscus sample relative to the 2D spiral-T1ρ sequence (10-12 ms versus 16 ms, respectively). The cadaveric human Achilles tendon sample could only be imaged with the 3D UTE-Cones-T1ρ sequence (T1ρ  = 4.0 ± 0.9 ms), with the 2D spiral-T1ρ sequence demonstrating near-zero signal intensity. Human studies yielded T1ρ values of 36.1 ± 2.9, 18.3 ± 3.9 and 3.1 ± 0.4 ms for articular cartilage, meniscus and the Achilles tendon, respectively. The 3D UTE-Cones-T1ρ sequence allows volumetric T1ρ measurement of short T2 tissues in vivo

Quantitative magnetic resonance imaging of meniscal pathology ex vivo.

ObjectiveTo determine the ability of conventional spin echo (SE) T2 and ultrashort echo time (UTE) T2* relaxation times to characterize pathology in cadaveric meniscus samples.Materials and methodsFrom 10 human donors, 54 triangular (radially cut) meniscus samples were harvested. Meniscal pathology was classified as normal (n = 17), intrasubstance degenerated (n = 33), or torn (n = 4) using a modified arthroscopic grading system. Using a 3-T MR system, SE T2 and UTE T2* values of the menisci were determined, followed by histopathology. Effect of meniscal pathology on relaxation times and histology scores were determined, along with correlation between relaxation times and histology scores.ResultsMean ± standard deviation UTE T2* values for normal, degenerated, and torn menisci were 3.6 ± 1.3&nbsp;ms, 7.4 ± 2.5&nbsp;ms, and 9.8 ± 5.7&nbsp;ms, respectively, being significantly higher in degenerated (p &lt; 0.0001) and torn (p = 0.0002) menisci compared to that in normal. In contrast, the respective mean SE T2 values were 27.7 ± 9.5&nbsp;ms, 25.9 ± 7.0&nbsp;ms, and 35.7 ± 10.4&nbsp;ms, without significant differences between groups (all p &gt; 0.14). In terms of histology, we found significant group-wise differences (each p &lt; 0.05) in fiber organization and inner-tip surface integrity sub-scores, as well as the total score. Finally, we found a significant weak correlation between UTE T2* and histology total score (p = 0.007, Rs2 = 0.19), unlike the correlation between SE T2 and histology (p = 0.09, Rs2 = 0.05).ConclusionUTE T2* values were found to distinguish normal from both degenerated and torn menisci and correlated significantly with histopathology

Three-dimensional ultrashort echo time cones T1ρ (3D UTE-cones-T1ρ ) imaging.

We report a novel three-dimensional (3D) ultrashort echo time (UTE) sequence employing Cones trajectory and T1ρ preparation (UTE-Cones-T1ρ ) for quantitative T1ρ assessment of short T2 tissues in the musculoskeletal system. A basic 3D UTE-Cones sequence was combined with a spin-locking preparation pulse for T1ρ contrast. A relatively short TR was used to decrease the scan time, which required T1 measurement and compensation using 3D UTE-Cones data acquisitions with variable TRs. Another strategy to reduce the total scan time was to acquire multiple Cones spokes (Nsp ) after each T1ρ preparation and fat saturation. Four spin-locking times (TSL&nbsp;=&nbsp;0-20&nbsp;ms) were acquired over 12&nbsp;min, plus another 7&nbsp;min for T1 measurement. The 3D UTE-Cones-T1ρ sequence was compared with a two-dimensional (2D) spiral-T1ρ sequence for the imaging of a spherical CuSO4 phantom and ex vivo meniscus and tendon specimens, as well as the knee and ankle joints of healthy volunteers, using a clinical 3-T scanner. The CuSO4 phantom showed a T1ρ value of 76.5&nbsp;±&nbsp;1.6&nbsp;ms with the 2D spiral-T1ρ sequence, as well as 85.7&nbsp;±&nbsp;3.6 and 89.2&nbsp;±&nbsp;1.4&nbsp;ms for the 3D UTE-Cones-T1ρ sequences with Nsp of 1 and 5, respectively. The 3D UTE-Cones-T1ρ sequence provided shorter T1ρ values for the bovine meniscus sample relative to the 2D spiral-T1ρ sequence (10-12&nbsp;ms versus 16&nbsp;ms, respectively). The cadaveric human Achilles tendon sample could only be imaged with the 3D UTE-Cones-T1ρ sequence (T1ρ &nbsp;=&nbsp;4.0&nbsp;±&nbsp;0.9&nbsp;ms), with the 2D spiral-T1ρ sequence demonstrating near-zero signal intensity. Human studies yielded T1ρ values of 36.1&nbsp;±&nbsp;2.9, 18.3&nbsp;±&nbsp;3.9 and 3.1&nbsp;±&nbsp;0.4&nbsp;ms for articular cartilage, meniscus and the Achilles tendon, respectively. The 3D UTE-Cones-T1ρ sequence allows volumetric T1ρ measurement of short T2 tissues in vivo

Bleeding after Percutaneous Transhepatic Biliary Drainage: Incidence, Causes and Treatments

Of all procedures in interventional radiology, percutaneous transhepatic biliary drainage (PTBD) is amongst the most technically challenging. Successful placement requires a high level of assorted skills. While this procedure can be life-saving, it can also lead to significant iatrogenic harm, often manifesting as bleeding. Readers of this article will come to understand the pathophysiology and anatomy underlying post-PTBD bleeding, its incidence, its varied clinical manifestations and its initial management. Additionally, a structured approach to its treatment emphasizing endovascular and percutaneous methods is given