IDENTIFICAZIONE DELLE LESIONI POLMONARI IN RM CON UNA SEQUENZA VIBE MODIFICATA E CON UNA SEQUENZA VIBE STANDARD: UN CONFRONTO CON LA TC.

Scopo valutare l\u2019accuratezza della RM a 3 Tesla nell\u2019individuazione di lesioni polmonari con una sequenza VIBE modificata e con una sequenza VIBE standard, usando la TC come riferimento. Materiale e metodi abbiamo rivalutato retrospettivamente 37 pazienti oncologici (11 pediatrici e 26 adulti; 19 F) sottoposti a TC e PET/RM da 3T il cui protocollo prevedeva una sequenza VIBE acquisita a respiro trattenuto con echo time (TE) di 0.89 ms e flip angle (FA) di 3\ub0. Le VIBE sono state valutate da tre osservatori per l'identificazione di noduli >5mm o =5mm. Un quarto osservatore ha valutato delle sequenze VIBE standard (TE di 1.2 ms e FA di 10\ub0), anch\u2019esse incluse nel protocollo, ed infine un quinto lettore ha analizzato le immagini TC (considerate come standard di riferimento).Sia per paziente che per singola lesione sono state calcolate sensibilit\ue0 e specificit\ue0 per le due categorie di noduli ed il coefficiente di correlazione intraclasse (ICC) per i lettori delle VIBE modificate. Risultati analisi per paziente (positivit\ue0=1 lesione): sensibilit\ue0 84.6% e specificit\ue0 di 100% per noduli>5mm (VIBE standard 69.2% e 100%) e 44.4% e 100% per noduli=5mm (VIBE standard 33.3% e 100%). Analisi per lesione (presenza/assenza): sensibilit\ue0 di 83.9% per noduli>5mm (VIBE standard 67.74%) e 37.5% per noduli=5mm (VIBE standard 18.7%). L\u2019ICC nell\u2019analisi per paziente era 0.911 per noduli>5mm e 0.902 per noduli=5mm; nell\u2019analisi per lesione 0.866 per noduli>5mm e 0.699 per noduli=5mm. Conclusioni la sequenza VIBE modificata \ue8 riproducibile ed accurata per l\u2019individuazione di noduli >5mm, mentre l\u2019accuratezza risulta meno soddisfacente per i noduli=5mm. L\u2019utilizzo della sequenza modificata nei protocolli RM sembra ragionevole per migliorare la visualizzazione del polmone

Assessing FDG-PET/3-T MRI after Preoperative Chemoradiotherapy for Rectal Cancer

PURPOSE To assess the accuracy of pelvic 3-T MRI and combined FDG-PET/3-T MRI (PET/MRI) in predicting pathological tumor and node (ypTN) stages, and to compare the accuracy of whole-body PET/MRI with thoraco-abdominal CT (CT) in predicting metastases (ypM) stage. METHOD AND MATERIALS This prospective study concerned 17 patients (16 male) with locally advanced rectal cancer who underwent preoperative chemoradiotherapy, PET/MRI and CT for staging purposes. PET/MRI included T2 and diffusion weighted images. Total mesorectal excision was the treatment of choice for 13 patients; the remainders were MRI node negative and underwent transanal local excision with at least 1-year endoscopic and pelvic MRI follow-up. Concurrent distant metastases were confirmed by surgery/biopsy or followed up with CT. One radiologist assessed pelvic MRI and CT images. Another radiologist and a nuclear medicine physician jointly assessed PET/MRI findings. All three were blinded to all other imaging and pathology results. RESULTS ypT was T0 in 4 patients, T1 in 3, T2 in 1, T3 in 7, and T4 in 2. ypN was positive in 5/17 cases, and metastases were detected in 3/17 patients. MRI and PET/MRI findings for ypT were concordant and correct in 11/17 patients (64.7%), concordant and incorrect in 2/17 (11.8%), and discordant in 4/17 (23.5%), PET/MRI staging being correct in 2 cases. As for ypN staging, MRI and PET/MRI were concordant and correct in 14/17 patients (82.3%) and discordant in 3/17 (17.7%), with PET/MRI staging predicting ypN status in 2 cases. Two patients with metastases were diagnosed correctly, while PET/MRI misdiagnosed one case of a small lung metastasis. CONCLUSION Integrated whole-body PET/MRI improves the accuracy of ypTN staging, but is less accurate than CT in ypM staging. Further studies are needed, including efforts to refine PET/MRI by using specific sequences for the lung and intravenous gadolinium, to examine the role of this technique in monitoring distal cancer spread. If successful, it would be possible to combine local and distant rectal cancer staging in a single examination. CLINICAL RELEVANCE/APPLICATION FDG-PET/3-T MRI can be a useful tool for the whole-body staging (TNM) of patients with advanced rectal cancer after chemoradiotherapy

18F-fluorodeoxyglucose positron emission tomography ([18F]-FDG PET)/MRI in locally advanced rectal cancer after preoperative chemo-radiotherapy: a comparison with conventional imaging

Purpose: To assess the accuracy of restaging after preoperative chemoradiotherapy (pCRT) with whole-body PET/MRI, pelvic T2-weighted (T2W) plus diffusion-weighted imaging (DWI) MRI (pelvic-MRI), pelvic T2W MRI (standard- MRI) and thoracoabdominal CT when predicting histopathologic TNM stage in locally advanced rectal cancer (LARC). Material and methods: 26 patients with LARC underwent PET/MRI and CT before and after pCRT for TNM staging. 21 were treated with total mesorectal excision and 5 with transanal local excision. Histopathologic findings or a follow-up of at least 1-year were the reference standards. One radiologist evaluated pelvic MRI and CT. A second radiologist evaluated standard MRI. A third radiologist and a nuclear medicine physician assessed PET/MRI. T staging results were grouped in T0 and residual disease (T 651). N stage was classified on a per-patient basis as positive or negative using MRI dimensional criteria ( 655mm per node), MRI lymph node global size reduction rate criteria (reduction<70%) and PET/MRI dimensional criteria and/or nodal FDG uptake. Results: Sensitivity and specificity for ypT0 were 100%-85.7% for PET/MRI, 94.7%-85.7% for pelvic-MRI and 94.7%-57.1% for standard-MRI. For ypN+ with dimensional criteria, sensitivity and specificity were 100%-88.9% for PET/ MRI and 75%-88.89% for pelvic-MRI. The values for pelvic-MRI changed to 87.5% and 72.2% using lymph node global size reduction rate criteria. PET/ MRI correctly diagnosed two liver and one distant nodal metastases while missed a lung metastasis. Conclusion: PET/MRI improves the accuracy of ycTN staging compared to MRI, but performs worse than CT in ycM staging. Initial results are promising; however, a larger cHelveticaNeueLT StdHelveticaNeueLT Stdohort of patients should be examined introducing sequences for lung and gadolinium for liver metastases

Short TE and Low Flip Angle VIBE Sequence for Lung Evaluation in PET-MRI

PURPOSE Low-dose CT in standard PET/CT offers a better morphological lung characterization when compared with Dixon sequences in PET/MRI. Our aim is to improve diagnostic accuracy for lung lesions detection with PET/MRI avoiding a significant increase in the acquisition time, adding a short TE (Echo Time) and low FA (Flip Angle) T1-weighted sequence (gradient-echo volumetric interpolated breath-hold examination [VIBE]) to the standard acquisition protocol. METHOD AND MATERIALS We enrolled 21 oncological patients (11 M and 10 F) who underwent both thoracic CT scan and 3T PET-MRI (Siemens Biograph mMR) including lung dedicated short TE and low FA VIBE (inspiration, 3 mm slice thickness, axial plane). Time interval between the two examinations was < 2 weeks. VIBE sequences were retrospectively and independently evaluated by two radiologists for the detection of pulmonary nodules, parenchymal consolidations and dense bands; to assess inter-observer agreement Cohen's kappa coefficient (\u3ba) was calculated. Results were then compared with CT scans findings, considered as the gold standard. Sensitivity and specificity were calculated. RESULTS VIBE sensitivity in lung nodules evaluation was 80% (8/10 patients) for nodules >5 mm and 57,1 % (4/7 patients) for nodules 5 mm (\u3ba =0.90, p<0.001), 85% for nodules <= 5 mm (\u3ba=0.44 p<0.005), 90% for dense bands (\u3ba =0.56, p<0.001) and 100% for parenchymal consolidations. CONCLUSION VIBE showed high sensitivity in the evaluation of lung nodules > 5 mm; sensitivity was less satisfactory for smaller nodules. This sequence obtained also a very good inter-observer agreement, resulting a very reproducible imaging technique in pulmonary lesion investigation. Considering also the short acquisition time (15-18 s), it seems be reasonable to integrate PET/MRI protocols with a short TE and low FA VIBE, improving its diagnostic performance in lung evaluation. CLINICAL RELEVANCE/APPLICATION Short TE and low FA VIBE sequence can improve PET-MRI diagnostic performance in pulmonary lesions detection, without a significant increase in the acquisition time

Prediction of N0 Irradiated Rectal Cancer Comparing MRI Before and After Preoperative Chemoradiotherapy

BACKGROUND: The prediction of lymph node status using MRI has an impact on the management of rectal cancer, both before and after preoperative chemoradiotherapy. OBJECTIVE: To maximize the negative predictive value and sensitivity of mesorectal lymph node imaging after chemoradiotherapy because post-chemoradiation nodenegative patients may be treated with rectum-sparing approaches. DESIGN: Retrospective study. SETTINGS: The study was conducted at a tertiary-care hospital. PATIENTS: Sixty-four patients with locally advanced rectal cancer who underwent preoperative chemoradiotherapy and MRI for staging and the assessment of response were evaluated. MAIN OUTCOME MEASURES: The sums of the sizes of all mesorectal lymph nodes in each patient on both pre- and post-chemoradiotherapy imaging datasets were calculated to determine the lymph node global size reduction rates, taking these to be the outcomes of the histopathologic findings. Other included measures were interobserver agreement regarding the prediction of node status based on morphologic criteria and the diagnostic performance of contrast-enhanced images. RESULTS: Using a cutoff value of a 70% lymph node global size reduction rate with only 15 node-positive patients on histopathology, the sensitivity in the prediction of nodal status and negative predictive value were 93% (95%CI: 70.2-98.8) and 97% (95%CI: 82.9-99.8) for Observer 1, and 100% (95%CI: 79.6-100) and 100 % (95%CI:62.9-100) for Observer 2. The areas under the receiver operating characteristic curves for the two observers were 0.90 (95%CI: 0.82-0.98, p<0.0001) for Observer 1 and 0.65 (95%CI: 0.50-0.79, p=0.08) for Observer 2. The efficacy of the morphologic criteria and contrast-enhanced images in predicting node status was limited after chemoradiotherapy. LIMITATIONS: This study is limited by its small sample size and retrospective nature. CONCLUSIONS: Assessing the lymph node global size reduction rate value reduces the risk of undetected nodal metastases and may be helpful in better identifying suitable candidates for the local excision of early-stage rectal cancer

Lung visualisation on PET/MRI: implementing a\ua0protocol with a short echo-time and low flip-angle volumetric interpolated breath-hold examination sequence

To assess the diagnostic performance in detecting lung lesions of a short echo-time (TE) and low flip-angle (FA) volumetric interpolated breath-hold examination (VIBE) sequence included in the integrated positron-emission tomography (PET)/magnetic resonance imaging (MRI) protocol

Double fractures of the femur: a review of 16 patients

Background Double ipsilateral femoral fractures account for 1\u20139% of femoral fractures. There is no clear advantage between single or double implant osteosynthesis. We present a series of patients with double ipsilateral femoral fractures, to address the challenges in treatment, namely the implants for osteosynthesis and complications of treatment. Materials and methods We retrospectively studied 16 patients (7 men, 9 women; mean age, 51 years) treated from January 2015 to December 2018. Motor vehicle accidents were the leading cause of injury. Types of fractures were pertrochanteric and shaft (6), pertrochanteric and distal (2), double shaft (3), neck and shaft (2), neck and distal (1), shaft and distal (1), and triple fracture including a pertrochanteric, shaft and distal (1). In five patients, two different implants were used (plate and screws, cannulated hip screws, femoral nail), whereas in 11 patients a long femoral nail was used. Results Fourteen patients experienced union at a mean of 3 months (2\u20136 months). Two patients experienced nonunion: both had plate and screws osteosynthesis. One patient died 15 days after admission from polytrauma and another patient experienced central venous catheter thrombosis and pneumonia. Surgical complications (2 patients) included a thigh skin necrosis, and external fixator pin tract infection/infected non-union. Weight-bearing was delayed in all patients; full weight-bearing was allowed in 11 patients at 4 months postoperatively, and in four patients at 5 months. Conclusion Due to the rarity and the difficulty of standardization of double ipsilateral femoral fractures, there is variable information on the optimal osteosynthesis of the fractures and the outcome of the patients. It seems that closed reduction and long hip nailing is the treatment of choice, with few complications