S. Aubry

Viscoelasticity in Achilles Tendonopathy: Quantitative Assessment by Using Real-time Shear-Wave Elastography

PURPOSE To investigate the differences in viscoelastic properties between normal and pathologic Achilles tendons (ATs) by using real-time shear-wave elastography (SWE). MATERIALS AND METHODS The institutional review board approved this study, and written informed consent was obtained from 25 symptomatic patients and 80 volunteers. One hundred eighty ultrasonographic (US) and SWE studies of ATs without tendonopathy and 30 studies of the middle portion of the AT in patients with tendonopathy were assessed prospectively. Each study included data sets acquired at B-mode US (tendon morphology and cross-sectional area) and SWE (axial and sagittal mean velocity and relative anisotropic coefficient) for two passively mobilized ankle positions. The presence of AT tears at B-mode US and signal-void areas at SWE were noted. RESULTS Significantly lower mean velocity was shown in tendons with tendonopathy than in normal tendons in the relaxed position at axial SWE (P < .001) and in the stretched position at sagittal (P < .001) and axial (P = .0026) SWE. Tendon softening was a sign of tendonopathy in relaxed ATs when the mean velocity was less than or equal to 4.06 m · sec(-1) at axial SWE (sensitivity, 54.2%; 95% confidence interval [CI]: 32.8, 74.4; specificity, 91.5%; 95% CI: 86.3, 95.1) and less than or equal to 5.70 m · sec(-1) at sagittal SWE (sensitivity, 41.7%; 95% CI: 22.1, 63.3; specificity, 81.8%; 95% CI: 75.3, 87.2) and in stretched ATs, when the mean velocity was less than or equal to 4.86 m · sec(-1) at axial SWE (sensitivity, 66.7%; 95% CI: 44.7, 84.3; specificity, 75.6%; 95% CI: 68.5, 81.7) and less than or equal to 14.58 m · sec(-1) at sagittal SWE (sensitivity, 58.3%; 95% CI: 36.7, 77.9; specificity, 83.5%; 95% CI: 77.2, 88.7). Anisotropic results were not significantly different between normal and pathologic ATs. Six of six (100%) partial-thickness tears appeared as signal-void areas at SWE. CONCLUSION Whether the AT was relaxed or stretched, SWE helped to confirm and quantify pathologic tendon softening in patients with tendonopathy in the midportion of the AT and did not reveal modifications of viscoelastic anisotropy in the tendon. Tendon softening assessed by using SWE appeared to be highly specific, but sensitivity was relatively low.

Cecal volvulus: CT findings and correlation with pathophysiology

The purpose of this study is to report the computed tomography (CT) features of cecal volvulus and to determine the accuracy of CT in distinguishing the three pathophysiological types of cecal volvulus. The CT studies of ten patients with surgically confirmed cecal volvulus were reviewed. For each patient, CT findings were looked for and recorded. The precise location of the cecum within the abdomen, the presence of an ileocecal twist, and the clockwise or counterclockwise direction of the whirl sign were specifically analyzed. All these results were confronted to the surgical diagnosis retrospectively correlated with the three types of cecal volvulus. According to our classification based on the analysis of the location of the cecum within the abdomen and the presence or the absence of a whirl sign on CT scans, the cecal volvulus was defined as the axial torsion type in four (40%) patients, loop type in four (40%) patients, and cecal bascule type in two (20%). For each patient, the result was in full accordance with the type of cecal volvulus diagnosed at surgery. CT is not only a valuable diagnostic technique in diagnosing cecal volvulus and its complications, but it is also useful in distinguishing the three pathophysiological types of cecal volvulus.

Microwave Thermal Ablation of Spinal Metastatic Bone Tumors

PURPOSE To assess feasibility, safety, and efficacy of microwave ablation of spinal metastatic bone tumors. MATERIALS AND METHODS Retrospective study of 17 patients with 20 spinal metastatic tumors treated with microwave ablation under computed tomographic guidance between March 2011 and August 2013 was performed. Ablations were performed under local anesthesia and nitrous oxide ventilation. Lesions were lumbar (n = 10), sacral (n = 7), and thoracic (n = 3) in location. Primary neoplastic sites were lung (n = 9), prostate (n = 4), kidney (n = 6), and uterus (n = 1). Adjunct cementoplasty was performed in nine cases, and a temperature-monitoring device was used in four cases. Procedure effectiveness was evaluated by visual analog scale (VAS) during a 6-month follow-up. Patient medical records were reviewed, and demographic and clinical data, tumor characteristics, and information on pain were assessed. RESULTS Mean ablation time was 4.4 minutes ± 2.7 (range, 1-8 min), with an average of 3.8 cycles per ablation at 60 W (range, 30-70 W). The preprocedure mean VAS score was 7.4 ± 1.2 (range, 6-9). Pain relief was achieved in all but one patient. Follow-up VAS scores were as follows: day 0, 1.3 ± 1.8 (P < .001); day 7, 1.6 ± 1.7 (P < .001); month 1, 1.9 ± 1.6 (P < .001); month 3, 2.2 ± 1.5 (P < .001); and month 6, 2.3 ± 1.4 (P < .01). No complications were noted. CONCLUSIONS Microwave ablation appears to be feasible, safe, and an effective treatment of painful refractory spinal metastases and may be considered as a potential alternative percutaneous technique in the management of spinal metastases.

Toxic megacolon in patients with severe acute colitis: computed tomographic features

OBJECTIVE The objective of the study was to evaluate computed tomography (CT) in the differential diagnosis of patients with toxic megacolon (TM) complicating severe acute colitis (SAC) and patients with SAC but no TM. MATERIALS AND METHODS We identified 16 patients who presented clinically complicated SAC and CT examination before surgery. The CT scans of these patients were retrospectively evaluated in consensus by two abdominal radiologists blinded to the clinical and pathological results for CT findings of SAC, i.e., diffuse colonic wall thickening, submucosal edema, pericolonic fat stranding and ascites, and CT findings of TM reported in the literature, i.e., segmental colonic wall thinning, air-filled colonic distension over 6 cm with abnormal haustral pattern, nodular pseudopolyps and associated small bowel distension. Fishers Exact Test was used for all statistical analyses. RESULTS Segmental colonic wall thinning with abnormal haustral pattern was noted in TM only (P=.001). As compared to patients with SAC but no TM as a complication, patients with TM showed statistically more frequent air-filled colonic distension over 6 cm (P=.001) and nodular pseudopolyps (P=.001). Diffuse colonic wall thickening (P=.036) and submucosal edema (P=.036) were more present in cases of uncomplicated SAC. Pericolonic fat stranding (P=.12), ascites (P=.6), and small bowel and gastric distension (P=1) were not distinctive criteria. CONCLUSION Computed tomography is useful in distinguishing patients with TM from patients with SAC but no TM as a complication. The association of air-filled colonic distension >6 cm, abnormal haustral pattern and segmental colonic parietal thinning seems pathognomonic of TM and should lead to rapid surgery.

Analgesic Effects of Microwave Ablation of Bone and Soft Tissue Tumors Under Local Anesthesia

OBJECTIVE To assess the feasibility and efficacy of microwave ablation (MWA) of painful refractory bone and soft tissue tumors performed under local anesthesia. STUDY DESIGN A retrospective study between 2011 and 2013. SETTING A single center, Academic Interventional Pain Management Unit. SUBJECTS Fifteen patients with 25 refractory painful bone (N = 19) or soft tissue (N = 6) tumors treated with MWA were consecutively included. METHOD Local Institutional Review Board approval was obtained, and written informed consent was waived. Lesions included spinal (N = 3), sacral (N = 4), and extraspinal (N = 18) locations. Pain was measured on a visual analog scale (VAS) from 0 to 10 before and immediately after procedure, at 1 week, and on a monthly basis following procedure. MWA procedures were always performed under computed tomography guidance and local anesthesia along with nitrous oxide inhalation. RESULTS Mean ablation time was 4.09 minutes (range 1-11) with an average of 4.2 cycles with a mean ablation power of 60 W. Preprocedure mean VAS score was 7.2 ± 0.97 (range 6-9). Follow-up postprocedure VAS scores were as follows: day 0: 1.64 ± 1.86, day 7: 1.82 ± 1.79, month 1: 2.05 ± 2.03 (14/15 patients), month 3: 2.13 ± 1.81, month 6: 2.36 ± 2.17; and were statistically significant (P < 0.001). Mean pain relief was 5.5 months. CONCLUSION MWA is feasible, safe, and effective in the management of painful refractory bone and soft tissue tumors. It may therefore be considered as a potential alternative to existing percutaneous ablation techniques in the management of bone and soft tissue tumors.

An MRI evaluation of changes in piriformis muscle morphology induced by botulinum toxin injections in the treatment of piriformis syndrome.

PURPOSE Botulinum toxin (BT) injection is a new treatment for piriformis syndrome (PS). The main purpose of our study was to use MRI to evaluate changes in piriformis muscle morphology after treatment with BT injections. PATIENTS AND METHODS Twenty patients presenting with PS who had undergone an MRI were included retrospectively: 12 patients treated with BT injections and eight untreated patients. The following parameters were assessed and compared to a normal contralateral muscle: maximum thickness, volume, and Goutalliers classification grade of fatty infiltration of the piriformis and internal obturator muscles. Pain was assessed through a visual analogue scale (VAS). RESULTS The untreated patients had no significant difference in the volume (P=1.0) or thickness of the piriformis muscle (P=0.61). The treated patients showed a significant reduction in the thickness (-4.2mm; P<0.001) and volume (-74.4mm(3); P<0.001) and an increase in the fatty infiltration (P<0.001) of the piriformis muscle treated by BT injection. Muscular atrophy was correlated with the number of BT injections and with the time until an MRI was performed. There was also significant pain relief after BT treatment. CONCLUSION BT leads to atrophy and fatty degeneration of the piriformis muscle that can be quantified by MRI and these factors explain why BT injections are effective in the treatment of PS.

Preoperative imaging in the planning of deep inferior epigastric artery perforator flap surgery

Breast reconstruction with adipocutaneous free flap from the abdominal wall combines the benefits of abdominoplasty to those of a prosthesis-free breast reconstruction. The deep inferior epigastric artery perforator (DIEP) flap is supplied by intramuscular perforators from the deep inferior epigastric artery (DIEA). It consists of the dissection of perforating branches of the DIEA within the rectus abdominis muscle, thus sparing both muscle and fascia. Preoperative imaging in the planning of DIEP flap surgery has been shown to facilitate faster and safer surgery. This review article aims to discuss advantages and drawbacks of current imaging modalities for mapping the course of perforating vessels in the planning of DIEP flap surgery, and to present state-of-the-art imaging techniques.

Magnetic resonance imaging in patellar lateral femoral friction syndrome (PLFFS): Prospective case-control study

OBJECTIVES To describe morphologic abnormalities and signs of patellar lateral femoral friction syndrome (PLFFS) detected by magnetic resonance imaging (MRI). MATERIALS AND METHODS Prospective study of 56 knees (21 patients and 30 controls) studied by 3Tesla MRI. Comparative analysis of clinical data, quantitative and qualitative imaging criteria in a population of patients with anterior knee pain associated with an abnormal MRI signal along the lateral alar folds of the infrapatellar fat pad, a characteristic sign of PLFFS, and a control population with no anterior knee pain or abnormal signal from the infrapatellar fat pad. RESULTS Patients with PLFFS have anterior and/or lateral knee pain. Their knee has anatomical predispositions for instability, primarily with patella alta (P<0.0001), patellar tilt more than 13.5° (P<0.0001), a patellar nose length less than 9 mm (P=0.0037), a patellar nose ratio less than 0.25 (P<0.0001), a TT-TG distance more than 10 mm (P<0.0001), and a trochlear prominence more than 4 mm (P=0.0056). In 35% of patients, patellar chondropathy is visible, and 48% of patients have patellar or trochlear subchondral abnormalities. CONCLUSION Anterior, lateral, and medial knee pain may be related to PLFFS. Anatomical predispositions contributing to instability are found in these patients. There may be associated chondropathies and osteochondropathies.

An evaluation of the EOS X-ray imaging system in pelvimetry.

OBJECTIVES To demonstrate the reliability of the EOS imaging system in measuring the internal diameters of the bony pelvis. MATERIALS AND METHODS A prospective study comparing the results of the pelvimetry of 18 dry pelvises carried out on the EOS imaging system to measurements taken manually and using the two current gold standard CT methods. Pelvimetric measurements of each pelvic bone were obtained using four methods and compared: direct manual measurements, spiral and sequential CT pelvimetry, and 2D-3D low-dose biplanar X-rays. The various obstetric diameters were measured to the millimetre and compared. RESULTS There was no significant difference in the different diameters assessed, with the exception of the interspinous diameter. There was a highly significant correlation (P < 0.001) between the values measured manually and by EOS for the Magnin index (Pearson = 0.98), the obstetric conjugate diameter (Pearson = 0.99), and the median transverse diameter (Pearson = 0.87). CONCLUSION The EOS imaging system allows for an ex vivo determination of the obstetrical diameters that is reliable enough to estimate obstetric prognosis, producing comparable measurements to CT. In view of concerns about protection from radiation, this low-dose imaging technique could become, after in vivo prospective validation, the new gold standard for pelvimetry and therefore a good alternative to CT.

The pubic tubercle: a CT landmark in groin hernia

The aim of our study is to investigate the pubic tubercle as a reliable CT landmark in distinguishing the three types of groin hernia. CT scans of 42 patients with surgically confirmed groin hernia were reviewed. For each patient, both the anatomical structure within the hernia and the state of the hernia to the inferior epigastric artery were specifically recorded. Hernias were also located within a schematic construction of orthogonal lines focused on the pubic tubercle. In this construction, inguinal hernias were ventral to the X-axis while femoral hernias were dorsal to the X-axis. Among the inguinal hernias, direct inguinal hernias were located strictly lateral to the Y-axis while indirect inguinal hernias medially crossed the Y-axis. All these CT results were compared to the surgical findings. The inferior epigastric artery was visualized in 90% patients and, in these cases, the situation of the hernia to the artery on CT showed no discordance with surgical findings. Within the schematic construction of orthogonal lines focused on the pubic tubercle, 50% were considered as indirect inguinal hernias, 31% as direct inguinal hernias and 19% as femoral hernias. For each patient, the CT diagnosis was consistent with the surgical report.