CT and MR imaging features of soft tissue rhabdoid tumor: compared with rhabdomyosarcoma in children.

Objective: To assess the computed tomography (CT) and magnetic resonance (MR) imaging characteristics of soft tissue rhabdoid tumors (RT) and compare them with those of rhabdomyosarcoma (RMS). Methods: We conducted a retrospective analysis of 49 pediatric patients from 2011 to 2022, comprising 16 patients with soft tissue RT and 33 patients with RMS who underwent CT or MRI scans. Key imaging features, as well as clinical and pathological data, were compared between the two groups. The multivariate logistic regression analysis was used to determine independent differential factors for distinguishing soft tissue RT from RMS, and the model was established. The final prediction model was visualized by nomograms and verified internally by using a bootstrapped resample 1,000 times. The diagnostic accuracy of the combined model was assessed in terms of discrimination, calibration, and clinical utility. Results: Age, sex, number of lesions, and primary locations were similar in both groups. The imaging characteristics, including margin, calcification, surrounding blood vessels, and rim enhancement, were associated with the two groups of soft tissue tumors, as determined by univariate analysis (all p < 0.05). On multivariate logistic regression analysis, the presence of unclear margin (p-value, adjusted odds ratio [95% confidence interval]: 0.03, 7.96 [1.23, 51.67]) and calcification (0.012, 30.37 [2.09, 440.70]) were independent differential factors for predicting soft tissue RT over RMS. The presence of rim enhancement (0.007, 0.05 [0.01, 0.43]) was an independent differential factor for predicting RMS over soft tissue RT. The comprehensive model established by logistic regression analysis showed an AUC of 0.872 with 81.8% specificity and 81.3% sensitivity. The decision curve analysis (DCA) curve displayed that the model achieved a better net clinical benefit. Conclusion: Our study revealed that the image features of calcification, indistinct margins, and a lack of rim enhancement on CT and MRI might be reliable to distinguish soft tissue RT from RMS.

Tissue expander capsule as an induced vascular bed to prefabricate an axial vascularized buccal mucosa-lined flap for tubularized posterior urethral reconstruction: preliminary results in an animal model.

Surgical repair of complex posterior urethral disruptions remains one of the most challenging problems in urology. The efficacy of using a tissue expander capsule as an induced vascular bed to prefabricate axial vascularized buccal mucosa-lined flaps for tubularized posterior urethral reconstruction in a rabbit model was tested. The experiments were performed in three stages. First, silicone tissue expanders were inserted into the groin to induce vascularized capsule pouch formation. Next, buccal mucosa grafts were transplanted into the newly formed capsular tissue supplied by axial vessels for buccal mucosa-lined flap prefabrication. Then, circumferential posterior urethral defects were created and repaired with the buccal mucosa graft (Group 1), the capsule flap (Group 2), and the prefabricated capsule buccal mucosa composite flap (Group 3). After surgery, notable contracture of the tubularized buccal mucosa graft was observed in the neourethra, and none of the rabbits in Group 1 maintained a wide urethral caliber. In Group 2, the retrieved neourethra showed little evidence of epithelial lining during the study period, and the lumen caliber was narrowed at the 3-month evaluation. In Group 3, the buccal mucosa formed the lining in the neourethra and maintained a wide urethral caliber for 3 months. The capsule may serve as an induced vascular bed for buccal mucosa-lined flap prefabrication. The prefabricated buccal mucosa-lined flap may serve as a neourethra flap for posterior urethral replacement.

Tubularized urethral reconstruction using a prevascularized capsular tissue prelaminated with buccal mucosa graft in a rabbit model.

Tubularized graft urethroplasty fails largely because of inadequate graft take. Prefabrication of buccal mucosa lined flap has theoretical indications for constructing neourethra with an independent blood supply. The efficacy of using a tissue expander capsule as an induced vascular bed to prefabricate an axial vascularized buccal mucosa-lined flap for tubularized urethral reconstruction in a rabbit model was tested. The experiments were performed in three stages. First, silicone tissue expanders were inserted into the groin to induce vascularized capsule pouch formation. Next, buccal mucosa grafts were transplanted to the newly formed capsular tissue supplied by the axial vessel for buccal mucosa-lined flap prefabrication. Then, circumferential urethral defects were created and repaired by buccal mucosa graft (Group 1), capsule flap (Group 2) and prefabricated capsule buccal mucosa composite flap (Group 3). With retrograde urethrography, no rabbits in Group 1 maintained a wide urethral caliber. In Group 2, the discontinued epithelial layer regenerated at 1 month, and the constructed neourethra narrowed even though the lumen surface formed intact urothelial cells at 3 months. In Group 3, buccal mucosa formed the lining in the neourethra and kept a wide urethral caliber for 3 months. The capsule may serve as an induced vascular bed for buccal mucosa-lined flap prefabrication. The prefabricated buccal mucosa-lined flap may serve as a neourethra flap for circumferential urethral replacement.

Percutaneous Retrieval of Foreign Bodies Around Vital Vessels Aided with Vascular Intervention: A Technical Note.

OBJECTIVE: To describe a new interventional technique to remove foreign bodies (FBs) embedded in soft tissues around vital vessels. METHODS: Under fluoroscopic guidance and using local anesthesia, percutaneous removal of FBs was performed using forceps in nine patients. All patients suffered from a metallic soft tissue FB located in close proximity to important vessels and one also had a small traumatic pseudoaneurysm adjacent to the FB. Prior to removal of the FB, the position of the nearest vessel was identified using a guide wire or catheter placed into the vessel. Balloon catheter was also simultaneously used to temporarily stop the blood flow of the nearest artery during the FB removal in three of the nine patients. RESULTS: All of the nine FBs with 0-2 mm interval to the nearest vessel were successfully removed in the nine patients without any serious complications. The removed FBs measured 3-12 mm in length and 1-3 mm in width. The total fluoroscopic time of retrieval of each FB was 5-9 min (mean, 6.4 min). The volume of intraoperative bleeding ranged from 5 to 12 ml (mean, 7.5 ml). The length of hospital stay for each patient ranged from 4 to 8 days (mean, 5.5 days). CONCLUSION: Vascular intervention-aided percutaneous FB removal is minimally invasive and an effective method for removal of FBs around vital vessels.

Value of 3-dimensional CT virtual anatomy imaging in complex foreign body retrieval from soft tissues.

OBJECTIVE: To investigate the value of 3-dimensional (3D) CT virtual anatomy imaging (VAI) in the complex foreign body (FB) retrieval of the soft tissues. MATERIALS AND METHODS: Four hundred and seventy-five patients with radiopaque FB(s) diagnosed by radiograph underwent contrast-enhanced 3D CT examination. VAI was reconstructed by volume-rendering opacity software, by sliding down the lowest threshold from -600 to 100 HU. The imaging was grouped into three groups: A (axial and multi-planar reformation [MPR] images), B (standard 3D imaging with axial and MPR images), and C (VAI with axial and MPR images). They were analyzed to reveal the type, size, number, location, complications, and the interventional removability of the object, with the comparisons in the management and clinical outcomes on the patient follow-up studies. The data were subjected to chi-square tests, with p value < 0.05 indicating significant statistical difference. RESULTS: The FB shape, size, number, site distribution and vessels around FB, as well as the FB-associated vascular complications and the FB interventional removability were assessed more accurately in Group C than in Group B or Group A (p < 0.005). There was no significant difference in disclosing the type and depth of the FB among the three groups (p > 0.75). On the basis of the 3D CT, especially the enhanced 3D CT VAI, the followings were processed: the recommendation of interventional removal in 286 (60.47%) and non-intervention in 187 (39.53%) of the 473 patients with soft-tissue FB(s); in 352 (56.50%) of the 623 radiopaque FBs patients, 258 (54.55%) patients accurately detected on 3D CT and the successful removal by intervention (343 FBs) or surgery (9 FBs) without any sequela; and 215 (45.45%) patients with 271 FBs lost in the follow-up, with their departure from the hospital. CONCLUSION: The 3D CT, especially 3D enhanced CT VAI, has great incremental value in further diagnosis and management of complex FB extraction from soft tissues.

Seroepidemiological investigation of lyme disease and human granulocytic anaplasmosis among people living in forest areas of eight provinces in China.

OBJECTIVE: Lyme disease and Human granulocytic anaplasmosis are tick-borne diseases caused by Borrelia burgdorferi and Anaplasma phagocytophilum respectively. We have investigated infection and co-infection of the two diseases in the population of forest areas of eight provinces in China by measuring seroprevalence of antibodies against B. burgdorferi and A. phagocytophilum. METHODS: Forest areas in 8 provinces were chosen for investigation using whole sampling and questionnaire survey methods. 3 669 serum samples from people in the forest areas were tested for the presence of antibodies by indirect immunofluorescent assay (IFA). RESULTS: Seroprevalence against B. burgdorferi was 3% to 15% and against A. phagocytophilum was 2% to 18% in the study sites in the 8 provinces in China. We also found co-infection of B. burgdorferi and A. phagocytophilum in 7 of the 8 provinces (the exception being the Miyun area in Beijing). The seroprevalence for both B. burgdorferi and A. phagocytophilum was significantly higher among people exposed to ticks than among people who were not exposed to ticks. CONCLUSION: We conclude that both pathogens are endemic in the forest areas in the eight provinces, but the prevalence of B. burgdorferi and A. phagocytophilum differs between the provinces.

DSA observation of hemodynamic response of femoral head with femoral neck fracture during traction: a pilot study.

OBJECTIVE: To investigate the early influence of traction on blood supply to the femur head after femoral neck fractures using digital subtraction angiography (DSA). DESIGN: Prospective case series. SETTING: University Level I trauma center. PATIENTS: Nine patients who sustained a unilateral femoral neck fracture underwent selective femoral artery DSA within 2-23 days after their injury. INTERVENTION: DSA of the medial and lateral circumflex femoral artery was performed for all 9 fractured hips before traction. Repeat DSA study of the femoral head circulation was performed after the addition of 3 kg of traction in 7 patients and 5 kg of traction in 6 patients. For comparison, DSA was also performed on the uninjured hip in 8 of the 9 patients. MAIN OUTCOME MEASURE: Blood circulation of the femoral head was evaluated by observing morphology of the feeding arteries, perfusion volume, venous drainage, and the circulation time of the microvasculature. RESULTS: Femoral neck fracture damaged the retinaculum artery and led to femoral head hemodynamic disorder in all 9 cases. Application of linear traction and repeat DSA decreased femoral head perfusion (faint arterial imaging and delayed venous display) in all patients' retinaculum arteries except the inferior branch compared with the pretraction imaging. These findings were more pronounced as the traction was increased from 3 to 5 kg. These findings were significant (P < 0.05). CONCLUSIONS: Traction impairs blood perfusion to the femoral head. Blood flow in the retinacular arteries was reduced and venous drainage impeded. Traction may be one of the major causes of femoral head osteonecrosis after femoral neck fracture.