Vesicouterine fistulas: imaging findings in three cases

OBJECTIVE: The objective of our report is to present three cases of vesicouterine fistulas secondary to a cesarean delivery, a uterine rupture during labor, and radiation therapy. The delay between the onset of symptoms and the diagnosis varied between 3 and 7 years. Different techniques such as color Doppler sonography, excretory urography, cystography, CT, MRI, cystoscopy, vaginoscopy, and hysterography were performed with variable results, mostly negative and sometimes undefined. CONCLUSION: The definitive diagnosis was made with contrast-enhanced helical CT after cystography in one case, unenhanced helical CT after hysterography in another case, and cystography in the third case. Vesicouterine fistula rarely is thought of in the differential diagnosis because of its rarity and negative results on radiologic and endoscopic tests. The diagnosis is made on imaging after opacification of the uterus or the bladder depending on the pressure gradient obtained and the location of the fistula in relation to the uterine isthmus.     

Adnexal torsion: magnetic resonance findings in the viable adnexa with emphasis on stromal ovarian appearance

PURPOSE: To evaluate ultrasound (US) and magnetic resonance (MR) findings in the viable twisted adnexa. MATERIALS AND METHODS: Ten patients underwent US and MR studies before surgical detorsion. Corrected cross-sectional area of the ovary was defined as cross-sectional area minus areas of cysts and follicles superior to 1 cm. On T2-weighted images, signal intensity of the stroma was graded as type 1 when it was equal to that of urine and type 2 when it was less than that of urine but markedly more than the contralateral side. RESULTS: The tube was twisted in six cases and the ovary in nine cases. All adnexa were viable. The largest ovarian cross-sectional area and the largest corrected ovarian cross-sectional area of the twisted ovary were significantly larger than those of the contralateral ovary (P = 0.043 for US; P = 0.012 and 0.017, respectively, for MR). These ovaries contained types 1 and 2 hyperintensity in six cases and only type 2 hyperintensity in three cases. Tubal thickening was seen on MR in five cases. CONCLUSION: Tubal thickening, enlargement of ovarian stroma as reflected by the corrected cross-sectional area, and hyperintensity of this stroma on T2-weighted images probably related to edema were useful findings in these viable torsions.     

Peritoneal implants from ovarian tumors: CT findings

Metastatic peritoneal implants were assessed preoperatively with computed tomography (CT) in 38 patients with ovarian tumors. In the 106 biopsy specimens of gross peritoneal implants and the 118 random biopsy specimens obtained from these patients, metastatic deposits were detected in 27 of 38 (71%) patients and in 104 biopsy sites. CT depicted metastatic lesions in 17 of 27 (63%) patients and in 63 of 104 (61%) biopsy sites. The three sites most commonly involved were the right subphrenic region, the greater omentum, and the pouch of Douglas. The usefulness of CT in detecting lesions depended mainly on the location of the implant and the presence of adjacent ascites, rather than on lesion size.     

MR staging of bladder carcinoma: correlation with pathologic findings

Forty patients with bladder carcinoma were examined preoperatively by means of magnetic resonance (MR) imaging. In all patients, total cystectomy with enterocystoplasty and pelvic node dissection was performed. The surgical and pathologic findings were correlated with the MR findings. Extension through the deep muscle of the bladder wall was present in 20 of the 40 patients and was diagnosed with a sensitivity of 95% and a specificity of 95%. Extension to perivesical fat was present in 18 of 40 patients and was diagnosed with a sensitivity of 66% and a specificity of 100%. Invasion of the adjacent organs was present in nine of 40 patients and was diagnosed with a sensitivity of 44% and a specificity of 96%. On the basis of the MR findings, the tumor was correctly staged, according to the TNM classification, in 24 of 40 (60%) patients, tumor extension was overestimated in three of 40 (7.5%) patients, and tumor extension was underestimated in 13 of 40 (32.5%) patients. MR imaging has been shown to be accurate in identification of macroscopic lymph node involvement and deep muscle involvement. It appears to be at least as useful as computed tomography (CT) in the evaluation of perivesical fat involvement and to be superior to CT in the detection of invasion of adjacent organs. One limitation of MR imaging is in the evaluation of tumor extension into the periurethral glands.     

Thermal Protection During Percutaneous Thermal Ablation Procedures: Interest of Carbon Dioxide Dissection and Temperature Monitoring

Percutaneous image-guided thermal ablation of tumor is widely used, and thermal injury to collateral structures is a known complication of this technique. To avoid thermal damage to surrounding structures, several protection techniques have been reported. We report the use of a simple and effective protective technique combining carbon dioxide dissection and thermocouple: CO₂ displaces the nontarget structures, and its low thermal conductivity provides excellent insulation; insertion of a thermocouple in contact with vulnerable structures achieves continuous thermal monitoring. We performed percutaneous thermal ablation of 37 tumors in 35 patients (4 laser, 10 radiofrequency, and 23 cryoablations) with protection of adjacent vulnerable structures by using CO₂ dissection combined with continuous thermal monitoring with thermocouple. Tumor locations were various (19 intra-abdominal tumors including 4 livers and 9 kidneys, 18 musculoskeletal tumors including 11 spinal tumors). CO₂ volume ranged from 10 ml (epidural space) to 1500 ml (abdominal). Repeated insufflations were performed if necessary, depending on the information given by the thermocouple and imaging control. Dissection with optimal thermal protection was achieved in all cases except two patients where adherences (one postoperative, one arachnoiditis) blocked proper gaseous distribution. No complication referred to this technique was noted. This safe, cost-effective, and simple method increases the safety and the success rate of percutaneous thermal ablation procedures. It also offers the potential to increase the number of tumors that can be treated via a percutaneous approach.     

Significance of the pseudocapsule on MRI of renal neoplasms and its potential application for local staging: a retrospective study

OBJECTIVE: The purpose of our study was to evaluate the role of MRI in showing a pseudocapsule for local staging of renal tumors, and its potential application to select patients for partial surgery. MATERIALS AND METHODS: Eighty tumors (73 renal cell carcinomas [RCCs] and seven oncocytomas) were preoperatively evaluated by MRI. MRI findings were assessed with a special focus on perinephric fat and pseudocapsule. Correlations were performed with pathologic staging after surgery. RESULTS: At pathology, a pseudocapsule was recognized in 79 cases. Twenty-three RCC were staged pT3a (21 clear cell; two papillary). MR images exhibited a pseudocapsule in 90% of cases as a hypointense rim surrounding the tumor on T2-weighted images. MRI findings concerning isolated analysis of the pseudocapsule for differentiating stage T1/T2 from T3a were sensitivity: 86%, 50%; specificity: 95%, 92%; positive predictive value: 95%, 33%; negative predictive value: 88%, 92%; and accuracy: 93%, 89%, for clear cell and papillary types, respectively. For stage T3a, with both abnormalities of the pseudocapsule and perirenal fat, results were, for overall RCC sensitivity: 84%; specificity: 95%; positive predictive value: 91%; negative predictive value: 91%; and accuracy: 91%. CONCLUSION: The identification of the pseudocapsule offers an additional value for local staging by MRI. The presence of an intact pseudocapsule is a sign of lack of perinephric fat invasion. It is more likely to predict that the tumor can be removed by partial surgery.     

Percutaneous Vertebroplasty in a Broken Vertebral Titanium Implant (Titanium Mesh Cage)

We report the case of a percutaneous consolidation of a broken vertebral implant (Surgical Titanium Mesh Implants; DePuy Spine, Raynham, MA, USA) by vertebroplasty. Four years after anterior spondylectomy with cage implantation and stabilization with posterior instrumentation, the patient was admitted for excruciating back pain. Radiographs showed fracture of the cage, screw, and rod. An anterior surgical approach was deemed difficult and a percutaneous injection of polymethyl methacrylate into the cage was performed following posterior instrumentation replacement. This seems to be an interesting alternative to the classical anterior surgical approach, which is often difficult in postoperative conditions.     

Radiologie interventionnelle et tumeurs des tissus mous : du diagnostic au traitement

Interventional radiology plays an increasing role in the management of soft tissue tumors. For initial diagnosis, precise and safe image-guided biopsies; soft tissue tumor biopsies must be performed in accordance with international guidelines. Then, in a therapeutic phase, interventional radiology, particularly with thermal ablation techniques (radiofrequency, cryoablation), can be proposed for specific indications like salvage treatment of recurrent tumor after surgery and radiotherapy, focal ablation for oligometastatic sarcomas, or treatment of benign locally aggressive tumors such as symptomatic hemangiomas or desmoid tumors. A multidisciplinary approach remains mandatory to achieve optimal patient selection for interventional radiology techniques.