Postoperative Follow-up Imaging Research Articles

Urine steroid metabolomics as a novel diagnostic tool for early detection of recurrence in adrenocortical carcinoma

Introduction: Adrenocortical carcinoma (ACC) is an aggressive malignancy with a high rate of recurrence. Regular post-operative follow-up imaging is necessary, but associated with high radiation exposure and frequent diagnostic ambiguity. Urine steroid metabolomics has recently been introduced as a novel diagnostic tool for the detection of adrenocortical malignancy in patients with adrenal incidentalomas. Here we present the first clinical study assessing the performance of this innovative approach in the context of follow-up after complete (R0) ACC resection. Patients and methods: We included 166 patients from 13 centres registered with the European Network for the Study of Adrenal Tumours (ENSAT). We selected all patients recorded between 2008 and 2015 fulfilling the following criteria: i) recorded on the ENSAT registry as confirmed adrenocortical carcinoma with R0 primary tumour resection and ii) availability of at least two postoperative 24-h urines, one whilst disease-free and the other after recurrence. Twenty-four-hour urines were analysed by gas chromatography–mass spectrometry, with quantification of 38 distinct steroid metabolites. A machine learning-based computational algorithm was employed to detect ACC recurrence. Results: Twenty-one patients developed 22 ACC recurrences during the study period as documented by serial cross-sectional imaging and biopsy where appropriate. Steroid metabolomics predicted disease recurrence at the time of first abnormal imaging with a sensitivity of 84% and specificity of 95%. Adjuvant mitotane in 12/21 patients did not affect accuracy. In the subgroup of patients for whom a diagnostic pre-operative 24-h urine sample was available (n=7), we were able to accurately detect all cases of recurrence (sensitivity and specificity 100%). In seven cases, biochemical evidence of disease recurrence pre-dated the first radiological detection by more than 2 months (range 2–11 months). Conclusion: Our study provides proof-of-principle evidence suggesting a role for urine steroid metabolomics as a potent diagnostic tool in the follow-up monitoring of ACC.

Standalone Anterior Lumbar Interbody Fusion for Spondylolisthesis

Introduction Debate continues over the optimal approach for fusion of isthmic and degenerative spondylolisthesis. We favor anterior lumbar interbody fusion (ALIF) as it permits liberal discectomy and placement of a large, lordotic device which restores disc height and sagittal balance, reduces listhesis, and indirectly decompresses exiting nerve roots. There are only a few articles in the literature looking at the degree of reduction and the durability over time in patients undergoing ALIF with spondylolisthesis. Material and Methods We studied the initial degree of reduction achieved, and the durability of this reduction over time when ALIF was used for patients with isthmic and degenerative spondylolisthesis. Analysis of prospectively collected radiographic data was conducted. All patients with lumbar spondylolisthesis who underwent standalone ALIF between 2009 and 2013 by a single surgeon (R. J. M.) were included. Radiological analysis of slip percentage and disc height on preoperative, postoperative, and latest follow-up imaging was performed with Surgimap Spine software. Demographic factors, surgical data and radiological results were compared. Results Average patient age was 64.5 years (range, 37–84) with 16 females, 15 males. There were 36 levels treated with 20 at L4/5, 15 at L5/S1, and one at L3/4. Mean listhesis was 16% which immediately postoperatively reduced to 2.3%, but at latest follow-up had recurred to 58% of the original value. An average disc height increase of 184% was observed postoperatively. Analysis of these measurements showed a high degree of inter- and intraclass correlation. Mean follow-up was 17 months. BMI correlated with immediate postoperative reduction ( p = 0.004), as did posterior disc height ( p = 0.04). The overall radiological fusion rate was 91%. Three patients required subsequent posterior instrumentation, which will be discussed. Conclusion ALIF achieves disc height restoration and indirect listhesis reduction in isthmic and degenerative spondylolisthesis. Although this reduction may regress over time, we found it remained reduced by approximately 50% at latest follow-up. Around 10% of patients required further strengthening by posterior pedicle screw fixation. Standalone ALIF without posterior pedicle screw fixation is successful in the majority of patients with spondylolisthesis.

A Liver Mass Found After Subtotal Gastrectomy

Question: A 37-year-old woman underwent routine postoperative follow-up imaging study. Two months prior, she had undergone radical subtotal gastrectomy for advanced gastric cancer and a hysterectomy with bilateral salpingo-oophorectomy for Krukenberg tumor from gastric cancer. After surgery, she had no particular symptoms or abnormal findings on physical examination. Preoperative serum carcinoembryonic antigen (CEA) was 0.84 ng/mL (normal range, 0-5), CA 72-4 was 19.26 U/mL (normal range, 0-8.2), and CA 19-9 was 94.2 U/mL (normal range, 0-37).

Cholesterol Granuloma of the Petrous Apex: A 5-Year Review of Radiology Reports with Follow-Up of Progression and Treatment.

Objectives To assess the stability and outcomes of patients with cholesterol granulomas at Brigham and Women's Hospital. Design A retrospective review of neuroradiology magnetic resonance imaging (MRI) studies was performed. The number of newly diagnosed cases of cholesterol granuloma per year was determined. Additional data included age and gender, clinical presentation if applicable, growth on imaging follow-up, and recurrence on postoperative follow-up if applicable. Participants Inclusion criteria included patients who underwent MRI studies between January 1, 2009 and July 1, 2013. Upon review of imaging of these patients, 18 patients had findings compatible with cholesterol granuloma. Results During the study period, an average of three cases of cholesterol granuloma were diagnosed on MRI per year. Three of 18 patients underwent treatment. Two underwent surgery, both of whom demonstrated recurrence on postoperative follow-up imaging. One patient who underwent computed tomography-guided percutaneous aspiration and Gelfoam (Pfizer, New York, United States) embolization had no recurrence on imaging follow-up of up to 23 months. Among the patients who were observed without intervention, growth was identified in only one patient. Conclusions Cholesterol granulomas are a rare entity; however, their appearance on imaging may be greater than previously reported. Most of the lesions demonstrate stability and can be observed.

Noninvasive intraductal papillary mucinous neoplasms and mucinous cystic neoplasms: Recurrence rates and postoperative imaging follow-up

Although surveillance guidelines for resected invasive mucinous neoplastic cysts are well-established, those for noninvasive cysts are not defined. We used our experience with resected noninvasive mucinous neoplastic cysts to define recurrence rates and the optimal frequency of postoperative imaging follow-up. We reviewed the medical records of 134 patients with resected, pathologically confirmed noninvasive mucinous neoplasms between 2002 and 2012. Demographics, comorbidities, cyst characteristics, and recurrence were evaluated. Survival analysis was used to estimate the distribution of time to recurrence and regression models were used to investigate factors associated with recurrence. Eighty-seven patients with intraductal papillary mucinous neoplasms (IPMNs) were compared with 47 patients with mucinous cystic neoplasms (MCNs). Those with MCNs were more often females (P=.001), significantly younger (P=.001), more symptomatic (P=.009), and had cysts more often located in the tail (P<.001). Median follow-up was 42months. Recurrence rates for IPMNs were 0%, 5%, and 10% versus 0% for MCNs respectively at postoperative years 1, 2, and 3 (P=.014). On multivariable analysis, size >3cm (P=.027), higher grade dysplasia (P=.043), and positive resection margins (P<.001) were significantly associated with recurrence. Resected noninvasive IPMNs with moderate- or high-grade dysplasia and negative resection margins require imaging follow-up every 2years, given the 16% overall recurrence rate. Although the follow-up interval for noninvasive, low-grade, dysplastic IPMNs with negative margins could be lengthened, all noninvasive IPMNs having positive margins require yearly follow-up at the minimum. Resected noninvasive MCNs--irrespective of grade and margin status--do not require surveillance, although the development of branch duct-IPMNs in the remnant pancreas can be investigated in the long term at the discretion of the provider.

Tumor resection with carmustine wafer placement as salvage therapy after local failure of radiosurgery for brain metastasis

Prolonged survival in brain metastasis patients increases recurrence rates and places added importance on salvage therapies. Research examining carmustine polymer wafers as an adjuvant therapy for brain metastasis is limited. We present a single institution retrospective series documenting the use of BCNU wafers placed in the cavity of resected recurrent brain metastases that had failed prior stereotactic radiosurgery (SRS). Between February 2002 and April 2013, a total of 31 patients with brain metastases failed SRS and underwent resection with intracavitary placement of carmustine wafers. Clinical outcomes including local control, survival, cause of death, and toxicity were determined from electronic medical records. Kaplan–Meier analysis was performed to assess local control and survival. Imaging features were reviewed and described for patients with serial post-operative follow-up imaging examinations over time. Overall survival at 6months and 12months was 63% and 36%, respectively. Fourteen of 31 patients (45%) died from neurologic causes. Local control within the resection cavity was 87% and 70% at 6 and 12months, respectively. Five patients (16%) underwent further salvage therapy following carmustine wafer placement after local failure. Resection cavities of all six patients with follow-up imaging showed linear peripheral enhancement. Pericavity and wafer enhancement was present as early as the same day as surgery and persisted in all cases to 6months or longer. Carmustine polymer wafers are an effective salvage treatment following resection of a brain metastasis that has failed prior SRS. For patients with successful local control after wafer implantation, linear enhancement at the cavity is common.

Local curative effect of MRI-guided radiofrequency ablation on small hepatocellular carcinoma.

Radiofrequency ablation (RFA) is one of the treatment modes for liver cancer. The trauma caused by RFA is small, and its local curative effect is reliable. Computed tomography (CT) can only be used for axial scans, and parts of the lesion are unclear on plain scans. The aim of this study is to compare the local curative effect of RFA percutaneously guided by MRI and ultrasound for small hepatocellular carcinoma (HCC). This study is a retrospective study. In this study, we examined 60 cases of 88 liver lesions and 50 cases of 52 lesions, in which RFA was guided by MRI and ultrasound, respectively. All cases were clinically diagnosed. The therapeutic effect of ablation lesions was examined by postoperative imaging follow-up. The results indicated that there were 5 (5/88) recurrences of liver lesions with MRI-guided RFA and 14 (14/52) recurrences of liver lesions with ultrasound-guided RFA. The median time to recurrence in the case of recurrent lesions was 7 months. Postoperative ablation lesions showed a low-intensity signal surrounded by a thin high-intensity signal ring on T2WI images. On T1WI images, the ablation lesion showed a concentric pattern and the central area of the original lesion continued to show a low-intensity signal with a clear ring of high-intensity signal that had a clear boundary. In conclusion, the local curative effect of MRI-guided RFA for small HCC is superior to that of ultrasound-guided RFA.

Evaluation of a prototype correction algorithm to reduce metal artefacts in flat detector computed tomography of scaphoid fixation screws

The aim of this study was to evaluate a prototype correction algorithm to reduce metal artefacts in flat detector computed tomography (FDCT) of scaphoid fixation screws. FDCT has gained interest in imaging small anatomic structures of the appendicular skeleton. Angiographic C-arm systems with flat detectors allow fluoroscopy and FDCT imaging in a one-stop procedure emphasizing their role as an ideal intraoperative imaging tool. However, FDCT imaging can be significantly impaired by artefacts induced by fixation screws. Following ethical board approval, commercially available scaphoid fixation screws were inserted into six cadaveric specimens in order to fix artificially induced scaphoid fractures. FDCT images corrected with the algorithm were compared to uncorrected images both quantitatively and qualitatively by two independent radiologists in terms of artefacts, screw contour, fracture line visibility, bone visibility, and soft tissue definition. Normal distribution of variables was evaluated using the Kolmogorov-Smirnov test. In case of normal distribution, quantitative variables were compared using paired Student's t tests. The Wilcoxon signed-rank test was used for quantitative variables without normal distribution and all qualitative variables. A p value of < 0.05 was considered to indicate statistically significant differences. Metal artefacts were significantly reduced by the correction algorithm (p < 0.001), and the fracture line was more clearly defined (p < 0.01). The inter-observer reliability was "almost perfect" (intra-class correlation coefficient 0.85, p < 0.001). The prototype correction algorithm in FDCT for metal artefacts induced by scaphoid fixation screws may facilitate intra- and postoperative follow-up imaging. Flat detector computed tomography (FDCT) is a helpful imaging tool for scaphoid fixation. The correction algorithm significantly reduces artefacts in FDCT induced by scaphoid fixation screws. This may facilitate intra- and postoperative follow-up imaging.

Laparoscopic repair of paraesophageal hernias.

Background and Objectives:Laparoscopy has quickly become the standard surgical approach to repair paraesophageal hernias. Although many centers routinely perform this procedure, relatively high recurrence rates have led many surgeons to question this approach. We sought to evaluate outcomes in our cohort of patients with an emphasis on recurrence rates and symptom improvement and their correlation with true radiologic recurrence seen on contrast imaging.Methods:We retrospectively identified 126 consecutive patients who underwent laparoscopic repair of a large paraesophageal hernia between 2000 and 2010. Clinical outcomes were reviewed, and data were collected regarding operative details, perioperative and postoperative complications, symptoms, and follow-up imaging. Radiologic evidence of any size hiatal hernia was considered to indicate a recurrence.Results:There were 95 female and 31 male patients with a mean age (± standard deviation) of 71 ± 14 years. Laparoscopic repair was completed successfully in 120 of 126 patients, with 6 operations converted to open procedures. Crural reinforcement with mesh was performed in 79% of patients, and 11% underwent a Collis gastroplasty. Fundoplications were performed in 90% of patients: Nissen (112), Dor (1), and Toupet (1). Radiographic surveillance, obtained at a mean time interval of 23 months postoperatively, was available in 89 of 126 patients (71%). Radiographic evidence of a recurrence was present in 19 patients (21%). Reoperation was necessary in 6 patients (5%): 5 for symptomatic recurrence (4%) and 1 for dysphagia (1%). The median length of stay was 4 days.Conclusion:Laparoscopic paraesophageal hernia repair results in an excellent outcome with a short length of stay when performed at an experienced center. Radiologic recurrence is observed relatively frequently with routine surveillance; however, many of these recurrences are small, and few patients require correction of the recurrence. Furthermore, these small recurrent hernias are often asymptomatic and do not seem to be associated with the same risk of severe complications developing as the initial paraesophageal hernia.

The “Periscope” Technique Successfully Lengthens the Distal Landing Zone During TEVAR

We describe our early experience with the “periscope” technique to extend the distal landing zone and successfully treat distal thoracic pathology in patients with inadequate distal seal zones near the mesenteric vessels. Four consecutive patients with planned endovascular repair of complex TAA extending near mesenteric and renal arteries were reviewed. In the periscope configuration, which is similar to an upside-down snorkel/chimney approach, parallel stent grafts adjacent to the TEVAR device were placed into the mesenteric and renal vessels from the contralateral femoral approach. Six periscope grafts (4 SMA, 2 in solitary renal arteries) were utilized in four patients (mean age, 72 years). Mean aneurysm diameter was 69.5 mm (range, 59-85 mm), and the “periscope” configuration improved the distal seal zone from a diameter of 45 mm and length of 0 mm to a more appropriate landing zone of 33 mm diameter and 28 mm length. Technical success was 100% and all patients are alive at latest followup (mean, 15.1 months; range, 9-23). The only morbidity was reoperation for femoral access occlusion. Postoperative follow-up imaging revealed all six periscopes to be patent. One small type Ib and one type II endoleak have been observed without aneurysm sac enlargement. All aneurysms have regressed with mean sac change of -4.7 mm. In select high-risk patients opting for an all-endovascular approach of distal thoracic pathology, the “periscope” technique is successful in extending the landing zone into juxtamesenteric and juxtarenal anatomies to provide successful aneurysm exclusion. Long-term follow-up is obviously necessary to assess for continued protection from aneurysm rupture, but at this point it appears to be safe and effective until fenestrated/branched grafts become more widely available.

In situ laser fenestration during emergent thoracic endovascular aortic repair is an effective method for left subclavian artery revascularization

Retrograde laser fenestration of the left subclavian artery (LSA) during emergent thoracic endovascular aortic repair (TEVAR) uses a relatively simple intraoperative method of endograft modification to revascularize aortic branches for a variety of acute thoracic aortic pathologies. This study presents our expanded experience and midterm outcomes of TEVAR with laser fenestration to revascularize the LSA as an alternative to debranching. Patients who underwent TEVAR with LSA revascularization by laser graft fenestration from September 2009 through August 2012 were retrospectively reviewed. TEVAR was performed with deployment of a Dacron (DuPont, Wilmington, Del) endograft over the LSA orifice. Laser catheter fenestration of the graft was performed through retrograde brachial access, followed by balloon-expandable covered stent deployment through the fenestration to traverse the endograft and LSA. Routine postoperative follow-up imaging with computed tomography angiography was performed to assess TEVAR and LSA fenestration patency, endoleak, and aneurysm/dissection exclusion. TEVAR with laser fenestration was successfully performed in 22 patients (12 men; mean age, 57 years) in an urgent or emergent setting secondary to unremitting symptoms or rupture. Twelve patients had large symptomatic thoracic aortic aneurysms (eight secondary to chronic dissection); four patients had acute symptomatic type B aortic dissection, and six patients had an intramural hematoma or penetrating aortic ulcer, or both. An average of two endografts (range, 1-4) were deployed. LSA-covered stents were 8 to 10 mm in diameter. Mean operative time was 154± 65 minutes. Average hospital length of stay was 12± 7 days. No major fenestration-related complications occurred. One patient developed postoperative paraplegia. One patient died in the postoperative period, for an in-hospital mortality rate of 4.5%. Two patients died of non-TEVAR-related causes at a mean follow-up of 10 months (range, 1-40 months). Follow-up computed tomography angiography imaging demonstrated a 100% primary patency for the LSA stents. One patient had an asymptomatic LSA stent stenosis. Type II endoleaks from the LSA in two patients required endovascular coil embolization. No fenestration-related type I or III endoleaks were noted. In situ retrograde laser fenestration is a feasible and effective option for LSA revascularization during TEVAR involving a spectrum of acute thoracic aortic pathology. Laser fenestration provides a rapid, reproducible method of fenestrating the endograft material. The high technical success, low fenestration-related morbidity, and excellent midterm patency support this technique of intraoperative endograft modification.

In Situ Laser Fenestration During Thoracic Endovascular Aortic Repair Is an Effective Method for Left Subclavian Artery Revascularization

We have previously described our early experience using retrograde laser fenestration to revascularize the left subclavian artery (LSA) during zone II thoracic endovascular aortic repair (TEVAR). This technique uses a relatively simple intraoperative method of endograft modification to revascularize aortic branches for a variety of acute thoracic aortic pathologies. The aim of this study is to present our expanded experience and midterm outcomes of TEVAR with laser fenestration to revascularize the LSA as an alternative to debranching. A retrospective review of the electronic medical records was conducted of all patients who underwent TEVAR with LSA revascularization via laser graft fenestration from September 2009 through August 2012. TEVAR was carried out with deployment of a Dacron endograft over the orifice of the LSA. Through retrograde brachial access, a 0.018-inch guidewire was placed at the ostium of the LSA, followed by laser catheter fenestration of the graft. Balloon-expandable covered stents were deployed through the fenestration to traverse the endograft and LSA; the endograft portion of the covered stent was flared. Routine postoperative follow-up imaging with computed tomography angiography was performed to assess for TEVAR and LSA fenestration patency, endoleak, and aneurysm/dissection exclusion. TEVAR with laser fenestration was successfully performed in 22 patients (12 men; mean age, 57 years; range, 37-83 years) in an urgent or emergency setting secondary to unremitting symptoms. Thirteen patients had large symptomatic thoracic aortic aneurysms (10 secondary to chronic dissection); four patients had acute symptomatic type B aortic dissection, and five patients had intramural hematoma or penetrating aortic ulcer. An average of two endografts (range, 1-4) were placed during TEVAR. LSA-covered stents ranged from 8 to 10 mm in diameter. Mean operative time for TEVAR with laser fenestration was 154 ± 65 minutes. The average hospital length of stay was 12 ± 7 days. There were no fenestration-related complications. One patient developed postoperative paraplegia, and one patient died of massive hemoptysis in the postoperative period, for an in-hospital mortality rate of 4.5%. At a mean follow-up of 8 months (range, 1-32 months), two patients had died (9%) of non–TEVAR-related causes. Follow up computed tomography angiography imaging demonstrated a 100% primary patency for the LSA stents. One patient had an asymptomatic LSA stent stenosis. Two patients had type II endoleaks from the LSA that required reintervention. Both were successfully managed with endovascular coil embolization. There were no fenestration-related type I or III endoleaks. In situ retrograde laser fenestration is a feasible and effective option for LSA revascularization during TEVAR involving a spectrum of acute thoracic aortic pathologies. Laser fenestration provides a rapid, reproducible method of fenestrating the endograft material. The high technical success, low fenestration-related morbidity, and excellent midterm patency support this technique of intraoperative endograft modification. Longer follow-up remains necessary to determine the durability of this technique.

Extracranial–intracranial (EC–IC) bypass of symptomatic middle cerebral artery (MCA) total occlusion for haemodynamic impairment patients

A retrospective, single-centre, non-randomized study in the management of symptomatic middle cerebral artery (MCA) total occlusion disease to evaluate extracranial–intracranial (EC–IC) bypass as an intervention for patients with atherosclerotic MCA total occlusion, ischemic symptoms (transient ischemic attacks [TIAs]) or poor cerebral haemodynamics who had not responded well to maximal medical treatment was reported. Twenty-three patients were included in the study with the criteria of: having ischemic syndrome, for example, TIA; being associated with atherosclerotic MCA total occlusion disease (compatible with radiological assessment); being failed to respond to optimal medical therapy (e.g. antiplatelet therapy), indicating a repeat TIA or ischemic stroke attack was noted during maximal medical therapy; having poor cerebral perfusion on CT imaging; and having regional cerebrovascular reactivity (rCVR) of <20% when acetazolamide challenge was undergone. Patients had acute ischemic stroke or other major medical co-morbidities were excluded. No patient experienced any recurrent ischemic stroke during a mean follow-up period of 26.5 months except one patient suffered of immediate post-operative ischemic stroke because of the temporal vessel being clipped too long and the hypotension caused by anaesthesia. Post-operative follow-up imaging, which included MRI (MR angiography) and four-vessel digital subtraction angiography revealed a 100% patency of superficial temporal artery–middle cerebral artery (STA–MCA) anastomosis. No significant differences between observation periods (baseline status: 5.46 ± 5.13/85 ± 15; 0.5 month after surgery: 5.18 ± 5.29/85.91 ± 15.46 and 3 months after surgery: 5.09 ± 4.75/85.36 ± 12.27) were found for the neurological evaluations of NIHSS and Barthel Index (both expressed in mean ± SD) in all of the 23 patients. The annual risk of recurrent stroke was 0% after EC–IC bypass. However, studies with a larger scale are warranted to further confirm the effectiveness of EC–IC bypass.

Preuntethering and Postuntethering Courses of Syringomyelia Associated With Tethered Spinal Cord

There has been controversy regarding the management of syringomyelia associated with tethered spinal cord. Previous reports on the topic have included only a small number of patients, considered open/closed spinal dysraphism together, or had a short follow-up. To review a uniform group of patients with syringomyelia associated with tethered cord and treated mainly by untethering alone. Of the 135 patients operated on for closed spinal dysraphism between 2003 and 2008, 33 patients with preoperative syringomyelia were identified. The preoperative/postoperative clinical data and syrinx index (ratio of the syrinx area and the cord area) were retrospectively reviewed. The syrinx index of each patient was plotted as an individual graph to outline the temporal change of the syrinx before and after untethering surgery. Five patients showed symptom progression during the preoperative period, and 4 of the 5 had an additional magnetic resonance imaging before the operation that showed progression of the syringomyelia. Postoperatively, 31 of 32 patients (97%) who underwent postoperative follow-up imaging showed long-term stability or a decrease in the syrinx index. Four symptomatically stable patients showed a transient increase in the syrinx index during the initial postoperative 6 months, which later decreased spontaneously. In 1 patient with retethering, the syrinx index increased 6 months before the onset of new urinary symptoms. Untethering alone may be sufficient for the management of syringomyelia associated with tethered cord. A transient increase in the syrinx index during the initial postoperative period may be observed without additional surgery if patients are symptomatically stable.

Nodular enhancement within the internal auditory canal following retrosigmoid vestibular schwannoma resection: a unique radiological pattern

The authors describe the unique occurrence of nodular enhancement within the fundus of the internal auditory canal (IAC) lateral to the preoperative radiological tumor margin following gross-total vestibular schwannoma (VS) resection. The nature of the study was a retrospective chart review of records. The authors reviewed the cases of all patients who underwent microsurgical resection of a VS between January 2000 and January 2010 at a single tertiary referral center. Patients with incomplete resection, neurofibromatosis Type 2, and those with fewer than 2 postoperative MR images available for review were excluded. Postsurgical patients with IAC enhancement located lateral to the preoperative imaging-delineated tumor margin were identified. Lesion morphology was characterized on serial MR imaging studies. Clinical follow-up and outcomes were recorded. Over the past decade, 350 patients underwent microsurgical VS resection. Of these, 16 patients met study criteria and were found to have postsurgical enhancement in the distal aspect of the IAC lateral to the imaging limits of the preoperative tumor margin on the first postoperative MR imaging study (37.5% women, median age 45 years). Initial MR imaging was performed at a mean of 3.1 months following surgery, and the mean radiological follow-up duration was 39.8 months (range 16.4-101.9 months). None of the 16 patients developed recurrence during the follow-up course. In contrast to previous publications that have reported a high rate of recurrence in cases involving nodular enhancement within the original tumor bed, postoperative enhancement in the IAC lateral to the original tumor margin appears to carry much less risk for tumor recurrence. These findings may be helpful when counseling patients on the recommended frequency of postoperative follow-up imaging.

Intraluminal Chondrosarcoma Leading to Occlusion of the Brachiocephalic Trunk

A 62-year-old female patient was admitted with temporary neurological symptoms. CT scan revealed occlusion of the brachiocephalic trunk by an intraluminal mass suspicious for a thrombus and extending into the ascending aorta. The patient underwent aortic arch replacement with reinsertion of the supraaortic vessels. A 5 × 3 × 4 cm large mass was found in the aorta which had obviously caused occlusion of the brachiocephalic trunk. The patient had an uneventful postoperative recovery and follow-up imaging showed no pathological findings. Histopathological examination revealed inhomogeneous chondroid tissue such as that found in a G2 grade bone chondrosarcoma.

MR Neurography of Neuromas Related to Nerve Injury and Entrapment with Surgical Correlation

MR imaging of peripheral nerves has been described in relation to abnormalities such as nerve injury, entrapment, and neoplasm. Neuroma formation is a known response to peripheral nerve injury, and here we correlate the MRN appearance of postinjury neuroma formation with intraoperative findings. We also present the MR imaging features of surgical treatment with a synthetic nerve tube and nerve wrap on postoperative follow-up imaging.

MRI‐guided brain tumor cryoablation in a rabbit model

To report the results of an animal trial exploring the feasibility of minimally invasive MR imaging-guided rabbit brain tumor cryoablation with an argon-based cryo-unit. VX2 tumor segments (0.96x0.96x50 mm) were implanted into parietal lobes of 26 New Zealand white rabbits. Seventeen rabbits were treated with cryoablation. Six rabbits were not treated and formed a control group. Cryoablation was achieved with a MR-compatible cryoablation unit using 1.47-mm cryoprobes in an open 0.23 Tesla (T) MRI scanner. The therapeutic response was evaluated with follow-up MRI and the corresponding histopathology. A 3.0 T MRI scanner was used for preoperative and postoperative follow-up imaging. Posttreatment imaging with subsequent endpoints was performed at 3, 7, 14, and 60 days after the treatment. Of 17 rabbits, 6 died on the first postoperative day. Histopathology revealed coagulation necrosis in samples from the 3rd, 7th, and 14th day, and reactive changes at 60 days, these findings were consistent with MRI. The longest survival time in the treatment group, 60 days (n=2), was considerably longer than the survival times in control group. Successful rabbit brain tumor cryoablation can be achieved using argon-based cryodevice under MRI guidance. The complication rate in this series was relatively high.

Computerized Tomography Guided Percutaneous Renal Cryoablation With the Patient Under Conscious Sedation: Initial Clinical Experience

We report on our initial clinical experience with CT guided percutaneous renal cryoablation. CT guided percutaneous renal cryoablation was performed on 27 tumors using conscious sedation in 20 patients. Eligible patients had tumors of 5 cm or less and were poor surgical candidates or otherwise warranted nephron sparing treatment. Tumors were classified as central or noncentral depending on their relationship to the renal sinus fat. During cryoablation intraoperative active ice ball formation was monitored with real-time CT imaging to ensure adequate tumor coverage. Postoperative followup imaging was obtained at regular intervals. Our method appears technically feasible as of the 27 cryoablations performed, only 1 complication occurred requiring blood transfusion in a patient with a large, centrally located tumor. To date we have 16 tumors in 12 patients with imaging followup of 1 month or more (mean followup 5.9 months). Mean baseline tumor size in this group was 2.5 cm with 11 small (3 cm or less) and 5 large (more than 3 cm) tumors. Of the tumors 5 were centrally located and 11 were noncentrally located. Preliminary data suggest that of the 16 cryoablated tumors 15 showed no signs of enhancement on followup. CT guided percutaneous renal cryoablation appears to be a feasible treatment option for small, noncentrally located renal tumors. While early results appear promising, longer followup is needed to more clearly define the role of this treatment method.

Mammary fibromatosis mimicking recurrent breast cancer: radiological findings

Sir: A 61-year-old female was diagnosed with invasive ductal carcinoma in the left breast in February 2000. She underwent left wide local excision and axillary nodal dissection. Lymphnodes were negative for metastases. The patient received chemotherapy as well as radiotherapy to the preserved left breast. She was under postoperative imaging follow-up. Bilateral mammography in March 2001 revealed a spiculated density without calcifications under the surgical scar of the left breast that correlated with post-surgical changes. Suspect breast lesions were not found on clinical examination. The mammogram performed in February 2002 showed the same findings but the density in the left breast seemed to increase in size. The sonography showed a solid mass with irregular margins and anechoic nodules in a postsurgical breast, but although fat necrosis was suggested, periodic mammographic follow-up of this probably benign lesion was performed. The last mammography (Fig. 1) showed again an increase in size of the density suspected of local recurrence. The magnetic resonance imaging (MRI) (Fig. 2) revealed postoperative scarring in the left breast and there were findings compatible with early tumor recurrence after conservative surgery, so surgical excision was performed. Histopathologically the tumor was fibromatosis of the breast and there was no evidence of malignancy (Fig. 3). Mammary fibromatosis is an uncommon benign lesion that clinically and radiologically may simulate breast cancer [1–5]. This unusual lesion has been presented in literature as a diagnostic challenge in a few cases series, describing its clinical, radiological and pathological features, but we did not find any report of fibromatosis of the breast after conservative cancer treatment simulating recurrent carcinoma. This lesion is included as a variant of spindle cell tumor of the breast, which can result in a wide spectrum of