Retrospective analysis of patients for development of nephrogenic systemic fibrosis following conventional angiography using gadolinium-based contrast agents.

PURPOSE: The purpose was to retrospectively review the data of 27 patients with renal insufficiency who underwent conventional angiography with gadolinium-based contrast agents (GDBCA) as alternative contrast agents and assess the occurrence of nephrogenic systemic fibrosis (NSF) together with associated potential risk factors. METHODS: This HIPAA-compliant study had institutional review board approval, and informed consent was waived. Statistical analysis was performed for all available laboratory and clinical data, including dermatology reports. Type and amount of the GDBCA used were recorded for angiography and additional MRI studies, if applicable. Serum creatinine levels (SCr) pre- and post-angiography were recorded, and estimated glomerular filtration rates (eGFR) were calculated. RESULTS: Ten female and 17 male patients who underwent angiography with GDBCA were included. The mean amount of GDBCA administered was 44 +/- 15.5 ml (range 15-60 ml) or 0.24 + 0.12 mmol/kg (range 0.1-0.53 mmol/kg). At the time of angiography all patients had renal insufficiency (eGFR <60 ml/min/1.73 m(2)). Mean eGFR pre-angiography was 26 ml/min/1.73 m(2) and 33 ml/min/1.73 m(2) post-angiography. The mean follow-up period covers 28 months, range 1-84 months. Additional MRI studies with GDBCA administration were performed in 15 patients. One patient with typical skin lesions had developed biopsy-confirmed NSF. CONCLUSION: Conventional arterial angiography with GDBCA may play a role in the development of NSF in patients with renal insufficiency. Alternative contrast agents, such as CO(2) angiography or rather the use of low doses of iodinated contrast agents, should be considered in these patients.

Decision making in patients with acute abdominal pain at a university and at a rural hospital: does the value of abdominal sonography differ?

INTRODUCTION AND OBJECTIVES: Abdominal sonography is regarded as a quick and effective diagnostic tool for acute abdominal pain in emergency medicine. However, final diagnosis is usually based on a combination of various clinical examinations and radiography. The role of sonography in the decision making process at a hospital with advanced imaging capabilities versus a hospital with limited imaging capabilities but more experienced clinicians is unclear.The aim of this pilot study was to assess the relative importance of sonography and its influence on the clinical management of acute abdominal pain, at two Swiss hospitals, a university hospital (UH) and a rural hospital (RH). METHODS: 161 patients were prospectively examined clinically. Blood tests and sonography were performed in all patients. Patients younger than 18 years and patients with trauma were excluded. In both hospitals, the diagnosis before and after ultrasonography was registered in a protocol. Certainty of the diagnosis was expressed on a scale from 0% to 100%.The decision processes used to manage patients before and after they underwent sonography were compared. The diagnosis at discharge was compared to the diagnosis 2 - 6 weeks thereafter. RESULTS: Sensitivity, specificity and accuracy of sonography were high: 94%, 88% and 91%, respectively.At the UH, management after sonography changed in only 14% of cases, compared to 27% at the RH. Additional tests were more frequently added at the UH (30%) than at the RH (18%), but had no influence on the decision making process-whether to operate or not. At the UH, the diagnosis was missed in one (1%) patient, but in three (5%) patients at the RH. No significant difference was found between the two hospitals in frequency of management changes due to sonography or in the correctness of the diagnosis. CONCLUSION: Knowing that sonography has high sensitivity, specificity and accuracy in the diagnosis of acute abdominal pain, one would assume it would be an important diagnostic tool, particularly at the RH, where tests/imaging studies are rare.However, our pilot study indicates that sonography provides important diagnostic information in only a minority of patients with acute abdominal pain.Sonography was more important at the rural hospital than at the university hospital. Further costly examinations are generally ordered for verification, but these additional tests change the final treatment plan in very few patients.

Optimization of MDCT of the wrist to achieve diagnostic image quality with minimum radiation exposure.

OBJECTIVE: This study tests various acquisition and reconstruction protocols for MDCT of the wrist to determine the optimal protocol for obtaining diagnostic image quality with minimal radiation exposure. MATERIALS AND METHODS: Thirty anatomic specimens were examined with an MDCT collimation of 4.0 x 1.0 mm and 2.0 x 0.5 mm (80, 120, and 140 kV; 80, 100, 130, 160, and 200 mA; rotation time, 0.5 0.75, 1.0 sec; pitch, 1.0, 1.3, 1.5, and 2.0). Coronal images were reconstructed using a slice thickness of 0.5, 1.0, and 2.0 mm with 60% overlap. Three observers evaluated all images independently for gross and fine anatomic detail. Diagnostic confidence was tested using Shrout-Fleiss intraclass correlation coefficients. Interobserver agreement was assessed by Kappa statistics and the Kruskal-Wallis test. RESULTS: Fine anatomic detail was best presented in 0.5-mm or 1.00-mm reconstructions based on a 2.0 x 0.5 mm acquisition. A rotation time of > or = 0.75 sec resulted in fewer artifacts; a significant dose reduction was achieved with 80 kV and 100 mA at the expense of somewhat increased noise, but without significant loss of anatomic detail in bone presentation. Artifacts were tolerable with a pitch of 1.5 or less. CONCLUSION: MDCT at the described optimal settings allows significant dosage reduction without sacrificing image quality. An acquisition and reconstruction thickness of 0.5 mm results in the best depiction of anatomic detail. A reconstruction thickness of 1.0 mm with a reconstruction interval of 0.5 mm represents a good trade-off between noise and resolution when using low-dose protocols.

Importance of extracolonic findings at IV contrast medium-enhanced CT colonography versus those at non-enhanced CT colonography.

To compare the clinical importance of extracolonic findings at intravenous (IV) contrast-enhanced CT colonography versus those at non-enhanced CT colonography. IV contrast medium-enhanced (n=72) and non-enhanced (n=30) multidetector CT colonography was performed in 102 symptomatic patients followed by conventional colonoscopy on the same day. The impact of extracolonic findings on further work up and treatment was assessed by a review of patient records. Extracolonic findings were divided into two groups: either leading to further work up respectively having an impact on therapy or not. A total of 303 extracolonic findings were detected. Of those, 71% (215/303) were found on IV contrast-enhanced CT, and 29% (88/303) were found on non-enhanced CT colonography. The extracolonic findings in 25% (26/102) of all patients led to further work up or had an impact on therapy. Twenty-two of these patients underwent CT colonography with IV contrast enhancement, and four without. The percentage of extracolonic findings leading to further work up or having an impact on therapy was higher for IV contrast-enhanced (31%; 22/72) than for non-enhanced (13%; 4/30) CT scans (P=0.12). IV contrast-enhanced CT colonography produced more extracolonic findings than non-enhanced CT colonography. A substantially greater proportion of findings on IV contrast-enhanced CT colonography led to further work up and treatment than did non-enhanced CT colonography.

Multidetector CT angiography versus digital subtraction angiography for aortoiliac length measurements prior to endovascular AAA repair.

PURPOSE: To assess observer variation between calibrated-catheter digital subtraction angiography (DSA) and software-enhanced multidetector computed tomography angiography (CTA) in measuring vessel length prior to endovascular aortic aneurysm repair (EVAR). METHODS: Thirty patients (25 men; mean age 65 years, range 61-85) scheduled for EVAR underwent CTA in 4x2-mm collimation using advanced vessel analysis software. CTA measurements were performed twice by 2 blinded readers in random order with at least a 4-week interval between readings. Nine patients were found unsuitable for endovascular repair after the CTA, so DSA was performed in 21 patients for morphometric evaluation of the abdominal aorta and the iliac arteries. The following segments were measured: H1 (aneurysm neck), H2 (lower renal artery to distal aspect of the aneurysm), H3 (lower renal artery to aortic bifurcation), and H4a/H4b (lower renal artery to iliac bifurcations). Length measurements on DSA were made by (1) following the catheter path in the aortic lumen and (2) dividing tortuous vessel anatomy into segments and measuring each segment along an idealized centerline. Addition of the various segments allowed comparison with data obtained from CTA measurements. RESULTS: CTA was performed with good intraobserver agreement for all length parameters except H3 in reader 2 (p<0.05). While good interobserver agreement was demonstrated for CTA over long aortoiliac distances (H4a, H4b), higher interobserver agreement was obtained with DSA for shorter segments (H1, H2). Considerable differences were observed between CTA and DSA for the lengths H2 and H4b. CONCLUSIONS: CTA produces better intra and interobserver correlations in measuring vessel length than DSA. It has the potential to replace DSA as an imaging method before EVAR.

Combined surgical and endovascular approach to treat a complex aortic coarctation without extracorporeal circulation.

Various therapeutic approaches have been proposed to treat complex coarctation of the aorta (eg, recoarctation, which requires repetitive interventions, or coarctation with a hypoplastic aortic arch). Resection followed by end-to-end anastomosis or by graft interposition is technically demanding and exposes the patient to considerable perioperative risks. Cardiopulmonary bypass and deep hypothermic circulatory arrest may be necessary to control the distal aortic arch. The role of stent technology in treating this type of lesion has not yet been defined. We present a 21-year-old woman with a recurrent coarctation of the aorta associated with a hypoplastic aortic arch and a pseudoaneurysm of the proximal descending aorta. She had undergone 4 previous interventions. Treatment consisted of a combined surgical and endovascular approach without cardiopulmonary bypass and included extraanatomic aortic bypass, partial debranching of the supraaortic vessels, and stent-graft insertion to exclude the aneurysm.

Prospective comparison of contrast enhanced CT colonography and conventional colonoscopy for detection of colorectal neoplasms in a single institutional study using second-look colonoscopy with discrepant results.

BACKGROUND: Colorectal cancer is the second leading cause of death from cancer in Western countries. Early detection by colorectal cancer screening can effectively cut its mortality rate. CT colonography represents a promising, minimally invasive alternative to conventional methods of colorectal carcinoma screening. AIMS: The purpose of this prospective single institutional study was to compare the abilities of routine clinical CT colonography and conventional colonoscopy to detect colorectal neoplasms using second-look colonoscopy to clarify discrepant results. PATIENTS AND METHODS: CT colonography was performed in 100 symptomatic patients using contrast enhanced multidetector CT followed by conventional colonoscopy on the same day. If results were discrepant, a second-look colonoscopy was performed after unblinding. CT colonographic findings were compared with those of conventional colonoscopy. RESULTS: Conventional colonoscopy found 122 colorectal neoplasms in 49 patients. The overall sensitivity of CT colonography at detecting patients with at least one polyp 6 mm or larger was 76% and its specificity was 88%. Its by-patient sensitivity for polyps 10 mm or larger was 95% and its specificity was 98%. By-polyp sensitivities were 71% for polyps 10 mm or larger, and 61% for polyps 6 mm or larger. A second-look colonoscopy was performed in 19 patients and two initial false-positive findings of CT colonography were reclassified as true-positive. For conventional colonoscopy, this produced a by-polyp sensitivity of 94% for detection of lesions 6 mm and larger. CONCLUSIONS: CT colonography had both a high by-patient sensitivity and specificity for detection of clinically important colorectal neoplasms 10 mm or larger. This suggests that CT colonography has the potential to become a valuable clinical screening method for colorectal neoplasms.

Virtual colon dissection with CT colonography compared with axial interpretation and conventional colonoscopy: preliminary results.

OBJECTIVE: The aim of this study was to determine whether a new virtual colon dissection 3D visualization technique for CT colonography has a shorter analysis time and better sensitivity for detection of colonic polyps than interpretation of axial CT images. SUBJECTS AND METHODS. CT colonography was performed in 22 patients using 4-MDCT followed by conventional colonoscopy on the same day. The CT colonography data sets were analyzed by virtual colon dissection, which virtually bisects and unfolds the colon along its longitudinal axis to inspect the inner colonic surface for polyps. The same CT data sets were independently evaluated using axial interpretation. All data sets were independently interpreted by two radiologists in a blinded manner. RESULTS: Conventional colonoscopy revealed 31 colonic lesions in 20 patients. Twenty two of the lesions were smaller than 10 mm; nine were 10 mm or larger. Two of the original 22 patients were excluded, one because of residual stool and fluid and the other because of an impassable stenosing rectal wall cancer. For virtual colon dissection, the per-lesion sensitivity was 42% for observer 1 and 68% for observer 2; for axial interpretation, the respective sensitivities were 48% and 61%. For polyps 10 mm or larger, the respective sensitivities were 67% and 89% for virtual colon dissection and 89% and 100% for axial interpretation. The average time for reconstruction and analysis of virtual colon dissection was 36.8 min versus 29.2 min for axial images. Virtual colon dissection was feasible in both the supine and the prone positions in 45.5% of colonic segments, in either the supine or the prone position in 24.5%, and in neither position in 30% of segments. CONCLUSION: Although virtual colon dissection may facilitate detection of colonic polyps in isolated cases, its detection rate is not superior to axial interpretation, which is mainly attributable to failed rendering of insufficiently distended colonic segments or regions with residual feces. Virtual colon dissection is also the more time-consuming of the two procedures. With further improvement of path-finding and image segmentation, however, virtual colon dissection has the potential to be a useful interpretation tool for CT colonography.

Grading airway stenosis down to the segmental level using virtual bronchoscopy.

OBJECTIVE: To assess the sensitivity of noninvasive virtual bronchoscopy based on multirow detector CT scanning in detecting and grading central and segmental airway stenosis using flexible bronchoscopic findings as the reference standard. MATERIALS AND METHODS: In a blinded controlled trial, multirow detector CT virtual bronchoscopy and flexible bronchoscopy were used to search for and grade airway stenosis in 20 patients. CT scan data were obtained with a multirow detector CT scanner using 4 x 1 mm collimation. Flexible bronchoscopy findings were graded by a pulmonologist and served as the reference standard for 176 central airway regions (ie, trachea, main bronchi, and lobar bronchi) and 302 segmental airway regions. The extent of airway narrowing was categorized as grade 0 (no narrowing), grade 1 (< 50%), or grade 2 (> or =50%). RESULTS: Flexible bronchoscopy revealed 30 stenoses in the central airways and 10 in the segmental airways. Virtual bronchoscopy detected 32 stenoses in the central airways (sensitivity, 90.0%; specificity, 96.6%; accuracy, 95.5%) and 22 in the segmental airways (sensitivity, 90.0%; specificity, 95.6%; accuracy, 95.5%). The number of false-positive findings was higher in the segmental airways (13 false-positive findings) than in the central airways (5 false-positive findings), which caused a lower positive predictive value for the segmental airways (40.9%) than for the central airways (84.4%). Flexible and virtual bronchoscopic gradings correlated better for central airway stenosis (r = 0.87) than for segmental airway stenosis (r = 0.61). CONCLUSION: Although a high sensitivity was found for the detection of both central and segmental airway stenosis, the number of false-positive findings was higher for segmental airways. However, noninvasive multirow detector CT virtual bronchoscopy enables high-resolution endoluminal imaging of the airways down to the segmental bronchi.

Endovascular treatment of malignant superior vena cava syndrome: is bilateral wallstent placement superior to unilateral placement?

PURPOSE: To report our experience with unilateral versus bilateral stent placement in the treatment of malignant superior vena cava syndrome (SVCS). METHODS: The records and films of 84 consecutive patients (69 men; mean age 64+/-10 years, range 39-79) referred for stent placement in malignant SVCS were reviewed for venous compromise, technical and clinical success, complications, and reocclusions. Wallstents were placed covering the SVC and both (bilateral technique) brachiocephalic veins (BCV) preferentially; unilateral stenting of only one BCV in addition to the SVC was performed based on operator preference or inability to access both sides. Technical success was defined as the ability to stent the SVC and at least one BCV; clinical success was the elimination of SVCS symptoms. RESULTS: Technical success was achieved in 83 (99%) patients, using the unilateral technique in 22 and bilateral stenting in 61 patients. The groups did not differ with regard to age, sex, underlying diseases, or location and extent of venous compromise. Immediate clinical success was achieved in 20 (91%) of 22 patients in the unilateral group and 55 (90%) of 61 patients in the bilateral group. Two patients suffered late occlusion in the unilateral group, while in the bilateral group, 8 patients had early occlusion and 9 had late occlusion. Thus, the total occlusion rate was significantly (p<0.05) lower in the unilateral group. There was 1 other complication (pericardial tamponade) in the bilateral group, for a 28% total complication rate, which was significantly higher (p=0.039) than the 9% in the unilateral group. The 1, 3, 6, and 12-month primary stent patency rates were 90%, 81%, 76%, and 69%, respectively. Patency tended to last longer in the unilateral group, but the difference was not significant (p=0.11). CONCLUSIONS: Although bilateral Wallstent placement achieved equal technical and clinical success, it tended to confer shorter-lived patency and caused more complications.

Percutaneous treatment of placenta percreta using coil embolization.

PURPOSE: To report the use of embolotherapy to avoid hysterectomy in rare placenta percreta. CASE REPORT: A pregnant 34-year-old woman (gravida 3, para 2) was admitted with premature rupture of membranes and vaginal bleeding in the 32nd week. Prenatal B-mode and Doppler ultrasound revealed marked hypervascularity of the placenta with disruption of the uterine-bladder interface consistent with placenta percreta. Since the patient insisted on uterine preservation, uterus and placenta were left in situ after caesarean section, which was followed by coaxial microcoil embolization of 6 pelvic arteries and postoperative methotrexate administration. Three months later, the patient had severe bleeding from the retained placenta, possibly under the influence of anticoagulation administered for pulmonary embolism. Emergent hysterectomy was performed. CONCLUSIONS: Coil embolization may avoid immediate hysterectomy and reduce peri-delivery blood loss in placenta percreta. However, retained placenta poses a serious risk, even after months, and secondary hysterectomy should be performed as an elective procedure after embolization.

Low-dose multislice CT of the thorax in follow-up of malignant lymphoma and extrapulmonary primary tumors.

Our objective was to study the impact of low-dose multislice thoracic CT on image quality and lesion conspicuity in follow-up of patients with malignant lymphoma and extrapulmonary primary tumors. Forty consecutive patients with a history of malignant lymphoma or extrapulmonary malignant primaries who had undergone previous standard-dose thoracic spiral CT (120 kVp, 150 mAs, 8 mm) were subjected to low-dose multislice CT (15 mAs/rotation, 120 kVp, pitch 1.5, 4x2-mm collimation reconstructed to contiguous 8-mm slices. Image quality and lesion conspicuity were classified independently by two readers on a four-point ordinal scale (1=poor, 4=excellent). Mean image quality was significantly lower for low-dose CT, 2.35, than for standard-dose CT, 3.25 ( p<0.001); however, all low-dose CT examinations were fully readable, none had to be repeated, and no lesions (including 51 lung lesions and 31 soft tissue lesions) remained undetected. Only in the apical lung did the lowered tube current significantly reduce lesion conspicuity. Even in pulmonary lesions smaller than 10 mm ( n=21) lesion conspicuity did not significantly differ between standard and low-dose scans. Low-dose thoracic multislice CT based on a 90% reduction in dose compared with standard-dose techniques was not associated with impaired detection of suspicious lesions and may be useful in follow-up of malignant lymphoma and extrapulmonary tumors.

Fatal pericardial tamponade after Wallstent implantation for malignant superior vena cava syndrome.

PURPOSE: To report a rare, fatal complication of superior vena cava Wallstent implantation. CASE REPORT: A 59-year-old man presenting with superior vena cava syndrome caused by small-cell lung cancer underwent stent implantation of 2 kissing Wallstents >1.5 cm above the right atrium. Despite correct stent deployment, vessel perforation occurred in a section not encased by tumor, which led to fatal pericardial tamponade shortly after the procedure. Autopsy revealed perforation of a stent strut through the caval wall into the pericardial space. Anatomical and methodological reasons are discussed. CONCLUSIONS: The interventionist should be aware of this rare complication. Alternative stent designs avoiding the sharp ends of Wallstents and Palmaz stents should be considered.

Accidental small bowel perforation after antegrade femoral artery access for percutaneous thromboembolectomy and angioplasty.

PURPOSE: To report a rare complication of antegrade femoral access for percutaneous aspiration thromboembolectomy and transluminal angioplasty. CASE REPORT: A 73-year-old obese woman underwent antegrade femoral aspiration thromboembolectomy for lower limb arterial embolism. Fifteen hours later, she presented with acute abdomen and decreased hemoglobin. Computed tomography showed small bowel obstruction, incarcerated femoral hernia, and free peritoneal air and fluid suggesting bowel perforation. Emergent laparotomy revealed an incarcerated, perforated femoral bowel loop and 4-quadrant peritonitis. CONCLUSIONS: Femoral hernia injury is an exceptional complication of vascular interventions. Knowledge of this potential hazard may help to avoid its occurrence.

Endovascular aneurysm exclusion along a femorodistal venous bypass in active Behçet's disease.

PURPOSE: To report the endovascular repair of dual aneurysms along a femorodistal venous bypass graft in a patient with Behçet's disease. CASE REPORT: A 55-year-old man of middle European ancestry with Behçet's disease had dual aneurysms evolve along the proximal segment of a femorodistal venous bypass that had been implanted 2.5 years earlier for recurrent false aneurysm formation. Owing to the lack of suitable venous conduits and the active nature of the disease, the aneurysms were successfully excluded with overlapping Hemobahn and Jostent endografts; the immunosuppressive therapy was intensified. Rupture of the aneurysms was successfully prevented, but the stent-grafts thrombosed 6 weeks later owing to exacerbation of the underlying disease. CONCLUSIONS: Endovascular exclusion of aneurysm in venous bypass grafts in Behçet's disease is feasible. Although the stent-grafts thrombosed, they did prevent rupture of the aneurysms.

Subtotal colectomy with primary ileorectostomy is effective for unlocalized, diverticular hemorrhage.

BACKGROUND: A large proportion of patients with acute colonic diverticular bleeding undergo emergency surgery without successful prior localization of the bleeding site. This study sought to determine the surgical techniques of choice for unlocalized, diverticular hemorrhage. METHODS: We reviewed the data on 42 consecutive patients (median age 76 years, range 44-91) with acute colonic diverticular bleeding operated on between November 1993 and December 2000. Mean follow-up was 4.1 years. RESULTS: Preoperative localization of the bleeding site was possible in six patients (14%), by colonoscopy in two and by angiography in four. Ten patients underwent segmental colectomy with primary anastomosis (5 "directed", 5 "blind") and 32 subtotal colectomy with primary ileorectostomy (1 "directed", 31 "blind"). Subtotal colectomy is the more extensive surgical procedure (longer resected bowel, greater blood loss), and although it was performed in older patients, there were no significant differences between segmental and subtotal colectomy with respect to operation time, morbidity, mortality, hospital stay, number of bowel movements, continence scores, rebleeding rate, or patient satisfaction. CONCLUSIONS: Subtotal colectomy with primary ileorectostomy for unlocalized colonic diverticular bleeding is a safe and effective surgical procedure providing complete bleeding control and preserving continence.

Complex, traumatic rupture of the thoracic aorta in a child: diagnostic findings and delayed surgery.

We report the unusual case of a 4-year-old girl with traumatic aortic rupture. A conventional chest X-ray showed an enlarged mediastinum. Spiral CT and transthoracic echocardiography demonstrated a mediastinal hematoma, bilateral pleural effusion, and a rupture of the aortic arch. Semi-elective surgery, 4 days after the accident, confirmed rupture of the aortic arch with dislocation of the left carotid artery and the Ductus of Botalli. The vessels were subsequently repaired without complication. After a follow-up of 10 months, the child has fully recovered.