G. Lechner

Embolization of Bone Metastases

PURPOSE To assess the effectiveness and clinical usefulness of transcatheter embolization of bone metastases. PATIENTS AND METHODS The procedures and outcome of 61 transcatheter embolization procedures performed in 51 patients with hypervascular skeletal metastases were retrospectively evaluated. Results from computed tomography, magnetic resonance imaging, and diagnostic angiography, performed before and after embolization, were reviewed. RESULTS All embolizations were technically and clinically successful. Major blood loss during surgery was prevented in 32 cases; the size of viable tumor tissue in large, unresectable bone metastases was reduced before radiation or chemotherapy in 17 cases; and otherwise untreatable skeletal pain was decreased in 11 cases. Heavy bleeding from a metastasis was controlled in one case. The complications were temporary paresis of a lower extremity in three patients, cardiac arrest in one patients, and unintentional embolization of synthetic tissue adhesive in one patient. Median survival time was 28 months (range, 3-59 months). CONCLUSION Transcatheter embolization is effective and reliable in the treatment of bone metastases.

Improved detection of renal pathologic features on multiphasic helical CT compared with IVU in patients presenting with microscopic hematuria.

OBJECTIVES To examine the virtues of multiphasic helical computed tomography (CT) in the diagnosis of upper urinary tract lesions refractory to identification by intravenous urography (IVU). METHODS A total of 86 patients (59 men and 27 women), 27 to 88 years old, with microscopic hematuria and negative IVU findings were examined with multiphasic helical CT consisting of a pre-enhancement, late arterial-early cortical-medullary, nephrographic, and excretory phase helical CT of the kidneys, using 3 to 5-mm collimation and 7.5-mm/s table feed. RESULTS The multiphasic helical CT was conclusive in 84 lesions. Twenty-five cases of early papillary and medullary necrosis, 7 of 8 inflammatory lesions, 3 caliceal diverticula, 1 lupus nephritis, 26 small calculi, 2 medullary sponge kidney, 5 vascular anomalies, and 3 infarcts presented with characteristic manifestations on CT but lacked findings on IVU. Similarly 8 of 9 small malignant neoplasms, 2 small benign neoplasms, and 2 small cysts produced no detectable findings on IVU but were readily diagnosed on helical CT. CONCLUSIONS Characteristic findings, particularly on late arterial, early corticomedullary, parenchymal, and excretory phase helical CT make possible the diagnosis of early inflammatory disease, small masses and neoplastic lesions, and vascular abnormalities. Limited resolution (needed to identify small calculi) and the lack of ability to capture phases significantly reduce the diagnostic ability of IVU.

How accurate is MR imaging in characterisation of adrenal masses: update of a long-term study

OBJECTIVE The purpose of this study was to update a long-term study that evaluates the accuracy of MR imaging in the characterisation of adrenal tumours. In all patients, MR imaging findings were correlated with histopathologic results. PATIENTS In 204/560 patients who underwent MR imaging for characterisation of an adrenal mass, histopathologic results were available. The final study group consisted of 229 adrenal masses in 204 patients. MR imaging was performed using T2-weighted fast spin-echo imaging and unenhanced and gadolinium-enhanced T1-weighted spin-echo imaging in all patients. In addition, chemical shift imaging was performed in 182 patients and dynamic gadolinium-enhanced studies in 198 patients. Chemical shift images and dynamic studies were qualitatively assessed. All images were reviewed by an experienced investigator (Gertraud Heinz-Peer) who was blinded to the clinical history and the results of prior imaging studies. RESULTS The sensitivity of MR imaging for the differentiation of benign and malignant adrenal masses was 89%, the specificity 99%, and the accuracy was 93.9%. This results in a positive predictive value (PPV) of 90.9% and a negative predictive value (NPV) of 94.2%. These results are comparable to the data published previously by our study group with a lower number of cases. CONCLUSION Large study numbers show that MR imaging is a reliable method in characterisation of benign and malignant adrenal masses. Since laparoscopic adrenalectomy has become the new gold standard in the surgical treatment of benign adrenal lesions, the high accuracy of MR imaging in characterisation of those lesions offers even patients with large adrenal masses (>5 cm) the advantages of the minimally invasive technique.

Detection of focal hepatic lesions: comparison of unenhanced and SHU 555 A-enhanced MR imaging versus biphasic helical CTAP.

The purpose of this study was to compare the diagnostic sensitivity of unenhanced magnetic resonance (MR) imaging, and MR imaging with a new superparamagnetic iron oxide (SPIO)‐enhanced contrast agent (SHU 555 A) with biphasic helical computed tomography during arterial portography (CTAP) in patients with focal liver lesions. Eighteen patients with a total of 91 (78 malignant, 13 benign) proven liver lesions underwent unenhanced short tau inversion recovery (STIR), T2‐weighted (T2‐w) TSE, and SHU 555 A‐enhanced T2‐w turbo spin‐echo (TSE) MR imaging and biphasic helical CTAP. The standard of reference was histopathologic analysis of resected specimens in 59 lesions, intraoperative ultrasound with biopsy in 20 lesions, and CT‐guided biopsy and follow‐up in 12 lesions. Diagnostic performance of the imaging modalities was compared quantitatively and qualitatively by assessing lesion involvement in liver segments. There were 68 lesions detected on unenhanced T2‐w TSE, which resulted in a sensitivity of 75%. With the STIR sequence, 76 lesions were detected, for a sensitivity of 84%, and with SHU 555 A‐enhanced MRI, 84 lesions were detected, for a sensitivity of 92%. CTAP detected 88 lesions, for a sensitivity of 97%. The accuracy for unenhanced T2‐w TSE was 98%, for STIR 99%, for enhanced‐MRI 100%, and for CTAP 95%. The specificity was 100% for SHU 555 A‐enhanced MRI and 95% for CTAP. SHU 555 A‐enhanced MRI was superior to nonenhanced MRI (P < 0.05) and equivalent to CTAP in terms of sensitivity. Due to the absence of false‐positive results on SHU 555 A‐enhanced MRI, the specificity and accuracy of enhanced MRI were higher than those of CTAP, but the difference was not statistically significant (P = 0.134). J. Magn. Reson. Imaging 2000;11:665–672.

Evaluation of perianal sepsis: Comparison of anal endosonography and magnetic resonance imaging

The purpose of this study was to compare prospectively the diagnostic yield of anal endosonography (AES) and magnetic resonance imaging (MRI) in the assessment of perianal fistulae and abscesses. There were 39 patients (14 men, 25 women; mean age, 40 years) who underwent AES, performed with a 10‐MHz rotating endoanal probe and MRI at 1.0 T (axial and coronal T2‐weighted turbo spin‐echo (TSE) and turbo‐STIR sequences). Fistulae were classified as subcutaneous, intersphincteric, transsphincteric, high (i.e., high extrasphincteric or suprasphincteric), rectovaginal, and horseshoe and were compared with the surgical findings in all patients. Overall, 58 fistulae (subcutaneous, N = 7; intersphincteric, N = 9; transsphincteric, N = 16; high, N = 17; rectovaginal, N = 5; and horseshoe, N = 4) were detected at surgery. MRI showed a sensitivity of 84% and AES of 60% (P < .05). False‐positive diagnoses were made in 6 patients (15%) with MRI and in 15 patients (26%) with AES, for a specificity of 68% and 21%, respectively (P < .05). Our findings show that MRI is superior to AES in the assessment of fistula‐in‐ano before major surgery. AES should be used only for orientation before minor procedures, such as incision or drainage of subcutaneous fistulae. J. Magn. Reson. Imaging 2001;14:254–260.

The relationship between the common femoral artery, the inguinal crease, and the inguinal ligament: A guide to accurate angiographic puncture

The variability of the extraperitoneal puncture space between the inguinal ligament and the inguinal crease was evaluated in 100 patients. The distance between the inguinal crease and the inguinal ligament varied from 0 to 11 cm (average 6.7 cm±1.9 SD), the average value for women (7.5 cm±1.9 SD) being significantly greater than that for men (6.3 cm±1.9 SD, p=0.0128). The bifurcation of the common femoral artery was found below the inguinal crease in 20%, at the same levelin 3.5%, and above it in 76.5% of cases. Consideration of these results will help avoid intraperitoneal puncture and improve the rate of successful antegrade puncture of the femoral artery.

Parosteal osteosarcoma. 2-23-year follow-up of 33 patients.

In a study of the working group for bone tumors of the German Orthopedic Society, 33 patients with a histologically confirmed parosteal osteosarcoma at reexamination underwent clinical and radiographic follow-up. Local recurrence occurred in all the cases after intralesional surgery and in 4 of 8 cases after marginal excision. The grade of differentiation was decisive for the prognosis. Despite intralesional surgery, the prognosis for Grade 1 tumors was good. Metastases developed in 1 of 23 patients with a Grade 1 tumor and in 4 of 9 patients with a Grade 2 tumor. The single patient with a Grade 3 tumor was treated with adjuvant chemotherapy and was free of disease after 5 years.

Assessment of chronic constipation: colon transit time versus defecography

OBJECTIVE The aim of this study was to determine the value of radiological colon transit time (CTT) measurements in relation to defecography (DFG) in chronically constipated patients. MATERIALS AND METHODS In 30 patients with chronic constipation, total and segmental CTT was determined using radiopaque markers. In all of these patients defecography (DFG) was obtained. The patients were divided into three groups: In group I, 11 patients were classified with idiopathic constipation based on low stool frequency, normal DFG, or absence of symptoms of abnormal defecation. In group II, ten patients with rectal intussusception were diagnosed by DFG. In group III, there were nine patients with rectal prolapse or spastic pelvic floor syndrome, based on results of DFG. RESULTS Group I, idiopathic constipation (n = 11), showed increased total CTT (mean, 93 h) and segmental CTT (right colon, 33 h (36%), left colon, 31 h (33%), rectosigmoid, 29 h (31%)). In group II, intussusception (n = 10), patients had normal mean total CTT (54 h) and a relative decrease in rectosigmoid CTT (mean, 13 h (24%)). In group III (n =9), rectal prolapse (n = 5) or spastic pelvic floor syndrome (n = 4), patients showed elevated total (mean, 167 h) and rectosigmoidal CTT (mean, 95 h (57%)). Mean total CTT was significantly different between groups I and II and between groups II and III, and mean rectosigmoidal CTT was significantly different between all three groups (P < 0.05). CONCLUSION The use of total and rectosigmoidal CTT helps to identify the underlying pathophysiology of chronic constipation. Furthermore CTT helps to identify patients, who may benefit from DFG.

Sonographic demonstration of septicaemia with gas-forming organisms after liver transplantation

Sepsis with gas-forming organisms, e.g. Clostridium perfringens and anaerobic streptococci occurred in three of 120 liver-transplant recipients (2.5%). The diagnosis was made in all three patients by bedside ultrasound, before blood cultures revealed bacterial growth. Floating high amplitude echoes within the extra- and intrahepatic portal veins and persistent small high amplitude echoes in the non-dependent portion of the liver are indicative of portal venous gas and should prompt further laboratory investigations.

Detectability of small and flat polyps in MDCT colonography using 2D and 3D imaging tools: results from a phantom study

OBJECTIVE The objective of this phantom study was to determine the performance of MDCT colonography for the detection of small polyps under ideal imaging conditions and to determine the added value of 3D imaging when used as an adjunct to 2D imaging. MATERIALS AND METHODS Thirty-six polypoid and 39 flat polyps (44 lesions, 2-5 mm; 31 lesions, 6-8 mm) were placed in three explanted segments of a thoroughly cleaned porcine colon (overall length, 4.5 m) that was distended with air and submerged in a water phantom. MDCT data sets with 4 x 1 mm collimation and 6-mm table feed were reconstructed every 0.7 mm with 1.25-mm effective slice width. The data were reviewed by three radiologists using 2D images in all three projections and with 3D volume-rendered images available as an adjunct to the 2D images. RESULTS Additional 3D as a problem-solving tool significantly increased the overall sensitivity (96% vs 90%), decreased the total number of false-positive calls (n = 9 vs n = 5), and increased the diagnostic confidence level (p < 0.03) compared with 2D images alone. Small polyps less than or equal to 5 mm (89% vs 95%, p = 0.004) and flat polyps (82% vs 94%, p = 0.001) especially benefited from 3D. Sensitivity was generally higher for polypoid than for flat polyps (99% vs 94%, p = 0.041). CONCLUSION Under phantom conditions, simulating an ideal clinical setup, MDCT colonography is not limited by spatial resolution and detects polyps less than or equal to 5 mm in size with high sensitivity and specificity. Additional 3D image tools improve diagnostic accuracy and reviewer confidence, especially for the detection of flat and small polyps.