Transcatheter embolization of mycotic aneurysm of the subclavian artery with metallic coils

Mycotic aneurysms of the subclavian artery are rare. This report describes an experience of 2 rare cases in which transcatheter embolization with metallic coils was performed for the management of these lesions alternative to surgery. Two patients who had been treated with chemotherapy for malignant neoplasms were diagnosed as having mycotic aneurysms of the left subclavian artery. The causes of these lesions were presumed to be the invasion of the arterial wall by the pulmonary abscess in case 1, and wound infection after placement of the reservoir for intraarterial chemotherapy in case 2. In both cases, proximal and distal sites of the aneurysm were embolized with metallic coils. In case 1, the vertebral artery was also embolized with Guglielmi detachable coils to avoid retrograde blood flow. Both aneurysms were completely occluded by a single embolization. In case 1, although weakness and paresthesia of the left hand remained, lethal hemoptysis due to aneurysmal fistulization to the lung parenchyma ceased. In case 2, no neurological deficit except for mild paresthesia in the left thumb had been observed. Both patients died of primary disease 10 and 5 months after the procedure. Transcatheter embolization is technically feasible and effective enough to treat the mycotic aneurysm of the subclavian artery even in the situation in which the surgical option seems to be difficult or risky.

[Pitfalls in the assessment of radioresponse as determined by tumor regression: consideration based on the location and histologic constitution of tumors]

PURPOSE

To prove the following hypotheses regarding tumor shrinkage after radiotherapy. Tumors located on an outer tissue surface, e.g. esophageal tumors, shrink faster than parenchymal tumors, e.g. lymph-node metastasis, because two clearance mechanisms, exfoliation and absorption, can operate in the former type of tumors whereas only absorption can function in the latter. Tumors which are being controlled do not necessarily respond completely, because tumors are constituted not only of tumor cells but also stromal tissues that are difficult to be absorbed.

MATERIALS AND METHODS

Long-term shrinkage patterns of a parenchymal tumor were determined by using 18 curatively irradiated hepatomas. Preoperatively irradiated thymomas (10) and lymph-node metastases (37) from head and neck cancers were examined histopathologically. Twenty-one esophageal cancers were used for intra-patient response comparison between the primary disease and the lymph-node metastases.

RESULTS

Shrinkage patterns were generally biphasic: rapid exponential regression followed by a plateau phase. Histologically, thymomas generally consisted of predominant fibrous tissues and few remaining tumor cells. Radioresponse did not predict the presence of remaining cancer cells in the lymph nodes. Esophageal-cancer radioresponse was always higher for the primary disease than the lymph-node metastases.

CONCLUSION

The location and histologic constitution of tumors must be taken into account in predicting radiocurability using radioresponse.

Subtraction CT with low-flow-rate arterial contrast injection to estimate drug distribution during balloon-occluded arterial chemotherapy infusion for bladder cancer

PURPOSE

To simulate drug distribution during balloon-occluded arterial chemotherapy infusion (BOAI) for urinary bladder cancer using subtraction computed tomography (CT) with low-flow-rate arterial contrast injection (S-CTLA).

METHODS

Ten patients with bladder cancer underwent S-CTLA, and the distribution of contrast agent during BOAI into both internal iliac arteries simultaneously was evaluated in nine pairs of internal iliac arteries and one single artery. For S-CTLA, spiral CT data were acquired before and after 0.2 ml/sec intraarterial injection of contrast material. The enhancement of the urinary bladder wall, the gluteal muscles, and the pelvic bones was categorized using a 4-grade scale. The grades were compared in each of the three pelvic components and differences were tested for significance using the Wilcoxon test for paired groups.

RESULTS

S-CTLA revealed the distribution of the contrast agent clearly. Gluteal muscles grades were significantly higher than those of the other two assessed components.

CONCLUSION

BOAI does not improve the concentration of contrast agent to the bladder wall over neighboring structures, suggesting that the balloon occlusion technique does not achieve its desired goal for chemotherapy targeting.

Revealing hepatic metastases from colorectal cancer: value of combined helical CT during arterial portography and CT hepatic arteriography with a unified CT and angiography system

OBJECTIVE

The purpose of our study was to evaluate the use of combined helical CT during arterial portography and CT hepatic arteriography in the preoperative assessment of hepatic metastases from colorectal cancer using a unified CT and angiography system.

MATERIALS AND METHODS

Fifty-four patients with hepatic metastases from colorectal cancer preoperatively underwent combined CT during arterial portography and CT hepatic arteriography using the unified CT and angiography system. Three radiologists independently and retrospectively reviewed the images of CT during arterial portography alone, CT hepatic arteriography alone, and combined CT during arterial portography and CT hepatic arteriography. Image review was conducted on a segment-by-segment basis; a total of 432 hepatic segments with (n = 103) 118 metastatic tumors ranging in size from 2 to 160 mm (mean, 25.8 mm) and without (n = 329) tumor were reviewed.

RESULTS

Relative sensitivity of combined CT during arterial portography and CT hepatic arteriography (87%) was higher than that of CT during arterial portography alone (80%, p < 0.0005) and CT hepatic arteriography alone (83%, p < 0.005). Relative specificity of CT hepatic arteriography alone (95%, p < 0.0005) and combined CT during arterial portography and CT hepatic arteriography (96%, p < 0.0001) was higher than that of CT during arterial portography alone (91%). Diagnostic accuracy, determined by a receiver operating characteristic curve analysis, was greater with combined CT during arterial portography and CT hepatic arteriography than with CT during arterial portography alone (p < 0.05) or CT hepatic arteriography alone (p < 0.01).

CONCLUSION

Using a unified CT and angiography system, we found that combined CT during arterial portography and CT hepatic arteriography significantly raised the detectability of hepatic metastases from colorectal cancer.

Prognostic significance of the PC10 index for patients with stage II and III oesophageal cancer treated with radiotherapy

The monoclonal antibody PC10 is used for immunohistochemical staining of the proliferating cell nuclear antigen (PCNA). The percentage of PC10-positive cancer cells is defined as the PC10 index. We evaluated the relationship between the PC10 index in pretreatment endoscopic biopsies and the prognoses of 47 patients with Stage II-III oesophageal squamous cell carcinoma treated with radiotherapy. The patients with a PC10 index > 40% had significantly poorer prognoses than the other patients (p = 0.0007). Proportional hazards model analysis indicated that only the PC10 index was a prognostic factor (p = 0.0009). The patient group of complete responders showed significantly lower PC10 indices compared to patients with a partial response or no change (p = 0.049). The PC10 index can be a good predictive indicator of the prognosis in patients with Stage II-III oesophageal cancer treated with radiotherapy.

Peliosis hepatis and neoplastic/dysplastic lesions in aged male Long-Evans Cinnamon rats: MR imaging with pathologic correlation

The Long-Evans Cinnamon (LEC) rat, an animal model of Wilson's disease, abnormally accumulates copper in the liver. There have been a lot of reports on preneoplastic and neoplastic hepatic tumors in LEC rats, but few studies have been focused on other lesions. The aim of this study was to describe the MR findings of the liver of LEC rats with pathologic correlation to characterize the hepatic lesions developed in them. We measured MR images of the liver of six aged (over the age of 70 weeks old) male LEC rats. Measurements of T(1), T(2)-weighted images, and the dynamic and delayed studies after i.v. gadolinium injection were performed. The rats were sacrificed immediately after the measurements, and the diagnosis was histologically made. We identified seven lesions of peliosis hepatis, three neoplastic/dysplastic lesions, three cysts and one cholangiofibrosis. Peliosis hepatis was characterized as showing a significantly long T(2) relaxation time of 57.9 +/- 13.3 ms (mean +/- standard deviation) compared with 41.3 +/- 1.7 ms in normal liver, and prolonged enhancement after a gadolinium injection. Neoplastic/dysplastic lesions tended to show prolonged T(2), and they showed isointensity on T(1)-weighted images. They were best characterized by early enhancement followed by a rapid wash-out after a gadolinium injection. In conclusions, the frequent occurrence of peliosis hepatis observed in the present study suggests this can be a characteristic lesion in aged LEC rats. The characteristic MR findings enable us to distinguish between peliosis hepatis and neoplastic/dysplastic lesions.

MR imaging of radiation osteitis in the sacroiliac joints

The purpose of this study was to analyze magnetic resonance (MR) images of radiation osteitis of sacroiliac joints, retrospectively. Seven patients with radiation osteitis, which was diagnosed by pelvic plain radiographs and CT images, underwent MRI. T(1)-weighted spin echo images and T(2)-weighted fast spin echo images were obtained in all patients. Four patients were examined after gadolinium injection. Major signal changes of radiation osteitis were distributed on the iliac side. T(1)-weighted images showed diffuse low intensity both in sacral and iliac sides. T(2)-weighted images showed very low intensity adjacent to sacroiliac joints, but mixed intensity was illustrated apart from joints, and high intensity in the peripheral areas. Radiation osteitis showed slight to mild, but irregular enhancement in four patients after gadolinium administration. MRI can illustrate abnormal bone change distribution and is useful for diagnosing this entity by characteristic intensity patterns on T(1)-weighted images with and without gadolinium and T(2)-weighted image. However, the diagnosis of accompanied insufficiency fractures in the area of radiation osteitis is occasionally difficult with conventional MRI.

Flexure deformation of the temporomandibular joint disk in pseudodynamic magnetic resonance images

OBJECTIVE

The purpose of this study was to determine correlation of flexure disk deformation during jaw movement with other findings on magnetic resonance images and with clinical signs and symptoms in patients with anterior displacement of the temporomandibular joint disk.

STUDY DESIGN

T(1)-weighted magnetic resonance images and gradient recalled acquisition in steady state magnetic resonance images were obtained in 62 subjects with flexure deformed disk in the jaw opening phase. Each disk deformation observed on a pseudodynamic image during jaw opening was classified as an upward or downward flexure deformation. The relationships between type of disk deformation, clinical signs and symptoms, and other findings on the magnetic resonance images were statistically analyzed by chi(2) test.Results. Of 80 delineated joints, 30 showed upward deformation and 50 showed downward deformation. There were significant differences between the upward and downward deformations in TMJ sound, TMJ pain, restricted jaw opening, extent of anterior displacement, and presence of disk reduction.

CONCLUSIONS

The type of disk deformation appeared to correlate with the clinical signs and symptoms and with the progress of internal derangement.

Fibrous scar in the infrapatellar fat pad after arthroscopy: MR imaging

PURPOSE

We describe the MR appearance of fibrous scars in the infrapatellar fat pad after arthroscopy.

MATERIALS AND METHODS

The subjects were 96 patients who underwent arthroscope-assisted anterior cruciate ligament (ACL) reconstruction and were examined by oblique sagittal MR imaging at different follow-up intervals. Two observers evaluated the characteristics of the fibrous scars in the infrapatellar fat pad.

RESULTS

All fibrous scars with low signal intensity were accentuated at the portal and coursed horizontally through the infrapatellar fat pad. The fibrous scar within the fat pad occurred and peaked within 6 months after arthroscopy. It then subsided gradually and had disappeared by one year later in nearly half of the patients.

CONCLUSION

Identifying MR imaging characteristics of fibrous scars in the fat pad after arthroscopy may be clinically helpful to differentiate these scars from other abnormalities that involve the infrapatellar fat pad.

High-resolution imaging of coronary calcifications by intense low-energy fluoroscopic X-ray obtained from synchrotron radiation

PURPOSE

To obtain an intense monochromatic low-energy X-ray from synchrotron radiation (SR) and apply it to detect coronary calcifications.

METHODS AND RESULTS

The SR beam was reflected with a silicon crystal to be expanded (150 mm in height and 80 mm in width) and to be monochromatized at an energy level of 37 keV. The X-ray was intermittently irradiated to obtain dynamic imaging of 30 images/s. Images were recorded by a digital fluorography system. The low-energy X-ray from SR sharply visualized calcification of coronary arteries, while conventional X-ray could not visualize coronary calcification.

CONCLUSION

The intense monochromatic low-energy X-ray from SR is sensitive, has high-resolution for imaging coronary calcification and may serve as a screening method for coronary artery disease.

High-resolution MR imaging of the knee at 3 T

PURPOSE

To examine the practical feasibility of using a 3.0-T MR unit to obtain high-quality, high-resolution images of the knee joint.

MATERIAL AND METHODS

One human cadaveric and 5 porcine knees were imaged with the 3.0-T unit. Sets of T1-weighted spin echo images were obtained with in-plane resolution of 0.195x0.39 mm and an acquisition time of approximately 5 min. Two porcine knees were also imaged with the 1.0-T unit with an identical imaging protocol and the signal-to-noise (S/N) ratios were measured on images at 3 T and 1 T.

RESULTS

The 3-T MR system provided detailed delineation of the knees. Deep layers of the medial collateral ligament and associated fine fibers beneath the medial and lateral collateral ligament were demarcated. We observed precise demonstration of the tibial attachment of the anterior cruciate ligament, irregularity of the meniscal free edge, and conjoint tendon formation together with the lateral collateral ligament and the biceps femoris tendon. Compared to the 1-T unit, the S/N ratio with the 3-T unit was increased by a factor of 1.39 to 1.72.

CONCLUSION

Due to the potential advantage of obtaining detailed images, the 3-T MR system suggests a practical utility for fine demonstration of the knee morphology.

Human carcinoma: early experience with phase-contrast X-ray CT with synchrotron radiation--comparative specimen study with optical microscopy

Phase-contrast x-ray computed tomography (CT) indicates the distribution of the refractive index and has potential to reveal the structures inside soft tissues without a contrast agent. With a synchrotron x-ray source, phase-contrast x-ray CT with a triple Laue-case x-ray interferometer clearly differentiated various human pathologic tissues in the cases of hepatocellular carcinoma with cirrhosis and metastatic colon carcinoma to the liver, and the images closely corresponded to those obtained with low-magnification optical microscopy.

Intramuscular metastasis from malignant melanoma: MR findings

We present a rare case of intramuscular metastasis from malignant melanoma. The lesion showed intermediate to high signal intensity on T1-weighted magnetic resonance (MR) images and mixed signal intensities containing high and low signals on T2-weighted images. The signal intensity on T1-weighted images, which is due to the paramagnetic effect of melanin, is a characteristic MR finding of this entity.

MR imaging of Pellegrini-Stieda disease

OBJECTIVE

To describe the MR imaging of Pellegrini-Stieda disease, a post-traumatic ossification of the medial collateral ligament with typical radiographic findings.

METHODS

Coronal and/or axial T2*-weighted field echo and T1-weighted conventional spin echo MR images were obtained with 1.5-Tesla or 0.5-Tesla units. Four patients with radiographic and clinical diagnoses of Pellegrini-Stieda disease were examined. Surgery was performed on one patient, and histopathologic correlation was obtained.

RESULTS AND CONCLUSION

Delineating it as a signal void, T2*-weighted MR imaging indicated the precise extent of the osseous fragment in relation to the medial collateral ligament. T1-weighted imaging showed the presence of fatty marrow as a high signal region within the fragment, indicating maturity of the fragment. These findings may help to determine preoperative planning for resection of massive fragments around the ligament. Pellegrini-Stieda disease cannot be considered rare, since it is often encountered in daily MRI examinations.

[Patterns of initial treatment failure of esophageal cancer following radiotherapy]

Sixty patients with stage I-III esophageal squamous cell cancer treated by definitive radiotherapy (RT) were analyzed for patterns of treatment failure. Patients were treated by external RT alone (n = 45) or in combination with intraluminal RT (N = 15) when suitable, with prescribed total doses ranging from 59.4 to 104.4 Gy. Concurrent chemotherapy consisting of cisplatin and/or 5-fluorouracil was administered to 19 patients. The two-year actuarial survival rate and two-year disease-free survival rate were 29.5% and 18.3%, respectively. Two-year failure rates were 66.5%, 36.9%, and 3.8%, for the esophagus, lymph nodes, and other sites, respectively. Two-year esophageal failure rates for patients with T1-2 (n = 8), T3 (n = 30), and T4 disease (n = 22) were 14.3%, 64.7%, and 87.9%, respectively (p < 0.05). A multivariate analysis of esophageal failure with descriptive variables of T classification, tumor length, and performance of intraluminal RT revealed that only T classification was an independent factor (p = 0.021). Two-year lymph node failure rates were 24.8% and 33.6% for patients with N0 (n = 36) and N1 disease (n = 24), respectively (p = 0.0035). Lymph node failure in N0 patients was found exclusively outside the treatment field. These results suggest that inclusion of potential lymph node metastases in the radiation field could lessen the lymph node failure rate in T1-3N0M0 patients.

[MR imaging of the posterolateral aspect of the knee]

The structures of the posterolateral aspect of the knee were evaluated with axial MR images. One hundred twelve knees of clinical cases without posterolateral injury were retrospectively reviewed, and 30 knees of 15 volunteers with no history of knee injury or pain were evaluated. The amount of joint effusion and visualization of the lateral collateral ligament (LCL) and popliteal tendon were classified according to three grades. The LCL and popliteal tendon were identified in 111 clinical cases (99%) and 28 volunteer knees (93%). Visualization of the LCL and popliteal tendon was facilitated in the presence of both joint effusion and fluid collection between the LCL and popliteal tendon. Fluid collection posterior to the femoral attachment of the popliteal tendon was seen in 79 clinical cases (71%) and 20 volunteer knees (67%). Based on cadaveric study, this was considered to be a potential fluid space for communication to the joint space.