Extrahepatic metastases of hepatocellular carcinoma: A spectrum of imaging findings.

Hepatocellular carcinoma (HCC) is the most common primary tumour of the liver, responsible for significant morbidity and mortality worldwide. In the Western world, it primarily affects patients with cirrhosis, secondary to hepatitis C virus and alcoholism. In the rest of the world, HCC is closely associated with hepatitis B virus infections. Radiologists play a key role in accurately staging HCC, which has important implications for treatment planning. This pictorial review aims to describe the routes of HCC spread and the most frequent sites of metastases, to recognize extrahepatic HCC findings on computed tomography and magnetic resonance imaging, and to understand the implications of HCC staging on treatment planning.

Comparison of MERGE and axial T2-weighted fast spin-echo sequences for detection of multiple sclerosis lesions in the cervical spinal cord.

OBJECTIVE: The purpose of our study was to compare axial multiple-echo recombined gradient echo (MERGE) with axial T2-weighted fast spin-echo (FSE) imaging for the detection of multiple sclerosis (MS) lesions in the cervical spinal cord on MRI. MATERIALS AND METHODS: Twenty-nine cervical spine MRI studies of patients with MS lesions and 29 control cases were reviewed retrospectively. Two blinded neuroradiologists independently assessed randomized axial MERGE and axial T2-weighted FSE sequences from each study, documenting the location and number of cord lesions, the degree of confidence in calling each lesion, and the presence of artifacts. The reference standard was determined by an unblinded consensus review of all sequences performed for each case, with lesions considered present if detected on two or more sequences. Lesion detection rates and conspicuity, false-positive findings, and reader confidence and artifact scores were compared for the sequences, and interreader agreement was assessed. RESULTS: Eighty-three lesions were assessed. The mean true-positive lesion detection rate was 87% (95% CI, 79-93%) with MERGE and 67% (60-75%) with T2-weighted FSE, with interreader positive agreement scores of 74% and 75%, respectively. A greater number of false-positive findings were seen with MERGE for both the MS and control cases. Average confidence and artifact scores were similar for both sequences. Subjectively, lesions were more conspicuous in 21 cases with MERGE and four cases with T2-weighted FSE and were equally conspicuous in four cases. CONCLUSION: MERGE and T2-weighted FSE sequences are complementary. MERGE provided greater sensitivity for cord lesions whereas axial T2-weighted FSE provided improved lesion specificity. Further investigation is required to assess the clinical impact of MERGE in the diagnosis and management of MS.

Imaging in adult scoliosis: preoperative assessment and postoperative complications.

Adult scoliosis rates range from 2 to 32%. Surgery for scoliosis is common. Accurate and surgically relevant information should be provided to the referring surgeon from pre- and postoperative imaging. There are various methods to correct scoliosis surgically with the end points correction of the curve and relief of symptoms. This is achieved through the placement of spinal instrumentation with a goal of osseous fusion across the instrumented levels. There are many potential postoperative complications. The initial and postoperative imaging, types of surgery, and hardware are reviewed along with the common early and late complications with relevant illustrations.

Plain radiograph assessment of spinal hardware.

The frequency and variety of spinal instrumentation has increased tremendously over the past 100 years, and imaging plays an important role in evaluating the postoperative spine. Although assessment of spinal hardware often involves a multimodality approach, plain radiographs are the most commonly used modality, given accessibility, cost, relatively low radiation dose compared with computed tomography, and provision of positional information. An approach to assessment of plain radiographs of the postoperative spine is discussed, and examples of common postoperative complications are provided, including infection, hardware failure, incomplete fusion, and junctional failure.

An incidence of anteroinferior cerebellar artery/posteroinferior cerebellar artery anatomic variants penetrating the subarcuate fossa dura: operative technique and identification with 3-dimensional fast imaging employing steady-state acquisition magnetic resonance imaging.

OBJECTIVE: This case series reports an incidence of anomalous vascular anatomy within the cerebellopontine angle. The relevant literature effectively describes techniques for mobilization yet underestimates the incidence. There has been no literature on the use of magnetic resonance imaging (MRI) to preoperatively identify this anatomic variant. METHODS: We identify 8 cases of anomalous vascular anatomy within the cerebellopontine angle over a period of 6 years. They were uniformly identified through a retrosigmoid approach. Retrospective review of available 3-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) sequences was performed. Intraoperative video capture of technique for mobilization was obtained. Institutional neurosurgical database review identified retrosigmoid craniotomies performed by the senior surgeon. RESULTS: We identify 8 of 192 cases (4.2%) as having this anomalous vascular anatomy. This aberrant vascular loop resulted in subtotal resection in 3 of 8 cases (37.5%) and significant morbidity in 1 of 8 cases (12.5%). The retrospective review of the 3D-FIESTA MRI sequences positively identified this aberrant vascular course in 5 of 5 cases (100%). The digital video recording is of high quality and demonstrates proper technique for mobilization. CONCLUSION: The presence of this vessel creates the potential for technical difficulty and significant complications. We report the incidence and techniques of mobilization. This variant can potentially be identified on preoperative 3D-FIESTA MRI sequences. Knowledge of this anatomy may guide neurosurgeons in their case preparation.

Radiographic evaluation of scoliosis: self-assessment module.

OBJECTIVE: The educational objectives for this self-assessment module are for the participant to exercise, self-assess, and improve his or her understanding of evaluation of scoliosis using radiography. CONCLUSION: The solutions to the questions in this activity review the imaging characteristics of radiologic evaluation of scoliosis.

Injury of the posterior ligamentous complex of the thoracolumbar spine: a prospective evaluation of the diagnostic accuracy of magnetic resonance imaging.

STUDY DESIGN: Prospective diagnostic imaging study. OBJECTIVE: To determine the accuracy of magnetic resonance imaging (MRI) in diagnosing injury of the posterior ligamentous complex (PLC) in patients with thoracolumbar trauma. SUMMARY OF BACKGROUND DATA: Treatment decisions in thoracolumbar injury patients are currently based on the status of the PLC. It is, therefore, important to understand the accuracy of MRI in diagnosing varying degrees of PLC injury. Prior studies report that MRI is up to 100% sensitive for diagnosing PCL injury. METHODS: Patients with an acute injury from T1 to L3 who required posterior surgery were prospectively studied. A musculoskeletal radiologist, based on the preoperative MRI findings, characterized each of the 6 components of the PLC as intact, incompletely disrupted, or disrupted. During the surgical procedure, the surgeon identified each component of the PLC as intact, incompletely disrupted, or disrupted. The radiologist's interpretation and surgical findings were compared. RESULTS: Forty-two patients with 62 levels of injury were studied. There were 33 males (78.6%) and 9 females (21.4%), and the average age was 35.7 years. According to the kappa score, there was a moderate level of agreement between the radiologist's interpretation and the intraoperative findings for all PLC components except the thoracolumbar fascia, for which there was slight agreement. The sensitivity for the various PLC components ranged from 79% (left facet capsule) to 90% (interspinous ligament). The specificity ranged from 53% (thoracolumbar fascia) to 65% (ligamentum flavum). There was less agreement between the radiologist and surgeon for the patients with less severe neurologic compromise, i.e., those patients with an AIS grade of either D or E. CONCLUSION: The sensitivity and specificity of MRI for diagnosing injury of the PLC are lower than previously reported in the literature. The integrity of the PLC as determined by MRI should not be used in isolation to determine treatment.

SKyphoplasty.

OBJECTIVE: SKyphoplasty is a new method of percutaneous spinal augmentation. Despite its limited availability in the United States, SKyphoplasty has experienced considerable growth in recent years. In this article, we aim to provide a stepwise documentation of the technique, with brief reference to the 2 established methods, vertebroplasty and kyphoplasty. CONCLUSION: Experience with SKyphoplasty is relatively limited, and little information has appeared in the literature to support its theoretical benefits. After review of previously published material, an audit of our institutional experience, and discussion with other practioners who perform this procedure, it would appear that pain relief by using this device is at best similar to that of conventional vertebroplasty and kyphoplasty. There was no evidence of height restoration in our patient population, an advantage that has been brought into question.

Combined cementoplasty and radiofrequency ablation in the treatment of painful neoplastic lesions of bone.

PURPOSE: To assess the safety and effectiveness of combined radiofrequency (RF) ablation and cementoplasty in the treatment of painful neoplastic lesions of bone. MATERIALS AND METHODS: The authors performed a retrospective analysis of 25 combined treatments comprising RF ablation followed by injection of polymethylmethacrylate cement performed in 19 patients during a 22-month period. Patients ranged in age from 42 to 82 years (mean, 58.9 years) and included five women and 14 men. Eleven vertebrae (eight lumbar and three thoracic), nine acetabulae, three sacra, one pubis, and one humerus were treated with a total of 36 RF ablations (in several instances, overlapping ablations were used). The location of the primary neoplasm, lesion size, pain before and after the procedure (as determined with a 10-point visual analog scale [VAS]), number of RF treatments, type of device used for cementoplasty, RF time, cement volume, and extravasation were documented. RESULTS: A total of 25 combined RF ablations and cementoplasties were performed. The technical success rate was 100% (25 of 25 treatments). There were seven minor complications: six limited cement extravasations and a transient thermal nerve injury. The mean RF time was 9.1 minutes (range, 6-12 minutes). The mean cement volume injected was 6.1 mL (range, 0.8-16 mL). The mean preprocedure pain (as measured with a VAS) was 7.9 (range, 7.0-9.0) and the mean posttreatment pain was 4.2 (range, 0-6); the difference was statistically significant (mean score, 4.08; 95% confidence interval: 3.92, 4.87; P < .0001) using a paired t test. CONCLUSIONS: Combined RF ablation and cementoplasty appears to be safe and effective in the treatment of painful neoplastic lesions of bone.

Magnetic resonance imaging appearance of partial latissimus dorsi muscle tendon tear.

There is still a paucity of information about the clinical presentation, treatment and imaging findings of latissimus muscle tears. Only one study has specifically described the magnetic resonance imaging (MRI) features of latissimus tendon tears. We describe a case of a high-grade tear in the latissimus muscle tendon in an active water skier with no significant prior medical history. MRI demonstrated at least a 50% tear of the latissimus tendon, manifesting as increased signal intensity on T2-weighted sequences and surrounding edema, as well as a diminutive tendon at the humeral insertion.

Therapeutic and diagnostic joint injections.

Joint injections remain a valuable modality in the detection and treatment of intra-articular pathology. Over the past several decades, various diagnostic and therapeutic indications for joint injections have been developed. Imaging guidance for joint injection generally increases accuracy in joint aspirations and diagnostic blocks. Confirming intra-articular placement with steroid injections improves efficacy and reduces local complications. Administering intra-articular contrast can improve the diagnostic performance of CT and MR imaging in many circumstances. This article focuses on the rationale for injections at different sites and describes different fluoroscopic approaches for common joints.

Magnetic resonance imaging of the ankle at 3.0 Tesla and 1.5 Tesla in human cadaver specimens with artificially created lesions of cartilage and ligaments.

PURPOSE: To compare magnetic resonance imaging of the ankle joint at 1.5 Tesla (T) and 3.0 T in the assessment of cartilage and ligament pathology in fresh human cadaver specimens. MATERIALS AND METHODS: The study was performed in line with institutional and legislative requirements; all donors had dedicated their body for educational and research purposes before death. Thirteen fresh human cadaver ankle joints were imaged at 1.5 T and 3.0 T using an optimized clinical ankle protocol consisting of T1-weighted (T1-w), fat-saturated (fs) T2-w, and short tau inversion recovery fast spinecho (FSE) sequences. For dedicated cartilage imaging, fs-intermediate (IM)-w FSE, fs-spoiled gradient echo, and balanced free precession steady state sequences were acquired. Artificial cartilage and ligament lesions were created in 6 and 5 specimens, respectively. MR imaging was repeated in those ankles. Four radiologists independently assessed pathology in all image datasets. Macroscopic findings after dissection served as a reference standard. RESULTS: Sensitivities and ROC-values were higher at 3.0 T for detecting cartilage pathology (sensitivity up to 0.71 at 3.0 T vs. 0.49 at 1.5 T; AZ up to 0.88 vs. 0.74; both differences P < 0.05) and highest for the fs-IM FSE sequence at 3.0 T. Average sensitivity for detecting ligament pathology was higher at 3.0 T (0.69 vs. 0.50; P < 0.05). Specificity was high among all protocols and both field strengths for assessing ligament and cartilage pathology (>0.95). CONCLUSION: Compared with 1.5-T imaging, the 3.0-T imaging of the ankle joint at improved diagnostic performance in assessing cartilage significantly and there was a higher sensitivity for assessing ligamentous pathology.

Imaging the degenerative diseases of the lumbar spine.

Degenerative changes of the spine may involve the disc space, the facet joints, or the supportive and surrounding soft tissues. MR imaging is ideally suited for delineating the presence, extent, and complications of degenerative spinal disease. Other imaging modalities such as radiography, myelography, and CT may provide complimentary information in selected cases. Percutaneous procedures may be used to confirm that a morphologic abnormality is the source of symptoms. Correlation with clinical and electrophysiologic data is also helpful for accurate diagnosis. Combining the information obtained from imaging studies with the patient's clinical presentation is mandatory for determining the appropriate patient management strategy, especially true in patients afflicted with any condition directly attributed to the degenerative processes of the spine.

MR imaging of the ankle at 3 Tesla and 1.5 Tesla: protocol optimization and application to cartilage, ligament and tendon pathology in cadaver specimens.

The objective of this study was to optimize ankle joint MR imaging in volunteers at 1.5 Tesla (T) and 3.0 T, and to compare these optimized sequences concerning image quality and performance in assessing cartilage, ligament and tendon pathology in fresh human cadaver specimens. Initially our clinical ankle protocol consisting of T1-weighted (-w), fat-saturated (fs) T2-w, and short tau inversion-recovery fast spinecho (FSE) sequences was optimized at 1.5 T and 3.0 T by two radiologists. For dedicated cartilage imaging, fs-intermediate (IM)-w FSE, fs spoiled gradient echo, and balanced free-precession steady-state sequences were optimized. Using the optimized sequences, thirteen cadaver ankle joints were imaged. Four radiologists independently assessed these images concerning image quality and pathology. All radiologists consistently rated image quality higher at 3.0 T (all sequences p<0.05). For detecting cartilage pathology, diagnostic performance was significantly higher at 3.0 T (ROC-values up to 0.93 vs. 0.77; p<0.05); the fs-IM FSE sequence showed highest values among the different sequences. Average sensitivity for detecting tendon pathology was 63% at 3.0 T vs. 41% at 1.5 T and was significantly higher at 3.0 T for 2 out of 4 radiologists (p<0.05). Compared to 1.5 T, imaging of the ankle joint at 3.0 T significantly improved image quality and diagnostic performance in assessing cartilage pathology.

Magnetic resonance arthrography.

For decades, fluoroscopic arthrography was the only method available to image a joint with contrast enhancement. Advances in CT led to the natural development of CT arthrography. Development of MRI and its capability for multiplanar imaging led to direct magnetic resonance arthrography (MRA). This technique has been performed since 1987 and has surpassed CT arthrography in popularity in the United States. Indirect MRA developed subsequently to offer a less invasive alternative. This article presents an overview of direct MRA and addresses joint-specific issues regarding direct MRA. An overview of indirect MRA also is provided.