Epiphora: treatment by means of dacryocystoplasty with balloon dilation of the nasolacrimal drainage apparatus

A new interventional radiologic procedure was developed for treatment of epiphora. A small-bore, soft-tipped guide wire was introduced through the superior canaliculus and guided under fluoroscopic control through the nasolacrimal drainage system for retrieval through the nasal aperture. A small-bore angioplasty catheter was then introduced in a retrograde direction into the nasolacrimal drainage apparatus and dilated under fluoroscopic control. The procedure was attempted in 18 eyes of 17 patients with moderate to severe epiphora and was technically completed in 16; 13 of these cases demonstrated improvement, with 11 patients showing complete resolution of symptoms. In the three patients whose epiphora did not improve, no worsening of symptoms occurred. These results are preliminary; follow-up ranged from 7 weeks to 6 months. The authors believe that this technique may hold promise in the treatment of epiphora and may obviate the use of more invasive procedures.

Dual energy computed tomography in tophaceous gout

OBJECTIVE

To evaluate the potential utility of a dual energy CT (DECT) scan in assessing urate deposits among patients with tophaceous gout, and obtain computerised quantification of tophus volume in peripheral joints.

METHODS

20 consecutive patients with tophaceous gout and 10 control patients with other arthritic conditions were included. DECT scans were performed using a renal stone colour-coding protocol that specifically assessed the chemical composition of the material (ie, urate coloured in red, calcium coloured in blue). An automated volumetric assessment of DECT was used to measure the volume of urate deposits in all peripheral joint areas.

RESULTS

All 20 patients with gout showed red colour-coded urate deposits on their DECT scans, whereas none of 10 controls showed urate deposits. DECT scans revealed a total of 440 areas of urate deposition in 20 patients, whereas physical examination showed 111 areas of urate deposition (mean 22 vs 6 per patient, respectively, p<0.001). Total urate volume in a given patient ranged from 0.63 cm(3) to 249.13 cm(3), with a mean of 40.20 cm(3).

CONCLUSIONS

DECT scans can produce obvious colour displays for urate deposits and help to identify subclinical tophus deposits. Furthermore, tophus volume can be measured by DECT scans through an automated volume estimation procedure.

A new method for estimation of velocity vectors

The paper describes a new method for determining the velocity vector of a remotely sensed object using either sound or electromagnetic radiation. The movement of the object is determined from a field with spatial oscillations in both the axial direction of the transducer and in one or two directions transverse to the axial direction. By using a number of pulse emissions, the inter-pulse movement can be estimated and the velocity found from the estimated movement and the time between pulses. The method is based on the principle of using transverse spatial modulation for making the received signal influenced by transverse motion. Such a transverse modulation can be generated by using apodization on individual transducer array elements together with a special focusing scheme. A method for making such a field is presented along with a suitable two-dimensional velocity estimator. An implementation usable in medical ultrasound is described, and simulated results are presented. Simulation results for a flow of 1 m/s in a tube rotated in the image plane at specific angles (0, 15, 35, 55, 75, and 90 degrees) are made and characterized by the estimated mean value, estimated angle, and the standard deviation in the lateral and longitudinal direction. The average performance of the estimates for all angles is: mean velocity 0.99 m/s, longitudinal S.D. 0.015 m/s, and lateral S.D. 0.196 m/s. For flow parallel to the transducer the results are: mean velocity 0.95 m/s, angle 0.10, longitudinal S.D. 0.020 m/s, and lateral S.D. 0.172 m/s.

Pulmonary lymphangitic carcinomatosis: CT and pathologic findings

The authors retrospectively reviewed the computed tomographic (CT) scans, biopsy specimens, autopsy results, and lobectomy specimens of 21 patients who had lymphangitic carcinomatosis. Ten-millimeter collimation CT scans were obtained from all patients, and selected 1.5-mm CT scans were obtained from ten patients. In five patients, the diagnosis was established with open lung biopsy, lobectomy, or autopsy; in nine, with bronchial biopsy or transbronchial biopsy; and in seven, with clinical and radiologic criteria. Certain characteristic findings on CT scans were evident: uneven thickening of bronchovascular bundles, thickening of isolated interstitial lines, and the presence of polygonal lines. These findings may be seen on CT scans even if the findings on chest radiographs are normal or nonspecific. The pathologic basis for these characteristic CT findings may relate to tumor thrombi in lymphatic vessels rather than edema and fibrosis, at least in the early stages of disease.

Metal artifact reduction sequence: early clinical applications

Artifact arising from metal hardware remains a significant problem in orthopedic magnetic resonance imaging. The metal artifact reduction sequence (MARS) reduces the size and intensity of susceptibility artifacts from magnetic field distortion. The sequence, which is based on view angle tilting in combination with increased gradient strength, can be conveniently used in conjunction with any spin-echo sequence and requires no additional imaging time. In patients with persistent pain after femoral neck fracture, the MARS technique allows visualization of marrow adjacent to hip screws, thus enabling diagnosis or exclusion of avascular necrosis. Other applications in the hip include assessment of periprosthetic soft tissues after hip joint replacement surgery, postoperative assessment after resection of bone tumors and reconstruction, and localization of unopacified methyl methacrylate cement prior to hip arthroplasty revision surgery. In the knee, the MARS technique allows visualization of structures adjacent to implanted metal staples, pins, or screws. The technique can significantly improve visualization of periprosthetic bone and soft-tissue structures even in patients who have undergone total knee arthroplasty. In patients with spinal fixation hardware, the MARS technique frequently allows visualization of the vertebral bodies and spinal canal contents. The technique can be helpful after wrist fusion or screw fixation of scaphoid fractures.

Subunit structure of dihydrolipoyl transacetylase component of pyruvate dehydrogenase complex from Escherichia coli

Limited tryptic digestion of the pyruvate dehydrogenase complex of Escherichia coli or its dihydrolipoyl transacetylase core cleaves the trypsin-sensitive transacetylase subunits into two large fragments, A (lipoyl domain) and D (subunit binding domain). Release of fragments A from the complex does not significantly affect its sedimentation coefficient or its appearance in the electron microscope. Fragment A contains the lipoyl moieties ((3)H-labeled), is acidic with an apparent isoelectric point of about 4.0, has a M(r) of 31,600 as determined by sedimentation equilibrium analysis, and has a swollen or extended structure (f/f(o) = 1.78). Fragment A exhibits anomalous properties, probably due to its acidic nature. It is resistant to staining with Coomassie blue and it migrates on sodium dodecyl sulfate/polyacrylamide gels as if it had a M(r) of 46,000-48,000. Further tryptic digestion converts fragment A into a lipoyl-containing fragment of M(r) 20,000 (fragment B) and eventually into an apparently stable product of estimated M(r) about 10,000 (fragment C). Fragment D has a compact structure of M(r) about 29,600 as determined by sedimentation equilibrium analysis in 6 M guanidinium chloride, and it possesses the intersubunit binding sites of the transacetylase, the binding sites for pyruvate dehydrogenase and dihydrolipoyl dehydrogenase, and the catalytic site for transacetylation. The assemblage of fragments D is responsible for the cube-like appearance of the transacetylase in the electron microscope. High-resolution electron micrographs of the transacetylase show fiber-like extensions, apparently corresponding to tryptic fragment A, surrounding the cube-like core.

Image-guided percutaneous biopsy of musculoskeletal tumors: an algorithm for selection of specific biopsy techniques

OBJECTIVE

The purpose of this study was to design and use an algorithm for selection of the most appropriate biopsy technique.

MATERIALS AND METHODS

An algorithm was designed to maximize the tissue sampling and diagnostic accuracy of musculoskeletal tumor biopsy. We used fine-needle aspiration to sample small ( < 3 cm) soft-tissue masses, an 18-gauge automated Biopty Gun to sample large ( > 3 cm) soft-tissue masses, a bone-cutting core biopsy needle to sample sclerotic bone tumors, and a combination technique to sample lytic bone tumors with an intact bony shell. We reviewed the results of 46 consecutive biopsies obtained with this algorithm.

RESULTS

The overall diagnostic accuracy was 96%, with one inadequate biopsy and one inaccurate biopsy. The diagnostic accuracies within subgroups of tumor types were: primary malignant tumors (n = 15), 93%; primary benign tumors (n = 9), 100%; secondary malignant tumors (n = 11), 100%; secondary benign tumors (n = 8), 88%; and infections (n = 3), 100%.

CONCLUSION

This algorithm allows selection of the biopsy procedure most likely to safely provide adequate and accurate biopsy samples.

Intraarticular fractures of the calcaneus: value of CT findings in determining prognosis

The prognosis of intraarticular calcaneal fractures is variable, ranging from severe functional impairment and pain to complete return of normal function. Clinical assessment and CT scanning were performed 1-11 years after fracture in 45 patients (51 fractures) to determine the relationship between the CT findings and clinical status. Conservatively treated (n = 18) and surgically treated (n = 33) fractures were assessed. Clinical assessment included evaluation of subjective parameters (pain, activity, gait, and use of orthotics) and objective measurement of subtalar motion. CT evaluation included assessment of abnormalities in the posterior subtalar joint, loss of calcaneal height, tendon abnormalities, and calcaneocuboid joint abnormalities. A poor clinical outcome, caused by loss of subtalar motion, was more common when CT showed incongruity or degeneration of the posterior facet (p = .04) and when Bohler's angle was decreased (p = .0006). Other CT findings, such as loss of calcaneal height and tendon abnormalities, did not correlate with clinical outcome. An unexpected finding was that surgical screws were intraarticular in eight (24%) of 33 surgically treated patients; however, this finding was not significantly associated with poor clinical outcome. Our findings indicate that the CT findings of degenerative change and incongruity of the posterior subtalar joint correlate significantly with poor clinical outcome.

Adenocarcinoma of the pancreatic ducts: comparative evaluation with CT and MR imaging at 1.5 T

A prospective comparison of computed tomography (CT) and magnetic resonance (MR) imaging at 1.5 T was performed in 50 patients with the suspected diagnosis of pancreatic carcinoma. CT scans were obtained before and after administration of contrast material in 41 of 50 patients (82%); 34 of 41 postcontrast scans (83%) were obtained with dynamic CT. MR images were interpreted without knowledge of the results of CT, ultrasound, cholangiography, or endoscopic retrograde cholangiopancreatography in 48 patients (96%). Surgical correlation of findings at CT and MR imaging was performed in 24 patients (48%) at laparotomy and in two patients (4%) at autopsy. On T1-weighted MR images, relatively diminished signal intensity of tumor compared with that of the adjacent pancreas was a consistent finding. MR imaging proved superior to CT in identification of pancreatic carcinoma (particularly in smaller intrapancreatic tumors), peripancreatic extension, vascular and portal vein invasion, and duodenal invasion. These results suggest that MR imaging of the pancreas is superior in many instances to CT in preoperative evaluation of pancreatic carcinoma.

Three-dimensional sonographic reconstruction: techniques and diagnostic applications

In this review, we summarize the techniques of obtaining and reconstructing three-dimensional (3D) sonograms in a number of anatomic areas, catalog the clinical efforts at 3D sonography so far, and introduce more recent work in this area that takes advantage of the unique features of sonography. Although it is an active area of 3D imaging research, cardiac 3D imaging is not discussed because it has unique requirements stemming from the heart's anatomic inaccessibility and motion. Image analysis and display also are not covered, as no clear consensus has been reached about the usefulness of the large number of available methods.

Carotid artery stenosis in patients who have undergone radiation therapy for head and neck malignancy

Although it is established that small and medium sized arteries undergo extensive radiation damage, the effect on large vessels such as the carotid arteries is less well understood. We sought to determine if an increased severity of carotid artery stenosis is present in patients who have undergone radiotherapy for head and neck tumours. 45 patients aged 43-90 years (average 67) with head and neck malignancies treated with radiotherapy underwent colour Doppler ultrasonographic scanning of the carotid arteries. These patients were compared with a population of asymptomatic historical controls. 60% of patients demonstrated stenosis ranging from 21 to 86%. 38% of patients demonstrated a stenosis greater than or equal to 50%. Carotid artery stenosis appears to be increased in patients who have previously undergone treatment with radiotherapy to the head and neck regions compared with controls (p < 0.001). These findings suggest that radiation has an adverse effect on large vessels. Colour Doppler follow-up may be indicated for patients receiving head and neck radiation therapy.

The imaging spectrum of Baker's (Popliteal) cysts

Baker's (Popliteal) cysts are frequently encountered on cross-sectional imaging of the knee. These consist of enlarged gastrocnemius semimembranosus bursa which typically communicate with the knee. They may be imaged with a variety of techniques including arthopgraphy, CT, ultrasound and MRI, with the latter two being more commonly used. Examples of bursa imaged with all of the above techniques are demonstrated in the essay, as well as variance of normal appearance and pathological entities including ruptured bursa, abnormally positioned bursa, osteochondromatosis, septic complications of the bursa and pigmented villonodular synovitis.

Radiological features of synovial cell sarcoma

Synovial cell sarcoma is an uncommon soft-tissue malignant tumour. These tumours have common radiological features with a variety of both benign and malignant lesions. However, there is a variety of imaging findings that can suggest a pre-biopsy diagnosis of synovial cell sarcoma. This pictorial review aims to describe the imaging features of synovial sarcoma in a series of cases with various age ranges and tumour locations. In addition, the pathology, staging, prognosis and management of synovial sarcoma is briefly discussed.

Immature bone infarcts: findings on plain radiographs and MR scans

We studied the plain film findings in eight patients with immature bone-marrow infarction and correlated the findings with those of MR imaging in four of the cases. Seven patients had underlying systemic disease, including sickle cell disease (two), systemic lupus erythematosus (two), acute lymphocytic leukemia (one), non-Hodgkin lymphoma (one), and renal transplantation (one). In one patient, the bone infarct was idiopathic. Plain films in three of the eight cases were misinterpreted as showing aggressive lesions (i.e., malignancy or infection), and these patients underwent a biopsy that proved the diagnosis of bone infarction. In the other five cases, the diagnoses were established by clinical follow-up. The plain film findings in all eight cases consisted of subtle, mottled, ill-defined radiolucencies in the diametaphyseal region. Four of the patients had mild sclerosis. MR imaging in all four cases in which it was performed showed a central area with high or intermediate signal with a serpentine, thin, low-signal border. The lesions shown by MR imaging corresponded to the areas of abnormality on the plain films and had an appearance similar to that of previously reported bone infarcts. Our experience suggests that in patients with nonspecific subtle radiographic bone changes and an underlying systemic disease, MR imaging is helpful in establishing the diagnosis of bone marrow infarction.

The use of radiologically placed gastrostomy tubes in head and neck cancer patients receiving radiotherapy

PURPOSE

Patients undergoing radiotherapy to the head and neck area frequently experience radiation reactions that can markedly restrict oral intake, require hospitalization, and occasionally cause treatment interruptions. The Vancouver Cancer Center (VCC) has recently employed radiologically placed gastrostomy tubes (G-tubes) in the management of this problem. A review of the patients on whom this procedure had been performed is the subject of this review.

METHODS AND MATERIALS

Thirty-four patients had gastrostomy tubes inserted under radiologic guidance. This group is compared to a control group matched for age, sex, irradiated volume, and radiation dose, who did not have gastrostomy tubes. Patients with gastrostomy tubes were divided into two categories: (a) patients who had tubes inserted in anticipation of severe reactions, and (b) patients who developed severe radiation reactions necessitating nutritional support.

RESULTS

The gastrostomy group consisted of 65% males with an average age of 59 years and stage range of II (12%), III (24%), and IV (65%). In both the elective group and the nonelective group, patients maintained their weight at 95 to 97% of the pretreatment weight, at follow-up of 6 weeks and 3 months. This compared with an average weight loss in the control group of 9% at 6 weeks and 12% at 3 months. The length of hospitalization was a mean of 4.9 days in the elective group and 19 days in the nonelective group. Complication were low compared to those documented in the literature, but included two tube migrations, two aspirations, and one gastrointestinal bleed.

CONCLUSIONS

We believe that gastrostomy tubes contribute significantly to the management of patients with head and neck cancer, particularly in maintanence of nutrition, and they may decrease the need for hospitalization.

Malignant chest wall neoplasms of bone and cartilage: a pictorial review of CT and MR findings

Malignant tumours of the chest wall are uncommon. The purpose of this pictorial essay is to describe the CT and MRI findings of malignant neoplasms affecting the bony skeleton of the chest wall and the costal cartilages. The most common primary malignant neoplasms involving the bony skeleton of the chest wall are chondrosarcoma, osteosarcoma and Ewing's sarcoma/primitive neuroectodermal tumour. Metastases, multiple myeloma and invasive primary lung cancer are the most frequent secondary lesions. We performed a retrospective review of the radiology and pathology archive at our institution from 1 July 2000 to 31 December 2004 and identified 31 of these lesions. Several of these tumours have distinctive radiological features, allowing a confident radiological diagnosis to be suggested.

MR imaging features of bizarre parosteal osteochondromatous proliferation of bone (Nora's lesion)

The purpose of this study was to review the imaging findings of three patients with bizarre parosteal osteochrondromatous proliferation of bone (BPOP). The plain radiographs and MRI images of three patients with BPOP were obtained and retrospectively reviewed. In two cases, BPOP involved the feet. In one case BPOP involved the hand. In all three cases, plain radiographs showed a well-defined calcium containing mass adjacent to the cortical surface of the adjacent bone. The underlying bone appeared normal in all cases. On MRI, the lesion was of low signal intensity on T1 weighted sequences in all cases. On FSE T2 weighted and STIR sequences, the lesion was of high signal in all cases. The cortex, medullary cavity and adjacent soft tissues appeared normal in all cases. While BPOP is rare and often confused with a variety of both benign and malignant lesions, there are specific radiological findings that may help to distinguish BPOP from many of its mimickers.

Pigmented villonodular synovitis

Pigmented villonodular synovitis (PVNS) is a rare benign proliferative growth of the synovium of obscure aetiology with a wide spectrum of clinical presentations and imaging findings. The purpose of this review is to acquaint the reader with the spectrum of imaging features of PVNS using a variety of imaging techniques.

Anterior cruciate ligament tear: prospective evaluation of diagnostic accuracy of middle- and high-field-strength MR imaging at 1.5 and 0.5 T

PURPOSE

To compare the diagnostic efficacy of current-generation middle- and high-field-strength magnetic resonance (MR) imagers in the diagnosis of anterior cruciate ligament (ACL) tears.

MATERIALS AND METHODS

In 114 of 230 patients referred for knee imaging, MR imaging at 0.5 and 1.5 T was performed with identical sequences but with a slightly longer total imaging time and bandwidth optimization at 0.5 T. Radiologists were blinded to diagnosis and field strength. Sensitivity, specificity, and accuracy were determined, and ACL tear was confirmed by means of arthroscopy and pathology.

RESULTS

There was no difference between the field strengths in accuracy, sensitivity, or specificity for the diagnosis of ACL tears in 86 patients with disrupted ACLs and 28 patients with intact ACLs. Accuracy for all ACL tears was 90% at 0.5 T and 91% at 1.5 T. Similarly, there were no differences in diagnosis of meniscal tears (79 with, 149 without) or posterior cruciate ligament tears (seven with, 107 without).

CONCLUSION

Higher field strength does not confer higher accuracy in the diagnosis of ACL tears at MR imaging.