Bone marrow oedema associated with benign and malignant bone tumours.

Bone marrow oedema is associated with a wide variety of pathological processes including both benign and malignant bone tumours. This imaging finding in relation to intraosseous tumours can aid in providing a more focused differential diagnosis. In this review, we will discuss the MR imaging of bone marrow oedema surrounding intraosseous neoplasms. The different pulse sequences used in differentiating underlying tumour from surrounding oedema are discussed along with the role of dynamic contrast enhanced MRI. Benign lesions commonly associated with bone marrow oedema include osteoid osteoma, osteoblastoma, chondroblastoma and Langerhan's cell histiocytosis. Metastases and malignant primary bone tumours such as osteosarcoma, Ewing's sarcoma and chondrosarcoma may also be surrounded by bone marrow oedema. The imaging findings of these conditions are reviewed and illustrated. Finally, the importance of bone marrow oedema in assessment of post chemotherapeutic response is addressed.

Evaluation of tumor measurements in oncology: use of film-based and electronic techniques.

PURPOSE: To evaluate the variability in bidimensional computed tomography (CT) measurements obtained of actual tumors and of tumor phantoms by use of three measurement techniques: hand-held calipers on film, electronic calipers on a workstation, and an autocontour technique on a workstation. MATERIALS AND METHODS: Three radiologists measured 45 actual tumors (in the lung, liver, and lymph nodes) on CT images, using each of the three techniques. Bidimensional measurements were recorded, and their cross-products calculated. The coefficient of variation was calculated to assess interobserver variability. CT images of 48 phantoms were measured by three radiologists with each of the techniques. In addition to the coefficient of variation, the differences between the cross-product measurements of tumor phantoms themselves and the measurements obtained with each of the techniques were calculated. RESULTS: The differences between the coefficients of variation were statistically significantly different for the autocontour technique, compared with the other techniques, both for actual tumors and for tumor phantoms. There was no statistically significant difference in the coefficient of variation between measurements obtained with hand-held calipers and electronic calipers. The cross-products for tumor phantoms were 12% less than the actual cross-product when calipers on film were used, 11% less using electronic calipers, and 1% greater using the autocontour technique. CONCLUSION: Tumor size is obtained more accurately and consistently between readers using an automated autocontour technique than between those using hand-held or electronic calipers. This finding has substantial implications for monitoring tumor therapy in an individual patient, as well as for evaluating the effectiveness of new therapies under development.

Adjunctive surgery after chemotherapy for nonseminomatous germ cell tumors: recommendations for patient selection.

One hundred eighty-five patients who underwent surgery within 6 months of completing chemotherapy were identified from 360 patients with nonseminomatous germ cell tumors (NSGCT) treated with Memorial Hospital front-line cisplatin- or carboplatin-based combination chemotherapy protocols between 1979 and 1988. Clinical, pathologic, and radiologic features were correlated with the pathologic findings at surgery. The size of a residual retroperitoneal mass, the degree of shrinkage that occurred with chemotherapy, and the presence of teratomatous elements in pretreatment pathology specimens were each correlated with the pathologic findings of retroperitoneal resections after chemotherapy. Multivariable logistic regression analysis of those undergoing retroperitoneal resections identified the size and shrinkage of the residual mass and the prechemotherapy lactate dehydrogenase (LDH) and alphafetoprotein (AFP) levels as the best predictors of finding only necrotic debris. No factors could be found, however, that could selectively exclude patients who had residual viable malignancy or teratoma in the retroperitoneum. Of 39 patients with residual retroperitoneal masses measuring less than or equal to 1.5 cm in maximal diameter, three had residual malignancy and five had teratoma resected. No factors were identified for residual lung or mediastinal masses that could be used to select a group of patients who could safely avoid surgery. If serum markers have normalized after chemotherapy for NSGCT, resection of all residual abnormalities on imaging studies of the retroperitoneum, lungs, and mediastinum is recommended. In addition, retroperitoneal lymph node dissection (RPLND) is recommended for all patients with initial bulky metastases (greater than or equal to 3 cm in diameter) in the retroperitoneum, irrespective of the findings of postchemotherapy computed tomography (CT).

The chief residency in radiology. Results of a survey of A3CR2 members.

Detailed questionnaires were sent to the 192 members of the American Association of Academic Chief Residents in Radiology (A3CR2) to learn about the logistics of chief resident selection, the responsibilities of the chief resident, the attitudes and perceptions of the chief resident about his or her position, and suggestions for improving the chief residency. Completed questionnaires were returned by 149 (78%) chief residents from 111 different residency programs. The results show that radiology residents have a greater voice in selecting their chief residents than in the past. The number and types of responsibilities given to the chief resident at different institutions vary considerably. Although only 62% of respondents felt that being chief resident was worth their time and effort, 88% would accept the position again. The most commonly voiced suggestion was for greater input from the chief resident during the formulation of policies that affect the residents. Based on these results and a review of previous reports about the chief residency in other specialties, several proposals are offered for increasing the effectiveness of the radiology chief residency.

MRI as an alternative to CT-guided biopsy of adrenal masses in patients with lung cancer.

BACKGROUND: This study was performed to assess chemical shift magnetic resonance imaging (CSMRI) for characterizing adrenal masses in patients with lung cancer, and to compare charges associated with two algorithms for assessing adrenal masses in these patients. METHODS: Forty-two patients with lung cancer underwent both CSMRI (using in-phase and opposed-phase gradient echo images) and computed tomography-guided percutaneous biopsy of adrenal masses. Adrenal-to-spleen signal intensity ratios on the opposed-phase images were correlated with histopathologic results. The normalized charges for two algorithms were compared. In algorithm A, computed tomography-guided biopsy is used first to evaluate an adrenal mass; in algorithm B, CSMRI is used first, followed by computed tomography-guided biopsy only if CSMRI findings are not diagnostic of adenoma. RESULTS: Biopsy showed 24 (57%) adrenal adenomas and 18 (43%) metastases. Chemical shift magnetic resonance imaging was 96% sensitive for adenoma and 100% specific. The average normalized charges associated with algorithm A were $1,905 per patient versus $1,890 with algorithm B. CONCLUSIONS: Initial use of CSMRI in evaluating an adrenal mass in lung cancer patients can obviate biopsy in 55% of patients, and its charges are similar to those for performing computed tomography-guided biopsy in all patients.

Role of video-assisted thoracic surgery in the treatment of pulmonary metastases: results of a prospective trial.

BACKGROUND: A retrospective review revealed a 42% error rate between computed tomographic scan reports and thoracotomy findings; therefore, a prospective study was designed to compare the value of computed tomographic scans, video-assisted thoracoscopic exploration, and open thoracotomy in the management of pulmonary metastases. METHODS: Eligibility included any patient with only one or two ipsilateral pulmonary metastases identified on computed tomographic scan who was being considered for surgical resection. Initially video-assisted thoracic surgery was performed and all lesions identified were resected. A thoracotomy adequate for complete lung palpation was then carried out and any additional lesions found were removed. RESULTS: Eighteen patients of a planned 50 were treated before closure of the study. Four patients (22%) had no additional lesions found at thoracotomy. The primary sites of tumor were colon (10), breast (3), and one patient each skin (squamous), cervix, kidney, melanoma, and sarcoma. Four patients (22%) did have additional lesions at thoracotomy, which were benign. In the remaining 10 patients (56%) additional malignant lesions were found at thoracotomy after video-assisted thoracoscopic exploration. After 18 patients were entered, analysis of the early results disclosed a 56% failure rate of a computed tomographic scan and video-assisted thoracic surgery to detect all lesions. Being within the 95% confidence interval (32% to 78%), the study was abandoned. CONCLUSIONS: We conclude that video-assisted thoracic surgery should be used only as a diagnostic tool in managing lung metastasis. A thoracotomy is required to achieve complete resection, which is the major survival prognosticator for satisfactory long-term results.

Bacterial lung abscess: a review of the radiographic and clinical features of 50 cases.

The radiographic and clinical features of 50 patients with documented bacterial lung abscess are presented. Neither clinical nor radiographic features permit a specific diagnosis of lung abscess to be made; microbiologic or histopathologic material is needed to establish the diagnosis. A surprising percentage of patients (18%) had radiographically occult lung abscesses that were diagnosed only at the time of surgery or autopsy. Possible causes for and means of avoiding this diagnostic pitfall are presented.

Magnetic resonance imaging of the postpneumonectomy chest: normal and abnormal findings.

To determine the normal findings at magnetic resonance imaging (MRI) of the postpneumonectomy space (PPS), and to evaluate the utility of MRI in detection of recurrent tumor in the postpneumonectomy chest, 32 MRI scans were performed in 31 patients at varying time intervals after pneumonectomy. Eleven patients also had 12 computed tomography (CT) scans performed at the same time to evaluate possible tumor recurrence. Of the 32 scans, 5 demonstrated complete obliteration of the fluid containing PPS, and 4 showed gas in the PPS; the remainder (n = 23) demonstrated persistence of fluid-filled spaces of varying size. The presence of a fibrotic rim of tissue was constant. In 11 patients with clinically suspected tumor recurrences, both CT and MRI were obtained: the two modalities performed with similar accuracy in diagnosing tumor recurrence at 16 sites; CT detected opposite-lung metastatic nodules not seen on MRI in one patient, and a rib metastasis described as "indeterminate" on MRI in a second patient. MRI detected a focus of recurrence in the PPS that was indeterminate on CT. There is considerable variability in the amount of fluid seen in the PPS on MRI. CT remains the procedure of choice for routine follow-up or in suspected tumor recurrence in the postpneumonectomy patient; MRI can be helpful if the CT scan is nondiagnostic or equivocal.

Mucocele after endorectal pull-through for imperforate anus.

This report documents a patient with imperforate anus in whom an endorectal pull-through with incomplete excision of the macroscopic mucosa led to the formation of a 1,500 mL mucosal lined pelvic mucocele, obstructing both the rectum and ureter. All macroscopic mucosa should be removed during endorectal pull-through.

CT demonstration of infected SVC thrombus.

We report a case in which computed tomography (CT) demonstrated gas within a thrombus in the superior vena cava in a patient with fever of unknown origin (FUO), indicating that the thrombus was infected. This CT finding is important to recognize, as it affects subsequent therapy.

MR imaging of carcinoma within urinary bladder diverticulum.

Cystoendoscopic examination and standard radiological techniques occasionally fail to correctly establish that a pelvic mass is due to carcinoma arising within a urinary bladder diverticulum. MR imaging in oblique planes can facilitate the diagnosis in such cases by demonstrating the neck of the diverticulum. Also, T2-weighted images allow differentiation between tumor within a diverticulum and a necrotic extravesical mass.

Musculoskeletal pitfalls and pseudotumours in the pelvis: a pictorial review for body imagers.

Many musculoskeletal abnormalities in the pelvis are first seen by body imagers while reviewing pelvic cross-sectional studies, and some of these abnormalities may mimic malignancy or another aggressive process. This article describes nine musculoskeletal pseudotumours and interpretative pitfalls that may be seen on CT, MRI and ultrasound imaging of the pelvis. Awareness of these pitfalls and pseudotumours may help avoid misdiagnosis and prevent inappropriate intervention or management.

Prognostic significance of adrenal gland morphology at CT in patients with three common malignancies.

OBJECTIVES: To determine whether minor alterations in adrenal gland morphology at baseline CT in three common cancers indicate early metastasis. METHODS: 689 patients (237 with lung cancer, 228 with breast cancer, 224 with melanoma) underwent baseline and follow-up CTs that included the adrenals. Two readers independently scored each adrenal at baseline CT as normal, smoothly enlarged, nodular or mass-containing. Adrenals containing a mass >10 mm were excluded. The appearance of each adrenal on the latest available CT was assessed for change since baseline. Cox models were used to assess the association between adrenal morphology at initial CT and subsequent development of adrenal metastasis (defined as new mass >10 mm, corroborated by follow-up imaging). κ statistics were calculated to assess inter-reader agreement. RESULTS: Initial and follow-up CT evaluations were recorded for 1317 adrenals (median follow-up, 18.6 months). At initial CT, Readers 1 and 2 interpreted 1242 and 1230 adrenals as normal, 40 and 57 as smoothly enlarged, 29 and 25 as nodular, and 6 and 5 as containing masses ≤ 10 mm, respectively. κ-values were 0.52 (moderate) at initial CT and 0.70 (substantial) at follow-up. The hazard ratio for developing a metastasis at follow-up CT given an abnormal adrenal assessment at baseline was 0.7 [95% confidence interval (CI) 0.2-2.1; p = 0.47] for Reader 1, and 2.0 (95% CI 0.8-4.7; p = 0.12) for Reader 2. CONCLUSION: Minor morphological abnormalities of adrenals at initial CT did not represent early adrenal metastasis in most patients in this population.

Reproducibility and clinical correlations of post-treatment changes on CT of prostate cancer bone metastases treated with chemotherapy.

OBJECTIVES: The objective of this study was to determine whether, in patients with prostate cancer (PCa) bone metastases receiving chemotherapy, early post-treatment changes on CT are reproducible and associated with clinical outcomes. METHODS: Blinded to outcomes, two radiologists with 1 year and 5 years of experience independently reviewed CTs obtained before and 3 months after chemotherapy initiation in 38 patients with bone metastases from castration-resistant PCa, recording the size, matrix and attenuation of ≤5 lesions; presence of new lesions, extraosseous components, periosteal reactions and cortical thickening; and overall CT assessment (improved, no change or worse). Kappa statistics were used to assess inter-reader agreement; the Kruskal-Wallis test and Cox regression model were used to evaluate associations. RESULTS: Inter-reader agreement was low/fair for size change (concordance correlation coefficient=0.013), overall assessment and extraosseous involvement (κ=0.3), moderate for periosteal reaction and cortical thickening (κ=0.4-0.5), and substantial for CT attenuation (κ=0.7). Most metastases were blastic (Reader 1, 58%; Reader 2, 67%) or mixed lytic-blastic (Reader 1, 42%; Reader 2, 34%). No individual CT features correlated with survival. Readers 1 and 2 called the disease improved in 26% and 5% of patients, unchanged in 11% and 21%, and worse in 63% and 74%, respectively, with 64% interreader agreement. Overall CT assessment did not correlate with percentage change in prostate-specific antigen level. For the more experienced reader (Reader 2), patients with improved or unchanged disease had significantly longer median survival (p=0.036). CONCLUSIONS: In PCa bone metastases, interreader agreement is low in overall CT post-treatment assessment and varies widely for individual CT features. Improved or stable disease identified by an experienced reader is statistically associated with longer survival.

MR Imaging of Bone Marrow in Patients with Musculoskeletal Tumors.

Knowledge of the appearances of normal bone marrow, metastases involving marrow, and therapy-related marrow changes shown by MR imaging is necessary in order to avoid misdiagnosis. This article reviews MR imaging techniques and the findings that allow distinction of normal yellow (fatty) marrow and red marrow from tumor in marrow, as well as the identification of marrow changes resulting from radiation therapy or treatment with marrow-stimulating drugs in patients with musculoskeletal tumors.

Soft tissue edema around musculoskeletal sarcomas at magnetic resonance imaging.

The presence of soft tissue edema around a malignant musculoskeletal neoplasm can interfere with accurate local tumor staging at magnetic resonance imaging. This article discusses and illustrates such edema, emphasizing means for avoiding misinterpretation of edema and subsequent overstaging.

Subcentimeter pulmonary nodules detected in patients with sarcoma.

Background. Subcentimeter pulmonary nodules are being detected with increasing frequency in patients with sarcoma due to the greater use of chest CT, the advent of helical (spiral) CT scanning and multidetector scanners, and the attendant decrease in image section thickness.Assessing the clinical significance of these pulmonary nodules is of particular importance in sarcoma patients, due to the frequent occurrence of pulmonary metastasis from sarcomas.Purpose. This article reviews the technical advances that have contributed to the increased detection of subcentimeter pulmonary nodules, statistics about subcentimeter pulmonary nodules and options for evaluating such nodules.

Portal system thrombosis after splenectomy for neoplasm or chronic hematologic disorder: is routine surveillance imaging necessary?

PURPOSE: This study was undertaken to assess the frequency and sequelae of portal system thrombosis (PST) after splenectomy in patients with cancer or chronic hematologic disorders and to determine whether routine surveillance imaging for this potential complication is warranted. METHOD: The radiology reports of 203 consecutive patients with cancer or chronic hematologic disorders who underwent splenectomy between January 1990 and January 1997 were reviewed. Imaging examinations and medical records were reviewed for those in whom PST was found after splenectomy. RESULTS: One hundred twenty-three patients (60.6%) underwent CT (n = 88), sonography (n = 10), or both (n = 24) after splenectomy; one other patient underwent MRI. Twelve of these patients (9.8%) had thrombosis of the splenic, portal, and/or superior mesenteric veins. Their underlying diseases were myelofibrosis/ myelodysplastic syndrome (n = 8), lymphoma (n = 3), and leukemia (n = 1). At follow-up imaging (obtained in 10 of the 12 patients), PST had resolved (n = 5), worsened (n = 2), improved (n = 1), remained unchanged (n = 1), or resulted in cavernous transformation of the portal vein (n = 1). Nine of 12 patients were symptomatic. No patient died of PST. CONCLUSION: PST was an uncommon and typically unsuspected finding after splenectomy in this patient population, and no serious sequelae of PST were found. Routine surveillance imaging for PST after splenectomy does not seem warranted, but in symptomatic patients (particularly those with myelofibrosis/myelodysplastic syndrome), a high clinical suspicion and a low threshold for obtaining imaging examinations are needed.