Magnetic resonance imaging of abdominal and pelvic lymphadenopathy

Magnetic Resonance Imaging, Chest Radiography, Computed Tomography and Ultrasonography in Malignant Lymphoma

Magnetic resonance imaging (MRI) was compared with chest radiography, computed tomography (CT) and ultrasonography (US) for demonstration of spleen and liver engagement and enlarged lymph nodes in patients with malignant lymphoma. The investigation comprised 24 patients with Hodgkin's disease (HD) and 39 with non-Hodgkin lymphoma (NHL). MRI demonstrated enlarged lymph nodes, distinctly separated from vessels, fat, muscle, liver and occasionally also pancreas without any contrast medium. The distinction between lymph nodes and spleen was, however, poor in the images. In the mediastinum, MRI was superior to chest radiography and had an accuracy similar to that of CT. In the abdomen and the pelvis MRI had slight advantages over CT in detection of enlarged lymph nodes. Compared with US the MRI results were similar in the abdomen and somewhat better in the pelvis. MRI and US were better than CT in revealing HD infiltrates in the spleen. Infiltration of NHL in the spleen was slightly better disclosed at US than at CT and MRI; most of the NHL infiltration, confirmed at histopathology, could, however, not be revealed with any of the modalities, except when the size of the spleen was considered. Regions in the spleen, displayed with low image intensity in the T2 weighted image, were most likely due to increased amount of fibrotic tissue in the lymphomatous lesions. Good demonstration of lymph nodes and lymphomatous lesions in the spleen with MRI required two sequences; one with short TR and TE (T1 weighted image) and one with long TR and TE (T2 weighted image).

Imaging the renal mass: a historical review

A matter of months after Roentgen's landmark discovery in 1895, Roentgen's rays were focused on diseases and disorders of the urinary tract, specifically the kidney. At the dawn of the 20th century, urologists in the United States and around the world quickly recognized that by using a variety of metal stylets and radiopaque contrast agents, such as silver salts, the upper urinary tract, namely the ureter, pelvis, and calyces, could be depicted with radiography. Renal cysts and tumors were diagnosed on the basis of deformities in the kidney. Retrograde pyelography dominated the imaging evaluation of the kidney until the discovery of a safe intravenous method for urinary tract imaging (ie, intravenous pyelography). Pioneers and pathfinders in the field of contrast media development and radiologic procedures helped give radiologists the lead role in the work-up of renal masses, an area where urologists once held forth. The subspecialty of uroradiology was born in the middle of the 20th century. Intravenous urography, nephrotomography, and diagnostic angiography with pharmacologic manipulation followed by cyst or mass puncture and biopsy yielded unrivaled specificity for the diagnosis and staging of benign and malignant renal masses. The advent of cross-sectional and multiplanar imaging and the profound effects they had and continue to have on the discovery and characterization of renal masses has been detailed in the pages of Radiology since the 1920s. Ultrasonography, nuclear imaging, computed tomographic scanning, magnetic resonance imaging, and positron emission tomography each have made a claim to a part of the imaging algorithm of modern uroradiologic practice.

Effectiveness of the STIR turbo spin-echo sequence MR imaging in evaluation of lymphadenopathy in esophageal cancer

PURPOSE

We have investigated the utility of the STIR TSE sequence in the differentiation of benign from malignant mediastinal lymph nodes in patients with esophageal cancer.

PATIENTS AND METHODS

This study included 35 consecutive patients who were diagnosed as esophageal cancer and were undergone surgery. STIR TSE sequences were obtained as the ECG trigger. The signal intensity of the benign and malign lymph nodes, normal esophagus, and pathologic esophagus can be calculated on STIR sequence.

RESULTS

Pathologically, the number of total lymph nodes in 35 operated cases was 482. Approximately 152 lymph nodes were detected with MR imaging. Of these, 28 were thought to be malignant, and 124 were thought to be benign, although 32 were malignant and 120 were benign according pathological results. The ratio of benign lymph node intensity value to normal esophagus intensity value was 0.73±0.3. The ratio of malignant lymph node intensity value to normal esophagus intensity value ratio was 2.03±0.4. According to these results, the sensitivity of MR was 81.3%, the specificity was 98.3%.

CONCLUSION

We think that if motionless images can be obtained with MRI, we may be able to differentiate benign lymph nodes from malignant ones.

MRI with a lymph-node-specific contrast agent as an alternative to CT scan and lymph-node dissection in patients with prostate cancer: a prospective multicohort study

BACKGROUND

In patients with prostate cancer who are deemed to be at intermediate or high risk of having nodal metastases, invasive diagnostic pelvic lymph-node dissection (PLND) is the gold standard for the detection of nodal disease. However, a new lymph-node-specific MR-contrast agent ferumoxtran-10 can detect metastases in normal-sized nodes (ie, <8 mm in size) by use of MR lymphoangiography (MRL). In this prospective, multicentre cohort study, we aimed to compare the diagnostic accuracy of MRL with up-to-date multidetector CT (MDCT), and test the hypothesis that a negative MRL finding obviates the need for a PLND.

METHODS

We included consecutive patients with prostate cancer who had an intermediate or high risk (risk of >5% according to routinely used nomograms) of having lymph-node metastases. All patients were assessed by MDCT and MRL, and underwent PLND or fine-needle aspiration biopsy. Imaging results were correlated with histopathology. The primary outcomes were sensitivity, specificity, accuracy, NPV, and PPV of MRL and MDCT. This study is registered with ClinicalTrials.gov, number NCT00185029.

FINDINGS

The study was done in 11 hospitals in the Netherlands between April 8, 2003, and April 19, 2005. 375 consecutive patients were included. 61 of 375 (16%) patients had lymph-node metastases. Sensitivity was 34% (21 of 61; 95% CI 23-48) for MDCT and 82% (50 of 61; 70-90) for MRL (McNemar's test p<0.05). Specificity was 97% (303 of 314; 94-98) for MDCT and 93% (291 of 314; 89-95) for MRL. Positive predictive value (PPV) was 66% (21 of 32; 47-81) for MDCT and 69% (50 of 73; 56-79) for MRL. Negative predictive value (NPV) was 88% (303 of 343; 84-91) for MDCT and 96% (291 of 302; 93-98) for MRL (McNemar's test p<0.05). Of the 61 patients with lymph-node metastases, 50 were detected by MRL, of which 40 (80%) had metastases in normal-sized lymph nodes. The high sensitivity and NPV of MRL imply that in patients with a negative MRL, the chance of positive lymph nodes is less than 11/302 (4%).

INTERPRETATION

MRL had significantly higher sensitivity and NPV than MDCT for patients with prostate cancer who had intermediate or high risk of having lymph-node metastases. In such patients, after a negative MRL, the post-test probability of having lymph-node metastases is low enough to omit a PLND.

Retroperitoneal masses: magnetic resonance imaging findings with pathologic correlation

Primary retroperitoneal masses are a rare but diverse group of benign and malignant processes. Magnetic resonance (MR) imaging is playing an increasing role in evaluating retroperitoneal soft-tissue masses. Since the MR imaging features of most retroperitoneal soft-tissue masses are nonspecific, prediction of a specific histologic diagnosis remains a challenge for the radiologist. However, there are certain specific MR imaging appearances that are helpful. Dynamic enhancement patterns can reflect the vascularity of masses, differentiating benign from malignant soft-tissue masses. This article pictorially illustrates the MR imaging features of various common and uncommon retroperitoneal masses.

Magnetic resonance lymphography

PURPOSE OF REVIEW

The current methods of noninvasively staging retroperitoneal lymph nodes are suboptimal. Magnetic resonance lymphography is a new technique that might offer an important new tool in this area. Although it is still in development, more and more studies show that it is highly effective in detecting nodal metastases of various tumors.

RECENT FINDINGS

Magnetic resonance lymphography yields higher sensitivity than the reference methods for detecting malignant nodes in patients with prostate, bladder, or testicular cancer.

SUMMARY

In certain groups of patients with urologic cancer, magnetic resonance lymphography may obviate the need for lymphadenectomy and replace the currently used computed tomography scanning or unenhanced magnetic resonance imaging that are based on insensitive size criteria.

Axillary lymph node metastases in patients with breast carcinomas: assessment with nonenhanced versus uspio-enhanced MR imaging

PURPOSE

To prospectively assess the accuracy of nonenhanced versus ultrasmall superparamagnetic iron oxide (USPIO)-enhanced magnetic resonance (MR) imaging for depiction of axillary lymph node metastases in patients with breast carcinoma, with histopathologic findings as reference standard.

MATERIALS AND METHODS

The study was approved by the university ethics committee; written informed consent was obtained. Twenty-two women (mean age, 60 years; range, 40-79 years) with breast carcinomas underwent nonenhanced and USPIO-enhanced (2.6 mg of iron per kilogram of body weight intravenously administered) transverse T1-weighted and transverse and sagittal T2-weighted and T2*-weighted MR imaging in adducted and elevated arm positions. Two experienced radiologists, blinded to the histopathologic findings, analyzed images of axillary lymph nodes with regard to size, morphologic features, and USPIO uptake. A third independent radiologist served as a tiebreaker if consensus between two readers could not be reached. Visual and quantitative analyses of MR images were performed. Sensitivity, specificity, and accuracy values were calculated. To assess the effect of USPIO after administration, signal-to-noise ratio (SNR) changes were statistically analyzed with repeated-measurements analysis of variance (mixed model) for MR sequences.

RESULTS

At nonenhanced MR imaging, of 133 lymph nodes, six were rated as true-positive, 99 as true-negative, 23 as false-positive, and five as false-negative. At USPIO-enhanced MR imaging, 11 lymph nodes were rated as true-positive, 120 as true-negative, two as false-positive, and none as false-negative. In two metastatic lymph nodes in two patients with more than one metastatic lymph node, a consensus was not reached. USPIO-enhanced MR imaging revealed a node-by-node sensitivity, specificity, and accuracy of 100%, 98%, and 98%, respectively. At USPIO-enhanced MR imaging, no metastatic lymph nodes were missed on a patient-by-patient basis. Significant interactions indicating differences in the decrease of SNR values for metastatic and nonmetastatic lymph nodes were found for all sequences (P < .001 to P = .022).

CONCLUSION

USPIO-enhanced MR imaging appears valuable for assessment of axillary lymph node metastases in patients with breast carcinomas and is superior to nonenhanced MR imaging.

[MRI and staging evaluation of prostate cancer]

MRI can assess local and locoregional spread of a newly diagnosed prostate cancer by detecting extracapsular extension (ECE), seminal vesicle invasion (SVI) and lymph node invasion. Endorectal MRI remains the only accurate means to assess local extension. Pelvic MRI with surface coils and the use of superparamagnetic particules provide the sensitivity and the specificity which have never been obtained by the sole measurement of node size of the lymphatic chains draining the prostate gland. With the endorectal coil, only direct signs of extracapsular extension have been maintained and indirect signs have been discarded, giving their too low specificity. Early SVI can only be consistently detected if result of TRUS guided biopsies show involvement of the prostate base. With the pelvic phased array coil, superparamagnetic particules show that metastatic lymph nodes have a specific MR signal which can be detected in normal size nodes. Indications of imaging relies on results of parametrers available before MR imaging. More important than PSA level and Gleason score on biopsies is the so called quantitative histology, represented by the number of sextants involved by tumor and the amount of cancer (measured in mm of tumor) present on biopsies which determine a risk of extraprostatic spread. Of the risk of extraprostatic spread depends indication of MR, which is most probably unnecessary in patients at low risk (<20%) of extraprostatic extension.

Preoperative esophageal cancer staging: magnetic resonance imaging of lymph node with ferumoxtran-10, an ultrasmall superparamagnetic iron oxide

BACKGROUND

Accurate detection of metastasis to lymph nodes is an essential component of the approach to treatment. The purpose of this study was to evaluate the utility of magnetic resonance imaging with ferumoxtran-10 in diagnosing lymph node metastasis in esophageal cancer.

STUDY DESIGN

Sixteen patients with esophageal cancer who were scheduled for surgical lymph node dissection were enrolled. All patients underwent MRI scanning before and 24 hours after intravenous administration of ferumoxtran-10, an ultrasmall, superparamagnetic iron oxide. The presence or absence of metastasis was identified in lymph nodes by their enhancement patterns. Nonmalignant nodes contained macrophages that phagocytosed ferumoxtran-10. Metastatic nodes exhibited a decrease in phagocytic activity, and consequently showed little or no uptake of ferumoxtran-10. So we subdivided the enhancement patterns into the following three patterns: (A) node having an overall low signal intensity, (B) node having an area of high signal intensity, and (C) node having an overall high signal intensity. We identified that patterns (B) and (C) were metastatic patterns. The imaging results were compared with histopathologic findings.

RESULTS

Of the 408 resected lymph nodes, imaging results of 133 nodes could be compared with histopathologic findings. Twenty-four lymph nodes had histopathologic metastases. Using our enhancement criteria, sensitivity was 100%, specificity was 95.4%, and accuracy was 96.2% for diagnosis of metastatic nodes.

CONCLUSIONS

Ferumoxtran-10 is useful for characterizing benign or malignant lymph nodes in esophageal cancer patients based on the defined enhancement criteria.

MR imaging staging of pelvic lymph nodes

Accurate pelvic nodal staging is important in the workup of many pelvic tumors for assessing prognosis and directing therapy. Advances in diagnostic imaging have played an integral role in the staging of these tumors. Cross-sectional imaging, including MR imaging,however, uses size criteria and morphology to infer malignancy within a node,which is neither sensitive nor specific. This article reviews the normal pelvic nodal anatomy and techniques of conventional MR imaging for optimal nodal evaluation as well as introducing the recent technique of ultra small supraparamagnetic iron oxide(USPIO)-enhanced MR lymphangiography, which uses nodal function rather than structural criteria in assessing for metastatic nodes.

Newer MR imaging techniques for head and neck

Dynamic and functional imaging techniques are being developed to improve the evaluation of various pathologic processes of the head and neck region. These techniques include dynamic contrast-enhanced MR imaging for evaluating soft tissue masses and cervical lymph nodes, the use of ultrasmall superparamagnetic iron oxide contrast agent, and functional techniques such as in vivo and in vitro MR spectroscopy of head and neck cancer and lymph nodes and apparent diffusion coefficient mapping of parotid glands. These techniques can help to differentiate nonmalignant tissue from malignant tumors and lymph nodes and can aid in differentiating residual malignancies from postradiation changes. From methodological development, they are making the critical transition to preclinical and clinical validating methods and eventually to widespread clinical tools.

Computerised tomography in the staging of Hodgkin's disease and non-Hodgkin's lymphoma

The last 25 years have seen major changes in the imaging investigation and subsequent management of patients with Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL); accurate staging is vital for prognostication and treatment in both, and particularly in HD. The choice of imaging modality for staging depends on its accuracy, impact on clinical decision-making, and availability. Modern CT scanners fulfil most of the desired criteria. The advent of CT scanning, along with the development of ever more effective chemotherapeutic regimens, has resulted in the virtual demise of bipedal lymphangiography (LAG) as a staging tool in patients with lymphoma. It has rendered superfluous a battery of other tests that were in routine use. This contribution reviews the evidence for the use of CT in preference to LAG. CT accurately depicts nodal enlargement above and below the diaphragm, has variable sensitivity for intra-abdominal visceral involvement and is generally outstanding in depicting the extent of disease, especially extranodal extension. Despite the advances in CT technology, there are still areas where CT performs less well (e.g. disease in normal-sized lymph nodes, splenic and bone marrow infiltration). The influence of technical factors, such as the use of intravenous contrast medium, is discussed. In some instances, CT is not the imaging modality of choice and the place of newer techniques such as MRI and endoscopic ultrasound will be reviewed.

New techniques for imaging colorectal cancer: the use of MRI, PET and radioimmunoscintigraphy for primary staging and follow-up

Modern imaging techniques such as computed tomography (CT) and ultrasound (US) are in the majority of cases able to detect local and metastatic spread of malignancy. Increasingly, the requirement is for even more accurate pre-operative tumour staging to enable the use of new surgical techniques, neo-adjuvant therapies and, postoperatively, to enable detection of tumour recurrence on follow-up. Recent imaging research has focused on magnetic resonance imaging (MRI) for the detection of local tumour extension particularly for rectal tumours and on positron emission tomography (PET) and radioimmunoscintigraphy (RIS) for the detection of metastatic nodal and soft tissue disease. This article briefly describes these three imaging modalities and their role in primary staging, detection of hepatic metastases and local recurrence.

Comparison of dynamic helical CT and dynamic MR imaging in the evaluation of pelvic lymph nodes in cervical carcinoma

OBJECTIVE

This study compares dynamic helical CT with dynamic MR imaging in the evaluation of pelvic lymph nodes in cervical carcinoma.

SUBJECTS AND METHODS

Women with biopsy-proven cervical carcinoma prospectively underwent dynamic helical CT and MR imaging before surgery. A metastatic node on CT and MR imaging was defined as a rounded soft-tissue structure greater than 10 mm in maximal axial diameter or a node with central necrosis. Imaging results were compared with pathology, and receiver operating characteristic curves for size and shape were plotted on a hemipelvis basis. Nodal density and signal intensity on CT and MR images, respectively, were reviewed for differences between benign and malignant disease.

RESULTS

A total of 949 lymph nodes were found at pathology in 76 hemipelves in 43 women, of which 69 lymph nodes (7%) in 17 hemipelves (22%) were metastatic. Sensitivity, specificity, positive and negative predictive values, and accuracy of helical CT and MR imaging in the diagnosis of lymph node metastasis on a hemipelvis basis was 64.7%, 96.6%, 84.6%, 90.5%, and 89.5% and 70.6%, 89.8%, 66. 7%, 91.4%, and 85.5%, respectively. Receiver operating characteristic curves for helical CT and MR imaging gave cutoff values of 9 and 12 mm in maximal axial diameter, respectively, in the prediction of metastasis. Central necrosis had a positive predictive value of 100% in the diagnosis of metastasis. Signal intensity on MR imaging and density-enhancement pattern on CT in patients with metastatic nodes did not differ from those in patients with negative nodes.

CONCLUSION

Helical CT and MR imaging show similar accuracy in the evaluation of pelvic lymph nodes in patients with cervical carcinoma. Central necrosis is useful in the diagnosis of metastasis in pelvic lymph nodes in cervical cancer.

Magnetic resonance appearance of normal inguinal nodes

AIM

To identify adult inguinal lymph node anatomical subgroups using magnetic resonance imaging (MRI), to derive a normal range for nodal number and size and to describe their morphology.

MATERIALS AND METHODS

Eighty-three oncology patients with low stage pelvic tumours had inguinal lymph node assessment by MRI. Nodes were divided into proximal superficial (PS), distal superficial (DS) and deep inguinal (DI) subgroups, their number counted in two planes, and their transaxial short axis diameter recorded. Consistency of the largest node was recorded for each anatomical subgroup and two vertical distances measured, between the skin surface and the ipsilateral pubis, and between the skin surface and the deepest node.

RESULTS

Transaxial plane maximum nodal number at the three sites was: PS 5, DS 8, DI 3; and in the coronal plane: PS 7, DS 5, DI 3. Nodal size ranges were: PS 3-10 mm (mean 4 mm), DS 3-15 mm (mean 6 mm) and DI3-10 mm (mean 6 mm). There was no correlation between nodal size or number and age or gender. Nodes were usually uniformly solid (PS 44%; DS 37%, DI 45%), or fatty (PS 39%; DS 33%; DI 25%). The range of distances between the skin and deepest lymph node was 2.5-16 cm depending on patient fatness.

CONCLUSION

The mean number of nodes counted in the axial plane was six and in the coronal plane five. A maximum short axis diameter of 15 mm was recorded for inguinal lymph nodes.

Imaging as Back-Up in the Management of Bladder Cancer

All imaging techniques provide a valid back-up during diagnosis. The accuracy of CT and MRI in staging and follow-up is considered and their relative incapacity in differentiating between superficial and deep muscular invasion of the bladder and between benign and malignant lymphadenopathy. Encouraging results have been obtained by applying the PET to lymph node staging.

Diagnostic imaging modalities during pregnancy

This article discusses how imaging of distant disease, and imaging in general, may affect the fetus. Imaging examples of primary disease will be presented of the most common malignancies for women of child bearing years who happen to be pregnant.

Assessment of rectal tumor infiltration utilizing endorectal MR imaging and comparison with endoscopic rectal sonography

BACKGROUND

The preoperative assessment of depth of invasion of rectal carcinoma is increasingly important as new treatment methodologies are developed. Accuracy of preoperative endorectal MR imaging was therefore compared with that of the endoscopic rectal sonography in determining depth of invasion of rectal carcinomas.

METHOD

From March 1993 to April 1994, 10 consecutive patients with biopsy-proven rectal carcinomas were imaged with both endorectal MR imaging and endoscopic rectal sonography. These two studies were performed an average of 2.7 days apart in each patient. All 10 patients had surgical resection of the rectal carcinoma within days of imaging studies. TNM staging of each malignant lesion was correlated with the imaging reports.

RESULT

Staging accuracy was 80% for endorectal MR imaging and 70% for endoscopic rectal sonography. With MR imaging, one T2 lesion was overstaged and one T3 lesion was understaged. With sonography, two T2 lesions were overstaged and one T3 lesion was understaged. One MR error resulted from misinterpretation. All other staging errors occurred in patients with tumor spread into, but not through, the muscularis propria or with microscopic spread through this layer.

CONCLUSIONS

Endorectal MR imaging and endoscopic rectal sonography have similar accuracy for assessing depth of invasion of rectal carcinoma.

Current CT/MRI examination of the lower intestinal tract

For evaluating primary colonic and rectal malignancies, CT and MRI are often complementary imaging methods which are useful in assessing patients suspected of having extensive disease and in deciding whether a patient will benefit from preoperative radiation. CT is also helpful in designing radiation ports and in detecting complications related to the neoplasm such as perforation with abscess formation. MRI offers excellent tissue resolution which aids in distinguishing between localized colorectal disease and disease which invades muscle. Also, MRI can add information with coronal views for determining whether a sphincter-saving procedure can be performed, and may be of benefit for assessing the subtle extent of tumour into muscle and bone. However, CT and MRI lack the ability to assess depth of neoplastic involvement within bowel wall. This limitation is the major factor which, combined with the inability to diagnose metastatic tumour foci in normal-sized nodes and microinvasion of perirectal fat, prevents optimal tumour staging. Because of the low accuracy for assessing early cancer stages, neither CT nor MRI are recommended for routine use in preoperative staging. CT and MRI have a premier role in the assessment of recurrent colorectal neoplasm, with CT providing a slightly better overall evaluation due to volume imaging, easy image reconstructions in different planes, and availability of excellent oral and intravenous contrast agents. Cross-sectional imaging is the only method to evaluate fully patients with total AP resection, particularly male patients. Neither CT nor MRI can determine with certainty that a soft tissue density in the surgical bed following total AP resection represents recurrent tumour unless a clear mass is present which has increased in size over time. However, both methods surpass colonoscopy for detecting early mass-like tumour recurrence at the anastomotic site due to its extrinsic component. Cross-sectional imaging plays a prominent role in assessing inflammatory disease of the colon. Clinical history, laboratory data and extent of involvement are used together with results from radiographic examinations to reach a specific diagnosis. CT is preferred over MRI in the assessment of extent of inflammatory disease in and beyond the bowel wall. An additional benefit of CT over MRI is the fact that patients with abscesses or large fluid collection can undergo drainage while still in the CT scanner. CT and MRI can aid in the distinction between ulcerative colitis with minimal wall-thickening and Crohn's disease with marked wall-thickening combined with skip lesions and fistula and/or abscess formation.(ABSTRACT TRUNCATED AT 400 WORDS)

MR imaging of infradiaphragmatic lymphadenopathy in children and adolescents with Hodgkin disease: comparison with lymphography and CT

The ability of short-inversion-time inversion recovery (STIR) magnetic resonance imaging to depict infradiaphragmatic lymphadenopathy was evaluated in 25 consecutive patients with newly diagnosed Hodgkin disease. All patients underwent computed tomography (CT) and multiplanar STIR imaging prior to lymphography (LAG). The STIR and CT images were evaluated for paraaortic and parailiac node enlargement. Findings were compared with LAG findings, which showed the architectural pattern of the opacified lymph nodes. In the upper paraaortic region, STIR imaging showed more abnormal nodes than did CT or LAG. In the lower paraaortic and parailiac regions, lymph node enlargement was shown equally well with STIR and LAG, whereas CT showed fewer enlarged lymph nodes. LAG showed paraaortic or parailiac focal tumor infiltration in three patients with normal-size nodes, and hyperplasia in two patients with enlarged nodes. STIR imaging showed more abnormal infradiaphragmatic nodes than did CT because of improved lymph node conspicuity. STIR imaging may be a useful addition to CT for staging pediatric Hodgkin disease.

Diagnostic value of magnetic resonance imaging in gynaecology

In this study 23 patients with various gynaecological pathologies were evaluated. Ultrasonography and magnetic resonance imaging were performed in all cases, but only 14 were evaluated with computed tomography. On the basis of ultrasonography, 4 patients were labelled as having malignant ovarian tumours, however, this diagnosis was confirmed by magnetic resonance imaging in only 1 of the 4. Magnetic resonance imaging also determined the correct diagnosis in a patient with endometrioma whereas computed tomography showed only a simple cyst, and ultrasonography diagnosed a subserous myoma. Tumour was demonstrated by magnetic resonance imaging in 2 patients with cervical carcinoma although computed tomography and ultrasonography had previously shown no tumour mass in these patients. It was concluded that magnetic resonance imaging is much superior to computed tomography and ultrasonography in gynaecological diagnosis. This advantage results from the correct detection of the contents of ovarian cysts, the number and localization of uterine leiomyomas in T2 scans, invasion of uterine malignancies and differential diagnosis of subserous uterine leiomyomas from ovarian tumours.

Contrast enhancing lymph nodes in bladder cancer: a potential pitfall on CT

We report three cases of bladder cancer in which contrast enhanced computed tomography (CT) demonstrated minimally enlarged lymph nodes. These showed uniform uptake of contrast medium to a similar degree as adjacent venous structures, making the distinction between vessels and lymph nodes difficult. Magnetic resonance imaging (MRI) examination resolved the problem in two of the three patients.

Indium-111 monoclonal antibody B72.3 scintigraphy in colorectal cancer. Correlation with computed tomography, surgery, histopathology, immunohistology, and human immune response

As part of an open-labeled nonrandomized multi-institutional Phase III study, the authors compared the results of In-111 (In-111) B72.3 glycyl-tyrosyl-n-diethylenetriaminepentaacetic acid lysine (GYK-DTPA) monoclonal antibody scintigraphy with computed tomography (CT), surgery, histopathology, immunohistology, and human antibody response in 23 patients with primary colorectal carcinoma. There were no significant adverse reactions to 1 mg of In-111-labeled antibody. Planar imaging identified 16 of 23 primary colon lesions, whereas single photon emission computer tomography (SPECT) imaging identified 21. SPECT also correctly identified lymphatic involvement in four patients. (There were two false-positive results.) Liver metastases were identified with SPECT imaging. Twenty-six percent of patients developed human anti-mouse antibody (HAMA). These preliminary results demonstrate that In-111 B72.3 GYK-DTPA is a safe monoclonal antibody conjugate that has a high sensitivity for identifying primary colorectal cancer. Regional lymphatic and distant liver metastases also can be imaged, but false-positive results can occur.

Skeletal muscle lymphoma: MRI evaluation

The magnetic resonance imaging (MRI) features of two cases of malignant lymphoproliferative disease involving skeletal muscle are presented. In both cases involved muscles were quantitatively and subjectively hypointense to fat on T1-weighted spin echo images, hypointense or isointense on T2-weighted spin echo images, and hyperintense on short tau inversion recovery (STIR) images. The findings suggest that lymphoproliferative disease should be considered as an etiology of a skeletal muscle lesion that is hypointense or isointense to fat on T2-weighted spin echo magnetic resonance images.

Diagnostic imaging of gynecological diseases: the clinician's view

The introduction of ultrasonography, computerized tomography, and magnetic resonance imaging has led to tremendous progress in the diagnostic evaluation of gynecologic diseases. Refinements in these techniques have allowed the gynecologist to diagnose unsuspected pathology, define disease and its extent, and select the most appropriate treatment despite limitations in specificity experience and cost. Practically the most appropriate imaging modalities are: ultrasonography for adnexal masses, computerized tomography for advanced cervical cancers, and magnetic resonance imaging for corpus cancers and selected cervical cancers.

A clinically viable technique of fat suppression for abdomen and pelvis

Chemical-shift selective imaging with an improved selective presaturation pulse can be used to suppress the fat signal uniformly across the entire abdominal cavity. The required magnetic field homogeneity is no higher than for a routine diagnostic scan. Therefore, no extra setup time for shimming is needed. The technique has been implemented on our clinical system for routine fat suppression scans.

Lymphography--current role in oncology

A review of the use of lymphography at this hospital, a major oncology centre, is presented. The advent of computed tomography has brought a dramatic reduction in the number of lymphograms currently performed for diseases such as lymphoma, testicular tumours and gynaecological malignancies. This study analyses the reasons for this decline, and concludes that valuable information can still be obtained from lymphography in certain selected groups of patients.

Magnetic resonance imaging in the initial staging of Hodgkin's disease and non-Hodgkin lymphoma

Seventy-four consecutive previously untreated patients with Hodgkin's disease (HD) and non-Hodgkin lymphomas (NHL) were evaluated with chest, abdominal and pelvic magnetic resonance (MRI) for initial staging. All patients underwent routine radiological staging procedures which included chest radiographs and lymphography (LAG). These studies were followed in most of cases by laparoscopy, during which biopsies of the liver and the spleen were taken, and bone marrow aspiration and histology. A correlation of the results of MRI with both other imaging studies and histopathologic diagnoses was performed, and discordant cases were assessed to determine the impact on clinical staging. Additional evidence of disease involvement was provided mainly in the chest, where MRI demonstrated the presence of unsuspected disease in 21% of involved patients (9 of 42). Retroperitoneal lymph nodes were correctly assessed in 97% of cases if MRI was compared with LAG. Extranodal abdominal disease was identified both in the spleen (14%) and in the liver (1%). Bone marrow abnormalities were detected in 19% of patients (14 of 74). MRI findings influenced the staging of HD and NHL patients in 11 of 74 cases (15%).

Magnetic resonance imaging, computed tomography and endosonography in the local staging of carcinoma of the cervix

Thirty-seven patients with carcinoma of the cervix were prospectively staged by examination under anaesthesia (EUA), transvaginal and transrectal ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI). Pathological correlation was available for 20 patients. In the pathologically staged patients, EUA agreed with the staging in 17, understaging three patients. Endosonography agreed with the staging in 19, CT in 16 and MRI in 18 patients. For the remaining 17 patients, endosonography agreed with the EUA findings in 13, CT in 12 and MRI in 12. This study has shown that endosonography and MRI are more accurate than CT in the local staging of carcinoma of the cervix. Computed tomography was least accurate in staging early tumours and differentiating between Stage Ib and IIb disease. Lymph node involvement was detected with equal frequency by both CT and MRI. Magnetic resonance imaging was useful in identifying vaginal and bladder wall involvement and in one patient showed features due to an unsuspected early pregnancy.

Computed tomography and magnetic resonance imaging before salvage cystectomy

Nine patients who developed recurrence of bladder carcinoma following radical radiotherapy were assessed for salvage cystectomy by computed tomography (CT) and magnetic resonance imaging (MRI) to predict extravesical spread. Both tests correctly identified a patient with such advanced local disease that surgery was deemed inappropriate at examination under anaesthesia and both tests indicated that surgery might be difficult in a further patient with inoperable disease. Both tests demonstrated abnormalities in the perivesical and pelvic fat planes in all patients but they had difficulty in distinguishing between malignant infiltration and the effects of radiotherapy. Nevertheless, each test is useful in excluding gross pelvic disease and predicting involvement of adjacent organs. The advantages of the multiplanar images provided by MRI must be balanced against the high cost. CT readily demonstrates the upper abdomen, the kidneys and para-aortic nodes as well as the pelvis and is more widely available.

Imaging prostate derived tumors with PET and N-(3-[18F]fluoropropyl)putrescine

Because of the high uptake of polyamines by the prostate and by prostate derived tumors, polyamines have been considered as potential imaging agents for metastatic prostate cancer. We now report the successful PET imaging of the Dunning R3327H prostatic carcinoma with N-(3-[18F]fluoropropyl)putrescine (FPP), a positron-labeled putrescine analog. Additionally, the biodistribution of FPP in tumor bearing Copenhagen male rats is analyzed. The tumor uptake of FPP was high, and the tumor-to-muscle ratios at 1, 2, 3 and 4.5 h post-injection were 7.2 +/- 1.0, 5.61 +/- 1.65, 4.62 +/- 0.21 and 3.51 +/- 0.91 respectively. The estimated radiation dose for FPP was calculated from rat biodistribution data. The radiation dose estimates suggest that the critical organ, following the administration of FPP, is the upper large intenstine which receives 0.3 rad/mCi administered.

Magnetic resonance imaging in recurrent carcinoma of the cervix

Twenty patients with suspected recurrent cervical carcinoma were evaluated with computed tomography (CT) and high-field magnetic resonance imaging (MRI). Histological verification of the imaging findings were available in all cases. Computed tomography and MRI were equally effective in making the diagnosis of disease recurrence. The extent of vaginal recurrence and involvement of pelvic floor muscles was better shown on MRI than on CT.

High-field MRI of primary gallbladder carcinoma

The magnetic resonance (MR) imaging features are described in a case of gallbladder carcinoma presenting as a fungating mass associated with gallstones as well as biliary obstruction due to pancreaticoduodenal lymph node metastasis. The MR findings complemented diagnostic observations made on preoperative sonography and computed tomography of the abdomen.

Magnetic resonance imaging of the retroperitoneum

Magnetic resonance imaging (MRI) represents the most recent development in imaging of the retroperitoneum. This article discusses the utility of MRI in evaluating the abdominal aorta, inferior vena cava, lymph nodes, and psoas muscle.

MRI of hepatic lymphoma

Thirteen patients with biopsy proven hepatic lymphoma (2 Hodgkin, 11 Non-Hodgkin) and a control group of 15 patients with hepatic metastases were analyzed quantitatively and qualitatively by MRI. Focal hepatic lymphoma was most reliably detected (eight of eight patients) and appeared hypointense relative to liver on T1 weighted (CNR - 7.4 +/- 2.3) and hyperintense on T2 weighted (CNR + 8.4 +/- 2.9) images. The mean T1 and T2 relaxation times of focal hepatic lymphoma (T1 = 832 +/- 234 msec, T2 = 84 +/- 16 ms) differed significantly from adjacent non-tumorous liver (T1 = 420 +/- 121 ms, T2 = 51 +/- 9 ms; p less than 0.05), however CNR values and relaxation times were similar to those of hepatic metastases. Diffuse hepatic lymphoma (microscopic periportal infiltration) was undetectable by MRI in three patients by either morphologic features or quantitative criteria. A mixed pattern of hepatic lymphoma (focal lesions and diffuse infiltration) showed focal areas of slightly decreased signal intensity on T1 weighted images (CNR = -1.7 +/- 0.4) while T2 weighted images revealed multiple regions of focal hyperintensity (CNR = +13.3 +/- 8.4) superimposed on a diffusely hyperintense liver. Our experience demonstrates that either T1 or T2 weighted techniques are useful in detecting focal and that T2 weighted techniques are useful in detecting mixed hepatic lymphoma. Conventional image derived relaxation time measurements and quantitative parameters were of no additional diagnostic value.