The role of lymphangiography in vulvar carcinoma

The records of all patients with vulvar carcinoma seen at Washington University School of Medicine between 1970 and 1983 were reviewed to determine the role of lymphangiography in the management of patients with vulvar malignancy. Forty-three patients were identified who had a preoperative lymphangiogram followed by radical vulvectomy and lymph node dissection. Thirty-two films were available for review. Seventy-seven sets of lymph nodes were obtained from the 32 patients. Overall diagnostic accuracy was 42 of 77 (54.5%), with a sensitivity of three of 19 (15.7%) and a specificity of 39 of 59 (66.1%). Corresponding values for inguinal nodes were 26 of 57 (45.6%), two of 16 (12.5%), and 24 of 41 (58.5%), respectively. Accuracy rates for pelvic nodes were 16 of 21 (76.2%) with a sensitivity rate of one of three (33%) and a specificity of 15 of 18 (83%). Negative scans were more likely to be accurate than positive scans, 88.6% versus 30%. While a negative lymphangiogram may be helpful in predicting the absence of metastases, its poor specificity limits its widespread usefulness.

Oblique magnetic resonance imaging of the cardiovascular system

This exhibit demonstrates that cardiac anatomy can be imaged by MRI in oblique planes that are equivalent to views obtained radiographically or at angiocardiography. These MR images may be obtained either by simple patient positioning or by electronic rotation of the imaging axis. The advantages of this technique include its simplicity and its ability to show detailed anatomy noninvasively. Major cardiac structures including chambers, walls, vessels and bronchi are optimally demonstrated in long axis or cross section. This permits estimation of chamber volume, wall thickness, vessel position and variations from normal. Smaller structures are also well visualized. These include the pericardium, papillary muscles, azygos vein and some cross sectional anatomy of the coronary arteries and veins. The valvular structures can be shown during diastole or systole. The ability of MRI to show these cardiac structures due to the intrinsic contrast differences in signal intensity between muscle, fat, flowing blood and lung suggest an important future for MR cardiac imaging in a broad group of congenital and acquired diseases of the heart, pericardium and great vessels.

MRI of extracranial hematomas: preliminary observations

Thirteen patients (16 examinations) with extracranial hematomas (four mediastinum, three pelvis, two calf, two psoas muscle, one liver, one abdominal wall) were examined with magnetic resonance imaging (MRI). With the exception of an acute hematoma (less than 48 hr), which did not have a distinctive MRI appearance, subacute and chronic hematomas (up to 10 months' duration) had areas of high signal intensity on both T1- (TR 500/TE 30) and T2- (TR 1500/TE 90) weighted pulse sequences. The hematomas in 10 of the patients were also evaluated by computed tomography (CT). The MRI findings complemented those seen on CT. Low-intensity parts of the hematoma on both T1- and T2-weighted images corresponded to areas of high attenuation on CT, whereas high-intensity zones correlated with regions of low attenuation. This observation was more apparent on the T1-weighted images. While older hematomas did not exhibit areas of hyperdensity that would allow a specific diagnosis on CT, MRI did demonstrate regions of high signal intensity indicative of hemorrhage.

Anatomy of the perirenal area

The authors comment on the use of the renal bridging septa as a sign in distinguishing compartmentalization of the perinephric space. They also address new concepts regarding the spread of pancreatic effusions and provide information on other anatomic features of the perirenal area.

Prostatic carcinoma and benign prostatic hyperplasia: inability of MR imaging to distinguish between the two diseases

Forty patients with prostatic carcinoma or benign prostatic hyperplasia (BPH) underwent magnetic resonance (MR) imaging of the prostate. In vitro MR images of six prostate specimens were also obtained. The prostatic parenchyma was best evaluated by a T2-weighted spin-echo pulse sequence. The prostate both in patients with prostatic carcinoma and patients with BPH often had an inhomogeneous and nodular appearance on T2-weighted images. While most of the prostatic carcinomas appeared hyperintense relative to muscle and adjacent prostatic parenchyma, some of the hyperplastic nodules had a signal intensity similar to carcinoma. With current imaging techniques, MR imaging cannot differentiate prostatic carcinoma from BPH with certainty.

High resolution CT of the porta hepatis and hepatoduodenal ligament

The authors present a detailed analysis of the sectional anatomy of the porta hepatis and hepatoduodenal ligament, and illustrate the use of high resolution CT in the clinical evaluation of the area.

Intravenous cholangiography in the CT era

With the availability of computed tomography (CT), ultrasonography (US), percutaneous transhepatic cholangiography (PTC), and endoscopic retrograde cholangiopancreatography (ERCP), the use of intravenous cholangiography (IVC) has waned. A retrospective study of 69 intravenous cholangiograms performed from 1979 through 1982 assessed the utility of intravenous cholangiography, as well as its effect on patient management, at an institution where CT was highly developed. In no case after normal findings on CT and/or ultrasound examination did IVC make a positive pathologic diagnosis. After abnormal results on CT and/or US examinations, in no case did IVC add to the diagnosis. Finally, after technically suboptimal results of CT and/or US examinations, IVC made only 1 positive pathologic diagnosis. Overall, IVC correctly demonstrated only 5 of 9 cases of common duct stones or strictures. Of the 26 cases with anatomical correlation there were a total of 7 false-positive and -negative IVC examinations. In this series, IVC was rarely useful in the diagnosis of biliary tract disease. Given the high inaccuracy rate of IVC in this study, its use for the exclusion of biliary tract disease is discouraged.

Fatty infiltration of the liver: evaluation by proton spectroscopic imaging

The reliability of proton spectroscopic imaging in evaluating fatty infiltration of the liver was investigated in 35 subjects (12 healthy volunteers and 23 patients with fatty livers). With this modified spin-echo technique, fatty liver could be separated from normal liver both visually and quantitatively. On the opposed image, normal liver had an intermediate signal intensity, greater than that of muscle, whereas fatty liver had a lower signal intensity, equal to or less than that of muscle. In normal livers, the lipid signal fraction was less than 10%, while in fatty livers it was greater than 10% and usually exceeded 20%. With this technique, nonuniform fatty infiltration of the liver can be differentiated from hepatic metastases, and the technique may prove useful in the differentiation of some hepatic disorders.

Thoracic wall involvement by Hodgkin disease and non-Hodgkin lymphoma: CT evaluation

Thoracic computed tomographic (CT) scans of 250 patients with newly diagnosed or recurrent lymphoma revealed thoracic wall involvement in 24 patients (11 with Hodgkin disease, 13 with non-Hodgkin lymphoma). Thoracic wall involvement occurred without contiguous mediastinal or parenchymal involvement in 17 patients. Of these, 13 patients had masses beneath the pectoralis muscles or within the breast, and four had masses arising from the ribs. Five additional patients had mediastinal masses with thymic involvement and parasternal extension through the thoracic wall. Pulmonary parenchymal lymphoma with thoracic wall invasion was noted in the remaining two patients. In five of nine patients receiving radiation therapy, treatment plans were modified by CT demonstration of thoracic wall lymphoma.

The uterus: in vitro MR-anatomic correlation of normal and abnormal specimens

Magnetic resonance (MR) images of 12 fresh uterine specimens obtained with a high-resolution surface coil were correlated with findings on gross and microscopic pathologic examination. The uterine wall can be differentiated into three distinct zones: a central high-intensity zone, a junctional low-intensity band, and a peripheral medium-intensity area. Whereas the endometrium (basale and functionale) corresponded to the high-intensity zone, the myometrium correlated best with the combined width of the areas of low and medium signal intensity. The signal intensity of a leiomyoma varied, depending on its cellularity. Primary endometrial and cervical carcinomas were clearly shown on MR images, as were other abnormalities such as adenomyosis and Nabothian cysts. The potential usefulness of MR imaging in detecting and staging uterine neoplasms is discussed.

The thoracic aorta studied by MR imaging

Thirty-three patients with a variety of disorders of the thoracic aorta (aneurysm, dissection, Marfan syndrome, coarctation/pseudocoarctation, L-transposition, and Takayasu disease) were evaluated with magnetic resonance (MR) imaging. MR imaging delineated the presence and extent of thoracic aortic aneurysms and showed the relationship of the aneurysm to arch vessels; it also demonstrated intimal flaps and individual lumina in types A and B aortic dissection. Dilation of the ascending aorta in Marfan syndrome and focal narrowing of the aorta in coarctation were well visualized. The anteroposterior and side-to-side relationships of the aorta and pulmonary artery in L-transposition were demonstrated, as were aortic wall thickening and branch vessel narrowing in Takayasu arteritis. Initial experience suggests that MR imaging may provide a noninvasive method for evaluating thoracic aortic disease. Limitations include inferior spatial resolution, occasional difficulty in imaging the entire region of interest in one section, lack of signal from calcifications, and inability to monitor critically ill patients.

Radiation fibrosis: differentiation from recurrent tumor by MR imaging

Magnetic resonance (MR) images of 21 patients who had undergone radiation therapy were analyzed and compared with those of 15 patients who had untreated tumors. T2-weighted images (TR = 1,500 msec, TE = 90 msec) were most helpful in distinguishing recurrent tumor from radiation fibrosis. Radiation fibrosis, like muscle, usually remained low in signal intensity on T2-weighted images, while tumor demonstrated higher signal intensity. In no patient was the signal intensity of tumor the same or less than muscle on the T2-weighted images. However, relatively high signal intensity on T2-weighted images is not specific for tumor recurrence and may be seen in acute radiation pneumonitis, infection, hemorrhage, and even pulmonary radiation fibrosis.

Detection of hepatic metastases by proton spectroscopic imaging. Work in progress

Fourteen patients with hepatic metastases underwent magnetic resonance (MR) imaging using both the conventional spin-echo (SE) technique and the opposed phase of the proton spectroscopic imaging method. The opposed image showed more lesions than the conventional SE image in five patients and provided better contrast between the liver parenchyma and metastases in two patients. Four of these seven patients had associated fatty infiltration of the liver. When compared with the computed tomography (CT) scan, the opposed image either showed more lesions or provided better contrast in six patients, four of whom had fatty infiltration. More significantly, the MR image showed several 1-cm lesions not shown by the CT scan in one patient. Our study discloses the possible explanations for the increased sensitivity of the opposed image in detecting hepatic metastases.

Hepatic metastases studied with MR and CT

Examinations of the liver using magnetic resonance (MR) and computed tomography (CT) were performed on 50 patients with hepatic metastases. MR and CT were comparable in their ability to detect metastases, which generally appeared hypointense compared with normal liver parenchyma on T1-weighted MR images and hyperintense on T2-weighted images. The MR imaging techniques that were most reliable in detecting metastases were inversion recovery and a relatively T2-weighted, spin-echo technique (TR = 1,500 msec, TE = 60 msec). We conclude that CT, because of its shorter imaging time, greater spatial resolution, and lower cost, should remain the preferred screening test for hepatic metastases. MR imaging should be reserved for patients with equivocal CT findings and for patients in whom there is persistent clinical suspicion of hepatic metastases despite a negative CT examination.

Magnetic resonance imaging of mediastinal and hilar masses: comparison with CT

Magnetic resonance imaging (MRI) was compared to computed tomography (CT) of the mediastinum and/or hila in 37 patients with bronchogenic carcinoma (35 unresectable for cure) and 11 patients with other masses. Spin-echo pulse sequences using a short pulse repetition rate (TR) and short echo delay (TE) were most helpful for detection of abnormal soft-tissue mediastinal and hilar masses. The accuracy of MRI and CT in staging bronchogenic carcinoma for curative resectability/nonresectability was comparable. CT staged 35 of 37 cases appropriately, while MRI correctly staged 36 of 37 cases. Several pitfalls in MRI evaluation of the mediastinum were identified. By MRI the esophagus may be misinterpreted as an enlarged retrotracheal lymph node unless serial scans are studied. Scattered calcifications in enlarged mediastinal and hilar lymph nodes due to old granulomatous disease are not detectable by MRI. Small adjacent lymph nodes shown individually by CT may appear as a single enlarged lymph node by MRI due to partial-volume averaging. Small lung nodules may be undetected by MRI due to respiratory motion and partial-volume averaging. Certain patients are unsuitable for MR scanning. Because of the requirement for patient selection and the identified pitfalls of MRI, CT remains the radiologic procedure of choice in the staging of patients with bronchogenic carcinoma and the evaluation of other mediastinal and hilar masses at present. However, because of the ability to show blood vessels without an intravascular contrast agent, MRI is useful in evaluating patients with potential contrast allergy and solving diagnostic problems not solved by CT.

Barium pharyngography: comparison of single and double contrast

In 119 patients referred for barium pharyngography, both single- and double-contrast examinations were performed. The air-contrast examinations were easier to perform and yielded fewer suboptimal studies than the single-contrast examinations. Neither technique proved to be sensitive in the detection of lesions in the oral cavity, but for lesions in the pharynx, the air-contrast technique had a higher sensitivity (87% vs. 33%) and overall accuracy (94% vs. 84%) than the combination of single-contrast radiography and videotaped fluoroscopy. Single-contrast films provided no further information than the combination of the air-contrast views and the videotaped fluoroscopy. The air-contrast examination was clinically helpful in those patients in whom indirect laryngoscopy was difficult.

Utilization characteristics of a superconductive MR system undergoing initial clinical trial

The authors describe their initial 7 month experience with magnetic resonance (MR) imaging using a superconductive MR system. Factors affecting system utilization were scheduled and unscheduled downtime, specific system characteristics, and physician experience with the new technology. Technical improvements that reduced the duty cycle and radiologist experience in tailoring examinations have improved patient throughput by reducing the average patient study time by approximately 40% during the 7 month survey. These considerations have important economic consequences for patients and operators of MR equipment.

Demonstration of a splenic artery pseudoaneurysm by MR imaging

The magnetic resonance (MR) features of a splenic artery pseudoaneurysm are described in a patient with recurrent pancreatitis. Correlation of MR, CT, and pathologic findings is made, and the advantage of MR imaging for the diagnosis of vascular abnormalities is outlined.

Oblique views of the heart by magnetic resonance imaging

We describe a simple method that uses patient positioning to obtain oblique views of the human heart by magnetic resonance (MR) imaging. These views provide MR images that directly correlate with conventional anterior or posterior oblique radiography.

Magnetic resonance imaging of abdominal aortic aneurysms

Magnetic resonance imaging (MRI) was performed in 20 patients with radiologically or surgically proven abdominal aortic aneurysms using a Siemens Magnetom scanner with a 0.35-T superconductive magnet. On MRI, rapidly flowing blood emits little or no signal and appears black; stagnant blood, turbulent flow, and atheromatous plaques produce signals of various intensities and are imaged as light to medium gray. Of nine patients who underwent surgical repair, MRI correctly demonstrated the origin of the aortic aneurysm in nine and accurately determined the status of the iliac arteries in eight. In two patients in whom intravenous contrast administration was contraindicated, MRI provided the correct diagnosis of a mycotic pseudoaneurysm in one and clearly distinguished the iliac arteries from the surrounding fibrosis in the other. Of 11 patients who did not have surgical repair, MRI findings correlated well with other radiologic studies. MRI was found to be more reliable than sonography in determining the relation between the aneurysm and the renal arteries as well as the status of the iliac arteries. Despite these advantages, the authors still advocate sonography as the screening procedure of choice in patients with suspected abdominal aortic aneurysms because of its lower cost and east of performance. MRI should be reserved for patients who have had unsuccessful or equivocal sonographic examinations.

The neck after total laryngectomy: CT study

Computed tomographic scans in 23 patients who had undergone total laryngectomy were analyzed retrospectively to determine normal postoperative appearance and to evaluate the role of CT in assessing recurrent neoplasm. Nine patients without clinical evidence of recurrence illustrated the normal postoperative changes: a round or ovoid neopharynx connecting the base of the tongue with the cervical esophagus and intact fat planes surrounding the neopharynx, neurovascular bundles, and sternocleidomastoid muscles. In the 12 patients with recurrent neoplasm, the CT manifestations included masses involving the internal jugular lymph node chain (adjacent to the neopharynx, neurovascular bundles, or sternocleidomastoid muscles), tracheostomy site, or paratracheal region. Recurrence was mimicked on CT in two patients, one with an abscess and one with metastases from an adenocarcinoma of unknown primary site. In eight patients, a distended neopharyngeal lumen correlated with benign or malignant stricture. CT supplemented physical examination and indirect mirror examination, providing data regarding presence and extent of recurrent tumor and aiding in planning the mode and scope of therapy.

A double-blind clinical study comparing the safety and efficacy of Hexabrix and Renografin-76 in contrast enhanced computed body tomography

Hexabrix, a new low osmolality, iodinated contrast medium and the ionic diatrizoate Renografin-76 were studied in a double-blind parallel group comparison to examine safety and efficacy in patients undergoing contrast assisted CT of the liver, spleen and kidney. No significant differences in pulse, respiration and blood pressure before and after injection were noted in the 100 patients studied. Heat sensation in the Hexabrix group was distinctly lower than in those receiving Renografin, but the two groups did not differ with respect to average scores for pain. There was no difference in adverse side effects. Clinical laboratory studies between the groups showed some differences which could not be attributed to the individual contrast agents. While scan quality of both agents was good to excellent, it should be noted that the dose of Hexabrix was not adjusted to compensate for the difference in iodine content (320 mg I/ml vs. 370 mg I/ml for Renografin-76).

Papillary renal cell carcinoma: CT and sonographic evaluation

The CT, sonographic, and pathologic appearances of 13 surgically confirmed cases of papillary renal cell carcinoma were reviewed. CT-pathologic correlation was available in all 13 cases. Sonography was performed in eight patients (10 distinct renal masses). CT features closely correlated with the previously established clinicopathologic and angiographic appearances. Papillary renal cell carcinoma demonstrated low stage at presentation in most cases (10 of 13 had stage I or II), had a high frequency of calcification (seven), and had less enhancement (diminished vascularity) than typical hypernephroma on CT scans. No consistent sonographic pattern existed; one of 10 masses was hyperechoic, five were hypoechoic, and four were isoechoic compared with normal kidney cortex. On the basis of these observations, a prospective CT diagnosis of papillary renal cell carcinoma can be confidently made in many circumstances. This is particularly important when renal-sparing surgery is a clinical consideration.