Management-changing errors in the recall of radiologic results - a pilot study

AIM

To evaluate the occurrence of alterations to diagnostic information from radiological studies, which are altered by person-to-person communication and/or faulty recall, and whether they affect patient management

MATERIALS AND METHODS

A structured telephone survey was conducted at a large tertiary care medical centre of house staff managing inpatients who had undergone chest, abdominal, or pelvic computed tomography (CT) or magnetic resonance imaging (MRI) and remained in the hospital at least 2 days later. Fifty-six physicians were surveyed regarding 98 patient cases. Each physician was asked how he or she first became aware of the results of the study. Each was then asked to recall the substance of radiological interpretation and to compare it with the radiology report. Each was then asked to assess the level of difference between the interpretations and whether management was affected. Results were correlated with the route by which interviewees became aware of the report, the report length, and whether the managing service was medical or surgical.

RESULTS

In nearly 15% (14/98) of cases, differences between the recalled and official results were such that patient management could have been (11.2%) or had already been affected (3.1%). There was no significant correlation between errors and either the route of report communication or the report length.

CONCLUSION

There was a substantial rate of error in the recall and/or transmission of diagnostic radiological information, which was sufficiently severe to affect patient management.

Imaging renal masses

Imaging plays a crucial role in the detection, characterization, and post-operative follow-up of renal masses. With rapidly advancing technology, imaging techniques are continuously evolving. This review will discuss the current modalities and techniques available for renal imaging, and recent developments.

Dexamethasone does not significantly contribute to the response rate of docetaxel and estramustine in androgen independent prostate cancer

PURPOSE

We evaluated the independent response rate of dexamethasone before docetaxel and estramustine administration as measured by changes in serum prostate specific antigen (PSA) in patients with androgen independent prostate cancer.

MATERIALS AND METHODS

A total of 12 patients received 20 mg. dexamethasone orally every 6 hours for 3 doses repeated every 3 weeks before starting cytotoxic therapy with estramustine and docetaxel. After progression on dexamethasone 280 mg. estramustine orally 3 times daily on days 1 to 5 and 70 mg./m.2 docetaxel intravenously for 1 hour on day 2 were given.

RESULTS

None of the patients initially treated with dexamethasone monotherapy (median 1 cycle, range 1 to 5) had a PSA decline of 50% or greater. Median PSA increase on monotherapy was 47% (range 0% to 22%). On estramustine and docetaxel therapy PSA decreased 50% or greater in 11 patients (92%, 95% confidence intervals [CI] 60 to 99) and 80% or greater in 7 (58%, 95% CI 29 to 84), and normalized in 5 (42%, 95% CI 16 to 71), with a median duration of response of 153 (range 42 to 371), 132 (range 84 to 287) and 84 (range 21 to 174) days, respectively. Median times to reach 50% and 80% decreases in baseline PSA were 21 (range 21 to 209) and 63 (range 21 to 138) days, respectively. In 9 patients (75%, 95% CI 43 to 93) PSA decreased at least 50% by week 9. Of 4 patients with bidimensionally measurable disease 3 had a partial response. Median time to progression was 263 days (range 91 to 378).

CONCLUSIONS

Administration of 20. mg. dexamethasone orally every 6 hours for 3 doses every 3 weeks does not significantly contribute to the PSA response rate of estramustine and docetaxel.

Which patients with newly diagnosed prostate cancer need a computed tomography scan of the abdomen and pelvis? An analysis based on 588 patients

OBJECTIVES

Although a computed tomography (CT) scan of the abdomen and pelvis is often recommended as part of the staging evaluation for newly diagnosed prostate cancer, most scans are negative for metastases. We hypothesized that biopsy Gleason score, serum prostate-specific antigen (PSA) levels, and clinical stage could predict for a positive CT scan and that a low-risk group of patients could be identified in whom CT might be omitted.

METHODS

All patients who had both pathologic review of their prostate cancer biopsies and abdominopelvic CT scans at our institution between January 1990 and May 1996 were studied. Gleason score, PSA, and stage were evaluated by univariate (chi-square) and multivariate (logistic regression) analyses for their ability to predict for a positive CT.

RESULTS

Of 588 patients, 41 (7%) had a positive CT scan. Multivariate analysis showed Gleason score, PSA, and clinical stage to be significant independent predictors of a positive CT scan, all P <0.001. The odds ratios for a positive CT scan were 6.17 (95% confidence interval [CI] = 1.58 to 24) for Gleason score 8 to 10 versus 2 to 6; 2.25 (CI = 1.24 to 4) for PSA greater than 50 versus 0 to 15 ng/mL; 2.08 (CI = 1.70 to 3.21 ) for Stage T2c-T4 versus T2b or lower. All 244 patients with Gleason score 2 to 7, PSA 1 5 ng/mL or less, and clinical Stage T2b or less had negative CT scans. Of the other 174 patients with a Gleason score of 2 to 7, 8 (5%) had a positive CT scan. Of the 1 26 patients with a Gleason score of 8 to 10, 28 (22%) had a positive CT scan.

CONCLUSIONS

Gleason score, PSA, and clinical stage were independent predictors for a positive CT scan of the abdomen and pelvis in patients with newly diagnosed prostate cancer. In this cost-conscious era, we can decrease expenditure by obviating the need for a CT scan in low-risk patients (clinical Stage T2b or less, Gleason score 2 to 7, and PSA 15 ng/mL or less). A CT scan should be considered in all other patients.

Large degenerated adrenal adenomas: radiologic-pathologic correlation

PURPOSE

To correlate the radiologic and pathologic findings and differential diagnosis of large, degenerated adrenal adenomas.

MATERIALS AND METHODS

The authors reviewed the radiologic and pathologic characteristics of 30 large adenomas with cystic regions or areas of heterogeneity that were either intrinsic or demonstrated at contrast material-enhanced computed tomography (CT) or magnetic resonance (MR) imaging. Images of 24 adrenocortical carcinomas were also reviewed to determine whether differentiating characteristics existed.

RESULTS

Most of the adrenocortical adenomas were in asymptomatic women. Ten adenomas contained calcification. Pathologic examination revealed good correlation between heterogeneity and liquefied regions. Histologic examination confirmed regions of adenomatous tissue with areas of hemorrhage, amorphous degenerated material, calcification, and fibrosis. Some tumors contained myelolipomatous foci. Although some clinical and imaging findings differed between the groups, no features could be found that enabled the radiologic differentiation of adenomas from carcinomas.

CONCLUSION

A subgroup of adrenal adenomas are larger, more heterogeneous, and more frequently calcified than those with the usual imaging findings. Central necrosis, hemorrhage, or both are responsible for many of the imaging features. Differentiation of these lesions from other large adrenal masses, including adrenal carcinoma, cannot be made by means of imaging alone; resection is required for the definitive diagnosis.

Radiologic follow-up of patients with T1-3a,b,c or T4N+M0 renal cell carcinoma after radical nephrectomy

OBJECTIVES

To determine the pattern of disease recurrence after radical nephrectomy in patients with node-positive renal cell carcinoma (RCC) in order to design a schedule for subsequent radiologic evaluation.

METHODS

We reviewed the postoperative radiologic studies of 45 patients with T1-3a,b,c or T4N+M0 RCC enrolled in a prospective trial of adjuvant autolymphocyte therapy (ALT) after radical nephrectomy for node-positive disease. Chest radiograph and abdominal computed tomography (CT) were performed quarterly, and bone scan and head CT were performed every 6 months until disease recurrence, or earlier if clinically indicated. Time from surgery to recurrence and sites of recurrence were analyzed.

RESULTS

Twenty-nine patients (64%) had disease progression, with a mean time to progression of 14.9 months. Mean follow-up of patients without progression was 39 months. The sites of recurrence were retroperitoneal lymph nodes (n=14), lung (n=11), liver (n=5), bone (n=5), mediastinal lymph nodes (n=4), renal fossa (n=3), pelvis (n=2), brain (n=2), contralateral kidney (n=1), retrocecum (n=1), and skin (n=1). Fourteen patients had recurrence at more than one site. Of the patients whose disease progressed, 59% did so by 12 months, 83% by 24 months, and 93% by 36 months. Mean time to progression in the ALT group was delayed compared with the observation group, but the sites of disease recurrence were not different between the two groups. Abdominal CT alone detected recurrent lesions in 79% of patients with progression, and the combination of abdominal CT and chest radiograph detected lesions in 100% of patients with progression.

CONCLUSIONS

Abdominal CT with chest radiograph detects recurrence in all patients with T1-3a,b,c or T4N+M0 RCC whose disease progresses, and more than 90% of recurrences occur within the first 3 years after surgery. We recommend abdominal CT and chest radiograph every 6 months for at least 3 years and yearly thereafter in this high-risk group of patients.

Occult cancer in women with dense breasts: detection with screening US--diagnostic yield and tumor characteristics

PURPOSE

To evaluate bilateral screening ultrasound (US) in the detection of otherwise occult masses and cancer in women with dense breasts and normal mammographic and physical examination findings.

MATERIALS AND METHODS

Of 11,220 consecutive patients prospectively examined, all 3,626 women with dense breasts and normal mammographic and physical examination findings underwent physician-performed screening US. The size and stage of cancers detected with US alone were compared with those of cancers detected on mammograms, at physical examination, or both, in the remainder of the patients.

RESULTS

In the group of 3,626 women, 11 surgically proved cancers in 11 women (prevalence, 0.30%) were identified with US alone. These cancers were not statistically significantly different in mean surgical size and stage from those of 61 nonpalpable, mammographically detected cancers and were smaller and lower in stage than 64 palpable cancers (P < .01) that were diagnosed in the remainder of the population. In the women with dense breasts, overall cancer detection increased by 17% (from 63 to 74 tumors), and the number of tumors detected only with imaging increased by 37% (from 30 to 41 tumors).

CONCLUSION

Screening US can depict small, early-stage, otherwise occult cancers similar in size and stage to mammographically identified nonpalpable cancers and smaller and lower in stage than palpable cancers in dense breasts.

CT of pancreatitis with renal and juxtarenal manifestations

Involvement of the juxtarenal spaces and kidneys in pancreatitis has been well known. Although delineation of the regions of accumulation of exudate has been elegantly confirmed with the advent and advance of refined computerized tomography (CT) there has been relatively little description in the earlier literature of these phenomena. This essay serves to illustrate the wide range of findings that have been encountered and recorded more recently.

Eight echo T2 measurements of adrenal masses: limitations of differential diagnosis by relaxation time determination

PURPOSE

Previous studies have revealed that benign and malignant adrenal masses differ in their T2-related MRI characteristics, but there is sufficient overlap in these characteristics that very accurate differential diagnosis is not possible. This ambiguity might be due to variations inherent in the measurement techniques or to real overlap in the T2 relaxation times of the lesion groups. We attempted to reduce the scatter and overlap of data from adenomas and malignancies by using an eight echo T2 assessment, which we compared with a two echo technique and with reference tissue brightness ratio determinations.

METHOD

Forty-eight adrenal masses in 44 adult patients were assessed; 30 were diagnosed as adenomas and 18 as malignancies by means other than MR. Each lesion was subjected to a single slice eight SE (spin echo) image (TR 2,000, TE 20-160), from which a T2 relaxation time was calculated. T2 relaxation times were also calculated using two echoes (TE 20 and 100), as were lesion/liver, lesion/fat, and lesion/muscle brightness ratios (TE 100). The differential diagnostic efficacies of the techniques were compared by receiver operating characteristic (ROC) analysis.

RESULTS

Although the means of the malignant and benign groups differed, significant overlap was present for each assessment technique. ROC analysis showed that the best differentiation was achieved by the lesion/fat brightness ratio, followed very closely by the eight echo technique. The eight echo technique was significantly better at differentiation than the two echo technique.

CONCLUSION

Although eight echo T2 determination has less variability and permits slightly better differential diagnosis than most other T2-dependent MR techniques, considerable ambiguity persists that may be due to intrinsic overlap in the T2 relaxation characteristics of the lesions rather than to variability in imaging techniques.

MRI anatomy of the rat kidney at 1.5 T in different states of hydration

The objective of this study was to determine correlation between structural anatomy and surface coil spin-echo MR imaging of the rat kidney and the effect of hydration state on MR signal intensities of the cortex and medulla. Twelve rats were studied in a pilot study with a 3-inch surface coil in a 1.5 T magnet under five different states of hydration. Serum and urine osmolality measurements were obtained immediately prior to each scan. Signal intensity measurements were made from both T1- and T2-weighted images of the cortex and medulla of both kidneys in each state of hydration. Gross and histological anatomy of the rat kidneys was correlated with the MR images. Four distinct layers were detected in vivo on MRI images of the rat kidney; these correlated with the histological layers. T1-weighted cortico-medullary differentiation was most pronounced at 48 h dehydration; T2 cortico-medullary differentiation was greatest at 72 h of dehydration. We concluded that different parts of the mammalian nephron can be identified by MR imaging and that cortico-medullary differentiation is affected by the hydration state of the animal.

Efficacy and safety of iopromide for excretory urography

RATIONALE AND OBJECTIVES

Iopromide is a nonionic monomeric contrast agent. Initial laboratory and clinical data have shown that it is relatively safe. Efficacy for excretory urography has been shown to be good, comparable with other low-osmolality agents. The authors attempted to confirm these impressions in a randomized, double-blind comparison with equivalent doses of ioversol and iopamidol.

METHODS

Two hundred adult patients undergoing excretory urography were studied. One hundred received iopromide, 40 received ioversol, and 60 received iopamidol (300 mg I/kg) as an intravenous bolus. Urographic films (obtained 1, 5, 15, and 20 minutes after the bolus, and postvoid) were interpreted by an observer blinded to contrast type. Visualization of renal parenchyma, pelvis and calyces, ureters, and bladder was independently assessed as excellent, good, poor, or nonvisualized. Vital signs were recorded before, 30 to 60 minutes after, and 24 hours after injection. Adverse reactions were sought, physical examinations were performed, and standard hematology and serum chemistry values were measured before and 1 day after injection; a 72-hour serum creatinine level was also measured.

RESULTS

Ninety-eight percent of visualization scores were good or excellent; no significant differences among iopromide, iopamidol, and ioversol were found, nor were there any significant differences among groups in vital signs. Only one patient experienced a contrast-related physical examination change (subcutaneous extravasation). No significant changes with regard to hematology or serum chemistry values were observed; there was no contrast-induced nephropathy. Mild adverse reactions were experienced by 10% of patients; there were no significant differences in reaction rates among contrast agents.

CONCLUSIONS

Iopromide at a dose of approximately 300 mg I/kg is safe and effective as an excretory urographic agent and is comparable in performance with ioversol and iopamidol.

The radiologic evaluation of the patient with renal cancer

Radiologic procedures are used for detection, differential diagnosis, staging, and follow-up in virtually every patient with renal cancer. This article reviews the best imaging techniques for each of these tasks, the capacities and limitations of each modality, the clinical situations that call for their use, and the proper timing and order of radiologic workup.

Evaluation of teleradiology for interpretation of intravenous urograms

The diagnostic yield of a commercial teleradiology/picture archiving and communication system (ATT-Philips Comm View T/PACS) was evaluated for 100 urograms. A single image from each examination was digitized (2048 x 1684 x 12-bit pixels) and transmitted from a satellite hospital over a T-1 line using the T/PACS system. The video display of each digitized image was reviewed independently by four radiologists. The same four radiologists reviewed the original film images at a different time without knowledge of their T/PACS interpretation. There was no statistically significant difference in the sensitivity for clinical findings between T/PACS (86%) and film (89%). The false positive rate, however, was significantly higher with T/PACS than with film (44 versus 32 false positive findings per 100 films). We conclude that T/PACS of the type studied here demonstrates sufficient sensitivity for the detection of clinically important urographic findings in the emergency setting. A final reading of the original films is still necessary, however, to assure appropriate specificity.

Clinical use of urinary tract magnetic resonance imaging

MR imaging should not be used to evaluate the majority of the lesions described herein but should be reserved for specific clinical situations. The detection and differential diagnosis of adrenal masses is a legitimate application of this technique. The staging of renal tumors in patients in whom CT fails to do so may be accomplished by MR imaging. Establishment of patency of the renal veins and of surgical shunts involving these veins may be performed by MR imaging if Doppler ultrasonography proves unsatisfactory. MR imaging may differentiate between stable retroperitoneal fibrosis and malignant disease in patients in whom this differential is a problem. Hematomas may be distinguished from nonhemorrhagic fluid collections anywhere in the abdomen or pelvis. In selected patients, the local extent of certain bladder tumors may be evaluated by MR imaging when CT and biopsy fail to do so. In testicular disease, MR imaging may aid in the differential diagnosis of abnormalities that are not sufficiently characterized by ultrasonography, and MR imaging may detect undescended testes in some patients in whom ultrasonography fails to do so. In the future, wider application of fast scanning with bolus administration of soluble paramagnetic contrast agents may refine the differential diagnosis of adrenal masses and aid in the detection of renal masses. MR angiographic techniques ultimately may constitute a screening procedure for renal arteriostenosis. A subset of patients with prostate carcinoma may prove to benefit from local staging of the disease by MR imaging.

MRI of the adrenal gland

Current status of magnetic resonance imaging (MRI) of the adrenal gland is reviewed, and basic techniques and sensitivity of MRI for differentiating histologic lesions are also discussed.

MR evaluation of renal space-occupying lesions: diagnostic criteria

In order to assess the ability of magnetic resonance (MR) imaging to distinguish simple renal cysts from renal tumors, images from 53 patients with 74 lesions were reviewed. MR image characteristics, including signal strength and homogeneity for each lesion, were evaluated and compared with the final diagnoses. There were 53 cysts and 21 tumors. For 56 lesions (76%), MR allowed accurate diagnosis; on T1-weighted images, homogeneous low-intensity lesions were always cysts and inhomogeneous medium- or high-intensity lesions were always tumors. The remaining 18 lesions (24%) could not be distinguished, and T2-weighted images failed to improve differential diagnostic ability. In our experience, MR imaging allows differentiation of renal cysts and tumors less frequently than does computed tomography (CT) or ultrasound (US). MR criteria for simple renal cysts and tumors are offered, with the understanding that modification may be necessary as experience with these lesions increases.

Mn (III) hematoporphyrin. A potential MR contrast agent

Manganese (III) hematoporphyrin (MnHP), a new and stable complex, was prepared, and its toxicity and magnetic resonance (MR) imaging properties were evaluated. In tests of acute and subacute toxicity, no deaths resulted from bolus intravenous injections of 13 or 19 mumols/kg of MnHP, but there was a 33% mortality when the dose was 38 mumols/kg. Laboratory results were normal in the surviving rats. Ultraviolet- visible spectroscopy of the urine and serum of two rats injected 24 hours previously with 38 mumols/kg MnHP revealed no free HP, suggesting in vivo stability of MnHP. Finally, using a standardized imaging protocol, there was a mean increase of 37% in the liver-to-muscle intensity ratios in four rats injected 24 hours previously with 25 mumols/kg MnHP when compared to paired controls (P less than .005). In addition, obvious visual increase in the signal intensity of the liver on T1-weighted images was seen in animals tested with 13 and 19 mumols/kg of MnHP. The results suggest that further evaluation of MnHP as an MR contrast agent for the liver is warranted.

Application of region of interest definition to quadtree-based compression of CT images

A quadtree-based data compression algorithm can provide different levels of compression within and outside of regions of interest (ROIs). The current study shows whether ROI compression can provide greater compression or diagnostic accuracy than uniform quadtree compression. In 75 single CT images from 75 consecutive abdominal examinations, 43 abnormalities were identified and surrounded by ROIs. Three radiologists interpreted the images following (1) 50:1 compression of the entire image; (2) ROI compression at five decreasing compression ratios (with 50:1 compression outside the ROI); and (3) reversible (lossless) compression of the entire image. Reversible compression (compression ratio 3:1) yielded a sensitivity of 96%. ROI compression of 15:1 was achieved with no loss of sensitivity; ROI compression of 28:1 yielded a sensitivity of 91% (not significantly different). At any given compression ratio, diagnostic sensitivity was greater with ROI compression than with uniform quadtree compression. For purposes of image archiving, quadtree-based ROI compression is superior to uniform compression of CT images.

Quadtree-based data compression of abdominal CT images

An ROC study was performed to evaluate the effect of quadtree-based data compression on the diagnostic yield of CT images. Seventy images were selected from a series of consecutive abdominal/pelvic CT scans. Following the application of quadtree-based compression, all images were reviewed independently by three radiologists. The images were analyzed at six decreasing irreversible compression ratios (30.6:1 to 7.4:1), as well as after reversible compression (2.9:1). ROC curves reveal a gradual decrease in clinical accuracy with increasing compression ratios. At a compression ratio of 7.4:1, sensitivity for all major abnormalities was 99% with a specificity of 93%. As the compression ratio was increased to 30.6:1, sensitivity and specificity dropped to 75% and 83% respectively. Execution times for compression and decompression of the CT images with a PC-AT based digital radiography system varied from 24.7 to 18.5 seconds and from 16.2 to 5.1 seconds respectively, decreasing with higher levels of compression. We conclude that quadtree-based compression of abdominal CT images may have practical applications for a PC based digital radiography system.

Nephrogenic adenoma of the bladder: urographic spectrum

Nephrogenic adenoma is a rare, proliferative response of urothelium to urinary infection or injury of the bladder mucosa. Histologically, the lesion resembles proximal tubules of the nephron. While it can occur throughout the urinary tract, it usually appears in the bladder, with diverse radiographic manifestations. Of 6 patients with nephrogenic adenoma of the bladder, 3 presented with masses in the bladder and 2 with irregularities of the bladder mucosa on urography, while 1 showed no focal urographic abnormalities. There were no distinctive radiographic features of nephrogenic adenoma that would allow it to be differentiated from tumor or other inflammatory lesions. Although it is considered benign, bladder involvement may be extensive and eradication of the tumor may be difficult.

Pneumoperitoneum resembling air in the biliary tree: CT features

The various CT appearances of free abdominal air have been described. We present a hitherto undescribed CT manifestation of this condition. When subhepatic free air tracks along the porta hepatis and suspensory ligaments of the liver, it may resemble biliary air.

CT of primary lymphoma of the liver

Primary lymphoma of the liver is a rare disease. In each of six cases, a large, often poorly defined mass of low attenuation was present within the liver. Four lesions originated in the right lobe and two originated in the left lobe. Satellite nodules were seen at presentation in one case and developed after presentation in two others. Other features, such as enhancement after contrast administration, necrosis, and calcification, were variable. Three of six lesions had areas of very low density, suggestive of necrosis. One mass had calcifications. After IV contrast administration, no enhancement occurred in three tumors, patchy enhancement occurred in two, and an enhancing ring was seen in the remaining tumor. The radiologic presentation of primary lymphoma of the liver differs from that of secondary involvement of the liver in systemic lymphoma. Whereas secondary lymphoma is often diffusely infiltrative and difficult to detect on CT, the lesions of primary lymphoma of the liver are easily identified on CT scans even before the administration of IV contrast material. Although rare, primary lymphoma of the liver should be included in the differential diagnosis of a large, hypodense liver mass on CT.

Evaluation of a quadtree-based compression algorithm with digitized urograms

The effect of a quadtree-based data-compression algorithm on the diagnostic yield in digitized radiographs was studied for 100 urograms. Each image was digitized and reviewed at nine decreasing compression ratios ranging from 90:1 to 4.2:1, followed by a review of the uncompressed digital images. Four radiologists independently reviewed the digitized images and the original radiographs and agreed on a reference standard of 201 findings. Sensitivity, measured by the number of findings noted on the compressed digital images, decreased with increasing compression ratios at and above the 11:1 level. No loss of sensitivity was noted with a compression ratio of 4.2:1. Sensitivity decreased more precipitously for calcifications than for soft-tissue masses. Only a minimal loss of sensitivity for bilateral renal function was noted, even with high compression ratios. False-positive rates were unaffected by compression. The authors conclude that quadtree compression ratios of 11:1 and higher may result in loss of sensitivity in clinically relevant findings.

The relationship between renal scarring and stone disease

The urographic findings of focal clubbing of the renal calices and associated parenchymal scarring usually prompt a diagnosis of chronic pyelonephritis, which is frequently thought to be due to ongoing or previous vesicoureteral reflux. However, we noticed that upper tract stone disease appeared to be the condition that most often preceded or accompanied caliceal clubbing and parenchymal scarring in adults. To test the hypothesis that stones were the most common cause of this renal abnormality, we analyzed the IV urograms in 1500 consecutive patients for evidence of upper tract stone disease, vesicoureteral reflux, and caliceal clubbing and scarring. Of 39 patients with clubbing and scarring, 67% had stone disease, but only 8% had a history of reflux. Of 90 patients with stone disease, 29% had clubbing and scarring. We conclude that, in adults, upper tract stone disease may be the most important etiologic factor in the production of renal caliceal clubbing and scarring.

MRI of multilocular cystic nephroma

We report the magnetic resonance imaging (MRI) findings in 2 patients with multilocular cystic nephromas. Both underwent MRI immediately prior to resection. The images accurately reflected the morphology of the tumors: in each, the capsule was hypointense on all pulse sequences. Varied intensities of signal from the fluid in the visualized locules presumably represented differing concentrations of old hemorrhage and protein. In one case soft tissue elements became hyperintense on T2-weighted images. We speculate that MRI of multilocular cystic nephromas will produce imaging features that are highly suggestive, but not always pathognomonic, of the disease.

MR imaging of portal vein thrombosis

MR imaging is emerging as a potential means of detecting portal venous thrombosis (PVT). Therefore, we attempted to establish specific criteria with which to diagnose PVT on conventional spin-echo images. In a retrospective review of 342 consecutive abdominal MR scans performed with a 0.5-T magnet, we identified nine patients with persistent signal in the portal vein and used the findings in these patients to establish criteria with which to diagnose PVT. We subsequently applied these criteria to 109 additional consecutive abdominal MR scans performed with the same magnet. Fifteen cases were found in which all images showed either (1) signal involving the entire width of the portal vein lumen, which approximated (with T1 weighting) and exceeded (with T2 weighting) the intensity of the hepatic parenchyma in images in which the hepatic veins showed a complete flow void or (2) complete nonvisualization of the portal vein and its major branches in images that showed a flow void in portal venous collaterals and hepatic veins. All patients had unequivocal findings of PVT on at least one other imaging study (CT or sonography) or at surgery. Although the sensitivity of these signs could not be calculated, their specificity was 100%. We conclude that in the presence of these signs, the diagnosis of PVT can be made with confidence.