Determining the factors influencing the symptoms related to naviculo-medial cuneiform coalition

PURPOSE

We aimed to determine the factors that influence the symptoms of naviculo-cuneiform (NC) coalition using radiography and computed tomography (CT).

METHODS

We retrospectively reviewed the radiographic and CT findings of 37 NC coalition cases. The existence of a large pit (depth >3 mm), irregular articular surface, joint space narrowing, dorsal bony spur, subchondral sclerosis, multiple subchondral bony cysts, and intra-articular loose body were evaluated on radiographs or CT. The size of the largest subchondral bony cyst was also measured using CT. All cases were divided into two subgroups according to the symptoms. Fisher's exact test was used to distinguish the factors influencing the symptoms.

RESULTS

Twenty-three and fourteen feet were enrolled into the symptomatic and asymptomatic groups, respectively. The rates of the large pit on either radiograph (47.83 vs. 21.43%) or CT (65.22 vs. 28.57%) were significantly different between both groups ( p = 0.001). The mean size of the largest subchondral bony cyst on CT was also significantly greater in the symptomatic group (4.25 vs. 1.53 mm, p = 0.005).

CONCLUSION

A large deep pit and huge subchondral bony cyst on the radiograph or CT can be related to symptoms for the patient with NC coalition. A CT is highly recommended for a more accurate evaluation in patients with NC coalition.

CT Features of Naviculocuneiform Coalitions

Category:

Midfoot/Forefoot

Introduction/Purpose:

The purpose of our study was to evaluate and compare the CT features in patients with symptomatic and asymptomatic naviculocuneiform coalition

Methods:

We retrospectively reviewed the CT images of 37 naviculocuneiform coalitions in 26 patients (mean age 30 years). The 26 patients were 12 males and 14 females, with 19 right and 18 left feet, including 11 patients with bilateral coalition. The CT images were analyzed with regard to irregular articular surface, subchondral sclerosis, subchondral cyst, bone spur, joint space distance, loose body and bony fusion. The size of subchondral cyst was measured. The location and extent of joint involvement was also evaluated. CT features were compared between symptomatic and asymptomatic feet.

Results:

There were 20 feet (54%) in symptomatic group and 17 feet (46%) in asymptomatic group. The mean size of the subchondral cyst was 6.3 mm in the symptomatic group and 2.5 mm in the asymptomatic group (statistically significant). Bone spurs were significantly more common in the symptomatic group (11 of 20 feet) than in the asymptomatic group (2 of 17 feet) (p < 0.01). All 8 feet received operative treatment had subchondral cysts (mean size 6.7 mm) or bone spurs. Irregular articular surfaces were seen in all feet. Subchondral sclerosis, joint space distance, loose body, location and extent of joint involvement did not differ statistically significantly between two groups.

Conclusion:

Because of a statistically significant overlap of CT features, only large subchondral cysts and bone spurs can be more commonly detected with CT in the symptomatic feet compared to the asymptomatic feet, and may indicate aggressive treatment in patients with naviculocuneiform coalition.

Beta-amyloid imaging in dementia

Alzheimer's disease (AD) is a neurodegenerative disorder associated with extracellular plaques, composed of amyloid-beta (Aβ), in the brain. Although the precise mechanism underlying the neurotoxicity of Aβ has not been established, Aβ accumulation is the primary event in a cascade of events that lead to neurofibrillary degeneration and dementia. In particular, the Aβ burden, as assessed by neuroimaging, has proved to be an excellent predictive biomarker. Positron emission tomography, using ligands such as ¹¹C-labeled Pittsburgh Compound B or ¹⁸F-labeled tracers, such as ¹⁸F-florbetaben, ¹⁸F-florbetapir, and ¹⁸F-flutemetamol, which bind to Aβ deposits in the brain, has been a valuable technique for visualizing and quantifying the deposition of Aβ throughout the brain in living subjects. Aβ imaging has very high sensitivity for detecting AD pathology. In addition, it can predict the progression from mild cognitive impairment to AD, and contribute to the development of disease-specific therapies.

Quantitative assessment of simultaneous F-18 FDG PET/MRI in patients with various types of hepatic tumors: Correlation between glucose metabolism and apparent diffusion coefficient

PURPOSE

Metabolism and water diffusion may have a relationship or an effect on each other in the same tumor. Knowledge of their relationship could expand the understanding of tumor biology and serve the field of oncologic imaging. This study aimed to evaluate the relationship between metabolism and water diffusivity in hepatic tumors using a simultaneous positron emission tomography/magnetic resonance imaging (PET/MRI) system with F-18 fluorodeoxyglucose (FDG) and to reveal the metabolic and diffusional characteristics of each type of hepatic tumor.

METHODS

Forty-one patients (mean age 63 ± 13 years, 31 male) with hepatic tumors (18 hepatocellular carcinoma [HCC], six cholangiocarcinoma [CCC], 10 metastatic tumors, one neuroendocrine malignancy, and six benign lesions) underwent FDG PET/MRI before treatment. Maximum standard uptake (SUVmax) values from FDG PET and the apparent diffusion coefficient (ADC) from the diffusion-weighted images were obtained for the tumor and their relationships were examined. We also investigated the difference in SUVmax and ADC for each type of tumor.

RESULTS

SUVmax showed a negative correlation with ADC (r = -0.404, p = 0.009). The median of SUVmax was 3.22 in HCC, 6.99 in CCC, 6.30 in metastatic tumors, and 1.82 in benign lesions. The median of ADC was 1.039 × 10-3 mm/s2 in HCC, 1.148 × 10-3 mm/s2 in CCC, 0.876 × 10-3 mm/s2 in metastatic tumors, and 1.323 × 10-3 mm/s2 in benign lesions. SUVmax was higher in metastatic tumors than in benign lesions (p = 0.023). Metastatic tumors had a lower ADC than CCC (p = 0.039) and benign lesions (p = 0.004). HCC had a lower ADC than benign lesions, with a suggestive trend (p = 0.06).

CONCLUSION

Our results indicate that SUVmax is negatively correlated with ADC in hepatic tumors, and each group of tumors has different metabolic and water diffusivity characteristics. Evaluation of hepatic tumors by PET/MRI could be helpful in understanding tumor characteristics.

Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Findings of Post Traumatic Lymphangioma in a Young Adult Male

The authors report the case of a 34-year-old male, who underwent a fluorine-18 fluoro deoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) scan 7 years after trauma for the evaluation of multifocal masses in the right iliac and right inguinal areas. CT findings showed multifocal low density masses and ¹⁸F-FDG PET revealed slightly increased uptake (maximum standardized uptake value [SUVmax] 3.1). These findings did not exclude the possibility of a benign or malignant lesion. To achieve differential diagnosis, partial surgical excision was performed and a pathologic examination subsequently revealed lymphangioma. Here, the authors describe the ¹⁸F-FDG PET/CT findings of a rare case of lymphangioma resulting from trauma.

Late Onset Osteonecrosis of the Proximal Phalanx of the Great Toe in a Child

Osteonecrosis, also known as avascular necrosis or osteochondrosis, refers to the death of bone tissue resulting from a to lack of blood supply. Osteonecrosis of the foot is most commonly seen in the talus and metatarsals and not as frequently in other bones. We report an extremely rare case of late-onset osteonecrosis of the proximal phalangeal head of the great toe in a 9-year-old male. Plain radiographs and computed tomography did not show any findings of osteonecrosis initially. However, because of persistent pain at the interphalangeal joint of the first toe and a decrease in the range of movement at the interphalangeal joint at 7 months after injury, the patient underwent additional examination with repeated radiographs and magnetic resonance imaging. We diagnosed late-onset osteonecrosis as a result of a subtle traumatic type I dislocation. Conservative treatment led to spontaneous recovery, leaving a bony fragment in the interphalangeal joint. To our knowledge, this is the first report of late-onset proximal phalangeal osteonecrosis after trauma in the great toe.

Enchondroma of the Foot

The present study is a review of 20 patients with enchondroma of the foot treated from January 2005 to March 2012. All patients were examined clinically, followed by an evaluation of their enchondroma of the foot radiographically and an assessment of the outcome of their surgical intervention. The patients' sex and age, enchondroma location, findings from imaging studies such as plain radiography, computed tomography, and magnetic resonance imaging, clinical findings, operative findings, and treatment outcomes were recorded. The average postoperative follow-up period was 24 months. Eighty percent of the tumors were located in the proximal phalanx and 14 (70%) patients presented with pathologic fracture. The plain radiographs and computed tomography findings revealed 13 (65%) cases of internal calcification and 11 (55%) with endosteal scalloping. A periosteal reaction was seen only in 4 (20%) cases. Magnetic resonance imaging of 11 (55%) patients showed low T1-weighted and high T2-weighted signal intensity in all cases. Internal septa and nodules with low T2-weighted signal intensity were observed in 9 (82%) out of 11 cases, and adjacent soft tissue edema was noted in 9 (82%). All patients underwent curettage of the tumor and bone grafting as their surgical treatment. No recurrence or postoperative complications were observed during the 24-month follow-up period. Enchondroma of the foot most frequently involves the proximal phalangeal bone and is often associated with pathologic fracture. The unique clinical signs and characteristic radiographic images are easily recognized, making this a relatively easy diagnosis. With appropriate treatment, a good surgical outcome can be expected.

Postoperative ultrasonography of the musculoskeletal system

Ultrasonography of the postoperative musculoskeletal system plays an important role in the Epub ahead of print accurate diagnosis of abnormal lesions in the bone and soft tissues. Ultrasonography is a fast and reliable method with no harmful irradiation for the evaluation of postoperative musculoskeletal complications. In particular, it is not affected by the excessive metal artifacts that appear on computed tomography or magnetic resonance imaging. Another benefit of ultrasonography is its capability to dynamically assess the pathologic movement in joints, muscles, or tendons. This article discusses the frequent applications of musculoskeletal ultrasonography in various postoperative situations including those involving the soft tissues around the metal hardware, arthroplasty, postoperative tendons, recurrent soft tissue tumors, bone unions, and amputation surgery.

Freiberg's disease: quantitative assessment of osteonecrosis on three-dimensional CT

BACKGROUND

The extent of necrosis is the main determining factor in the outcome of osteonecrosis. There is no method for measuring the extent of osteonecrosis of the metatarsal head in Freiberg's disease. The purpose of this study was to determine the reliability and prognostic ability of a new method for measurement of the extent of osteonecrosis in Freiberg's disease on three-dimensional computed tomography.

METHODS

A retrospective review of 11 cases with symptomatic Freiberg's disease in ten patients (5 males and 5 females; mean age, 27 years) undergoing computed tomography between July 2005 and September 2007 was performed. Two investigators (K.A.C. and H.K.O.) used a new method to measure the necrotic extent of the metatarsal head: the necrotic angle ratio of necrotic arc angle to normal arc angle of the articular surface on the sagittal reconstruction image of computed tomography. The interobserver reliability was determined for computed tomography measurement. Correlation between the Smillie staging using radiographs and the necrotic angle ratio on computed tomography was also evaluated.

RESULTS

One patient presented with stage I disease (Smillie staging), one with stage II, two with stage III, five with stage IV, and two with stage V, respectively. The necrotic angle ratio of the metatarsal head was 14% in stage I, 21% in stage II, 34% in stage III, 43% in stage IV, and 53% in stage V. The interobserver reliability for computed tomography measurement was high (Cronbach α=0.96). We found the increase of the necrotic extent in proportion to the Smillie stage. The Smillie staging using radiographs and the necrotic angle ratio on computed tomography were significantly correlated. (P<0.05)

CONCLUSIONS

Three-dimensional computed tomography measurement of the necrotic extent of the metatarsal head is a reliable and useful method in evaluating the staging of Freiberg's disease and may eventually help to optimize treatment.

(18)F-FDG PET/CT with Contrast Enhancement for Evaluation of Axillary Lymph Node Involvement in T1 Breast Cancer

BACKGROUND

(18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography ((PET) safely predicts axillary status in patients with breast cancer, but is not sufficiently accurate in early breast cancer patients. This study analyzed the value of (18)F-FDG PET/computed tomography (CT) with contrast enhancement in detecting axillary lymph node involvement in T1 breast cancer patients.

METHODS

Contrast-enhanced (18)F-FDG PET/CT was performed within 20 days of surgery in 143 breast cancer patients with tumors ≤2 cm in size. The patients underwent either axillary lymph node dissection (ALND) or sentinel lymph node biopsy (SLNB), and histopathology reports were used to provide the definitive diagnosis against which the contrast-enhanced (18)F-FDG PET/CT study results were compared.

RESULTS

The sensitivity, specificity, and negative and positive predictive values of contrast-enhanced (18)F-FDG PET/CT in detecting axillary involvement were 70.0%, 92.2%, 88.8%, and 77.8%, respectively, in the entire series of 143 patients, with eight false-positive and 12 false negative results. The false-negative results were associated with the number of metastatic lymph nodes and the rate of FDG uptake.

CONCLUSION

Contrast-enhanced (18)F-FDG PET/CT cannot replace histologic staging using SLNB in patients with breast cancer, but (18)F-FDG PET/CT increases the sensitivity for predicting axillary node metastasis, and allows for a selective approach to either ALND or SLNB, even in patients with T1 breast cancer.

Comparisons of the various partial-thickness rotator cuff tears on MR arthrography and arthroscopic correlation

Objective

To assess the diagnostic performance of MR arthrography in the diagnosis of the various types of partial-thickness rotator cuff tears by comparing the MR imaging findings with the arthroscopic findings.

Materials and Methods

The series of MR arthrography studies included 202 patients consisting of 100 patients with partial-thickness rotator cuff tears proved by arthroscopy and a control group of 102 patients with arthroscopically intact rotator cuffs, which were reviewed in random order. At arthroscopy, 54 articular-sided, 26 bursal-sided, 20 both articular- and bursal-sided partial-thickness tears were diagnosed. The MR arthrographies were analyzed by two radiologists for articular-sided tears, bursal-sided tears, and both articular- and bursal-sided tears of the rotator cuff. The sensitivity and specificity of each type of partial-thickness tears were determined. Kappa statistics was calculated to determine the inter- and intra-observer agreement of the diagnosis of partial-thickness rotator cuff tears.

Results

The sensitivity and specificity of the various types of rotator cuff tears were 85% and 90%, respectively for articular-sided tears, 62% and 95% for bursal-sided tears, as well as 45% and 99% for both articular- and bursal-sided tears. False-negative assessments were primarily observed in the diagnosis of bursal-sided tears. Conversely, both articular- and bursal-sided tears were overestimated as full-thickness tears. Inter-observer agreement was excellent for the diagnosis of articular-sided tears (k = 0.70), moderate (k = 0.59) for bursal-sided tears, and fair (k = 0.34) for both articular- and bursal-sided tears, respectively. Intra-observer agreement for the interpretation of articular- and bursal-sided tears was excellent and good, respectively, whereas intra-observer agreement for both articular- and bursal-sided tears was moderate.

Conclusion

MR arthrography is a useful diagnostic tool for partial-thickness rotator cuff tears, but has limitations in that it has low sensitivity in bursal- and both articular- and bursal-sided tears. In addition, it shows only fair inter-observer agreement when it comes to predicting both articular- and bursal-sided tears.

A case of silent giant cell arteritis involving the entire aorta, carotid artery and brachial artery screened by integrated PET/CT

We report a case of giant cell arteritis involving the aorta and several large arteries identified by integrated positron emission tomography (PET)/computed tomography (CT) obtained in a patient with a high erythrocyte sedimentation rate (ESR). A 63-year-old man with anemia and a high ESR noted on a regular medical examination was transferred to our department. The patient complained of only a low-grade general weakness for several months; there were no specific symptoms or signs. A PET was recommended. The image showed strong (18)F-fluorodeoxyglucose ((18)F-FDG) uptake at the ascending aorta, aortic arch, descending aorta, thoraco-lumbar aorta, brachial artery, and the carotid artery wall, bilaterally. Suspicious for large-vessel vasculitis, a temporal artery biopsy was performed, which confirmed giant cell arteritis. After treatment with prednisolone, the high ESR and anemia resolved, and (18)F-FDG uptake decreased on follow-up integrated PET/CT.

Non-traumatic peroneal nerve palsy: MRI findings

AIM

To present magnetic resonance imaging (MRI) findings of non-traumatic peroneal nerve palsy and to evaluate the usefulness of MRI in patients with non-traumatic peroneal nerve palsy.

MATERIALS AND METHODS

In a retrospective study, 11 consecutive patients presenting with peroneal nerve palsy were included. MR images of the lower leg and electrophysiological examinations were also reviewed. The cause of peroneal nerve palsy was determined on the basis of MRI findings and was evaluated using electrophysiological data. Nine patients with causative lesions detected on MRI, underwent surgery.

RESULTS

Clinical examination and electromyography (EMG) disclosed 11 peroneal lesions. MRI and EMG revealed three types of signal intensity change, i.e. deep peroneal nerve palsy type, common peroneal nerve palsy type, and superficial peroneal nerve palsy type. The MRI and EMG findings were in agreement in seven (65%) of the 11 study patients. In nine patients the causative lesions were identified using MRI, including ganglion cyst (n=6), osteochondroma (n=1), synovial cyst (n=1), and aneurysm (n=1).

CONCLUSION

Ganglion cyst is the most common cause of non-traumatic peroneal nerve palsy. MRI offers a noninvasive method for obtaining useful information to assess, localize, and monitor peripheral peroneal nerve palsy.

Direct comparison of adenosine and adenosine 5'-triphosphate as pharmacologic stress agents in conjunction with Tl-201 SPECT: Hemodynamic response, myocardial tracer uptake, and size of perfusion defects in the same subjects

BACKGROUND

Adenosine 5'-triphosphate (ATP), a potent and inexpensive coronary vasodilator, was introduced as a pharmacologic stress agent for thallium 201 single photon emission computed tomography (SPECT). However, there has been no direct comparison of ATP and adenosine as myocardial stressors in the same subjects.

METHODS AND RESULTS

Thirty-six patients underwent consecutive Tl-201 SPECT imaging with adenosine and ATP in a randomly assigned order. There were no changes in clinical status and no invasive procedures were performed between the two tests. The hemodynamic response and side effects were monitored, and myocardial tracer uptake was assessed by use of a visual grading system and quantitative analysis via a CEqual map. The hemodynamic changes and adverse effects did not differ significantly between the two groups. There were no changes in the detection of any perfusion defect on a per-subject basis, except in one. The exact agreement rate for the visual grading of the myocardial tracer uptake was 84.8%. However, the average extent of the perfusion defect and the severity score were higher with adenosine.

CONCLUSION

The hemodynamic changes and the degree of myocardial uptake were similar between the adenosine and ATP infusion. However, quantitative analysis by use of a CEqual map revealed smaller perfusion defects and lower severity scores in subjects undergoing Tl-201 SPECT with ATP.

A protective role for heme oxygenase-1 in INS-1 cells and rat islets that are exposed to high glucose conditions

Heme oxygenase-1 (HO-1) has been described as an inducible protein that is capable of cytoprotection via radical scavenging and the prevention of apoptosis. Chronic exposure to hyperglycemia can lead to cellular dysfunction that may become irreversible over time, and this process has been termed glucose toxicity. Yet little is known about the relation between glucose toxicity and HO-1 in the islets. The purposes of the present study were to determine whether prolonged exposure of pancreatic islets to a supraphysiologic glucose concentration disrupts the intracellular balance between reactive oxygen species (ROS) and HO-1, and so this causes defective insulin secretion; we also wanted to evaluate a protective role for HO-1 in pancreatic islets against high glucose levels. The intracellular peroxide levels of the pancreatic islets (INS-1 cell, rat islet) were increased in the high glucose media (30 mM glucose or 50 mM ribose). The HO-1 expression was induced in the INS-1 cells by the high glucose levels. Both the HO-1 expression and glucose stimulated insulin secretion (GSIS) was decreased simultaneously in the islets by treatment of the HO-1 antisense. The HO-1 was upregulated in the INS-1 cells by hemin, an inducer of HO-1. And, HO-1 upregulation induced by hemin reversed the GSIS in the islets at a high glucose condition. These results suggest HO-1 seems to mediate the protective response of pancreatic islets against the oxidative stress that is due to high glucose conditions.

Patellar Fractures After Total Knee Replacement

OBJECTIVE

The objective of our study was to describe the patterns of patellar fracture after total knee replacement and assess their clinical significance.

MATERIALS AND METHODS

A retrospective review of patellar fractures after total knee replacement was performed. Seventeen cases were identified over a 10-year period. Radiographs, radiology reports, medical records, and operative notes were reviewed and analyzed. The clinical analysis included the time to fracture, the patient's symptoms and signs, whether the extensor mechanism was disrupted, and the treatment administered for the fracture. The radiographic analysis included fracture pattern, displacement, patellar position, presence of patellar osteonecrosis, and presence of soft-tissue abnormality.

RESULTS

The incidence of patellar fractures after total knee replacement was 1.14%. The mean time from total knee replacement to patellar fracture was 17.5 months. Nine fractures were asymptomatic and identified on routine follow-up radiographs. The patterns of fracture were diverse: Transverse (n = 6), comminuted (n = 2), vertical (n = 5), and avulsion (n =4) fractures were seen. Thirteen fractures were displaced. Patellar osteonecrosis was suspected in four fractures, and three fractures were associated with disruption of the quadriceps tendons. Thirteen fractures were treated nonoperatively, and four were treated surgically.

CONCLUSION

Patellar fractures are an uncommon, but important, complication after total knee replacement. Radiologists should be familiar with the imaging features of these fractures and their clinical significance.

Adenosine-induced long-standing postischemic left ventricular dysfunction evaluated with gated SPECT

OBJECTIVES

This study was performed to determine the after-effects of pharmacologic stress (adenosine) on left ventricular (LV) function-end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (LVEF)-with Tl-201 and Tc-99m MIBI SPECT.

METHODS

A total of 263 patients were grouped according to the time interval between isotope injection and imaging. Group A: within 1 hour (n = 99; men, n = 48; women, n = 51; mean age: 63.2 years), subgrouped as patients with no perfusion defect (NPD; n = 61), reversible defect (RD; n = 33), and fixed defect (FD; n = 5). Group B: 1 to 2 hours (n = 110; men, n = 66; woman, n = 44; mean age, 63 years), NPD (n = 64), RD (n = 26), and FD (n = 20). 3) Group C: 2 to 3 hours (n = 54; men, n = 30; women, n = 24; mean age, 62 years); NPD (n = 22), RD (n = 17), and FD (n = 15). All patients were in sinus rhythm during the study and had no prior history of myocardial infarction.

RESULTS

In group A, in the patients with RD, poststress LVEF was significantly depressed after adenosine infusion (53.1 +/- 9.5% vs 58.3 +/- 10.2%, P < 0.001) and showed a wall motion abnormality, which was worse after stress than during rest. The mean difference in LVEF (DeltaLVEF) between rest and stress was 5.2%. The DeltaLVEF in those patients with RD was significantly higher than that in the NPD (0.9%, P < 0.01) or FD (2.1%, P < 0.05) subgroups. Twenty of the 33 patients (60.6%) with RD showed an increase in LVEF > or = 5% from poststress to rest, and the poststress ESV (43.3 +/- 19.0 mL) was significantly higher than the ESV (38.5 +/- 18.4 mL, P < 0.01) at rest, but there was no significant difference in the EDV (90.5 +/- 26.4 vs 89.7 +/- 26.2 mL). In group B, DeltaLVEF was 1.5%, 4.4%, and 1.2% in patients with NPD, RD, and FD respectively. In group C, DeltaLVEF was 2.5%, 3.2%, and 0.9% in patients with NPD, RD, and FD respectively, and there was no significant difference in DeltaLVEF among patients. In group C, 4 of 17 patients (23.5%) with RD showed an increase in LVEF > or = 5% from poststress to rest.

CONCLUSION

These results showed that adenosine stress-induced postischemic LV dysfunction is well noted on early quantitative gated SPECT in patients with RD and can also be observed on delayed gated SPECT, even though the incidence of LV dysfunction is less than that in early gated SPECT.

Entrapment of the acetabular labrum following reduction of traumatic hip dislocation in a child

In traumatic hip dislocation, concentric reduction can be prevented by various causes. Soft-tissue interposition, such as entrapment of the acetabular labrum, is a rare but important cause of failed reduction of a hip. Early diagnosis of incomplete reduction due to interposition of soft tissue is important, because delayed treatment is associated with a greater incidence of avascular necrosis of the femoral head and early onset of osteoarthritis. This report describes a case of acetabular labral entrapment following reduction of traumatic hip dislocation in a child. The importance of CT and MRI in arriving at an early diagnosis is emphasized.

Osteoblastoma as a cause of osteomalacia assessed by bone scan

A 27-year-old female patient was admitted to our hospital with a history of leg pain and mass. She had a benign osteoblastoma in right tibia. Resection of the tumor without treatment by vitamin D antagonist resulted in rapid cure of the osteomalacia. Bone scintigraphy with Tc-99m MDP revealed multiple hot uptakes in initial scan, and follow up scan showed a clear resolution of the lesions.

Atypical benign lipomatous tumors in the soft tissue: radiographic and pathologic correlation

This article describes the characteristic imaging findings and correlates them with the pathology in the nonfatty regions of benign atypical lipomatous tumors, which have different findings compared with typical lipomas and well-differentiated liposarcomas. For differentiating these tumors from typical lipomas and well-differentiated liposarcomas, it may be helpful to analyze nonfatty regions in benign atypical lipomatous tumors.

Sonographic evaluation of gallbladder-wall thickening in hemorrhagic fever with renal syndrome: prediction of disease severity

PURPOSE

Gallbladder-wall thickening (GBWT) frequently occurs in patients with hemorrhagic fever with renal syndrome (HFRS), an acute infectious disease caused by hantaviruses. HFRS is manifested by fever, hemorrhage, renal failure, and in many cases gastrointestinal symptoms, such as abdominal pain and tenderness. The clinical significance of GBWT in HFRS has not been reported. The purpose of this study was to investigate the incidence of GBWT and the relationship between GBWT and the severity of HFRS.

METHODS

We retrospectively reviewed the medical records and sonograms of 68 patients with HFRS (47 males and 21 females, with an age range of 10-76 years) who underwent abdominal sonography in the acute stage of the disease. We measured the gallbladder-wall thickness on the sonograms and reviewed other sonographic and radiographic findings. Clinical factors that reflect the severity of HFRS were compared between the patients with GBWT (defined as thickness of 4 mm or more) and those without GBWT.

RESULTS

Of the 68 patients, 29 (43%) had GBWT, which was even and diffuse in all cases. The patients with GBWT had a significantly lower mean platelet count and serum albumin level and significantly higher serum aspartate aminotransferase and serum lactate dehydrogenase levels than did the patients without GBWT. In addition, the incidence of renal failure requiring hemodialysis and the incidences of ascites and pleural effusion were higher in the patients with GBWT than in those without GBWT. Five patients died of HFRS; all 5 had GBWT (p = 0.011 for comparison with patients without GBWT).

CONCLUSIONS

Our results suggest that the sonographic measurement of gallbladder-wall thickness during the acute stage of HFRS is useful for determining the severity of HFRS.

Access blood flow as a predictor of early failures of native arteriovenous fistulas in hemodialysis patients

Blood flow imaging using color doppler has proven effective in predicting graft failures in hemodialysis patients, but its effect on native arteriovenous fistulas (AVF) is not well known. This study was performed to investigate whether measurements of the access blood flow can be used as predictors of an early failure of a native AVF in hemodialysis patients. Fifty-three consecutive patients who received native AVF operations were included in this study. Access blood flow was measured at 1 week after operations, and AVF function was followed for 4 months. During the follow-up, access failures developed in 10 patients at 9.8 +/- 3.5 weeks. AVF blood flow was significantly lower in the failure group (n = 10) than in the patent group (n = 43) (450 +/- 214 vs. 814 +/- 348 ml/min, p = 0.003). The incidence of access failures was higher in the patients with a flow <350 ml/min (n = 9) compared to the patients with a flow >350 ml/min (n = 44) (55.5 vs. 11.3%, p = 0.008). The diameters of veins were significantly smaller in the failure group than in the patent group (3.5 +/- 0.5 vs. 4.1 +/- 0.7 mm, p = 0.018). The incidence of diabetes mellitus was higher in the failure group than in the patent group (90 vs. 51%, p = 0.025). However, age, sex, duration from an operation to first cannulation, and different AVF sites did not make a significant difference between the two groups. Our data suggest that access blood flow measurements using color doppler ultrasound during early postoperative periods are useful parameters in predicting an early failure of a native AVF in hemodialysis patients.

Comparison of Tc-99m sestamibi and TI-201 uptake in multiple myeloma

The authors report abnormal Tc-99m sestamibi (MIBI) and TI-201 uptake in a 62-year-old patient with histologically and biochemically proved myeloma. TI-201 imaging was undertaken for tumor evaluation, and 3 days later a Tc-99m MIBI study showed diffuse and focal marrow uptake with focal skull lesions, whereas TI-201 did not show skull lesions. After treatment, follow-up Tc-99m MIBI whole-body imaging was performed and the marrow uptake was decreased.

CT features of systemic lupus erythematosus in patients with acute abdominal pain: emphasis on ischemic bowel disease

PURPOSE

To evaluate the computed tomographic (CT) features of systemic lupus erythematosus (SLE) in patients with acute abdominal pain. Special emphasis was placed on the analysis of ischemic bowel disease.

MATERIALS AND METHODS

The authors retrospectively reviewed the images from 39 abdominal CT examinations performed in 33 patients with SLE and acute abdominal pain. Images were evaluated for bowel wall changes, mesenteric changes, fluid collection, retroperitoneal lymphadenopathy, peritoneal enhancement, and hepatomegaly as well as for changes in other abdominal organs. Ischemic bowel disease was diagnosed if at least three of the following signs were seen: bowel wall thickening, target sign, dilatation of intestinal segments, engorgement of mesenteric vessels, and increased attenuation of mesenteric fat.

RESULTS

Thirty-one (79%) of the 39 examinations had CT findings diagnostic of ischemic bowel disease, including symmetric bowel wall thickening (n = 29), target sign (n = 26), and mesenteric vascular engorgement and haziness (n = 31). In 24 cases, bowel wall thickening was multifocal, with variable length, and did not appear to be confined to a single vascular territory.

CONCLUSION

The most common CT finding in patients with SLE and acute abdominal pain is ischemic bowel disease. CT is useful for detecting the primary cause of gastrointestinal symptoms, planning treatment, and monitoring for infarction or perforation.

MR findings in ovarian granulocytic sarcoma

Granulocytic sarcoma (chloroma) is a mass of malignant myeloid precursor cells in an extramedullary location. The female genital tract, including the ovary, may be the first site for clinical manifestation of granulocytic sarcoma. The MR findings are reported in a case of ovarian granulocytic sarcoma which preceded acute myelogenous leukaemia. Granulocytic sarcoma shows a mixed cystic and solid adnexal mass with intermediate signal intensity on T1 weighted images and hypointensity on T2 weighted images.

Intramedullary fat necrosis of multiple bones associated with pancreatitis

We describe findings of intramedullary fat necrosis on five imaging studies in a patient with alcoholic pancreatitis. Radiography and CT of extremities showed multiple osteolytic lesions that were initially considered to be metastases. However, a 99mTc-methylene diphosphonate whole-body bone scan revealed abnormal areas of increased uptake in only the bones of extremities without involvement of the axial skeleton, a distribution quite unusual for metastatic disease. Furthermore, 99mTc-sestamibi scintigraphy was essentially normal. MRI revealed findings compatible with the diagnosis of fat necrosis/infarct. Findings from bone biopsy demonstrated necrotic bone marrow without malignant cells. It may not be necessary to perform all the imaging studies described in this report when clinical features suggesting metastatic fat necrosis are present. Appearance and distribution of abnormalities on the whole-body bone scan and MR images show that necrosis/infarct of the marrow may obviate bone biopsy, which is often needed to confirm the diagnosis of intramedullary fat necrosis and to exclude neoplastic processes.

Gastrointestinal leiomyoma and leiomyosarcoma: CT differentiation

PURPOSE

Our goal was to evaluate CT efficacy in differentiating gastrointestinal leiomyoma and leiomyosarcoma.

METHOD

We retrospectively reviewed CT scans of 45 patients (21 men, 24 women, mean age 55 years) with surgically proven gastrointestinal leiomyomas (n = 21) and leiomyosarcomas (n = 24) with respect to size, contour, enhancing pattern, mesenteric fat infiltration, calcification, ulceration, regional lymphadenopathy, direct invasion, distant metastasis, and growth pattern after visual inspection by two radiologists in agreement. On the basis of these CT features, subjective diagnosis was also categorized into three groups (Group I: probably benign, Group II: probably malignant, Group III: diagnostic malignant). The results were compared with the final histopathologic diagnosis.

RESULTS

In addition to the features of direct invasion and distant metastasis suggesting diagnostic malignancy, the CT features favoring malignancy with statistical significance included larger size (> 5 cm), lobulated contour, heterogeneous enhancement, mesenteric fat infiltration, ulceration, regional lymphadenopathy, and exophytic growth pattern (p < 0.005). However, calcification was not significant in differentiating the two entities (p = 0.25163). A subjective analysis revealed 89% sensitivity, 85% specificity, and 87% accuracy for diagnosis of leiomyosarcoma.

CONCLUSION

CT features are useful in differentiating leiomyoma and leiomyosarcoma in gastrointestinal tract.

Sarcomatous transformation of neurofibromas. Comparative imaging with Ga-67, Tl-201, Tc-99m pentavalent DMSA and Tc-99m MIBI

A 29-year-old man, with a history of von Recklinghausen's disease, presented with progressive dyspnea associated with a rapidly growing mass on the right chest wall. Plain radiograph and CT of the chest revealed a huge soft-tissue mass with central low-density area involving the right upper lung and chest wall. SPECT imaging with Ga-67 citrate, Tl-201 chloride, Tc-99m pentavalent DMSA (V-DMSA), and Tc-99m MIBI were performed to characterize the mass. The tumor concentrated Ga-67, Tl-201, and Tc-99m (V) DMSA, but not Tc-99m MIBI. Punch biopsy of the lesion revealed malignant transformation of a thoracic neuroma (neurofibrosarcoma). Subsequently, findings compatible with the presence of a multidrug resistance-1 (MDR1) gene in the tumor was documented, which may explain the poor uptake of Tc-99m MIBI. The patient did not respond to intensive chemotherapeutic regimens, and died 3 months later. This case demonstrates the potential use of combined radionuclide imaging for the detection of malignant transformation of neurofibroma, as well as for predicting tumor response to chemotherapy.

Xanthogranulomatous cholecystitis: CT features with emphasis on differentiation from gallbladder carcinoma

PURPOSE

To evaluate the computed tomographic (CT) features of xanthogranulomatous cholecystitis (XGC) and to distinguish it from gallbladder carcinoma.

MATERIALS AND METHODS

Retrospective analysis was performed in 11 patients with XGC and 17 patients with gallbladder carcinoma in which the wall was thickened. The following CT features were analyzed: maximum wall thickness, intramural hypoattenuated nodules, mucosal line, patterns of wall thickening and enhancement, and the presence of stones. The changes outside the gallbladder were also compared.

RESULTS

The mean thickness of the gallbladder wall was 1.8 cm in patients with XGC and 2.1 cm in patients with gallbladder carcinoma. Intramural hypoattenuated nodules were seen in all patients with XGC but in only seven patients with gallbladder carcinoma (P = .008). The mucosal line was observed in nine patients with XGC and in six with gallbladder carcinoma (P = .02). The gallbladder wall was more diffusely thickened in patients with XGC (10 of 11 patients) than in patients with gallbladder carcinoma (seven of 17 patients) (P = .01). The occurrence of changes outside the gallbladder did not differ statistically significantly.

CONCLUSION

Because of a statistically significant overlap of CT features, only when intramural hypoattenuated nodules occupy a large area of the thickened gallbladder wall can the diagnosis of XGC be highly suggestive. The diagnosis of XGC at CT may indicate a less aggressive surgical approach.