Conventional Imaging Findings Research Articles

Application of Basic Principles of Physics to Head and Neck MR Angiography: Troubleshooting for Artifacts

Neurovascular imaging studies are routinely used for the assessment of headaches and changes in mental status, stroke workup, and evaluation of the arteriovenous structures of the head and neck. These imaging studies are being performed with greater frequency as the aging population continues to increase. Magnetic resonance (MR) angiographic imaging techniques are helpful in this setting. However, mastering these techniques requires an in-depth understanding of the basic principles of physics, complex flow patterns, and the correlation of MR angiographic findings with conventional MR imaging findings. More than one imaging technique may be used to solve difficult cases, with each technique contributing unique information. Unfortunately, incorporating findings obtained with multiple imaging modalities may add to the diagnostic challenge. To ensure diagnostic accuracy, it is essential that the radiologist carefully evaluate the details provided by these modalities in light of basic physics principles, the fundamentals of various imaging techniques, and common neurovascular imaging pitfalls.

The Role of MR Imaging in Assessment of Brain Damage from Carbon Monoxide Poisoning: A Review of the Literature

The aim of this article is to review how MR imaging and associated imaging modalities provide clinicopathologic information on brain damage after carbon monoxide poisoning. Initially, many authors documented typical findings of conventional MR imaging in the gray matter structures such as the globus pallidus and in various regions of cerebral white matter. The focus of investigation has since shifted to observation of cerebral white matter areas that are more frequently detected on MR imaging and are more responsible for chronic symptoms than the gray matter. DWI has dramatically contributed to the ability to quantitatively assess cerebral white matter damage. Subsequently, DTI has enabled more sensitive evaluation than DWI and can demonstrate progressive pathologic changes in the early stage, allowing prediction of chronic conditions. In addition, MR spectroscopy reveals changes in metabolite levels, offering quantitative clinicopathologic information on brain damage after carbon monoxide poisoning.

Fibrous dysplasia of the maxilla: a case report together with its conventional imaging and dynamic magnetic resonance imaging findings

We previously reported that dynamic contrast-enhanced MRI parameters and time–signal intensity curves (TICs; also known as contrast index curves) are useful for the differential diagnosis of jawbone lesions. In particular, odontogenic fibroma and ossifying fibroma, which possess similar histopathological features (i.e., a mixture of hard and soft tissue components), display unique TIC patterns, and we consider that the TIC patterns of these lesions reflect their hard and soft tissue components. Therefore, fibrous dysplasia, which contains fibrous tissue and immature isolated trabeculae composed of woven bone, is expected to display an interesting TIC. The purpose of this study was to assess the utility of TICs for differentiating between the abovementioned lesions, which have similar histopathological components.

11C-Acetate PET/CT Before Radical Prostatectomy: Nodal Staging and Treatment Failure Prediction

Despite early detection programs, many patients with prostate cancer present with intermediate- or high-risk disease. We prospectively investigated whether (11)C-acetate PET/CT predicts lymph node (LN) metastasis and treatment failure in men for whom radical prostatectomy is planned. 107 men with intermediate- or high-risk localized prostate cancer and negative conventional imaging findings underwent PET/CT with (11)C-acetate. Five underwent LN staging only, and 102 underwent LN staging and prostatectomy. PET/CT findings were correlated with pathologic nodal status. Treatment-failure-free survival was estimated by the Kaplan-Meier method. The ability of PET/CT to predict outcomes was evaluated by multivariate Cox proportional hazards analysis. PET/CT was positive for pelvic LN or distant metastasis in 36 of 107 patients (33.6%). LN metastasis was present histopathologically in 25 (23.4%). The sensitivity, specificity, and positive and negative predictive values of PET/CT for detecting LN metastasis were 68.0%, 78.1%, 48.6%, and 88.9%, respectively. Treatment failed in 64 patients: 25 with metastasis, 17 with a persistent postprostatectomy prostate-specific antigen level greater than 0.20 ng/mL, and 22 with biochemical recurrence (prostate-specific antigen level > 0.20 ng/mL after nadir) during follow-up for a median of 44.0 mo. Treatment-failure-free survival was worse in PET-positive than in PET-negative patients (P < 0.0001) and in those with false-positive than in those with true-negative scan results (P < 0.01), suggesting that PET may have demonstrated nodal disease not removed surgically or identified pathologically. PET positivity independently predicted failure in preoperative (hazard ratio, 3.26; P < 0.0001) and postoperative (hazard ratio, 3.07; P = 0.0001) multivariate models. In patients planned for or completing prostatectomy, (11)C-acetate PET/CT detects LN metastasis not identified by conventional imaging and independently predicts treatment-failure-free survival.

Diffusion Tensor Imaging in a Child with Hypertrophic Olivary Degeneration

Hypertrophic olivary degeneration (HOD) is caused by disruptive lesions affecting components of the Guillain-Mollaret triangle (GMT). We present conventional magnetic resonance and diffusion tensor imaging (DTI) findings in a 6-year-old girl with HOD after surgery for a midbrain pilocytic astrocytoma. To our knowledge, this is the first dedicated DTI analysis of GMT in a child with HOD in the literature. In our patient, we found higher fractional anisotropy (FA) and axial diffusivity values of the inferior olivary nucleus (ION) and lower FA, but higher radial diffusivity (RD) values of all other GMT components compared to age-matched controls. Increased FA values of the ION may be explained by increased packing of white matter fibers. However, associated hyperintense T2 signal is contradictory and the association between increased FA values and hyperintense T2 signal remains unclear. Low FA and high RD values of the other GMT components likely reflect demyelination with axonal degeneration and correlate well with histopathological findings.

Perfusion MR Imaging of Seizure-related Cerebral Cortical Lesion: A Case Report

It has been reported that seizure-related hyperintense lesions can be demonstrated in the cerebral cortices on diffusion-weighted image (DWI). They are usually reversible but can become irreversible and permanent in severe or prolonged seizures (1, 2). Acute infarction is the most common cause of the cerebral cortical hyperintensities on DWI. However, seizure-related change and encephalitis can also show cortical hyperintensities on DWI (1-3). Some patients with acute infarction show seizures in the clinical manifestations (4). Therefore, it is necessary to differentiate whether the DWI hyperintensities in the cerebral cortices are caused by infarction or seizurerelated change. Sometimes, it is not easy to differentiate between acute infarction and seizure-related lesions with only conventional imaging findings. We report a case of seizure-related cortical hyperintensities in a patient with suspected acute infarction. With perfusion MR imaging, it was possible to differentiate from infarction.

Serum tumor markers and PET/CT imaging for tumor recurrence detection

When confronted with a suspicious rise in CA 15.3 in asymptomatic breast cancer patients following primary treatment and negative or equivocal conventional imaging findings, FDG PET/CT allows assessment of the site and extent of the recurring disease with an accuracy of 83%. Both FDG PET and FDG PET/CT are superior when compared to CT alone for the purpose of recurrence detection in patients suffering from ovarian carcinoma who have completed primary therapy but demonstrate a rising serum CA-125 level. As the global accuracy of CT alone for detection of recurrence of ovarian cancer approximates 80%, CT scan should be performed upfront to identify the site of recurrence. When confronted with negative or equivocal CT findings, FDG PET alone or FDG PET/CT should be added. In patients with rising serum CEA levels that have undergone primary treatment for a colorectal carcinoma, both FDG PET and FDG PET/CT allow detection of tumor recurrence with an accuracy of 95%, well above that of CT and MRI. Available studies further suggest that FDG/PET findings will affect treatment management in 28-50% of these patients. The detection rate of both 11C-choline and 18F-choline PET and PET/CT for local, regional, and distant recurrence in prostate carcinoma patients with a biochemical recurrence increases with rising PSA value at the time of imaging and reaches about 75% in patients with PSA > 3 ng/mL. Furthermore, PET and PET/CT with [11C]- and [18F]-choline derivates may be helpful in the clinical setting for optimization of individualized treatment.

MRI of persistent cloaca: Can it substitute conventional imaging?

PurposeTo define the role of MRI in the preoperative assessment of patients with persistent cloaca and whether it can substitute other imaging modalities. MethodsWe prospectively examined eleven patients with persistent cloaca between July 2007 and March 2012. Non contrast MRI examinations were performed on 1.5T magnet using head coil. Multiple pulse sequences (T1WI, T2WI, fat suppression) were obtained in axial, sagittal and coronal planes of the pelvis, abdomen, and spine. The scans were reviewed for the following: the level and type of rectal termination, the developmental state of striated muscle complex (SMC), associated genitourinary and spinal anomalies. MRI findings were compared to conventional fluoroscopic imaging, operative and endoscopic findings. We applied novel MRI parameters (urethral length, relative hiatal distance and vaginal volume). The relation between different parameters was tested statistically using Pearson correlation test. ResultsMRI could accurately demonstrate the level of bowel termination in patients with persistent cloaca, in addition to its high sensitivity for detection of mullerian anomalies which were present in 73% of patients. Furthermore, MRI could disclose associating renal and spinal anomalies, and assess the developmental state of SMC.The shorter the urethra (higher urogenital confluence), the narrower the pelvic hiatus, and the more was the obstruction (vaginal distension). ConclusionMRI is a valuable tool in exploring the different internal anatomical features of the cloacal anomaly; and when combined with endoscopy, MRI can make other preoperative conventional imaging unnecessary.

Bone Scan and SPECT/CT Findings in Marble Bone Disease.

Marble bone disease or osteopetrosis (OS), is a rare inborn disorder characterized by the failure of osteoclasts to resorb bone [1]. Overall incidence of the disease is estimated to be 1 case in 100,000-500,000 population [2]. Whereas the radiographic features of the disease are well known, information on bone scan imaging is sparse in the literature. We present technetium-99m methylene diphosphonate (99mTc MDP) bone scan features of osteopetrosis,along with single photon emission computed tomography–computed tomography(SPECT/CT) correlation in a young male (Fig. 1). Fig. 1 A 23-year-old man underwent a 99mTc MDP bone scan for the evaluation of sclerotic lesions in the pelvis found on a radiograph obtained for his hip pain. On planar scan (a, b), intense tracer uptake was noted in the entire skeleton, notably in the proximal ... On conventional imaging, generalized sclerosis, more commonly in metaphyseal regions is seen in bones. Various patterns described on bone scan include diffuse increased uptake that may also be a “Superscan” and non-uniform uptake with foci of hyperemia [3–5]. Use of SPECT/CT in OS has not been described in literature previously. In our case, SPECT/CT was performed to rule out fracture of left femur or pelvic bone as a cause of patient’s symptoms. It is known that pelvic X-ray has limited value for detecting pelvic fractures compared with CT scanning and hence we performed SPECT/CT even when the radiographs were available [6]. In such a case, planar imaging alone will miss the uptake secondary to fracture as it will be masked by metaphyseal areas of intense tracer uptake. Additional advantage of SPECT/CT in such cases is that it can confirm that the areas of abnormal tracer uptake are limited to metaphyseal regions and hence can clinch the diagnosis of OS. In general, radiographic findings are considered sufficient for diagnosis of OS and biopsy is reserved only in pre-bone marrow transplant work-up, in cases where diagnosis is unclear or for genetic diagnosis [7]. SPECT or SPECT/CT can be used as a problem solving tool when conventional imaging findings are inconclusive or pathological fracture is suspected. Our case illustrates bone scan and SPECT/CT findings of this rare disorder. Though rare, this diagnosis should be kept in mind when similar uptake pattern and CT characteristics are encountered in practice.

Use of conventional MR imaging and diffusion‐weighted imaging for evaluating the risk grade of gastrointestinal stromal tumors

To study the risk grade of gastrointestinal stromal tumors (GISTs) with conventional MR imaging and diffusion-weighted imaging (DWI). The abdominal MR images with DWI of 23 patients with pathologically proven GISTs during January 2010 to May 2011 were retrospectively reviewed. The conventional MR imaging findings and apparent diffusion coefficient (ADC) values of the tumors related to the risk grade were analyzed. In the 23 patients, there were 13 patients with high-risk, 5 with medium-risk, 5 with low-risk, and 0 with very low-risk GISTs. Most of the conventional MR findings of the tumors did not correlate with the risk grade. The only exception to this was the correlation between risk grade and the enhancement degree of the tumor after Gd-DTPA. The ADC values were, respectively, (1.04 ± 0.13) × 10(-3) mm(2) ·s(-1) , (1.59 ± 0.06) × 10(-3) mm(2) ·s(-1) and (1.94 ± 0.08) × 10(-3) mm(2) ·s(-1) (P < 0.05) in the high-, medium-, and low-risk grade groups. The ADC values of GISTs decreased with the increase of the risk grade of the tumors (r = -0.957; P < 0.05). DWI can be used to assess the risk grade of GISTs, but conventional MR imaging is of limited use.

Multimodality, Anatomical, and Diffusion-Weighted Fetal Imaging of a Spontaneously Thrombosing Congenital Dural Sinus Malformation

We report on the conventional and diffusion-weighted (DWI) magnetic resonance imaging (MRI) findings of a partially thrombosed torcular Herophili dural sinus malformation. DWI confirmed the intralesional partial thrombosis/blood clot characterized by restricted diffusion. In addition, focal or global intracerebral complications were excluded by fetal DWI. Our findings suggest that DWI is a valuable adjunct to the standard T1- and T2-weighted fetal MRI sequences.

White matter microstructure on diffusion tensor imaging is associated with conventional magnetic resonance imaging findings and cognitive function in adolescents born preterm

Diffusion tensor imaging (DTI) was used to evaluate white matter architecture after preterm birth. The goals were (1) to compare white matter microstructure in two cohorts of preterm- and term-born children; and (2) within preterm groups, to determine if sex, gestational age, birthweight, white matter injury score from conventional magnetic resonance imaging (MRI), or IQ was associated with DTI measures. Participants (n=121; 66 females, 55 males) were aged 9 to 16 years. They comprised 58 preterm children (site 1, n=25; and site 2, n=33) born at less than 36 weeks' gestation (mean 29.4 wks; birthweight 1289g) and 63 term children (site 1, n=40; site 2, n=23) born at more than 37 weeks' gestation. DTI was analyzed using tract-based spatial statistics. Diffusion measures were fractional anisotropy, axial, radial, and mean diffusivity. In no region of the white matter skeleton was fractional anisotropy lower in the preterm group at either site. Within the preterm groups, fractional anisotropy was significantly associated with white matter injury score, but not sex, gestational age, or birthweight. At site 1, fractional anisotropy was associated with IQ. DTI contributes to understanding individual differences after preterm birth but may not differentiate a relatively high-functioning group of preterm children from a matched group of term-born children.

Sterile Brain Abscess due to Juvenile Xanthogranuloma:DWI Characteristics

Juvenile xanthogranuloma (JXG) is a disorder of non-Langerhans cell histiocytosis that usually displays as a self-limiting course in children. Rare systemic involvement implies poor prognosis. Although conventional and spectroscopic magnetic resonance imaging (MRI) findings of JXG in CNS have been described, diffusion imaging of intracranial JXG has not been reported. Our case report is the first manuscript to describe diffusion restriction of a cerebral lesion seen in the setting of JXG. Since diffusion restriction has not been described in the setting of JXG but it is more commonly associated with infectious cerebral abscess, this finding has had significant impact in the management. Central nervous system (CNS) lesion of our patient has also had additional imaging features similar to typical infectious cerebral abscess. Extensive work-up has been unrevealing any infectious source. Patient has had biopsy proven peripheral sterile abscesses. After extensive discussion with the family, brain biopsy is deferred. Intravenous steroid therapy is initiated in intensive care setting. All of the lesions have gradually responded to steroid therapy. CNS lesion has taken the longest time to clear.

Digital breast tomosynthesis (DBT): initial experience in a clinical setting

Digital breast tomosynthesis (DBT) is a promising new technology. Some experimental clinical studies have shown positive results, but the future role and indications of this new technique, whether in a screening or clinical setting, need to be evaluated. To compare digital mammography and DBT in a side-by-side feature analysis for cancer conspicuity, and to assess whether there is a potential additional value of DBT to standard state-of-the-art conventional imaging work-up with respect to detection of additional malignancies. The study had ethics committee approval. A total of 129 women underwent 2D digital mammography including supplementary cone-down and magnification views and breast ultrasonography if indicated, as well as digital breast tomosynthesis. The indication for conventional imaging in the clinical setting included a palpable lump in 30 (23%), abnormal mammographic screening findings in 54 (42%), and surveillance in 45 (35%) of the women. The women were examined according to present guidelines, including spot-magnification views, ultrasonography, and needle biopsies, if indicated. The DBT examinations were interpreted several weeks after the conventional imaging without knowledge of the conventional imaging findings. In a later session, three radiologists performed a side-by-side feature analysis for cancer conspicuity in a sample of 50 cases. State-of-the-art conventional imaging resulted in needle biopsy of 45 breasts, of which 20 lesions were benign and a total of 25 cancers were diagnosed. The remaining 84 women were dismissed with a normal/definitely benign finding and without indication for needle biopsy. The subsequent DBT interpretation found suspicious findings in four of these 84 women, and these four women had to be called back for repeated work-up with knowledge of the tomosynthesis findings. These delayed work-ups resulted in two cancers (increasing the cancer detection by 8%) and two false-positive findings. The side-by-side feature analysis showed higher conspicuity scores for tomosynthesis compared to conventional 2D for cancers presenting as spiculated masses and distortions. Tomosynthesis is a promising new technique. Our preliminary clinical experience shows that there is a potential for increasing the sensitivity using this new technique, especially for cancers manifesting as spiculated masses and distortions.

Pelvic inflammatory disease: evaluation of diagnostic accuracy with conventional MR with added diffusion-weighted imaging

To determine the incremental value of magnetic resonance (MR) diffusion-weighted (DW) imaging for the diagnosis of pelvic inflammatory diseases (PID). We added DW sequences to conventional MR imaging in 187 patients with clinically suspected PID. The imaging findings included shape, signal intensity on T1-weighted, T2-weighted, and DW imaging, shade in the peripheral lesions, free pelvic fluid, and lymphadenopathy. Laparoscopic and pathological findings confirmed the diagnosis in all patients. Conventional MR findings were consistent with a diagnosis of PID in 90.7% (117/129) and of non-PID in 93.3% (28/30) of the 159 patients. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of conventional MR imaging findings vs. the addition of DW imaging to conventional MR protocols for predicting PID were 90.7%, 93.3%, 98.3%, 70.0%, and 91.2% and 98.4%, 93.3%, 98.4%, 93.3%, and 97.5%, respectively. The addition of DW sequences to conventional MR imaging can improve the accuracy of diagnosis in PID.

Clinical applications of 18F-FDG PET in the management of hepatobiliary and pancreatic tumors

The assessment of hepatobiliary and pancreatic tumors is commonly achieved by ultrasound, computed tomography (CT), and magnetic resonance. The 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) detects increased glucose metabolism associated with neoplastic lesions, provides high accuracy in most cancer imaging applications and is now widely used in clinical practice. However, PET is not always useful and accurate knowledge of appropriate indications is essential for a proper clinical management. (18)F-FDG is transported into cells and phosphorylated by the enzyme hexokinase to (18)F-FDG-6-phosphate, which cannot proceed down the glycolytic pathway and therefore is accumulated in the malignant tissue. PET allows accurate quantification of FDG uptake in tissue, and previous studies have demonstrated that standardized uptake values provide highly reproducible parameters of tumor glucose use (Weber et al., J Nucl Med 40:1771-1777, 1999). The recent development and diffusion of hybrid PET-CT scanners allows functional and anatomic data to be obtained in a single examination, improving lesion localization and resulting in significant diagnostic improvement (Wahl, J Nucl Med 45:82S-95S, 2004). Moreover, CT can be performed diagnostically with the use of intravenous and oral contrast and simultaneous PET-contrast-enhanced CT scanning appears to be an efficient method in cancer evaluation. However, in most centers, a low-dose CT is routinely performed without contrast media infusion.Proper patient preparation, scanning protocol, combined assessment of PET and CT data, and the evaluation of conventional imaging findings are essential to define disease and to avoid diagnostic pitfalls. The role of PET and PET-CT in malignancies of the liver, biliary tract, and pancreas is here reviewed; normal patterns, representative cases, and common pitfalls are also presented.

NOMID: The radiographic and MRI features and review of literature

Neonatal onset multisystem inflammatory disease (NOMID) is a rare autoinflammatory disorder, which manifests early in infancy. We describe a case of a 10-year-old boy who has been unwell since infancy. He presented with urticarial rash, intermittent fever and hepatosplenomegaly followed by progressive arthropathy. His joint symptoms started at two years of age, which progressively involved multiple joints, resulting in bone and joint deformities. A series of joint radiographs demonstrated bizarre enlarging physeal mass with heterogenous calcification. Magnetic resonance imaging (MRI) of the involved right ankle and knee showed characteristic thickened and calcified physeal lesions, which enhanced post-gadolinium. This debilitating disease is also known to involve the central nervous system and eyes. This case report aims to highlight the conventional radiographic and magnetic resonance imaging (MRI) findings of this physeal abnormality in NOMID syndrome.

Tenosynovial Giant Cell Tumor of Diffuse Type in Ankle and Foot - A Case Report

A 18 year old male presented with longitudinally oriented mass at the posteromedial aspect of his left distal lower extremity, most prominent just superior to medial malleolus. FNAC of this lesion is inconclusive Suggestive of Giant Cell Lesion. Conventional radiograph and MR Imaging findings were suggestive of Soft Tissue Sarcoma. Finally biopsy report proved to be out Giant Cell Tumor of Diffuse Type. A below Knee amputed specimen received to the Pathology Department which on Gross dissection showed well encapsulated, multinodular tumor mass. Sections showed benign pattern of tumor tissue conclusive as Giant Cell Tumor of Diffuse Type. It accounts approximately 1.6% of all soft tissue tumors with a substantial incidence of recurrence. Thus to conclude we reported a case of Tenosynovial Giant Cell Tumor of Diffuse Type in Ankle and Foot in a Young Adult.

Hepatosplenic and Muscular Sarcoidosis: Characterization with MR Imaging

Sarcoidosis is a multisystem disorder of unknown etiology that involves multiple organs. Computed tomography is the first-line imaging modality for diagnosing sarcoidosis because of its capacity to detect hilar lymphadenopathy and pulmonary lesions. Magnetic resonance (MR) imaging provides good soft tissue contrast that is useful for detecting sarcoidosis in some body parts, including skeletal muscle. Signal intensity on pre- and postcontrast T(1)- and T(2)-weighted imaging may reflect disease activity and the pathological appearance of sarcoidosis. In this review, we demonstrate these conventional MR imaging findings of hepatosplenic and muscular sarcoidosis and describe the usefulness of diffusion-weighted imaging for detecting sarcoidosis.

Tractography of the corticospinal tracts in infants with focal perinatal injury: comparison with normal controls and to motor development

Our aims were to (1) assess the corticospinal tracts (CSTs) in infants with focal injury and healthy term controls using probabilistic tractography and (2) to correlate the conventional magnetic resonance imaging (MRI) and tractography findings in infants with focal injury with their later motor function. We studied 20 infants with focal lesions and 23 controls using MRI and diffusion tensor imaging. Tract volume, fractional anisotropy (FA), apparent diffusion coefficient (ADC) values, axial diffusivity and radial diffusivity (RD) of the CSTs were determined. Asymmetry indices (AIs) were calculated by comparing ipsilateral to contralateral CSTs. Motor outcome was assessed using a standardized neurological examination. Conventional MRI was able to predict normal motor development (n = 9) or hemiplegia (n = 6). In children who developed a mild motor asymmetry (n = 5), conventional MRI predicted a hemiplegia in two and normal motor development in three infants. The AIs for tract volume, FA, ADC and RD showed a significant difference between controls and infants who developed a hemiplegia, and RD also showed a significant difference in AI between controls and infants who developed a mild asymmetry. Conventional MRI was able to predict subsequent normal motor development or hemiplegia following focal injury in newborn infants. Measures of RD obtained from diffusion tractography may offer additional information for predicting a subsequent asymmetry in motor function.