The Benefits of High Relaxivity for Brain Tumor Imaging: Results of a Multicenter Intraindividual Crossover Comparison of Gadobenate Dimeglumine with Gadoterate Meglumine (The BENEFIT Study).

BACKGROUND AND PURPOSE: Gadobenate dimeglumine (MultiHance) has higher r1 relaxivity than gadoterate meglumine (Dotarem) which may permit the use of lower doses for MR imaging applications. Our aim was to compare 0.1- and 0.05-mmol/kg body weight gadobenate with 0.1-mmol/kg body weight gadoterate for MR imaging assessment of brain tumors. MATERIALS AND METHODS: We performed crossover, intraindividual comparison of 0.1-mmol/kg gadobenate with 0.1-mmol/kg gadoterate (Arm 1) and 0.05-mmol/kg gadobenate with 0.1-mmol/kg gadoterate (Arm 2). Adult patients with suspected or known brain tumors were randomized to Arm 1 (70 patients) or Arm 2 (107 patients) and underwent 2 identical examinations at 1.5 T. The agents were injected in randomized-sequence order, and the 2 examinations were separated by 2-14 days. MR imaging scanners, imaging sequences (T1-weighted spin-echo and T1-weighted high-resolution gradient-echo), and acquisition timing were identical for the 2 examinations. Three blinded readers evaluated images for diagnostic information (degree of definition of lesion extent, lesion border delineation, visualization of lesion internal morphology, contrast enhancement) and quantitatively for percentage lesion enhancement and lesion-to-background ratio. Safety assessments were performed. RESULTS: In Arm 1, a highly significant superiority (P < .002) of 0.1-mmol/kg gadobenate was demonstrated by all readers for all end points. In Arm 2, no significant differences (P > .1) were observed for any reader and any end point, with the exception of percentage enhancement for reader 2 (P < .05) in favor of 0.05-mmol/kg gadobenate. Study agent-related adverse events were reported by 2/169 (1.2%) patients after gadobenate and by 5/175 (2.9%) patients after gadoterate. CONCLUSIONS: Significantly superior morphologic information and contrast enhancement are demonstrated on brain MR imaging with 0.1-mmol/kg gadobenate compared with 0.1-mmol/kg gadoterate. No meaningful differences were recorded between 0.05-mmol/kg gadobenate and 0.1-mmol/kg gadoterate.

Are there differences between macrocyclic gadolinium contrast agents for brain tumor imaging? Results of a multicenter intraindividual crossover comparison of gadobutrol with gadoteridol (the TRUTH study).

BACKGROUND AND PURPOSE: Gadobutrol (Gadavist) and gadoteridol (ProHance) have similar macrocyclic molecular structures, but gadobutrol is formulated at a 2-fold higher (1 mol/L versus 0.5 mol/L) concentration. We sought to determine whether this difference impacts morphologic contrast-enhanced MR imaging. MATERIALS AND METHODS: Two hundred twenty-nine adult patients with suspected or known brain tumors underwent two 1.5T MR imaging examinations with gadoteridol or gadobutrol administered in randomized order at a dose of 0.1 mmol/kg of body weight. Imaging sequences and T1 postinjection timing were identical for both examinations. Three blinded readers evaluated images qualitatively and quantitatively for lesion detection and for accuracy in characterization of histologically confirmed brain tumors. Data were analyzed by using the Wilcoxon signed rank test, the McNemar test, and a mixed model. RESULTS: Two hundred nine patients successfully completed both examinations. No reader noted a significant qualitative or quantitative difference in lesion enhancement, extent, delineation, or internal morphology (P values = .69-1.00). One hundred thirty-nine patients had at least 1 histologically confirmed brain lesion. Two readers found no difference in the detection of patients with lesions (133/139 versus 135/139, P = .317; 137/139 versus 136/139, P = .564), while 1 reader found minimal differences in favor of gadoteridol (136/139 versus 132/139, P = .046). Similar findings were noted for the number of lesions detected and characterization of tumors (malignant/benign). Three-reader agreement for characterization was similar for gadobutrol (66.4% [κ = 0.43]) versus gadoteridol (70.3% [κ = 0.45]). There were no significant differences in the incidence of adverse events (P = .199). CONCLUSIONS: Gadoteridol and gadobutrol at 0.1 mmol/kg of body weight provide similar information for visualization and diagnosis of brain lesions. The 2-fold higher gadolinium concentration of gadobutrol provides no benefit for routine morphologic imaging.

Sinonasal polyposis: investigation by direct coronal CT.

To demonstrate the typical clinical and CT features of sinonasal polyposis, we reviewed the clinical records and preoperative direct coronal CT scans of 35 patients with surgically proven disease. Symptoms included progressive nasal stuffiness (100%), rhinorrhea (69%), facial pain (60%), headache (43%) and anosmia (17%). We found associations with rhinitis (46%), asthma (29%) and aspirin sensitivity (9%). Coronal CT features included polypoid masses in the nasal cavity (91%), partial or complete pansinus opacification (90%), enlargement of infundibula (89%), bony attenuation of the ethmoid trabeculae (63%) and nasal septum (37%), opacified ethmoid sinuses with convex lateral walls (51%) and air-fluid levels (43%). The latter feature correlated with symptoms and signs of acute sinusitis in only 40% of patients. Recognition of sinonasal polyposis is important to the endoscopic surgeon since it can be the most troubling sinonasal inflammatory disease to manage due to its aggressive nature and tendency to recur despite appropriate treatment.

Recurring patterns of inflammatory sinonasal disease demonstrated on screening sinus CT.

PURPOSE: In order to define specific features on screening sinus CT (SSCT) that will aid the endoscopic surgeon in his approach to patients with inflammatory sinonasal disease, we sought to answer four questions: 1) what recurring patterns of inflammatory sinonasal disease are evident on SSCT; 2) what is the relative frequency of these recurring patterns; 3) how do these CT patterns correlate with the known sinus mucociliary drainage routes; and 4) what are the characteristic radiologic features of each pattern? METHODS: We reviewed the clinical and radiologic records of 500 consecutive patients who underwent SSCT as a prelude to possible functional endoscopic sinus surgery. RESULTS: Five recurring radiologic patterns of sinonasal inflammatory disease were identified: 1) infundibular (129/500 or 26%), 2) ostiomeatal unit (126/500 or 25%) 3) sphenoethmoidal recess (32/500 or 6%), 4) sinonasal polyposis (49/500 or 10%), and 5) sporadic (unclassifiable) (121/500 or 24%) patterns. Normal SSCT was seen in 133/500 patients (27%). CONCLUSION: Identification of specific patterns of sinonasal disease permits grouping of patients into nonsurgical (normal CT), routine (infundibular, ostiomeatal unit, and most sporadic patterns) and complex (sinonasal polyposis and sphenoethmoidal recess patterns) surgical groups. Assignment of patients to radiologic patterns allows a tailored surgical approach.

The impact of screening sinus CT on the planning of functional endoscopic sinus surgery.

The clinical and radiologic records of 500 sequential patients who underwent screening sinus CT as a prelude to possible functional endoscopic sinus surgery (FESS) were reviewed in order to answer three clinical-radiologic questions: (1) Can distinct radiologic patterns of inflammatory disease be identified on screening sinus CT (SSCT)? (2) If so, what are these radiologic patterns? (3) How do the findings seen on SSCT influence the endoscopic surgical plan? Five basic radiologic patterns of sinonasal inflammatory disease were identified among the 500-member patient population. These were based on known patterns of mucociliary drainage correlated with obstructive patterns observed on the CT scans. These radiologic patterns included: (1) infundibular (129 of 500 or 26%), (2) ostiomeatal unit (126 of 500 or 25%), (3) sphenoethmoidal recess (32 of 500 or 6%), (4) sinonasal polyposis (49 of 500 or 10%), and (5) sporadia (unclassifiable) (121 of 500 or 24%) patterns. Normal SSCT was seen in 133 of the 500 patients (27%). Although the ostiomeatal unit is the central feature in sinonasal inflammatory disease, obstruction of the infundibulum alone or of the sphenoethmoidal recess can cause unique inflammatory patterns of disease that require tailored FESS. The identification of sinonasal polyposis raises a different set of FESS considerations. The sporadic pattern of inflammatory disease, when identified, creates unique FESS challenges, depending on the specific sinus or sinuses involved. Assignment of these patterns to the individual case also assists in patient management by grouping patients into nonsurgical (normal CT), routine (infundibular, ostiomeatal unit, and most sporadic patterns) and complex (sinonasal polyposis and sphenoethmoidal recess) surgical groups.

The major obstructive inflammatory patterns of the sinonasal region seen on screening sinus computed tomography.

In conclusion, inflammatory sinonasal disease can be conveniently grouped into five distinct radiological patterns, each with a different therapeutic course and surgical options. A more precise interpretation of SSCT scans is rendered when inflammatory sinonasal disease is categorized into these distinct radiological patterns. The three obstructive patterns occur due to dysfunction of the mucociliary drainage routes of the paranasal sinuses and result in specific diagnostic patterns that are recognizable on coronal SSCT examinations. When one of the three obstructive patterns is identified, detailed attention can be directed to the likely site of occlusion, with possible definition of a specific etiology. A detailed road map of relevant surgical anatomy and pathology is then available for the endoscopic surgeon. This road map can then be used for a more directed and specific functional endoscopic sinonasal surgery. This results in improved patient care and surgical result.

Sinonasal polyposis.

The SSCT findings of the SNP pattern are nearly diagnostic for this entity. SNP is characterized by the major findings of nasal polypoid masses and infundibular enlargement. Patients may also show individual sinus involvement with polypoid masses and/or opacification of the paranasal sinuses without visualization of polypoid masses. The presence of polypoid masses within the sinuses also can be inferred if the major findings are present, especially if there are the minor findings of nasal septal and sinus trabeculae attenuation and bulging of the lateral ethmoid sinus walls. Air/fluid levels are frequent in SNP but do not always indicate acute sinusitis. Patients typically present with nasal stuffiness and rhinorrhea. They often have facial pain and less often headaches. Common associations exist between SNP and atopy (either allergic or nonallergic), asthma, infection, cystic fibrosis, and aspirin intolerance. Therapy may be either medical or surgical, with steroids being the mainstay of the medical treatment. FESS provides a relatively atraumatic means of removing polyps and creating better sinus drainage. Regardless of the type of therapy, recurrences are common, requiring repeated bursts of systemic steroids, nasal steroid maintenance, and frequent additional surgical procedures. Identification of the SNP pattern on SSCT helps the otolaryngologist to institute an appropriate therapy aimed at alleviating symptoms. The SSCT is adequate for evaluation of SNP in the vast majority of cases and serves as a detailed road map for the treating endoscopic surgeon.

The nose and nasal vault.

In this article we have reviewed the anatomy of the nose and nasal vault, with emphasis on specific features that are imaged with the SSCT. Important areas of the lateral wall anatomy include the OMU and SER, areas that are key to understanding the obstructive patterns of inflammatory sinonasal disease. Lesions that result in these specific obstructive patterns include anatomic variants and other focal pathological lesions, such as polyps. Other types of sinonasal inflammatory disease include sinonasal polyposis and granulomatous and fungal disease. Congenital lesions of the nose may be understood through a knowledge of the relevant developmental anatomy. These lesions include nasal dermoids and epidermoids, cephaloceles, gliomas, and choanal atresia. Important benign masses include antrochoanal polyps, inverting papillomas, angiomatous polyps, JNAs, and osteomas. Benign nasal masses have characteristic features that distinguish them from malignant lesions. Malignant nasal tumors, such as SSCa, esthesioneuroblastoma, and others, are characterized by their more aggressive and destructive behavior.

Optimization of techniques in screening CT of the sinuses.

The number of screening examinations of the sinuses performed with CT has markedly increased owing to the widespread and increasing use of endoscopic sinonasal surgery. We reviewed scans from 500 patients who had screening CT examinations of the sinuses for preendoscopic evaluation of inflammatory sinonasal disease to better define an optimal imaging protocol. Three aspects of direct coronal imaging of the paranasal sinuses were investigated: (1) preparation of the patient prior to the examination; (2) technical factors of the CT study, including positioning of the patient, optimal coronal angle, slice thickness, and CT exposure factors; and (3) data display. Our experience indicates that pretreatment of the patient with maximal medical therapy enables the best preendoscopic definition of anatomy, disease pattern, and nonreversible disease component for the treating surgeon. CT technical factors are optimized with scanning in the prone position with thin (3-mm) sections obtained through the anterior paranasal sinuses. This allows optimal visualization of the ostiomeatal unit. The remaining posterior portions of the sinuses are adequately imaged with thicker slices (5 mm). The coronal scan angle used is less critical. Exposure factors (mAs) can be reduced dramatically without image compromise. Data display is optimized when the bone algorithm is used to acquire the data and with image display at intermediate window center and width level. Use of the techniques outlined in this article results in a cost-effective yet diagnostic scan of the sinuses with decreased radiation exposure to the patient.