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    s

    Case Reports

    from

    multislice CT SOMATOM

    Volume Zoom

    SOMATOMS E S S I O N S

    S P E C I A L I S S U E I I

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    This is the second special issue of Siemens SOMATOM

    Sessions with case reports from the early users of

    our new multislice CT: SOMATOM Volume Zoom. This

    special issue focuses on presenting the clinical results on

    the improvement of the spatial resolution of the diagnostic

    images especially by using the UHR (Ultra High Resolu-

    tion) technique and 0.5 mm slice collimation. On the other

    hand, it also shows you the improvement of the routine

    applications on CTA and soft tissue studies.

    As always we would appreciate your suggestions and

    comments.

    Special thanks to Dr. Roman Fishbach for his valuable

    assistance.

    Xiaoyan Chen, M.D.

    Editor of SOMATOM Sessions

    From the Editor

    Dies ist nurBlindtext. Dies ist nurBlindtext. Dies ist nurBlindtext. Dies ist

    nur Blindtext. Dies ist nurBlindtext. Dies ist nurBlindtext. Dies ist nur

    Blindtext.Dies ist nur Blindtext.Dies ist nur Blindtext.Dies ist nur Blindtext.

    Dies ist nurBlindtext. Dies ist nurBlindtext. Dies ist nurBlindtext. Dies ist

    nur Blindtext. Dies ist nurBlindtext. Dies ist nurBlindtext. Dies ist nur

    Blindtext.Dies ist nur Blindtext.

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    Contents

    Letter from the Editor Page 2

    Petrous Bone (Case 1)

    Ulrich Baum, MD

    Institute of Diagnostic Radiology, University of Erlangen-Nuremberg Page 4

    Petrous Bone (Case 2)

    Ulrich Baum, MD

    Institute of Diagnostic Radiology, University of Erlangen-Nuremberg Page 6

    SinusesUlrich Baum, MD

    Institute of Diagnostic Radiology, University of Erlangen-Nuremberg Page 8

    Lung Fibrosis

    Micheal Lell, MD

    Institute of Diagnostic Radiology, University of Erlangen-Nuremberg Page 10

    Thoracic Spine

    Ulrich Baum, MD

    Institute of Diagnostic Radiology, University of Erlangen-Nuremberg Page 12

    Thoracic Cord Herniation Through Ventral Dural Defect

    Daniel A. Finelli, M.D.

    Section of Neuroradiology,The Cleveland Clinic Foundation Page 14

    Wrist

    Micheal Lell, MD

    Institute of Diagnostic Radiology, University of Erlangen-Nuremberg Page 16

    Bilateral Renal Angiomyolipoma

    Cheng Hong, MD, Roland Bruening, MDKlinikum Grosshadern, University of Munich Page 18

    Supraglottic and Glottic Larynx Cancer

    Cheng Hong, MD, Roland Bruening, MD

    Klinikum Grosshadern, University of Munich Page 20

    Squamous Cell Carcinoma of the Oropharynx

    Micheal Lell, MD

    Institute of Diagnostic Radiology, University of Erlangen-Nuremberg Page 22

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    History:64-year-old female patient with a hearing deficit on

    the right side for the last 6 months.The computed tomo-

    graphy exam was performed in clinical suspicion of a

    cholesteatoma on the right side.

    Technical data:

    Results:Computed tomography confirms the suspicion of a

    cholesteatoma on the right side.There is a small formation

    at the top of the middle ear and the external auditory

    canal. The malleoincudal articulation is fixed by the tumor.

    This is more impressive in the coronal plane than in the

    axial plane. In axial plane there is only the suspicion of

    fixation of the auditory ossicles over a short distance; in

    the coronal plane you can clearly see that the malleolusis fixed by the tumor over a long distance.The anatomy of

    the inner ear and the mastoid cells are normal.

    Comments:In another case (case 2) we reported about a new special

    scan mode called UHR (Ultra High Resolution) implemented

    in the SOMATOM Volume Zoom. Ultra High Resolution

    improves the spatial resolution in the scan plane but not in

    the longitudinal axis. A further improvement implementedin the SOMATOM Volume Zoom is the reduced slice colli-

    mation of 0.5 mm. 0.5 mm slices allow an improved spatial

    resolution along the longitudinal axis. A slice thickness of

    0.5 mm means nearly isotropic imaging of petrous bone

    with a voxel size of 0.2 x 0.2 x 0.5 mm 3 and improves the

    visibility of details in the multiplanar reconstructions.

    Petrous Bone

    Scan

    Region Petrous bone

    Scan length 40 mm

    Slice collimation 2 x 0.5 mm

    Table feed/rotation 1 mm

    Pitch 1

    Scan direction caudocranial

    Rotation time 0.75 s

    kV 140

    mAs 200

    Kernel U80

    Scan time 62 s

    Image reconstruction

    Reconstructed slice width 0.5 mm

    Reconstruction increment 0.3 mm

    Postprocessing

    Multiplanar reformations +

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    Fig. 2: Multiplanar reformations.

    Isotropic imaging allow high resolution MPR without

    step artifacts. The MPR show the contact of the tumor

    a b

    Fig.1: Axial plane.

    Sharp delineation of the malleoincudal articulation,

    the inner ear, the canal for facial nerve and the mastoid.

    Soft tissue formation at the top of the middle ear.

    A differentiation of tumor parts in the external auditory

    canal and the middle ear is not possible.

    Osteodestruction cannot be excluded. Fixation of the

    auditory ossicles is suspected.

    to the auditory ossicles and the extent in the middle

    ear and the external auditory canal.

    ba

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    History:54-year-old male patient with hearing deficiency

    (more pronounced on the left side than on the right).

    Technical data:

    Results:The anatomy of the inner, middle ear and the mastoid cells

    are normal. CT can rule out a capsular otosclerosis.

    Comparison of high and ultra high resolution images

    demonstrates a much better delineation of the ossicular

    chain in the middle ear, the ossicular joints and the bone

    structure of the mastoid.

    Comments:UHR stands for Ultra High Resolution. This is a special

    scan mode implemented in the SOMATOM Volume Zoom

    the new multislice spiral CT scanner from Siemens. In

    addition to the normal detector collimator, a special proce-

    dure has been developed for fine collimation. This allows to

    achieve the ultra high resolution of bony structures within

    a 25 cm scan FOV. Besides, the shorter scan time (0.75 s)

    also reduces the motion artifacts and improves the visibilityof detail (better delineation of the ossicular chain, the semi-

    circular canals and the cochlea).

    Petrous Bone

    Scan

    Region Petrous bone*

    Scan length 46 mm

    Slice collimation 4 x 1 mm

    Table feed/rotation 2.7 mm

    Pitch 2.7

    Scan direction caudocranial

    Rotation time 0.75 s

    kV 140

    mAs 140

    Kernel U80/H70

    Scan time 14.7 s

    Image reconstruction

    Reconstructed slice width 1 mm

    Reconstruction increment 0.5 mm

    Postprocessing

    Multiplanar reformations +

    * The same region was scanned twice with the same

    parameter in UHR (Ultra High Resolution) mode and

    normal HiRes mode.

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    Fig. 1: Superiorsemicircular canal.Normal anatomy.

    Fig. 1a without, Fig. 1b with UHR.

    Fig. 2: Internal auditory canal and lateral semicircular.

    Normal anatomy. Fig. 2a without,Fig. 2b with UHR.

    Fig. 4: Cochlea and malleoincudal articulation.

    Normal anatomy. Fig. 4a without,Fig. 4b with UHR.

    Fig. 5: MPR (Coronal).

    Fig. 5a without, Fig. 5b with UHR.

    a b a b

    Fig. 3: Malleoincudal articulation. Normal anatomy.

    Fig. 3a without, Fig. 3b with UHR.

    a b a b

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    History:A 12-year-old male patient has a history of surgery on

    bilateral cholesteatoma. CT was performed to rule

    out a recurrent cholesteatoma. Furthermore a chronic

    sinusitis was suspected.

    Technical data:

    Results:After prosthetic stapedectomy, a recurrent cholesteatoma

    is found on the left side, while normal postoperative findings

    after tympanoplasty on the right. Multiplanar reformations

    of the paranasal sinuses allow ruling out thickening of the

    mucosa or polyps in the sinuses.

    Comments:The conventional rule of the petrous bone study with singleslice CT was oriented parallel to the orbito-meatal line,

    and the sinus study was performed in the coronal plane in

    order to visualize the fine bony structures in the axial plane

    (floor of the orbit, cribrose plate). This was because the

    image quality of the secondary multiplanar reformations was

    not optimal, i. e. the stepping artifacts were not avoidable

    completely. Therefore, the gantry tilt has to be applied, the

    scan has to be performed twice (axial and coronal) and

    the patient has to undergo a difficult positioning for coronalscan.

    The UHR mode with the SOMATOM Volume Zoom allows

    imaging of the petrous bone with Ultra High Resolution

    in the axial plane as well as optimal coronal reformations

    of the middle ear and the paranasal sinuses. The image

    quality of the multiplanar reformations is comparable to the

    direct coronal scan without noticeable stepping artifacts.

    Assessment of bony structures parallel to the axial plane

    becomes possible.Therefore, a second examination in theaxial and coronal plane is no longer necessary for studies

    involving the midface and the petrous bone (axial slice

    orientation) as well as the base of the skull, the floor of the

    orbit or the hard palate (coronal slice orientation).

    Sinuses

    Scan

    Region frontal sinus to alveolar

    body of maxilla

    Scan length 108 mm

    Slice collimation 4 x 1mm (UHR mode*)

    Table feed/rotation 2.7 mm

    Pitch 2.7

    Scan direction craniocaudal

    Rotation time 0.75 s

    kV 140

    mAs 165

    Kernel U80

    Scan time 20 s

    Image reconstruction

    Reconstructed slice width 1 mm

    Reconstruction increment 0.5 mm

    Postprocessing

    Multiplanar reformations +

    * Ultra High Resolution mode

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    Fig. 1: Axial image.

    Ethmoidal sinuses. Normal anatomy.

    Fig. 2: Coronal MPR.

    Maxillary and ethmoidal sinuses. Assessment of the

    base of skull and the orbital floor without stepping or

    metal artifacts.

    Fig. 4: Coronal MPR (right side).

    Tympanoplasty Typ V.

    Correct attachment of the tympanoplasty.

    Fig. 3: Coronal MPR (left side).

    Metallic stapes prothesis after postsurgical defect

    of the auditory ossicles. Cholesteatoma around the

    prothesis.

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    ung Fibrosis

    History:69-year-old female patient suffering from progressive

    dyspnea since six months. Decreased physical performance

    formonths, Raynauds phenomenon for over 20 years,

    pronounced dryness of mouth and eyes. Slow recovery

    after a febrile infection. The patient complains of left sided

    discomfort associated with breathing, which is most

    pronounced with deep inspiration.The conventional chest

    X-ray shows an increased interstitial pattern in the leftlower lobe and a left sided pleural effusion. Unremarkable

    bronchoscopy, increased lymphocyte count with increased

    CD4/CD8 ratio in the bronchoalveolar lavage. Pulmonary

    function test revealed a slightly decreased diffusion capacity.

    Technical data: Results:Enlarged mediastinal and left hilar lymph nodes. Streaky

    peribronchial thickening in the left lower lobe, left sided

    pleural effusion. The high resolution images show bilateralmicro nodules and ground glass opacities.

    Diagnosis: Pulmonary involvement in systemic sclerosis

    with secondary Sjgrens syndrome. Pulmonary fibrosis

    after left lower lobe pneumonia.

    Comments:The so called Combi-Scan, the acquisition of a high

    resolution volume data set with reconstruction of imagesof different slice thickness yields conventional and high-

    resolution CT images from one scan.This results in

    decreased radiation exposure, a gap free HR-CT data set,

    and thus optimal conditions for 2D and 3D image post-

    processing.

    10

    Scan

    Region apex of the lung to adrenal glands

    Scan length 272 mm

    Slice collimation 4 x1 mm

    Table feed/rotation 6 mm

    Pitch 6

    Scan direction caudocranial

    Rotation time 0.5 s

    kV 140

    mAs 165

    Kernel B50/B30

    Scan time 23.35 s

    Contrast Injection

    Volume 120 ml (non-ionic contrast medium)

    Concentration 300 mg iodine/ml

    Flow rate 2.5 ml/s

    Start delay 50 s

    Image reconstruction

    Reconstructed slice width 1.25 mm/5 mm

    Reconstruction increment 1 mm/2.5 mm

    Postprocessing

    Multiplanar reformations +

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    Fig. 1a: Coronal MPR, slice width 1.25 mm.

    Fibrotic changes in left lower lobe.

    Clear delineation of bronchi and interlobes.

    Fig. 2a: Enlarged lymph nodes in the upper

    mediastinum.

    Fig. 2b: Axial image (high resolution) showing

    inhomogenous distribution of ground glass opacities

    and fibrotic changes in left lower lobe.

    Fig. 3: Sagittal MPR

    Peribronchial thickening and ground glass opacities

    indicating active process.

    11

    a b

    Fig. 1b: Coronal MPR, slice width 5 mm.

    Degradation of image quality due to reduced

    z-resolution.

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    History:52-year-old female patient with known bone metastases

    from breast carcinoma. The MR study of the thoracic spine

    indicates loss of height of several vertebras in the middle

    section. Forplanning of possible surgery or radiation therapy

    a CT study of the spine was required.

    Technical data:

    Results:CT shows a diffuse mixed osteolytic and osteosclerotic

    metastatic involvement of the entire thoracic spine,

    predominately affected are the 2nd, 4th, 7th, 11th and 12th

    vertebras. Metastases are found not only in the vertebral

    bodies but also in the pedicles and spinous processes.

    Sagittal MPRs show a slight ventral compression of the

    anterior part of the 7th vertebra, but normal height of the

    posterior part. Sagittal MPR further exclude significant lossof vertebral body height of the other vertebras.

    Comments:Multislice spiral CT makes it possible to scan a large

    section of the spine (e.g. the entire thoracic segment) with

    high, almost isotropic resolution.This provides optimal

    secondary image reformations (e.g. MPR, SSD).

    Indications for large section with high resolution imaging

    of the spine are found in trauma cases and for therapyplanning (surgery, radiation therapy) in bone metastases

    as well.

    12

    Thoracic Spine

    Scan

    Region first thoracic vertebra to

    first lumbar vertebra

    Scan length 273 mm

    Slice collimation 4 x 1 mm

    Table feed/rotation 4 mm

    Pitch 4

    Scan direction craniocaudal

    Rotation time 0.75 s

    kV 140

    mAs 210

    Kernel B60

    Scan time 59 s

    Image reconstruction

    Reconstructed slice width 1 mm/3 mm

    Reconstruction increment 1 mm/3 mm

    Postprocessing

    Multiplanar reformations +

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    Fig. 1: Sagittal MPR.

    The sagittal MPRs show diffuse osteolytic metastases

    of the thoracic spine and additionally osteosclerotic

    metastases of the 2nd, 4th, 7th, 11th and12th vertebral body.

    Slight compression of the anterior part, but exclusion

    of loss of height of the posterior part of the 7th vertebra

    (b). Normal width of the spinal cord.

    Fig. 3: Axial image.

    Osteosclerotic metastases of the right part of the

    vertebral body, both posterior pedicle and the left rib.

    Normal width of the spinal canal.

    Fig. 2: Axial image.

    Osteosclerotic metastases of the body of the vertebral

    body and the right posterior pedicle. No stenosis of the

    spinal canal.

    a

    b

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    History:The patient is a 67-year-old woman who had experienced

    progressive left sided pain, numbness, and burning sen-

    sation, extending from her mid chest level to the left leg and

    foot over the past nine months. She also had right sided

    leg weakness, especially in the knee and hip regions.These

    symptoms were making it very difficult for the patient to

    walk, and she had sustained several falls, though without

    serious injury.The patient had been evaluated by severalneurology and spine surgery consultants at another insti-

    tution, who felt her constellation of symptoms, referred to

    as a Brown-Sequard Syndrome, suggested a right sided

    spinal cord lesion at the T8-9 level.The patient had an

    extensive workup including spinal tap, electromyographic

    (EMG) studies, MRI scans of thoracic and lumbar spine,

    and thoracolumbar myelogram with CT myelography,

    without reaching a definitive diagnosis, but her physicians

    felt they had excluded a compressive, neoplastic, or other

    surgical lesion.

    The patient was referred to CCF for another opinion, and

    on neurologic examination was felt to again have symptoms

    suggesting a Brown-Sequard Syndrome, however likely

    at a higher level, approximately T4. Review of the outside

    MRI studies demonstrated a local anterior and rightward

    deviation in the position of the spinal cord at T4, with a

    deformed local contour of the cord, and an associated thin

    collection of fluid in the anterior epidural space; findings

    which had not been appreciated previously.The outsidethoracolumbar myelogram and CT was found to have been

    targeted at the T8 level, and did not include adequate

    evaluation of the upper thoracic levels. The MR findings were

    quite suspicious for the rare clinical condition of a ventral

    spinal cord herniation through a dural defect.

    Technical data:For optimal further evaluation, confirmation, and pre sur-

    gical planning, the decision was made to perform another

    thoracic myelographic study, targeted at the T4 level, with

    post myelographic, high resolution spiral CT study on

    the Siemens SOMATOM Volume Zoom scanner. The high

    speed, high resolution attributes of the multislice array

    allowed a1 mm spiral dataset to be obtained in a single

    breathhold. This yielded an extremely detailed, artifact-freeset of images and multiplanar reconstructions for neuro-

    radiologic analysis and surgical planning, far superior to the

    patients prior CT or MRI studies.

    Results:The study clearly demonstrated the ventral, right-sided

    dural defect at T4-5, with contrast laden CSF both in the

    thecal sac, and in the anterior, epidural CSF collection, thus

    clearly outlining the dural margins. The thoracic spinal cordwas shown to be herniated into and partially through the

    dural defect. The cord was deformed locally, with the CT

    myelographic study clearly demonstrating a pinching

    of the cord at the margins of the dural tear.The study also

    showed that the T4-5 disk space was abnormal, with

    evidence of a remote right sided disk herniation, which had

    healed. This was likely the cause of the dural tear.

    The patient was taken to surgery, where T4-5 laminectomy

    was performed. The dorsal thecal sac dura was incised,exposing the spinal cord, which was carefully freed from

    the herniation. A 2 cm long tear in the anterior dura was

    found and repaired, and the dorsal dural incision was closed.

    The patient had an uneventful post operative course,

    and had an improvement in her neurologic deficits on the

    first postoperative day. She is now three weeks post-op,

    has undergone physical therapy, and has experienced near

    complete resolution of her symptoms.

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    Thoracic Cord Herniation Through Ventral Dural Defect

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    Fig. 1a: Axial post-myelographic CT image at the

    level of T6 demonstrates the anteriorextradural fluid

    collection containing myelographic contrast-laden

    cerebrospinal fluid, clearly outlining the ventral dura.

    Fig. 1b: Axial CT image at T4-5,shows the ventral,

    right-sided dural defect, with herniation of the thoracic

    spinal cord through the defect, causing pinching and

    local deformity of the cord.

    Fig. 1c, and Fig. 1d: parasagittal multiplanar recon-

    struction of the axial CT data shows the local deviation

    and deformity of the spinal cord at T4-5,where it is

    herniated through the 2 cm cranio-caudal dimension

    d

    ba

    c

    dural defect, centered at the disk space. Note the

    deformity of the upper end plate of T5, and the mild

    ventral impression due to remote disk protrusion,

    which was suspected to be the cause of the dural tear.

    Zoom, allowed the diagnosis of a rare spinal cord

    abnormality, the treatment of which kept a patient from

    becoming wheelchair bound.

    SummaryIn this case, the combination of clinical, surgical, and neuro-

    radiological expertise of CCF physicians, coupled with the

    imaging capabilities of the Siemens SOMATOM Volume

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    History:A 36-year-old patient who fell playing squash. Moderate

    swelling and pain of the wrist, typical triggerpoint at

    Tabatir. Suspected fissure of the scaphoid on conventional

    X-ray. After temporary immobilization, a CT scan was per-

    formed to confirm diagnosis.

    Technical data:

    Results:Fracture in the middle third of the scaphoid bone without

    fragment dislocation.

    CT scan was performed with patient lying prone, immo-

    bilized arm over head, longitudinal axis of scaphoid in

    scan plane. Despite plaster, good image quality could be

    achieved. With the high resolution achieved by using

    the Ultra High Resolution mode (UHR), subtle assessmentof the trabecular bone is possible. Thin slices with small

    reconstruction increment is the basis for optimal 2D and

    3D imaging. MPRs in sagittal and coronal plane allow easy

    recognition of anatomy and exact assessment of joints.

    Interactive volume rendering, especially with stereoscopic

    view, creates a spectacular view of the anatomy and the

    fragments, helping both patients and surgeons to visualize

    the pathology in 3-dimension.

    Wrist

    Fig. 1: Axial images show fracture in the middle third

    of the scaphoid.

    Scan

    Region distal radioulnar articula-

    tion to metacarpal bones

    Scan length 44 mm

    Slice collimation 4 x 1mm (UHR* mode)

    Table feed/rotation 3 mm

    Pitch 3

    Scan direction craniocaudal

    Rotation time 0.75 s

    kV 120

    mAs 90

    Kernel U80

    Scan time 12.2 s

    Image reconstruction

    Reconstructed slice width 1 mm

    Reconstruction increment 0.3 mm

    Postprocessing

    Multiplanar reformations +

    VRT +

    * Ultra High Resolution

    1

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    Fig. 2 and 3: Multiplanar reformations in planes

    parallel to the radial bone and in the radio-ulnar plane,

    Fig. 4 and 5: Volume rendering can create opaque and

    transparent image of the scaphoid and the relation of

    the fragments.

    demonstrate fracture, allowing exact assessment of

    the joints and fragments.

    2 3

    4 5

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    Bilateral Renal Angiomyolipoma

    History:A 34-year-old male presented with a one-year history of

    abdominal pain. He described this pain as being cramping

    at times, easing off when walking around. He felt that his

    abdomen had become swollen and heavy over the previous

    2 months. In the clinical examination, a huge soft mass

    was found in the abdomen. Ultrasound examination showed

    large masses in both kidneys. An abdominal CT was per-

    formed.

    Technical data:Abdominal spiral scanning with a multislice spiral CT scanner

    (SOMATOM Volume Zoom, Siemens Medical Engineering,

    Forchheim, Germany), and multiplanar reformations (MPR).

    Results and comments:Angiomyolipomas are seen on CT as circumscribed renal

    masses. The presence of intratumoral fat is almost diag-

    nostic of angiomyolipomas. Problems in diagnosis occur

    when angiomyolipomas are composed predominantly of

    muscle or vascular tissue and contain only minimal amounts

    of fat. Such small amounts of fat can be easily overlooked

    unless searched for carefully in the CT study. The recentmultislice CT technology offers the potential to cover much

    larger anatomic areas without sacrificing image resolution

    or quality and to clearly identify the fat-containing areas

    when compared to the single slice CT technology. This is

    evident in this case (Fig.1).

    The thin slice (4*1 mm) acquisition and reconstruction

    (1.25 mm) with an increment of 0.8 mm (36 % overlap) pro-

    vide the possibility to achieve a high quality coronal MPR

    image (Fig. 2). This allowed us to evaluate the abdominalmass and determine the relationship between the mass

    and its surrounding structures so that we could provide

    clearer diagnostic information for the surgery planning.

    18

    Scan

    Region Abdomen (Venous phase)

    Scan length 300 mm

    Slice collimation 4 x1 mm

    Table feed/rotation 6 mm

    Pitch 6

    Scan direction craniocaudal

    Rotation time 0.5 s

    kV 120

    mAs 130

    Kernel B20

    Scan time 25.9 s

    Contrast Injection

    Volume 120 ml (non-ionic contrast medium)

    Concentration 300 mg iodine/ml

    Flow rate 3.5 ml/s

    Start delay 70 s

    Image reconstruction

    Reconstructed slice width 1.25 mm

    Reconstruction increment 0.8 mm

    Postprocessing

    Multiplanar reformations +

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    Fig. 1: Patient with bilateral renal angiomyolipoma.

    Coronal reformatted image shows huge multiple

    bilateral renal masses.The kidneys are all displaced.

    The lesions contain low-density areas consistentwith fat.

    Fig. 2: Coronal reformatted image generated from

    the axial data set.There is extensive involvement of

    perinephric space by the bilateral angiomyolipomas.

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    History:A 58-year-old male with history of smoking with swallow-

    ing disorder of three months.

    Technical data:Spiral scanning with a multislice spiral CT scanner

    (SOMATOM Volume Zoom, Siemens, Forchheim, Germany),

    and multiplanar reformations (MPR).

    Results and comments:This case illustrates the advantages of multislice spiral CT.

    It affords the ability to simultaneously evaluate the soft

    tissue mass and the surrounding structures (Fig. 1). The

    increasing pitch and subsecond scan time allowed cover-

    age of the entire cervical region in one spiral. This shorter

    examination time reduces the number of motion artifacts

    and represents an advantage for patients who are not able

    to cooperate. The kernels used ensure a high quality softtissue detail.

    In this case, one could argue that multiplanar reformatted

    images are actually more critical than the axial images

    themselves. Coronal and sagittal reformatted image of axial

    sections can be useful to evaluate the extent of different

    lesions (Fig. 2). In special cases concerning the laryngeal

    skeleton, high resolution CT with a slice width of 1 mm is

    possible.

    Supraglottic and Glottic Larynx Cancer

    Scan

    Region Hyoid to subglottic space

    Scan length 160 mm

    Slice collimation 4 x 1 mm

    Table feed/rotation 4 mm

    Pitch 4

    Scan direction craniocaudal

    Rotation time 0.5 s

    kV 120

    mAs 110

    Kernel B30

    Scan time 21.56 s

    Image reconstruction

    Reconstructed slice width 1.25 mm

    Reconstruction increment 1.0 mm

    Postprocessing

    Multiplanar reformations +

    Contrast Injection

    Volume 80 ml (non-ionic

    contrast medium)

    Concentration 300 mg iodine/ml

    Flow rate 3 ml/s

    Start delay 40 s

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    Fig. 1: Patient with right-sided supraglottic and glottic

    carcinoma. Axial image demonstrates clearly soft

    tissue detail, the infiltration of the pre-epiglottic fat and

    the adjacent structures.

    Fig. 2: The sagittal reformatted image displays the

    extent of the tumor.Step artifacts are negligible due to

    the thin collimation used to acquire the original axial

    images.The extensive tumor spread cranially is well

    documented.

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    History:57-year-old male patient with progressive swallowing

    disorder. History of nicotine and alcohol abuse.

    Clinical examination raises suspicion of a tonsillar carcinoma

    with infiltration of the tongue and enlarged right sided

    cervical lymph nodes.

    Technical data:

    Results:The depth of the tumor infiltration is best visualised with

    a combination of axial and reformated coronal and sagittal

    images. MPR images minimize partial volume effects

    and allow better tumor delineation. Critical areas like the

    parapharyngeal, paralaryngeal, preepiglottic and preverte-

    bral space can be visualised in their full extension.

    Infiltration of the base of the skull with bone destruction

    can be diagnosed without additional coronal scanning.Criteria for lymph node malignancy, known from ultra-

    sound, like the L/T quotient (ratio of maximal longitudinal

    to maximal axial diameter) are more practicable. This leads

    to more accurate staging, and pathology can be better

    demonstrated to the clinical partner, allowing easier imagi-

    nation of the situs than with axial images.

    Squamous Cell Carcinoma of the Oropharynx

    Fig. 1: Tumor infiltrating right floor of the mouth, base

    of the tongue and tonsillar space.Typical rim enhance-

    ment of ipsilateral lymph node metastasis.

    Calcified plaque dorsally in the left carotid bifurcation

    leading to an asymptomatic internal carotid artery

    stenosis.

    Scan

    Region base of skull to aortic arch

    Scan length 260 mm

    Slice collimation 4 x 1 mm

    Table feed/rotation 6 mm

    Pitch 6

    Scan direction craniocaudal

    Rotation time 0.5 s

    kV 120

    mAs 165

    Kernel B30

    Scan time 22.4 s

    Image reconstruction

    Reconstructed slice width 4 mm/1.25 mm

    Reconstruction increment 2 mm/1 mm

    Postprocessing

    Multiplanar reformations +

    Contrast Injection

    Volume 150 ml (non-ionic

    contrast medium)

    Concentration 300 mg iodine/ml

    Flow rate 2.5 ml/s

    Start delay 80 s

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    Fig. 2: Central hypodensity indicating tumor necrosis.

    Tumor spreads close to the mandible,but there is no

    bony destruction. Parapharyngeal space is obliterated

    by tumor. Small lymph nodes along the great vessels

    on both sides with no signs of malignancy.

    Fig. 4: Sagittal image demonstrates size of tumor in

    relation to intrinsic muscles of the tongue, the floor of

    the mouth and the valleculae epiglotticae as well as

    the hard and soft palate. Good delineation of the spatium

    retropharyngeum, the hypodense space between the

    prevertebral fascia and the pharynx.

    Fig. 5: Sagittal images allow accurate assessment

    of lymph nodes. Lymph node metastases ventral

    of internal jugular vain, lymph nodes without signs

    of malignancy dorsal.

    Fig. 3: Coronal image clearly demonstrates

    craniocaudal tumor spread and relation to adjacent

    structures like the submandibular glands.

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    mpressum

    his Issues Authors

    Ulrich Baum, MD

    Institute of Diagnostic RadiologyUniversity of Erlangen-NurembergMaximiliansplatz 1, D-91054 ErlangenGermany

    Micheal Lell, MD

    Institute of Diagnostic RadiologyUniversity of Erlangen-NurembergMaximiliansplatz 1, D-91054 ErlangenGermany

    Cheng Hong, MD, Roland Bruening, MD

    Department of Diagnostic RadiologyKlinikum of theLudwig-Maximilians-UniversityMarchioninistr. 15, D-81377 Munich

    Germany

    Daniel A. Finelli, MD

    Section of NeuroradiologyThe Cleveland Clinic Foundation9500 Euclid Avenue, Cleveland,Ohio 44195USA

    Published by

    CT Marketing

    Siemens AG

    Medical Engineering

    Siemensstrasse 1

    91301 Forchheim, Germany

    Correspondence

    and U.S. Distribution

    Barbara Cammisa

    Siemens Medical Systems, Inc.

    186 Wood Avenue South

    Iselin, NJ, 08830, USA

    Phone +01 412 351 0803

    Fax +01 732 321 3291

    eMail barbara.cammisa@

    exchange sms siemens com

    International Distribution

    Xiaoyan Chen, M.D.

    CT Product Creation

    Siemens AG, Medical Engineering

    Siemensstrasse 1

    91301 Forchheim, Germany

    Phone +49-9191-18-9652Fax +49-9191-18-9998

    eMail [email protected]

    Lisa Reid, B.S., R.T. (R)

    CT Application Manager

    Siemens AG, Medical Engineering

    Siemensstrasse 1

    91301 Forchheim, Germany

    Phone +49-9191-18-8405

    Fax +49-9191-18-9998

    eMail lisa reid@med siemens de

    George Savatsky, B.A., M.A.

    CT Marketing

    Siemens AG, Medical Engineering

    Siemensstrasse 1

    91301 Forchheim, Germany

    Phone +49-9191-18-8142Fax +49-9191-18-9998

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    Order No. A91100-M2100-F236-01-7600Printed in GermanyBKW 62236 WS 010035


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